The URL can be used to link to this page

Home My WebLink AboutCP 3828; Agua Hedionda Trunk Sewer Main; Agua Hedionda Trunk Sewer Main Reach SAHT 1E; 2000-10-23CHRISTIAN WHEELEFl ENGINEERING REPORT OF PRELIMINARY SOIL INVESTIGATION AGUA HEDIONDA TRUNK SEWER MAIN REACH SAHT IE CARLSBAD, CALIFORNIA PREPARED FOR: THE TERRACES AT SUNNY CREEK, LLC 2006 PALOMAR AIRPORT ROAD, SUITE 113 CARLSBAD, CALIFORNIA 92009 PREPARED BY: CHRISTIAN WHEELER ENGINEERING 4925 MERCURY STREET SAN DIEGO, CALIFORNIA 92111 4925 Mercury Street -f San Diego, CA 92111 -f 858-496-9760 4- FAX 858-496-9758 CHRISTIAN WHEELER ENGINEERING October 23,2000 The Terraces at Sunny Creek, LLC 2006 Palomar Airport Road, Suite 113 Carlsbad, California 92009 CWE 199.293.9 Attention: Dale Young SUBJECT: SOIL-CEMENT COLUMNS UNDER SEWER MANHOLES, AGUA HEDIONDA TRUNK SEWER MAIN, REACH SAHT IE, CARLSBAD, CALIFORNIA. Ladies and Gentlemen: In accordance with the request of the City of Carlsbad, this report has been prepared to present recommendations for support of the subject sewer main manhole structures to be constructed between Stations 33+00 and 42+00 at the subject project. We assume that standard manholes, per San Diego Regional Standard Drawing S-2, are specified for this project. These manholes have an interior diameter of five feet and an exterior base of six feet, four-inches. Like the sewer main pipe, we recommend that the manholes be supported by three-foot diameter soil-cement columns. Each manhole should be supported by at least two soil-cement columns constructed a distance of two feet apart, as illustrated on the attached Plate No 1. The soil-cement columns should be centered on the 18-inch sewer pipe. If you have any questions regarding this matter, please do not hesitate to contact our office. Respectively submitted CHRISTIAN WHEELER ENGINEERING Charles H. Christian, RGB 00215 cc: (2) Client (4) Manitou Engineering Company 4925 Mercury Street -f San Diego, CA 92111 4- 858-496-9760 + FAX 858-496-9758 18" SEWER MAI SEWER MANHOLE SOIL CEMENT COLUM SOIL CEMENT COLUMN. MANHOLE SUPPORT DETAIL SCALE: 1"=2' CHRISTIAN WHEELER ENGINEERING Job Number: 199.293.9 Date: October 24, 2000 Plate Number: 1 I I I I I I I I I I I I I I I I I I I CHRISTIAN WHEELER.ENGINEERING March 16,2000 CWE 199.293.6The Terraces at Sunny Creek, LLC 2006 Palomar Airport Road, Suite 113 Carlsbad, California 92009 ATTENTION: Dale Young SUBJECT: REPORT OF PRELIMINARY SOIL INVESTIGATION, AGUA HEDIONDA TRUNK SEWER DRAIN, REACH SAHT IE, CARLSBAD, CALIFORNIA. Ladies and Gentlemen: In accordance with your request and our Proposal dated September 24,1999, we have completed a preliminary soil investigation and settlement analysis for the subject area. We are presenting herewith our findings and recommendations. In general, we found the subject area suitable for the proposed development, provided the recommendations provided are followed. The most pertinent geotechnical condition that will affect the development of the property consists of the soft, compressible recent alluvial deposits mat underlie the project area between approximately Station 34+00 and 41+00. These soft deposits will require special site preparation, in addition to performing deep ground modifications in the form of deep soil mixing. The groundwater table in this area was noted to be very near the pipe invert elevation, which will require a dewatering operation for the site preparation and sewer line construction. In addition, shallow ground water and caving soils were found in the project area east of Station 54+70, where the proposed pipe is to be jacked under Agua Hedionda Creek. If you have any questions after reviewing this report, please do not hesitate to contact our office. This opportunity to be of professional service is sincerely appreciated. Respectfully submitted, CHRISTIAN WHEELER ENGINEERING Charlie G. Carter Jr., Staff Engineer urtts R. Burdett, C.E.G. #1090 CERTIFIED ENGINEERING Charles H. Christian, R.G.E. #00215 CHC:CRB:cgc cc: (4) Submitted (2) Manitou Engineering (5) CanAm Properties (1) Stenerson Construction 4925 Mercury Street -f San Diego, CA 92111 -f 858-496-9760 + FAX 858-496-9758 JL TABLE OF CONTENTS PAGE Introduction and Project Description 1 Project Scope 2 Findings 3 Site Description 3 General Geology and Subsurface Conditions 5 Geologic Setting and Soil Description 5 Area I, Station 10+00 to Station 27+50 5 Area II, Station 32+00 to Station 42+50 7 Area III, Station 54+00 to Station 57+38 8 Consolidation Characteristics 10 General 10 Estimated Consolidation Magnitude 10 Estimated Consolidation Time 11 Conclusions 11 Recommendations 13 Site Preparation 13 General 13 Deep Ground Modification 13 Pipe Classification 15 Observation of Grading 16 Clearing and Grubbing 16 Preparation of Alluvial Soils 16 Compaction and Method of Filling 16 Limitations 17 Uniformity of Conditions 17 Change in Scope 17 Time Limitations 17 Professional Standard 18 Client's Responsibility 18 Field Explorations 18 Laboratory Testing 19 CWE 199.293 Agua Hedionda Trunk Sewer Main Reach SAHT IE Carlsbad, California PLATES Pktes Pktes Pktes Pktes Plates Plates Pktes 1-4 5-6 7-23 24-31 32-33 34-44 45-46 APPENDICES Appendix A Appendix B ATTACHMENTS Plot Plans Deep Mixing Column Details Borings Logs Trench Logs Lab Test Results Consolidation/Time Rate Graphs Table I-Summary of Settlement Results References, Topographic Maps, and Aerial Photographs Recommended Grading Specifications — General Provisions CWE 199.293 Agua Hedionda Trunk Sewer Main Reach SAHT IE Carlsbad, California PRELIMINARY SOIL INVESTIGATION A ai T A HFDTONDA TRUNK SEWER MAIN REACH SAHT IE CARLSBAD. CALIFORNIA INTRODUCTION AND PROJECT DESCRIPTION This report presents the results of our preliminary soils investigation and settlement analysis associated -with the installation of a proposed trunk sewer main, which will be situated in the Sunny Creek area in Carlsbad, California. The subject project will consist of the construction of an 18-inch PVC sewer main between Stations 10+00 and 57+38 as indicated on the Construction Plans provided to aid us in the preparation of this report This report addresses three areas along the sewer main alignment that cross alluviated valley areas. For the purpose of this report, we will refer to these areas as Area I, Area II and Area III. Area I starts at Station 10+00, which corresponds with the intersection of El Camino Real and Rancho Carlsbad Drive, and extends to Station 28+00. Area II is aligned with Sunny Creek Road and extends from Station 32+00 to Station 42+00. Area III is comprised of the eastern portion of the project where it crosses Agua Hedionda Creek, and extends from about Station 54+25 to Station 57+38. We understand that the sewer pipe will be jacked under El Camino Real to connect to the existing trunk sewer main running along the south side of the road. We also understand that the sewer pipe will be jacked under Agua Hedionda Creek at the eastern end of the project The Construction Plans for the Agua Hedionda Trunk Sewer Alignment, Reach SAHT IE (CMWD Project No. 92-406), prepared by Manitou Engineering Company, show the location, configuration and profile of the proposed trunk sewer main. Copies of these plans were used as the base maps for our Site Plans for Areas I, II and III and are included herewith as Plate Numbers 1,2 and 3. The following Figure Number 1 presents a vicinity map showing the location of the project area. This report has been prepared for the exclusive use of The Terraces at Sunny Creek LLC and their design consultants for specific application to the project described herein. Should the project be modified, the conclusions and recommendations presented in this report should be reviewed by Christian Wheeler Engineering for conformance with our recommendations and to determine if any additional subsurface investigation, laboratory testing and/or recommendations are necessary. Our professional services have been performed, our findings obtained and our recommendations prepared in CWE 199.293.6 March 16. 2000 Page No. 2 accordance with generally accepted engineering principles and practices. This warranty is in lieu of all other warranties, express or implied. PROJECT SCOPE The scope of our preliminary investigation included: surface reconnaissance, subsurface exploration, obtaining representative soil samples, laboratory testing, analysis of the field and laboratory data and review of relevant geologic literature. Based on our past experience in the vicinity of the subject area and the scope of the project, six small-diameter borings were drilled in Area I of the project and four small- diameter test borings were drilled in Area II. Eight test trenches were excavated in Area in using a tractor-mounted backhoe, between Stations 54+25 and 57+38, to evaluate me caving soils within the trench zone where the sewer pipe will be jacked under the creek. More specifically, the intent of this investigation was to: • Explore the subsurface conditions of the site to the depths influenced by the trunk sewer construction. • Evaluate, by laboratory tests, the engineering properties of the various strata present to determine if caving soils and unstable soils exist along the alignment, and to evaluate the settlement potential of the alluvial deposits where fill loads will be added above existing grades. • Describe the general geology at the site including possible geologic factors that could have an effect on the trunk sewer construction. • Address potential construction difficulties that may be encountered due to soil conditions, groundwater, or geologic hazards, and provide recommendations concerning these problems. • Calculate the potential settlement and consolidation time along the alignment of the trunk sewer due to the placement of the embankment fill for Sunny Creek Road and College Boulevard. CWE 199.293.6 March 16. 2000 Page No. 3 • Provide recommendations to minimize the effects of the anticipated settlement such diat the trunk sewer may be installed prior to the placement of the roadway embankment • Develop soil engineering criteria for site preparation and grading for the installation of the trunk sewer. • Present our professional opinions in a written report, which includes in addition to our conclusions and recommendations, copies of the improvement plans, logs of our subsurface explorations, and a summary of the laboratory test results. It was not within the scope of our services to perform laboratory tests to evaluate the chemical characteristics of the on-site soils in regard to their potentially corrosive impact to on-grade concrete and below grade improvements. If desired, we can obtain samples of representative soils and submit them to a chemical laboratory for analysis. Further, it should be understood Christian Wheeler Engineering does not practice corrosion engineering. If such an analysis is necessary, we recommend that the client retain an engineering firm that specializes in this field to consult with them on this matter. FINDINGS SITE DESCRIPTION As previously discussed, we have divided the subject project into three areas of concern for the purpose of this report. Area I extends from Station 10+00 to Station 27+50, and includes property owned or under the control of Rancho Carlsbad Golf Course and Rancho Carlsbad Homeowners Association. This area starts on the south side of El Camino Real and extends north along the northbound lane of Rancho Carlsbad Drive to Station 16+70. This road is paved with asphalt concrete and varies from about elevation 63.1 feet near the south end, to elevation 60.5 feet at about Station 16+80 where the alignment leaves the paved roadway. From this point, the alignment turns northeast and passes through the asphalt and dirt parking lot for Rancho Carlsbad Golf Course. At about Station 20+50, the alignment swings a little more towards the east and follows a dirt road leading to the maintenance yard for the golf course. Elevations in the parking lot and along the maintenance road are generally constant and at about elevation 58 feet The sewer main alignment in this area parallels Agua Hedionda Creek, which is about 50 feet northwest of the alignment At CWE 199.293.6 March 16. 2000 Page No. 4 about Station 24+87, the alignment wraps around the end of a small, northerly trending ridge, and heads east/southeast past the golf course maintenance yard. At about Station 27+50, which is the end of the designated Area I, the alignment begins to follow the base of a hillside. Designated Area II begins at about Station 32+00, where the alignment leaves the base of the hillside and extends into another portion of the alluviated valley. In this area, the alignment runs easterly to Station 41+85, where it turns about 90 degrees and heads in a southerly direction. Area II ends at about Station 42+50 where it extends perpendicularly into another hillside area. The alignment in Area II basically follows the alignment of Sunny Creek Road, which has a dirt and gravel surface. The area along the aAd lignment is relatively flat and varies from about elevation 65 feet atdteend to 70 feet at the east end. A horse ranch exists to the north of the project in this area, and vacant land that is to be developed into a shopping center site exists to the south. Large eucalyptus trees line the north side of Sunny Creek Road. At about Station 41+57, an 84-inch-diameter, RCP storm drain is currently being constructed that crosses the sewer line in a perpendicular (north/south) direction. A seven-foot-long, 36-inch-diamenter PVC casing has been installed under the storm drain pipe for the subject sewer line. The invert of this casing corresponds with the bottom of the proposed sewer pipe. In addition, a grid of vertical wick drains and a horizontal "burrito" drain were installed under the proposed embankment area of College Boulevard to reduce the consolidation time of the underlying clayey alluvial deposits. From the east end of Area II, the alignment heads south to Station 43+05 and then turns 90 degrees and heads east again. The first approximately 400 feet is located in an area underlain by formational soils. From about Station 47+00 to about Station 54+25, the alignment follows the base of the hillside that forms the southerly side of the valley. Area III extends from Station 54+25 to the east end of the project at Station 57+40. In this area, the alignment again follows Sunny Creek Road. At Station 54+25, the alignment re-enters the alluviated valley area and between approximately Stations 55+50 and 56+00, the alignment crosses the Agua Hedionda Creek. The road crossing the creek at this location is elevated above the creek and is underlain by five, 16-inch-diameter corrugated metal pipes to allow the water from the creek to flow beneath the roadway. At the time of our field investigation, the water in the creek was noted to be flowing under the pipes, probably through a rock layer or through tunnels eroded through the alluvium. In Area III, the project area is bounded by undeveloped property. The land to the south of Area III has been slated for a proposed residential tract Topographically, the project areas are relatively level and based upon the CWE 199.293.6 March 16.2000 Page No. 5 referenced topographic maps and plans provided, on-site elevations are noted to range from approximately 70 feet to 80 feet above Mean Sea Level. GENERAL GEOLOGY AND SUBSURFACE CONDITIONS GEOLOGIC SETTING AND SOIL DESCRIPTION: The subject project is located in the Coastal Plains Physiographic Province of San Diego County. Based on the results of our exploration and analysis of readily available, pertinent geologic and geotechnical literature, the alignment of the project is underlain by the Tertiary-age Santiago Formation and Quaternary-age Terrace Deposits, which are mantled along a significant portion of the project by a relatively thick layer of Quaternary-age alluvium. Some portions of the project area also have a relatively thin layer of fill materials at the surface The soils of the Santiago Formation were generally noted to consist of white, light gray to orangish- brown, dark brown to light orangish-brown, and gray to orangish-brown, fine- to medium-grained, clayey sand and sandstone (SC). These materials were observed to be generally moist and very dense. The soils of the Terrace Deposits were generally noted to consist of moist, medium dense to dense, silty sands and clayey sands. The Alluvial Deposits can be classified as either Older Alluvial Deposits or Recent Alluvial Deposits. The Older Alluvial Deposits were generally found to consist of yellowish- brown, olive and gray, clayey sand (SQ and sandy clay (CL), with varying amounts of kon staining, caliche, and gravel. The sandy portions of this material were noted to be generally moist to saturated and dense to very dense, while the clayey portions were generally moist to saturated and very stiff to hard. The Recent Alluvial Deposits generally consist of light to dark brown, yellowish-brown, light to dark gray, olive, fine- to medium-grained, fine- to coarse-grained, poorly-graded sand (SP), clayey sand (SC), silty sand (SM), and sandy clay (CL). Varying amounts of caliche and gravel were observed in these alluvial deposits. The sandy portions of this alluvium were noted to be generally damp to saturated and loose to medium dense, while the clayey portions were generally moist to saturated and medium stiff to stiff. The soil and groundwater conditions encountered in each of the three designated areas along the alignment of the sewer main are described below. AREA I, STATION 10+00 TO STATION 27+50 Area I includes the entrance road for the Rancho Carlsbad condominiums and golf course, an asphalt and dirt parking lot for the golf course and a dirt maintenance road. No fills or grading CWE 199.293.6 March 16.2000 Page No. 6 are proposed in this area. The entrance road is underlain by a mantle of fill material that is about eight to ten feet thick This material is comprised mostly of sandy clay that was noted to be medium stiff to stiff and moist. At Boring 5, the underlying alluvium generally consisted of moist, stiff, sandy, silty clay. At Boring 6, the alluvium was noted to consist of about two feet of loose, clayey sand mixed with medium stiff, sandy clay, over moist, medium stiff, sandy day. No caving soil types were found in these two borings. In Borings 5 and 6, the groundwater table was found at a depth of about 18 feet and 16.5 feet, respectively. This is about three to four feet below the invert elevation of the proposed sewer line. Borings 7 and 8 were extended in the parking lot area, and both borings exposed about one foot of fill material aver the alluvial deposits. The fill was observed to consist of medium dense, clayey sand and loose, silty sand. The alluvium in Boring 7 generally consisted of four feet of moist, loose to medium dense, clayey sand, over about two feet of moist, loose, slightly clayey, poorly graded sand, over three feet of moist, medium dense, slightly silty sand, over wet to saturated, sandy clay. The poorly graded sand and the slightly silty sand have very low cohesion and may not stand well in vertical trench cuts. The invert elevation of the pipe at Boring 7 is about six feet below the ground surface, which is approximately at the center of the two-foot- thick layer of the slightly clayey, poorly graded sand layer. Groundwater was noted at a depth of about 13 feet below the ground surface, or seven feet below the pipe invert elevation. At Boring 8, the alluvium was noted to consist of about four feet of moist, loose, silly sand, over two feet of moist, very loose, clayey sand, over about five feet of moist to wet, soft, sandy clay, over saturated, very loose, poorly graded sand. The groundwater table was noted to be at 11.5 feet below the ground surface, where the pipe invert elevation is proposed at about seven feet below the ground surface. No caving soil types were found in this boring. Boring 9 was extended in the maintenance road between the golf course parking lot and the maintenance yard. This boring exposed about two feet of moist, loose, silty sand, over three feet of moist, loose to medium dense, clayey sand, over four feet of very loose clayey sand, over about two feet of moist, loose, silty sand, over saturated, soft, sandy clay that extended to 16 feet below the ground surface and had a one-foot-thick layer of poorly graded sand between 14 and 15 feet The very loose consistency of alluvial soils in this boring may be susceptible to caving in trench excavations. The groundwater table was noted at a depth of 11 feet, while the pipe invert elevation is proposed at about ten feet below the ground surface. CWE 199.293.6 March 16. 2000 Page No. 7 Boring 10 exposed about six feet of recent alluvium comprised of moist, loose, silty sand, above two feet of moist, soft, sandy clay, over one foot of moist, loose, silty sand, over three feet of moist, soft, sandy clay. At an approximate depth of 12 feet, older alluvium consisting of moist, medium stiff to stiff, sandy day was observed. This material extended to the bottom of our boring at 16 feet below the ground surface. No groundwater was found in this boring. The pipe invert elevation at this location is about 9.5 feet below the ground surface. AREA II, STATION 32+00 TO STATION 42+50 Area II basically follows the alignment of Sunny Creek Road from where it makes a 90-degree turn to the east to just east of the future extension of College Boulevard. This alignment is on the south side of the alluviated valley and north of a large, secondary alluviated plain that is to be developed into a shopping center. Grading in the area of the sewer line is expected to consist of fills from about two to ten feet above the existing grades; this fill is expected to be placed after the sewer line has been constructed This area is underlain by about one to two feet of fill material associated with Sunny Creek Road, recent alluvial deposits, older alluvial deposits, and formational soils. The fill materials generally consisted of gravelly, silty sands that were noted to be damp and medium dense. Three of our four borings, Bl, B3 and B4, in this area encountered a two- to three-foot-thick alluvium layer comprised of moist, medium dense, poorly graded sand below the roadway fill. This material and the fill in B3 was underlain by additional recent alluvium, the upper portion of which was comprised of moist, medium dense, clayey sands. Beginning with Boring B4 which is located on the west side of Area n, the clayey sands became saturated at a depth of about 11 feet and also became loose to medium dense. The sewer pipe invert elevation at this location is about 12 feet below grade, which is about the same depth as the groundwater table. This loose to medium dense material extended to a depth of about 17 feet where saturated, stiff, sandy day was encountered. At 22 feet, the alluvium graded into saturated, medium dense, dayey sand At 31 feet, the recent alluvium grades back into a sandy clay and remains the same to a depth of 68 feet Older alluvial deposits were encountered between a depth of 68 and 82 feet bdow grade. This material consisted of saturated, very stiff, silty, sandy day. The Santiago Formation was found at a depth of 82 feet and this material consisted of very dense, clayey sand. CWE 199.293.6 March 16. 2000 Page No. 8 At Boring B3, a moist, medium stiff sandy day was noted between eight and ten feet, and this material was underlain by moist to saturated, loose clayey sand that extended to a depth of 18 feet Groundwater was noted to be at a depth of about 12 feet below the ground surface; the sewer pipe invert at this location is proposed at approximately the same elevation as the ground water. The alluvium between 18 and 21 feet graded into a saturated, stiff, sandy clay and then back into a saturated, medium dense, clayey sand. Saturated, stiff, sandy day was found between 29 feet and 65 feet, which is the contact with the older alluvial deposits. At this location the older alluvial deposits consisted of 12 feet of saturated, very stiff, sandy clay. The Santiago Formation was encountered at a depth of 79 feet below the ground surface. Between a depth of nine and 12 feet in Boring B2, we encountered a layer of moist, medium dense, silty sand The groundwater table was found at a depth of 12 feet below the ground surface; this is approximately the same elevation as the sewer pipe invert elevation at this location. Below this depth, we encountered a four-foot-thick layer of saturated, loose, clayey sand. From 16 to 22 feet, saturated, stiff, sandy day was found, and from 22 to 28 feet saturated, medium dense, ckyey sand was logged. The recent alluvium below this depth graded in and out of sandy clays and clayey sands and extended to a depth of 67 feet where the older alluvial deposits were found. This material consisted of saturated, very stiff, gravelly, sandy clay. The Santiago Formation was logged at a depth of 77 feet bdow the ground surface at this location. Boring Bl encountered moist, stiff, sandy clay that extended from eight feet to a depth of 19 feet, where the older alluvial deposits were encountered The groundwater table was logged at a depth of 12 feet bdow grade, which is approximately the same elevation as the sewer pipe invert elevation. The older alluvium consisted of moist, very hard sandy day. The Santiago Formation was encountered at a depth of 29 feet. This material consisted of very dense, clayey sand. AREA III, STATION 54+00 TO 57+38 In Area III, the sewer line alignment extends easterly from the base of the hillside that forms the south side of the stream channd, crosses the creek and extends into an alluvial plain on the other side. We understand that the sewer pipe will be jadted under the active streambed at this location. No fill or grading is proposed for this area. Fight test trenches were excavated in this area to determine the soil profile within the pipe zone. All of the trenches in this area encountered fill material that varies from about one to two feet thick and consisted of silty CWE 199.293.6 March 16. 2000 Page No. 9 sands. Recent alluvial deposits were logged below the fill in all eight trenches. Beginning at the west side of this area, Trench Tl encountered about 4.5 feet of alluvium comprised of moist, stiff, sandy clay. Older alluvium was found under this material and extended deeper than our test trench which was terminated at 13.5 feet below the ground surface. The older alluvium consisted of moist dense to very dense, clayey sand. No groundwater or wet soils were found in this trench. Trench T2 exposed a 1.5-foot-thick layer of relatively dean, poorly graded sand below the fill material This was underlain by moist, stiff sandy day that extended to the contact with older alluvium at a depth of about nine feet The older alluvium was logged as moist, very dense, clayey sand. No groundwater or wet soil was encountered in this trench. Trench T3 exposed a two-foot-thick layer of moist, loose ckyey sand under the fill material. Bdow this was a four-foot-thick layer of the clean, poorly graded sand. From about eight to 16 feet, moist, stiff sandy day was exposed. This material became wet at a depth of about 11 feet The sewer line invert at mis location is 14 feet bdow the ground surface. The fill material encountered in Trench T4 was about 4.5 feet thick and consisted of medium dense, silty, very gravdy sand. The alluvium between 4.5 and six feet consisted of moist, loose, clayey sand, and the next layer, which extended to about 7.5 feet, consisted of moist, loose to medium dense, dean, poorly graded sand. From 7.5 feet to the bottom of our trench at 13 feet, stiff, sandy day was exposed. Groundwater was logged at 11.5 feet bdow the ground surface. At this location, the pipe invert is at about 13.4 feet bdow the ground surface. Trench T5 encountered 3.5 feet of fill over alluvial deposits consisting of moist, loose, slightly silty, poorly graded sand. This material extended to the bottom of our trench at 10.5 feet bdow the ground surface. Ground water was logged at 8.5 feet below the ground surface. It can be noted that this trench is very dose to the creek, whidi has a year-round flow. This trench was terminated at a depth of 10.5 feet due to excessive caving of the trench sidewalls. The pipe invert devation at this location is approximatdy 12.5 feet bdow the ground surface. Trench T6 encountered one foot of silty sand fill with abundant debris, over one foot of dean sand, over wet to saturated, medium stiff, sandy day. Groundwater was logged at a depth of four feet bdow the ground surface. This trench was terminated at a depth of six feet due to CWE 199.293.6 March 16.2000 Page No. 10 excessive caving of the trench sidewalk. The pipe invert at this location is about 12 feet below the ground surface. Trench T7 exposed 1.5 feet of fill, over 1.5 feet of damp, loose, dean sand, over clayey sand that extended to a depth of 9.5 feet. This material was moist and loose to seven feet and wet to saturated from seven to 9.5 feet. Groundwater was logged at 8.5 feet below the ground surface. From 9.5 feet to the bottom of our trench at 11 feet, saturated, stiff, sandy clay was logged. This trench was terminated at a depth of 11 feet due to excessive caving of the trench sidewalk. The pipe invert elevation at this location is approximately 15.6 feet below the ground surface. About 1.5 feet of fill was encountered in Trench T8 that consisted of damp, medium dense, silty sand. The alluvium below this consisted of moist, loose, clayey sand to a depth of 4.5 feet; moist, medium stiff, sandy clay to seven feet; moist, loose, clean, poorly graded sand to nine feet; and moist to saturated, stiff, sandy clay to the bottom of our trench at 13 feet. Groundwater was logged at a depth of 10.5 feet This trench was terminated at a depth of 13 feet due to excessive caving of the trench sidewalk. The pipe invert elevation at this location is about 16.4 feet below the ground surface. CONSOLIDATION CHARACTERISTICS GENERAL: It is our understanding that fills of about four to ten feet above the existing grades are expected in Area II of the proposed trunk sewer main alignment to provide access to the proposed shopping center from Sunny Creek Road. We ako understand that no grading or fills are proposed in any of the other alluviated areas along the pipe route. The weight of this fill material was taken into consideration in determining the amount of settlement and the time rate of consolidation of the recent alluvial deposits underlying Area II. The older alluvial deposits have low consolidation characteristics and are not expected to consolidate under the anticipated fill loads. It should be noted that the recent alluvial materials considered in the calculations discussed in this section were limited to those encountered below the water table. Our analysk assumed that the alluvium above the water table will be removed and replaced as compacted fill. ESTIMATED CONSOLIDATION MAGNITUDE: In general, the amount of consolidation or settlement that may occur in a layer of soil is dependent on a number of factors, including the amount of pressure exerted on the soil by a load, the compressibility of the underlying soils, and the layer thickness of each of the encountered soil types beneath the load. The amount of consolidation of each CWE 199.293.6 March 16. 2000 Page No. 11 encountered soil type has been calculated, with consideration given to the soil's depth and thickness. These results were utilized to determine the total amount of consolidation expected for the recent alluvium within the general vicinity of that particular exploratory boring and thus provide an estimate of the settlement the proposed trunk sewer will undergo after it is covered with four to nine feet of fill material A summary of the estimated consolidation of each soil type encountered is presented on the attached Plate Nos. 45 and 46. As can be seen from this summary, if four feet of fill materials are placed on the sewer line area, the total amount of settlement calculated varies from approximately 1.3 inches in the eastern portion to approximately 2Va inches in the center and western portions of the alignment. If nine feet of fill materials are placed on the sewer line area, the total amount of settlement calculated ranges from approximately 2V2 inches in the eastern portion of the alignment to approximately SVi inches in the western portion. ESTIMATED CONSOLIDATION TIME: In general, sandy soils will consolidate at a faster rate than ckyey soils when subjected to vertical loads such as those which will be imposed by the proposed trunk sewer and fill materials. This characteristic can be attributed to the sandy soils' ability to allow for 1 'ih ** water within the soil matrix to be displaced at a quicker rate than a clayey soil. The rather large layer of recent alluvium that underlies Area II contains a variety of sandy and clayey soils. As such, the amount of time required for the various soil layers to consolidate varies from a few days to a few years. Each test boring revealed a relatively thick deposit of clay, particularly in B-3 and B-4, which will require an extremely long time period to consolidate. In consideration of this, special ground modification procedures to speed up the consolidation time or special construction techniques to provide support for the sewer pipe are recommended CONCLUSIONS In general, we did not find any soil or geologic conditions along the proposed sewer main route that would prevent the construction of the subject project, provided the recommendations presented herein are followed. In Area I, the soils exposed above the pipe zone were found to generally not be susceptible to caving, and the groundwater table was found to be several feet below the pipe invert elevation. Therefore, no significant soil or geologic conditions were found in this area that will affect the proposed construction. CWE 199.293.6 March 17. 2000 Page No. 12 The most significant geotechnical condition that will affect the proposed construction is shallow groundwater and the relatively loose and compressible, recent alluvial deposits that underlie Area II of the project route. As discussed previously, the recent alluvial deposits will consolidate when subjected to the load imposed by the fill material to be placed in this area for the access road proposed north of the future shopping center. Another important factor to be considered is the extensive time period required for primary consolidation to occur in the clayey portions of this alluvium. A method to mitigate the adverse consolidation and settlement characteristics of the recent alluvial deposits in Area II would be to perform a deep ground modification technique, called Deep Soil Mixing, along the pipe alignment to support the pipe while the areas to the side of the pipe settle. We have been in contact with specialty contractor Hayward Baker regarding the feasibility of utilizing this deep ground modification technique. Deep soil mixing, which should extend to the competent older alluvial deposits, basically consists of mechanically blending the in-situ soils with cementitious materials (reagent binder) using a hollow stem auger and paddle arrangement The general intent of the soil mixing program for this case would be to achieve improved character of the recent alluvial soil deposits in the form of a design compressive strength or soil shear strength. The deep soil mixing process will basically result in the construction of a vertical soil-cement column under the pipe. Preliminary information from Hayward Baker indicates that a single row of soil-cement columns may be able to provide the necessary support for the sewer pipe. The elevation of the groundwater in Area II is very near the invert elevation of the proposed sewer pipe. This condition, combined with the special site preparation recommended hereinafter, will require dewatering during the site preparation operation and when the sewer pipe is installed. Since fill will be placed in Area II when the shopping center and access road is constructed, it will also be necessary to remove and recompact the loose alluvial deposits above the water table prior to installing the sewer pipe. This removal and recompaction should extend a sufficient horizontal distance from the pipe such that the pipe will not need to be disturbed during that grading operation. Another major adverse condition is the presence of high ground water and loose, caving soils at the east end of the project, starting at about Station 55+00 and extending to the end of the project at Station 57+30. The recent alluvial deposits in this area include a substantial amount of sands with low cohesion that are susceptible to caving and will not stand well in excavations. This area will require dewatering to CWE 199.293.6 March 17. 2000 Page No. 13 install the sewer pipe and diversion of the active stream around the project area, as well as laying back the trench excavations instead of cutting them vertical. RECOMMENDATIONS SITE PREPARATION GENERAL: Of the three areas investigated for this report, only Area II will require special site preparation prior to the installation of the trunk sewer main. This area extends between Station 33+00 and 42+00, and is along a portion of Sunny Creek Road that is underlain by deep, compressible, recent alluvial deposits. After the construction of the trunk sewer line, this area will be developed as part of a shopping center and as such, will receive fills varying from about two to ten feet thick. The north extension of College Boulevard will also produce fills on the order of ten feet in the area of the sewer line. Site preparation in areas to receive fills will require that the recent alluvial deposits be removed to just above the water table and be replaced as compacted fill prior to constructing the new fills. Since the sewer line will be constructed before the shopping center and College Boulevard, it will be necessary to perform this removal prior to the construction of the sewer line so that the proposed grading does not disturb the sewer line. In addition, due to the settlement characteristics of die recent alluvial deposits when subjected to fill loads, it will be necessary to perform deep ground modifications, in the form of deep soil mixing, to provide support for the sewer line so diat it will not settle. Specific recommendations for site preparation and deep ground modification for Area II are presented hereinafter. Since no fill or grading is proposed for Areas I and III, no special site preparation techniques are considered necessary other than the usual grubbing, clearing, demolishing and backfilling operations normally associated with the installation of underground utilities. DEEP GROUND MODIFICATION: The following recommendations for deep ground modification are intended to provide support for the sewer pipe during the consolidation of the underlying recent alluvial deposits. Deep Soil Mixing is a deep ground modification technique involving the mechanical in-situ mixing of soil with cementitious materials using a hollow-stem mixing tool. The injection of the binder may be in the form of either a slurry or dry powder. Sets of one to three shafts with mixing tools up to eight feet in diameter can be used to mix soft or loose soils to depths of up to 100 feet. As the tool is advanced into the soil, the hollow stem is used as a conduit to pump grout and mix it with the soil in contact with the tool. Single columns and/or panels can be created with this process as the tools are worked in overlapping configurations. A CWE 199.293.6 March 17. 2000 Page No. 14 range of compressive strengths between 10 and 500 psi is possible depending on the native soil type. Please refer to the attached Plate Nos. 5 and 6 for details of this deep ground modification operation. Since Ells will be added to this area during the development of the adjacent shopping center, removal and replacement of the alluvium above the water table will be necessary. It should also be noted that when the fills are placed for the shopping center, wick drains will also need to be installed for the portion of that project that extends out into the area underlain by recent alluvial deposits. The following presents our recommendations for the deep ground modification to provide support for the trunk sewer pipe. 1. Excavate a minimum 30-foot-wide slot along the pipe alignment down to the older alluvial deposits or to two feet above the water table, or to the point where pumping just begins. We estimate that the water table is at about elevation 56.5 feet at the east end and at about 55 feet at the west end of Area II. The slot should extend from about Station 33+00 on the west end to Station 41+35 on the east end, where it meets the area that was recently removed and recompacted for the storm drain pipe. The 30-foot-wide slot should be centered on the sewer pipe. The side slopes for the slot should be cut at an inclination of 1:1 or flatter. Additional removal and recompaction will be necessary for the sewer line east of the 40- foot-wide area recently removed and recompacted for the storm drain. This removal should extend 15 feet north and east of the sewer line, and should abut the storm drain removal limits on the west side. This removal area will be about 27 feet wide and 25 feet long (see Plate No. 3). It should be realized that wick drains have been installed in a portion of this area, and that it will be necessary to work around these wick drains when installing the "burrito" drains recommended in the following section. 2. Install two, twelve-foot-wide "burrito" drains in the bottom of the slot, one on the south side and one on the north side such that there is a six-foot-wide gap that is centered on the proposed pipe alignment. This gap is to allow the soil-cement columns to be constructed. The "burrito" drains should consist of a 6-inch layer of crushed rock surrounded with stabilization fabric such as Mirafi 600X and should extend easterly to the existing "burrito" drain installed during the site preparation operations for the construction of the storm drain in College Avenue. The "burrito" drains should also be CWE 199.293.6 March 17. 2000 Page No. 15 continued on the east side of the storm drain "burrito" drain until it contacts fbrmational soil or older alluvial deposits. The purpose of the "burrito" drains is to provide a medium for the ground water being squeezed out of the recent alluvial deposits to dissipate in. 3. After the "burrito" drains are installed, the excavated soil may be replaced in the excavation to establish the original grades. However, to reduce the depth of trenching for the sewer line in this area, it may be deskable to only fill the slot up to about four feet above the top of the pipe, perform the ground modifications, install the pipe and then finish filling in the slot. All fill material should be compacted to at least 90 percent relative compaction as determined by ASTM D1557-91. 4. Once the removal and replacement of the alluvial soils in the 30-foot-wide slot is completed, the deep ground modification operation should proceed. The sewer pipe should be supported on a single row of soil-cement columns, three (3) feet in diameter and spaced at eight (8) feet on center. Four columns should be placed under each manhole in this area. The soil-cement columns should also extend down to the older alluvial soils or formational soils. The volume of cement slurry used to create the soil- cement columns should be at least 30 percent by volume and the soil/cement mix should attain a compressive strength of at least 100 pounds per square inch. Plates 5 and 6, attached herewith, present a detail of the construction of the deep mix, soil- cement columns. 5. Once the deep ground modification is complete, the trunk sewer line may be installed by normal trenching operations. However, the backfill for the sewer line up to at least two feet above the top of the pipe should consist of clean, coarse sand with a sand equivalent of at least 50. This will allow the soil to flow around the pipe as the surrounding areas subside under the weight of the proposed fill. It should again be noted that the invert of the pipe is very close to the groundwater table in this area, and that some dewatering may be necessary. PIPE CLASSIFICATION: In consideration of the very sensitive settlement characteristics of the proposed trunk sewer line due to its very flat gradient, we recommend a heavy-duty pipe such as AWWA C905, Class 200, PVC pipe be used through Area II of the subject project. This pipe is capable of spanning an unsupported length of 19.5 feet when filled with water; however, for this case CWE 199.293.6 March 16.2000 Page No. 16 an unsupported length of only five feet will exist between soil-cement columns and an unsupported length of about nine feet will exist in the PVC sleeve installed under the storm drain. OBSERVATION OF GRADING: Continuous observation by the Geotechnical Consultant is essential during the removal and recompaction operation to confirm conditions anticipated by our investigation, to allow adjustments in design criteria to reflect actual field conditions exposed, and to determine that the grading proceeds in general accordance with the recommendations contained herein. This is particularly important in evaluating the necessary depths of removal of the loose, recent alluvial soils and the end limits. CLEARING AND GRUBBING: Site preparation should begin with the removal of all vegetation and other deleterious materials from the areas which will be prepared to receive the proposed trunk sewer main and the slot to be excavated in Area II. This should include all root balls from the trees to be removed and all significant root material. The resulting materials should be disposed of off-site. PREPARATION OF ALLUVIAL SOILS: The alluvial soils above the water table are relatively loose and could "bridge" when the proposed fills are added after the trunk sewer pipe is in place. This bridging could result in significant settlement of this nonsaturated alluvial material if it is allowed to increase in moisture content after the fill material is in place. In order to mitigate this condition, it is recommended that the recent alluvial deposits in Area II be removed and be replaced as recommended above in the Deep Ground Modification section of this report. COMPACTION AND METHOD OF FILLING: All fill placed at the site should be compacted to a relative compaction of at least 90 percent of maximum dry density as determined by ASTM Laboratory Test D1557. Fills should be placed at or slightly above optimum moisture content, in lifts six to eight inches thick, with each lift compacted by mechanical means. Fills should consist of approved earth material, free of trash or debris, roots, vegetation, or other materials determined to be unsuitable by our soil technicians or project geologist. Fill material should be free of rocks or lumps of soil in excess of six inches in maximum dimension. Based upon the results of our sub-surface exploration and laboratory testing most of the on-site soils appear suitable for use as fill material. Sufficient observation and testing should be provided so that an opinion can be provided as to the compaction achieved. Trench backfill for the trunk sewer pipe should be placed in lifts of less than 12 inches thick, with each lift mechanically compacted to at least 90 percent of the maximum dry density at a moisture content of just slightly above the optimum moisture content. CWE 199.293.6 March 16.2000 Page No. 17 All grading and fill placement should be performed in accordance with the City of Carlsbad Grading Ordinance, the Uniform Building Code, and the attached Recommended Grading Specifications and Special Provisions attached hereto as Appendix B. LIMITATIONS UNIFORMITY OF CONDITIONS The recommendations and opinions expressed in this report reflect our best estimate of the project requirements based on an evaluation of the subsurface soil conditions encountered at the subsurface exploration locations and the assumption that the soil conditions do not deviate appreckbly from those encountered. It should be recognized that the performance of the trunk sewer pipe might be influenced by undisclosed or unforeseen variations in the soil conditions that may occur in the intermediate and unexplored areas. Any unusual conditions not covered in this report that may be encountered during site development should be brought to the attention of the soils engineer so that he may make modifications if necessary. In addition, this office should be advised of any changes in the project scope or proposed site grading so that it may be determined if the recommendations contained herein are appropriate. This should be verified in writing or modified by a written addendum. CHANGE IN SCOPE This office should be advised of any changes in the project scope or proposed site grading so that we may determine if the recommendations contained herein are appropriate. This should be verified in writing or modified by a written addendum. TIME LIMITATIONS The findings of this report are valid as of this date. Changes in the condition of a property can, however, occur with the passage of time, whether they be due to natural processes or the work of man on this or adjacent properties. In addition, changes in the Standards-of-Practice and/or Government Codes may occur. Due to such changes, the findings of this report may be invalidated wholly or in part by changes beyond our control. Therefore, this report should not be relied upon after a period of two years without a review by us verifying the suitability of the conclusions and recommendations. CWE 199.293.6 March 16. 2000 Page No. 18 PROFESSIONAL STANDARD In the performance of our professional services, we comply with that level of care and skill ordinarily exercised by members of our profession currently practicing under similar conditions and in the same locality. The client recognizes that subsurface conditions may vary from those encountered at the locations where our borings, surveys, and explorations are made, and that our data, interpretations, and recommendations are based solely on the information obtained by us. We will be responsible for those data, interpretations, and recommendations, but shall not be responsible for the interpretations by others of the information developed. Our services consist of professional consultation and observation only, and no warranty of any kind whatsoever, express or implied, is made or intended in connection with the work performed or to be performed by us, or by our proposal for consulting or other services, or by our furnishing of oral or written reports or findings. CLIENT'S RESPONSIBILITY It is the responsibility of The Terraces at Sunny Creek LLC, or their representatives to ensure that the information and recommendations contained herein are brought to the attention of the structural engineer and architect for the project and incorporated into the project's plans and specifications. It is further their responsibility to take the necessary measures to insure that the contractor and his subcontractors carry out such recommendations during construction. FIELD EXPLORATIONS Ten test borings were drilled at the locations indicated on Pkte Numbers 1 through 3 between October 20,1999 and January 11, 2000. In addition, eight test trenches were excavated at the locations indicated on Plate Number 4 on October 26,1999. The ten small diameter borings were advanced with a truck- mounted drill-rig, while the eight test trenches were excavated with a backhoe. The fieldwork was conducted by or under the observation of our engineering geology personnel. The subsurface exploration logs are presented on the following Plate Numbers 7 though 31. The soils are described in accordance with the Unified Soils Classification. In addition, a verbal textural description, the wet color, the apparent moisture and the density or consistency are provided. The density of granular soils is given as either very loose, loose, medium dense, dense or very dense. The density of cohesive soils is given as either very soft, soft, medium stiff, stiff, very stiff, or hard. Relatively undisturbed, "ring" samples of typical and representative soils were obtained from the soil boring CWE 199.293.6 March 16. 2000 Page No. 19 exploration and returned to the laboratory for testing. The undisturbed samples were obtained by driving a split-tube sampler ahead of the auger, using a 140-pound hammer free falling a distance of 30 inches. The number of blows to drive the sampler one-foot is presented on the boring logs as 'Tenetration Resistance." Bulk samples of disturbed soil from the auger spoils were also collected in bags from the boring locations. LABORATORY TESTING Laboratory tests were performed in accordance with the generally accepted American Society for Testing and Materials (ASTM) test methods or suggested procedures. A brief description of the tests performed is presented below: a) CLASSIFICATION: Field classifications were verified in the laboratory by visual examination. The final soil classifications are in accordance with the Unified Soil Classification System. b) MOISTURE-DENSITY: In-place moisture contents and dry densities were determined for representative soil samples. This information was an aid to classification and permitted recognition of variations in material consistency with depth. The dry unit weight is determined in pounds per cubic foot, and the in-place moisture content is determined as a percentage of the soil's dry weight. The results of these tests are summarized in the boring logs. c) GRAIN SIZE DISTRIBUTION: The grain size distribution was determined from representative samples of soils obtained at various depths in accordance with ASTM D422. The results of these tests are presented on Plate Number 32 and 33. d) CONSOLIDATION TESTS: Consolidation tests were performed on selected "undisturbed" samples. The consolidation apparatus was designed to accommodate a 1-inch- high by 2.375-inch or 2.500-inch diameter soil sample laterally confined by a brass ring. Porous stones were placed in contact with the top and bottom of the sample to permit the addition or release of pore fluid during testing. Loads were applied to the sample in a geometric progression after vertical movement ceased, and resulting deformations were recorded. The percent consolidation is reported as the ration of the amount of vertical compression to the original sample height The test sample was inundated at some point in the test cycle to determine its behavior under the anticipated loads as soil moisture increases. In addition, at a CWE 199.293.6 March 16. 2000 Page No. 20 selected vertical load, time versus settlement was recorded to determine the time rate characteristics of the soil. The results of the consolidation and time rate tests are presented in the form of a curve on Plate Numbers 34 through 44. PLAN VIEW OF SOIL-CEMENT COLUMNS STORM DRAIN CROSSING SCALE: 1"=6' COMPACTED FILL */.////' / // / 8' * * _^^_• '•••** a' •• * •»• / // / •/ / / A -3' OLDER ALLUVIUM OF FORMATIONAL SOIL SECTION AA SCALE: T'=6' GROUND SURFACE CLEAN SAND BACKFILL 18" PVC SEWER AWWA C905 RECENT ALLUVIUM SOIL-CEMENT COLUMNS <FILL * -ci .UMNS %. r* »•ff s=—P>- •^ ~o^ y s/9i 36" *" ." * l£\'iv" ./« 1 **. ••I* <*i -=: •« '• P 24" zf •^ SECTION BB SCALE 1"=6' ,. J Plate Number: 5 36" PVC SLEEVE SOIL-CEMENT COLUMNS ^^^^^^^^^dw ^^^w _rf^*^*s_^^^^^^^^^^^S^^SGSSS^S3tf^^^B0m*gt^^^^H&F*^^^fS^S^S3lte^^^^*^nt^^**f RUBBER GASKET ///. / / PLAN VIEW OF SOIL-CEMENT COLUMNS @ STORM DRAIN CROSSING»=6' -x GROUND SURFACE COMPACTED FILL 84" RCP StORM DRAIN 36" PVC SLEEVE RUBBER GASKET •—«™j—•=—•^•j"*=~"»"™«™"=«™^«=fc===jp=*=««^3j»™=gg^^™™~325« OLDER ALLUVIUM OF FORMATIONAL SOIL \(V /•//////*• •CLEAN SAND BACKFILL 18" PVC SEWER AWWA C905 SOIL-CEMENT COLUMNS 'RECENT ALLUVIUM SECTION AA SCALE: T'=6' SECTION BB SCALE: T'=6'Plate Number: S LOG OF TEST BORING NUMBER B-l @ Station 40+00 Date Excavated: 10/20/99 Logged by: DRR Equipment IRA300 Project Manager. CHC Surface Elevation: 69 feet Depth to Water. 12 feet Hammer Weight 140 pounds Drop of Hammer. 30 inches DEPTH (1-1 - 6 - 8 -10 -12 B -14 . -16 -18 L.20 0 US o i| 1 1Ii1 aiBra Si 1m••i•••« m SUMMARY OF SUBSURFACE CONDITIONS FTT.T. (Qflf)-T Medium brown, dry, loose to medium dense, fine to medium grained SILTY SAND (SM), trace gravels. ^T.T.TTyTUM (Qal); Light brown, damp, medium dense, fine to coarse grained, POORLY GRADED SAND (SP), micaceous. Dark brown, moist, medium dense, fine to coarse grained CLAYEY SAND (SQ. Dark brown, moist, stiff, SANDY CLAY (CL). #KiM«mftfet Saturated. Grades to olive in color. / OT.TYRK ^T.T.UVIUM (Goal): Olive, moist, hard, ^^^ SANDY CLAY (CL), abundant iron stains. SAMPLES W IPLETYP% SPT CAL SPT CAL SPT CQ V lETRATIOs/ ft. of drii£1 29 32 8 20 45 ISTURE p0 7.2 u I > Q 107.0 ii ^ — Boring continues on Plate Number 11. AGUA HEDIONDA TRUNK SEWER fjjy Area II CHRISTIAN WHEELER BY: SD E NG'NBEIUNG ]Q^Q . ^ ^ DATE: Nov-99 PLATE NO.: 7 LOG OF TEST BORING NUMBER B-l (Continued) Date Excavated: 10/20/99 Logged by: DRR Equipment IRA300 Project Manager CHC Surface Elevation: 69 feet Depth to Water 12 feet Hammer Weight 140 pounds Drop of Hammer: 30 inches DEPTH (ft)-22 -24 -26 -28 GRAPHIC LOG• 1 I I I liij&sjiliilll -34 -36 -38 L-40 • SUMMARY OF SUBSURFACE CONDITIONS DTT>FK AT.T.UVIUM (Ooal): Olive, moist, hard, SANDY CLAY (CL), abundant iron stains. Abundant gravels. SANTIAGO FORMATION (Tsa): White, moist, very dense, fine to medium grained CLAYEY SAND (SQ. . Bottom of boring at 34 feet. SAMPLES SAMPLE TYPESPT SPT SPT DPQ PENETRATION(blows/ ft. of drive)50/6" 50/5" 50/5"MOISTURE (%)DRY UNIT WT. (pcf)LABORATORYTESTS•• AGUA HEDIONDA TRUNK SEWER "ira Area II CHRISTIAN WHEELER. BY: SD E NGINEER.ING JOB NO. : 199.293 DATE: Nov-99 PLATE NO.: 8 LOG OF TEST BORING NUMBER B-2 Station 38+00 Date Excavated: 10/20/1999 and 10/21/1999 Equipment IR A300 and CME 55 Surface Elevation: 69 feet Hammer Weight 140 pounds Logged by: DRR Project Manager CHC Depth to Water: 12 feet Drop of Hammer 30 inches SUMMARY OF SUBSURFACE CONDITIONS SAMPLES CQ w .3p. g.i 2D I FILL (Oaf): Medium brown, damp, loose to medium dense, \ fine to medium grained SILTY SAND (SM). (Qal); Light brown, damp, medium dense, fine to coarse grained, POORLY GRADED SAND (SP) with thin SPt 19 4.8 101.1 Medium brown to dark brown, moist, medium dense, fine to coarse grained CLAYEY SAND (SQ.SPT 13 Dark brown, moist, medium dense, fine to medium grained SILTY SAND (SM). Medium brown, saturated, loose, fine to coarse grained CLAYEY SAND (SQ. CAL 22 7.8 105.3 CAL 10 Medium brown, saturated, stiff, SANDY CLAY (CL). SPT Boring continues on Plate Number 13. CHRISTIAN WHEELER ENGINEERING AGUA HEDIONDA TRUNK SEWER Area II BY:SD JOB NO.199.293 DATE:Nov-99 PLATE NO.: LOG OF TEST BORING NUMBER B-2 (Continued) Date Excavated: 10/20/1999 and 10/21/1999 Logged by: DRR Equipment IR A300 and CME 55 Project Manager. CHC Surface Elevation: 59 feet Hammer Weight 140 pounds •8 8 -22 1C LOG£ d i • Depth to Water: 12 feet Drop of Hammer: 30 inches SUMMARY OF SUBSURFACE CONDITIONS Medium brown, saturated, stiff, SANDY CLAY (CL). Medium brown, saturated, medium dense, fine to coarse grained - 24 CLAYEY SAND (SC). " "1 -34 -36 -38 11 Olive to gray, saturated, medium stiff, SILTY CLAY (CL/CH). Olive to gray, saturated, stiff, SANDY CLAY (CL). /" ""•••.....-•'" Olive, saturated, medium dense, fine to coarse grained "•••.... CLAYEY SAND (SQ. SAMPLES a 1 I SPT SPT CAL 1 P 2 1 > § i 18 6 24 g §D feb55 21.2 I fa I?Q 104.3 ow O H i Boring continues on Plate Number 14. CHRIST! AN WHEELER. ENGINEERING AGUA HEDIONDA TRUNK SEWER Area II BY: SD JOB NO. : 199.293 DATE: Nov-99 PLATE NO.: 10 LOG OF TEST BORING NUMBER B-2 (Continued) Date Excavated: 10/20/1999 and 10/21/1999 Logged by: DRR Equipment IR A300 and CME 55 Project Manager CHC Surface Elevation: 69 feet Hammer Weight 140 pounds DEPTH§GRAPHIC 1• -46 -48 ' -50 -52 -54 -56 -58 1im 1 •»1 L-60 iil Depth to Water. 12 feet Drop of Hammer 30 inches SUMMARY OF SUBSURFACE CONDITIONS Olive, saturated, medium dense, fine to coarse grained CLAYEY SAND (SC). Olive, saturated, medium stiff, SANDY SILTY CLAY (CL). Dark gray, saturated, medium stiff, SANDY SILTY CLAY (CL). Olive, saturated, medium dense, CLAYEY SAND (SQ, trace gravels. SAMPLES W SAMPLE TY1SPT CAL SPT CA1 Dn *~y 4Ji^-* ^ P "£,<ri o J~j go M 0 7 16 6 28 MOISTURE (I | Q LABORATOlTESTSBoring continues on Plate Number 15. CHRISTIAN WHEELER ENGINEERING AGUA HEDIONDA TRUNK SEWER Area II BY: SD JOB NO.: 199.293 DATE: Nov-99 PLATE NO.: 11 LOG OF TEST BORING NUMBER B-2 (Continued) Date Excavated: 10/20/1999 and 10/21/1999 Logged by: DRR Equipment IR A300 and CME 55 Project Manager: CHC Surface Elevation: 69 feet Depth to Water. 12 feet Hammer Weight 140 pounds Drop of Hammer 30 inches Q -62 -64 ___ -66 -68 -70 -72 -74 . -76 -78 L-80 GRAPHIC LOGwi SUMMARY OF SUBSURFACE CONDITIONS Olive, saturated, medium dense, CLAYEY SAND (SQ, trace gravels. OLDER AT .T.TTVTJTM (Qoal): Olive to gray, saturated, very stiff, GRAVELLY SANDY CLAY (CL). SANTIAGO FORMATION (Tsa): Light gray to orangish- brown, moist, very dense, fine grained CLAYEY SAND X (SQ and Sandstone. ^^ SAMPLES SAMPLE TYPESPT SPT US us §PENETRATION(blows/ ft. of drive)10 20 42 SO/l'/i MOISTURE (%)DRY UNIT WT. (pcf)LABORATORYTESTSBottom of boring at 79 feet. AGUA HEDIONDA TRUNK SEWER VIA rffl Area II CHRISTIAN WHEELER BY: SD E NGINEER.ING _ _ DATE: Nov-99 PLATE NO.: 12 LOG OF TEST BORING NUMBER B-3 @ Station 36+00 Date Excavated: 10/21/99 Equipment CME 55 Surface Elevation: 68 feet Hammer Weight 140 pounds g ffi SQ 8 ag Sio - -H Q H£§gSS&o E0z§H -1.1 - 12 Bl1 -14 . -16 - 10 >*"'-•. N A.***it 1 Logged by: DRR Project Manager: CHC Depth to Water 12 feet, 2 inches Drop of Hammer: 30 inches SUMMARY OF SUBSURFACE CONDITIONS JTI-T,- (Q?f)f M^"1™1 h«««"i, <^amp, medium HMISP, fine fn \ medium grained SILTY SAND (SM). ^^ AT.T.TTVTUM (Qal): Light brown, damp, medium dense, fine to coarse grained CLAYEY SAND (SQ. Medium brown, moist, stiff, SANDY CLAY (CL). Dark brown, moist, loose to medium dense, fine to coarse "\ grained CLAYEY SAND (SQ. \ Saturated. *"- ;$?ipe. Invert % 54.4 feet. Medium brown, saturated,stiff, SANDY CLAY (CL). SAMPLES a £a 1 V3 CQ V 2? £ '5,^1 0 w "ST W o g [_,ini & ^fc2 £ Q fe Hw ^mO H 3 Boring continues on Plate Number 17. W < ' • CHRISTIAN WHEELER ENGINEERING AGUA HEDIONDA TRUNK SEWER Area II BY: SD JOB NO.: 199.293 DATE: Nov-99 PLATE NO.: 13 LOG OF TEST BORING NUMBER B-3 (Continued) Date Excavated: 10/21/99 Logged by. DRR Equipment CME 55 Project Manager CHC Surface Elevation: 68 feet Depth to Water 12 feet, 2 inches Hammer Weight 140 pounds Drop of Hammer 30 inches 5TG- hn wp o1-5 OHHffi ft •-41 I ~24II' -28 -30 -32 -34 -36 -38 _ fin IMI 1 I 1 SUMMARY OF SUBSURFACE CONDITIONS Medium brown, saturated, stiff, SANDY CLAY (CL). Medium brown, saturated, medium dense, fine to coarse grained CLAYEY SAND (SQ. Olive to gray, saturated, stiff, SILTY SANDY CLAY (CL). SAMPLES W P^ Fa ^00 m 7, ?O '5*=: 2^c o nj O* a cs^e^ 1HHO2 <s? A ^bzD SQ . £rt0^ •^ v5K MOH35 Boring continues on Plate Number 18. AGUA HEDIONDA TRUNK SEWER Areall CHRISTIAN WHEELER BY: SD ENGINEERING innisin • DATE: Nov-99 PLATE NO.: 14 LOG OF TEST BORING NUMBER B-3 (Continued) Date Excavated: 10/21/99 Equipment CME 55 Surface Elevation: 68 feet Hammer Weight 140 pounds g H!F— 3 wQ . -62 -64 -66 -68 • -70 -72 -74 -76 -78 O2 U o2O 1 • 1 jj jm • 1 1 jj • Logged by: DRR Project Manager: CHC Depth to Water: 12 feet, 2 inches Drop of Hammer: 30 inches SUMMARY OF SUBSURFACE CONDITIONS Olive, saturated, stiff, SANDY CLAY (CL). OT.DP.K AT.TJTVTUM (Ooal): Olive, saturated, very stiff, SANDY CLAY (CL). / SANTIAGO FORMATION (Tsa); Dark brown to light ^"^N. orangish-brown, moist, very dense, fine to medium grained CLAYEY SAND and Sandstone (SQ. SAMPLES W f£••* 3fri 1 y,_i CQ o Tt-j "3 ff> ^Sg d W "> w ^ g rv*p w 0 »>& (^ ^>fc2 ^Q & ^rn ^fflOE-' ^ Bottom of boring at 80 feet. w CHRISTIAN WHEELER. ENGINEER.ING AGUA HEDIONDA TRUNK SEWER Area II BY: SD JOB NO. : 199.293 DATE: Nov-99 PLATE NO.: ' 15 LOG OF TEST BORING NUMBER B-4 @ Station 34+00 Date Excavated: 10/21/99 Logged by: DRR Equipment CME 55 Project Manager: CHC Surface Elevation: N/A Deplh to Water 12 feet Hammer Weight 140 pounds Drop of Hammer: 30 inches s WQi O3us o 1 IIISiHi llli :-I -12 SJJSJSB •Ii gg&& 1| • im -14 -16 -18 L-20 1 X*> SUMMARY OF SUBSURFACE CONDITIONS FILL (Qaf): Medium brown, damp, medium dense, SANDY \ GRAVEL (GM). ^^ fall, J.TVJUM (Qal); Light brown, damp, medium dense, fine to \\ coarse grained, POORLY GRADED SAND (SP). .„..••"" Medium brown, moist, medium dense, fine to coarse grained CLAYEY SAND (SQ, occasional clay lenses Medium brown to dark brown, saturated, loose to medium •% dense, fine to coarse grained CLAYEY SAND (SQ. »— *Kpeinyerts@ 55 J feet. Medium brown, saturated, stiff, SANDY CLAY (CL). SAMPLES SAMPLE TYPE3 V PENETRATION(blows/ ft of drive)g HHi DRY UNIT WT. (pcf)LABORATORYTESTSBoring continues on Plate Number 20. AGUA HEDIONDA TRUNK SEWER Iftf Area II CHRISTIAN WHEELER. BY: SD E NGINEER.ING DATE: Nov-99 PLATE NO.: 16 LOG OF TEST BORING NUMBER B-4 (Continued) Date Excavated: 10/21/99 Equipment CME 55 Surface Elevation: N/A Hammer Weight 140 pounds ®vSi- £fe 8 . -22 , Qi—iag o 11I 1-24W " i 1 ""I -| -. — Rfl - ft9 -84 -Bfi iI I 11 4i IA. 1r I I 1 ^1 Logged by: DRR Project Manager CHC Depth to Water: 12 feet Drop of Hammer: 30 inches . SUMMARY OF SUBSURFACE CONDITIONS Medium brown, saturated, stiff, SANDY CLAY (CL). Medium brown, saturated, medium dense, fine to coarse grained CLAYEY SAND (SQ. Olive to gray, saturated, stiff, SILTY SANDY CLAY (CL). OLDER ALLUVIUM (OoaD: Olive to gray, saturated, very stiff, SILTY SANDY CLAY (CL). SANTIAGO FORMATION (Tsa): Gray to orangish-brown, \ moist, very dense, fine to medium grained CLAYEY / SAND (SQ. / Bottom of boring at 83l/2 feet W CHRJSTIAN WHEELER. ENGINEERING SAMPLES W P-l £ 9& '^ o5 us K/1 DCQ ?! TO •« 8 2 <* O p^ <l^ S RP, ^ 50/3" {?ei- 1 OS <& &, *Z fcZ3 SQ >183He ^5 AGUA HEDIONDA TRUNK SEWER Area II BY: SD JOB NO. : 199.293 DATE: Nov-99 PLATE NO.: 17 LOG OF TEST BORING NUMBER B-5 @ Station 11+00 Date Excavated: i/5/00 Logged by: DRR Equipment Penn Drill Project Manager CHC Surface Elevation: N/A Depth to Water: 18 feet Hammer Weight 140 pounds Drop of Hammer 30 inches g Q :2 - 4 - 6 :8 -10 -12 - 14 1 CZTo -18 L-20 GRAPHIC LOGI 1 •TSH «B 1 SUMMARY OF SUBSURFACE CONDITIONS JPTT-T. (Qqf); MprUum hrrre SANDY CLAY (CL). ra, moists, medium stiff, GRAVELLY ^T-T-TIVTUM (Qal); Medium brown, moist, medium stiff, \\ GRAVELLY SANDY CLAY (CL). .....•••" \ Orangish-brown, moist, loose to medium dense, \ CLAYEY SAND (SC). Medium brown, moist, medium stiff to stiff, SANDY CLAY (CL), slight caliche. Becomes gray in color. Gray, moist, medium dense, fine to medium grained CLAYEY \ \ SAND (SC). ....."••*" Gray to dark gray, moist, stiff, SANDY SILTY CLAY (CL), micaceous. «A K! - \"^ J1 ^ " /'*— *Blpe iiiveit @ 45,9 feet. Bottom of boring at 20 feet uv CHRISTIAN WHEELER. ENGINEERING SAMHJ SAMPLE TYPETUTT IfCK. CK CK CK CK \j CK is PENETRATION(blows/ ft of drive)- 13 /MOISTURE (%)DRY UNIT WT.(pcf)LABORATORYTESTSAGUA HEDIONDA TRUNK SEWER Area I BY: SD JOB NO. : 199.293 DATE: Jan-00 PLATE NO.: 18 LOG OF TEST BORING NUMBER B-6 @ Station 14+50 Date Excavated: 1/5/00 Logged by: DRR Equipment Perm Drill Project Manager. CHC Surface Elevation: 62 feet Depth to Water i&/2 feet Hammer Weight 140 pounds Drop of Hammer 30 inches g Q - 2 - 4 - 6 :: -14 -16 -18 L.20 GRAPHIC LOGI •I I SUMMARY OF SUBSURFACE CONDITIONS fill. (Q^fy MpHiiim hmwn, moist, stiff, SANTDY T.T.AY (r.T.), trace gravels..."•""'" Medium brown, moist, medium stiff, SANDY CLAY (CL). Olive to yellowish-brown, moist, stiff, SANDY CLAY (CL), increased sand content ALLUVIUM (Oal): light gray, moist, medium dense, fine to medium grained SILTY SAND (SM), slightly micaceous. Dark brown, moist, loose/stiff, fine grained CLAYEY SAND- SANDY CLAY (SC-CL), micaceous. Light brown, moist, moist, medium dense, fine to coarse (\ grained CLAYEY SAND (SQ, slight gravel. ^s^ Medium brown, moist, medium stiff, SANDY CLAY (CL), slightly micaceous. Saturated. Bottom of boring at 18 feet. w CHRISTIAN WHEEUER ENGINEERING SAMPLES SAMPLE TYPESPT SPT SPT SPT SPT SPT 1 V PENETRATION(blows/ ft. of drive)10 12 22 10 9 8 MOISTURE (%)DRY UNIT WT. (pcf)LABORATORYTESTSSA AGUA HEDIONDA TRUNK SEWER Area I BY: SD JOB NO. : 199.293 DATE: Jan-00 PLATE NO.: 19 LOG OF TEST BORING NUMBER B-7 @ Station 17+50 Date Excavated: 1/5/00 Logged by: DRR Equipment Penn Drill Project Manager: CHC Surface Elevation: 55 feet Depth to Water 13 feet Hammer Weight 140 pounds Drop of Hammer. 30 inches g 8 ;: -14 -16 -18 U20 GRAPHIC LOG• i P 1 SUMMARY OF SUBSURFACE CONDITIONS FTTJ- (Oaf); Light brown to Tned«\im bt>wn, moist, medium \ dense, fine to medium grained CLAYEY SAND (SQ. ^^ AT-T-T^TUM (OaT>: Medium brown, moist, loose to medium dense, fine to medium grained CLAYEY SAND (SQ. Light brown, moist, loose, fine to coarse grained, SLIGHTLY "\ CLAYEY/POORLY GRADED SAND (SP). Light brown, moist, medium dense, fine to coarse grained SLIGHTLY SILTY SAND (SM). Medium brown, wet, soft, SANDY CLAY (CL). Saturated, soft. Bottom of boring at 13 feet. SAMPLES SAMPLE TYPESPT SPT SPT SPT § ^ I PENETRATION(blows/ ft. of drive)10 9 15 4 g I— tO DRY UNIT WT. (pcf)LABORATORYTESTSAGUA HEDIONDA TRUNK SEWER iM Area I CHRISTIAN WHEELER. BY: SD E NCINEER.ING _ DATE: Jan-00 PLATE NO.: 20 LOG OF TEST BORING NUMBER B-8 @ Station 20+00 Date Excavated: 1/11/00 Logged by: DRR Equipment Penn Drill Project Manager CHC Surface Elevation: 58 feet Depth to Water. HV2 feet Hammer Weight 140 pounds Drop of Hammer: 30 inches g Q :. - 8 . -10 -12 -14 -16 -18 I-20 GRAPHIC LOG1 1I 1nm IEffljs® •i 1 ||| SUMMARY OF SUBSURFACE CONDITIONS Fnj, (QffO? Medina brown, rnoist, loose, fine to medium \ grained SILTY SAND (SM) with slight gravel. ^^ AT/^JYUTM (Q^l): Medium brown, moist, loose, fine to,-T. . 1 J > medium grained SILTY SAND (SM). Dark brown, moist, very loose, fine to medium grained CLAYEY SAND (SO.^_..._...... ,. Dark brown, moist to wet, soft, SANDY CLAY (CL). Light brown, saturated, very loose, fine to coarse grained, X POORLY GRADED SAND (SP). ^S^ Bottom of boring at 13 feet. SAMPLES SAMPLE TYPESPT SPT SPT SPT CO v PENETRATION(blows/ ft, of drive)6 4 4 4 g 1 DRY UNIT WT. (pet)LABORATORYTESTSSPT AGUA HEDIONDA TRUNK SEWER IJU Areal CHRISTIAN WHEELER. BY: SD E NGINEER.ING JOB NO. : 199.293 DATE: Jan-00 PLATE NO.: 21 LOG OF TEST BORING NUMBER B-9 @ Station 23+00 Date Excavated: 1/11/00 Logged by: DRR Equipment Peon Drill Project Manager: CHC Surface Elevation: 61 feet Depth to Water: 11 feet Hammer Weight 140 pounds Drop of Hammer: 30 inches ® S -;: :8 :10 -12 -14 -15 -18 L-20 GRAPHIC LOG111lii1 •H1 alii111QtfRoaSSSS&Bssi '',;' .;«* * [f'"f SUMMARY OF SUBSURFACE CONDITIONS ^y.T:T;TVTUM (Oal): Light brown, moist, loose, fine to medium grained SILTY SAND (SM). Dark brown, moist, loose to medium dense, fine to medium grained CLAYEY SAND (SQ, trace gravels, clay lenses up to 2" thick. Dark brown, moist, very loose, CLAYEY SAND (SQ. • ' r&pe'iftWt d!r$2$ &«t. Light brown, moist, loose, fine to medium grained SILTY SAND (SM). Medium brown to dark brown, moist to saturated, soft, SANDY CLAY (CL). Light brown, saturated, very loose, fine to coarse grained POORLY \ GRADED SAND (SP). X Dark brown, saturated, very soft, SANDY CLAY (CL). ^S^ Bottom of boring at 15 feet w CHRISTIAN WHEELER. ENGINEERING SAMPLES SAMPLE TYPESPT SPT SPT SPT SPT SPT SPT CQ V PENETRATION(blows/ ft. of drive)12 4 5 3 3 2 1/6"MOISTURE (%)DRY UNIT WT. (pcf)LABORATORYTESTSSA AGUA HEDIONDA TRUNK SEWER Area I BY: SD JOB NO. : 199.293 DATE: Jan-00 PLATE NO.: 22 LOG OF TEST BORING NUMBER B-10 @ Station 26+00 Date Excavated: 1/11/00 Logged by: DRR Equipment Penn Drill Project Manager CHC Surface Elevation: 62.5 feet Depth to Water N/A Hammer Weight 140 pounds Drop of Hammer: 30 inches DEPTH (ft):• - :• :• -10 -12 -14 -18 L-20 GRAPHIC LOGUsasa 1 l^ai 1 if • 9 1 1 SUMMARY OF SUBSURFACE CONDITIONS AT.T.TTVTTTM COaft: Lieht fine to medium grained SD Dark brown, moist, soft, S/ brown to medium brown, moist, loose, ,TY SAND (SM), micaceous. VNDY CLAY (CL). Light brown, moist, loose, fine to medium grained SILTY \ , \ SAND (SM), micaceous.. _ ^ Dark brown, moist, soft, SANDY CLAY (CL). QT.p'pf'JR AT-T-TTyTUM (QoaT): Olive, moist medium stiff to stiff, SANDY CLAY (CL). Bottom of boring at 16 feet. m CHRISTIAN WHEELER. ENGINEERING SAMPLES SAMPLE TYPESPT SPT SPT SPT SPT CQ .,....,PENETRATION(blows/ ft. of drive)6 5 6 12 17 MOISTURE (%).•....•.••»DRY UNIT WT. (pcf).............LABORATORYTESTSSA AGUA HEDIONDA TRUNK SEWER Area I BY: SD JOB NO. : 199.293 DATE: Jan-00 PLATE NO.: 23 LOG OF TRENCH NUMBER T-l @ Station 54+40 Date Excavated: 10/26/99 Equipment: Backhoe Surface Elevation: 80 feet Finish Grade: N/A 1 § -2 -4 - 6 - 8 1 1-14 -16 -18 Lao GRAPHIC LOGli¥; ig SJjfc 1H II I1Hi £j* ^ Logged by: DRR Project Manager. CHC Depth to Water:: N/A Drop of Hammer: N/A SUMMARY OF SUBSURFACE CONDITIONS FILL (Qaf): Medium brown, damp, loose, SILTY SAND (SM) with N^ slight construction debris. AT.T.UVTUNI (Palls Dads browr ^^ nT.DKR AT.T.TJVIUM (Qoal): Yellowish-brown, moist, dense, CLAYEY SAND (SQ, slight caliche. Becomes very dense. -tW^WM^. Test trench ended at 17'/2 feet, no groundwater encountered. w CHRISTIAN WHEELER. ENGINEERING SAMPLES SAMPLE TYPEDm GROUNDWATERg O >• Q LABORATORYTESTSAGUA HEDIONDA TRUNK SEWER AREA III BY: SD JOB NO. 199.293 DATE: Oct-99 PLATE NO.: 2-4 LOG OF TRENCH NUMBER T-2 @ Station 54+55 Date Excavated: 10/26/99 Logged by: DRR Equipment: Backhoe Project Manager: CHC Surface Elevation: 79 feet Depth to Water:: N/A Finish Grade: N/A . Drop of Hammer: N/A 1 Q :. -4 - 6 - 8 :" :" -14 1fiID -18 L-20 GRAPHIC LOG1 BIII 1I /£/ SUMMARY OF SUBSURFACE CONDITIONS T?TT J. (Q?f); Light brown, damp, medium dense, SILTY SAND (SM) with sli^it construction debris. AT.T.TTyrUM (Oal): Medium brown, damp to moist, loose, fine to coarse \ grained, POORLY GRADED SAND (SP). (IVz feet) ^^^^^"^ Dark brown to gray, moist, stiff, SANDY CLAY (CL). r>T.DKK ATJ.UVIUM (Ooal): Yellowish-brown, moist, very dense, CLAYEY SAND (SQ. ^...-liKj^ }ijVett'(g ^S^feet.0 Test trench ended at 16 feet, no groundwater encountered. w CHRISTIAN WHEELER. ENGINEERING SAMPLES w 3 to aDPQ GROUNDWATERg 1 DRY UNIT WT.(pcf)LABORATORYTESTS- AGUA HEDIONDA TRUNK SEWER AREA III BY: SD JOB NO. 199.293 DATE: Qct-99 PLATE NO.: 25 LOG OF TRENCH NUMBER T-3 @ Station 54+70 Date Excavated: 10/26/99 Logged by: DRR Equipment Backhoe Project Manager: CHC Surface Elevation: 78 feet Depth to Water:: N/A Finish Grade: N/A Drop of Hammer: N/A I Q GRAPHIC LOG• - 4 -6 - 8 -10 • 12 -14 -16 -18 L20 11IB1I - Ai•• SUMMARY OF SUBSURFACE CONDITIONS FTT.T. (Qflf); T.i'c*r hrr>wn, tnpHiiim (Ipnsp damp to mm'st, STT.TY SAND (SM) with slight construction debris. ALLUVIUM (Oal); Dark brown, moist, loose to medium dense, fine to coarse grained CLAYEY SAND (SC). Medium brown, moist, loose to medium dense, fine to coarse grained, POORLY GRADED SAND (SP). Medium brown to gray, moist, stiff, SANDY CLAY (CL). Becomes wet. ^.—.Pipe: inveit % €3*4 feet. Test trench ended at 16 feet. No groundwater encountered. SAMPLES SAMPLE TYPED GROUNDWATERMOISTURE (%)DRY UNIT WT.fecf)LABORATORYTESTSAGUA HEDIONDA TRUNK SEWER fffl AREA III HP IS"H AN WHFFi PR BY: SD ENGINEERING JOB NO. 199.293 DATE: Qct-99 PLATE NO.: 26 LOG OF TRENCH NUMBER T-4 @ Station 55+20 Date Excavated: 10/26/99 Equipment: Backhoe Surface Elevation: 77 feet Finish Grade: N/A I Q GRAPHIC LOG"• III_ o g&Hj Logged by: DRR Project Manager: CHC Depth to Water:: 1 IVk feet Drop of Hammer: N/A SUMMARY OF SUBSURFACE CONDITIONS FTT.T, (Qflf)- MfHiutn hrnwi^ mnist, mpHmtn rtensp, STT.TY SAND/ SANDY GRAVEL (SM/GM), abundant construction debris. ^B (4'/2 feet) • ^^^^^H;; - 8 -10 • 12 -14 -16 -18 -20 g§^$ IB • \ ftf .1 .TJYTTJM (Qal): Dads gray, i \ CLAYEY SAND (SQ. noist, loose, fine to coarse grained Medium brown, moist, loose to medium dense, fine to coarse /'' grained, POORLY GRADED SAND (SP). (IVz feet) /"" Gray to olive, moist, stiff, SANDY CLAY (CL). Saturated. Test trench ended at 13 feet due to excessive caving below lll/2 feet. Groundwater at 11 Vz feet. CHRISTIAN WHEELER. ENGINEERING - SAMPLES SAMPLE TYPEPQ GROUNDWATERY MOISTURE (%)DRY UNIT WT.(pcf)LABORATORYTESTSAGUA HEDIONDA TRUNK SEWER MMHM AREA III BY: SD JOB NO. 199.293 DATE: Qct-99 PLATE NO.: 27 LOG OF TRENCH NUMBER T-5 @ Station 55+50 Date Excavated: 10/26/99 Logged by: DRR Equipment: Backhoe Project Manager: CHC Surface Elevation: 76 feet Depth to Water:: 8Vz Feet Finish Grade: N/A Drop of Hammer: N/A DEPTH (feet)GRAPHIC LOGi -4 1 . -6 I « ft -10 • 12 -14 -16 -18 -20 [?1 • 1 1 1 HBi 8«J> S mmm SUMMARY OF SUBSURFACE CONDITIONS PJT.T. (Q«<f); Mfdil'TP brow", d<Wip f> mnist, lonse tr> medium dense, SILTY SAND (SM) with abundant debris. (3Vz feet) ^TJ.JTVT^TVt (Qal); Medium brown, moist, loose, fine to coarse grained. POORLY GRADED SAND/SILTY SAND (SP/SM). Saturated. Test trench ended at 10'/2 feet due to excessive caving from 7 to lO'/z feet SAMPLES SAMPLE TYPEDPQ GROUNDWATERV g i— iS DRY UNIT WT.(pcf)LABORATORYTESTSAGUA HEDIONDA TRUNK SEWER C f^| AREA III MRTCTIANWHFFI.FR BY: SD ENGINEERING JOB NO. 199.293 DATE: Oct-99 PLATE NO.: 28 LOG OF TRENCH NUMBER T-6 @ Station 56+00 Date Excavated: 10/26/99 Logged by: DRR Equipment: Backhoe Project Manager: CHC Surface Elevation: 76 feet Depth to Water:: 4 feet Finish Grade: N/A Drop of Hammer: N/A J s -2_ _ etD - 8 -10 • 12 -14 -16 -18 PO CD3 U g n ¥ m jjjjl jjjjjl 1 •••M SUMMARY OF SUBSURFACE CONDITIONS yTT J,. (Qflf); Light brown, damp to moist, loose, fine to coarse grained \ SILTY SAND (SM) with abundant organic debris. ^, — *\ ^T.T.TTyrTJM (Oal): light brown, moist, loose, fine to coars ...•*''\ .••*' \ grained, POORLY GRADED SAND (SP). Gray, wet, medium stiff, SANDY CLAY (CL). Test trench ended at 6 feet due to excessive caving from 3Vz to 6 feet ^-n^A^tt**** SAMPLES w 9 c/5 aDPQ £| | D 0 § V g §D!_,S(— (os b || >^ Q % |g O r^f-H J AGUA HEDIONDA TRUNK SEWER tyy| AREA III rHRISTFATvJWHFFI.FR BY: SD ENGINEERING JOB NO. 199.293 DATE: Qct-99 PLATE NO.: 29 LOG OF TRENCH NUMBER T-7 @ Station 56+80 Date Excavated: 10/26/99 Logged by: DRR Equipment Backhoe Project Manager: CHC Surface Elevation: 80 feet Depth to Water:: SVzFeet Finish Grade: N/A Drop of Hammer: N/A 1 P - 2 :•;: -10 - 12 -14 -16 -18 L-20 GRAPHIC LOGIt 1 B illIP m1 SUMMARY OF SUBSURFACE CONDITIONS FJT.T. (Qqfy Mprfiiim hrnwt^ damp, mcHiiim HMIS^ Sn.TY SAMTJ (SM) >^ with sligjit construction debris. (l'/2 feet) ^*- — ^T.T.TTyjUM (Oal): Yellowish-brown, damp, loose, fine to coarse \ grained, POORLY GRADED SAND (JSP). Dark brown, moist, loose to medium dense, fine to medium grained CLAYEY SAND (SQ. Gray, wet to saturated, medium dense, fine to coarse grained CLAYEY SAND (SQ. (2'/2 feet) Gray, saturated, stiff, SANDY CLAY (CL), trace gravels. Test trench ended at 11 feet due to excessive caving from 7 to 11 feet ' JPipe ia vert (^ 154.4 feet. - SAMPLES SAMPLE TYPESD«GROUNDWATER5 MOISTURE (%)Hh— 1 (JJiz ^ t!3 ^-^ bg LABORATORYTESTS•^ CI AGUA HEDIONDA TRUNK SEWER fffl AREA III -FRKTTANWHFFI.FR ' BY: SD ENGINEERING JOB NO. 199.293 DATE: Qct-99 PLATE NO.: 30 LOG OF TRENCH NUMBER T-8 @ Station 57+30 Date Excavated: 10/26/99 Equipment. Backhoe Surface Elevation: 81 feet Finish Grade: N/A y & §GRAPHICin -4 -6 - 8 -10 • 12 -14 -16 -18 -20 11 1 Logged by: DRR Project Manager: CHC Depth to Water:: 10.5 feet Drop of Hammer: N/A SUMMARY OF SUBSURFACE CONDITIONS ;FTTrJ, (Qflfy T.igVit hrnwt^ rlan^ mpHnim rtmsp, STT.TY SAND (STU) \ with slight trash. (IVi feet) _^-*^ AT.T.TTyrUM (Oal): Dark gray, moist, loose, fine to medium grained CLAYEY SAND (SQ. (3 feet) Light gray, moist, medium stiff, SANDY CLAY (CL) with trace gravels. Light brown, moist, loose to medium dense, fine to coarse grained, POORLY GRADED SAND (SP). Gray, moist, stiff, SANDY CLAY (CL). Saturated. Test trench ended at 13 feet due to excessive caving from 10 to 13 feet. *— — ;Pipe Hwert (ftj,&4>G feet. W" CHRISTIAN WHEELER. ENGINEER. .ING SAMPLES w SAMPLE TY. § B GROUNDWAV. ^MOISTURE^ P ^LABORATOTESTSAGUA HEDIONDA TRUNK SEWER AREA III BY: SD JOB NO. 199.293 DATE: Oct-99 PLATE NO.: 31 LABORATORY TEST RESULTS AGUA HEDIONDA TRUNK SEWER MAIN REACH SAHT IE CARLSBAD, CALIFORNIA GRAIN SIZE DISTRIBUTION Sample Number Boring No. 1 @ 20' Boring No. 2 @ 30' Sieve Size Percent Passing Percent Passing #4 100 100 #8 100 100 #16 100 100 #30 98 100 #50 92 99 #100 78 96 #200 57 83 0.05 mm 47 63 0.005mm 19 32 0.001 mm 7 25 Sample Number Boring No. 2 @ 45' Boring No. 2 @ 65' Sieve Size Percent Passing Percent Passing #4 100 100 #8 100 100 #16 98 96 #30 94 84 #50 87 65 #100 74 50 #200 53 38 0.05 mm 42 32 0.005 mm 24 21 0.001 mm 21 15 Sample Number Boring No. 2 @ 70' Boring No. 6 @ 10' Sieve Size Percent Passing Percent Passing #4 100 100 #8 100 97 #16 97 87 #30 89 75 #50 76 60 #100 63 39 #200 50 24 0.05 mm 45 0.005mm 26 0.001 mm 13 CWE 199.293.6 March 16, 2000 Plate No. 32 GRAIN SIZE DISTRIBUTION Sample Number Boring No. 7 @ 7'-10' Boring No. 8 @ Sieve Size Percent Passing Percent Passing #4 100 100 #8 93 99 #16 67 96 #30 43 93 #50 29 88 #100 20 74 #200 13 44 Sample Number Boring No. 8 @ 13' Boring No. 9 @ 10' Sieve Size Percent Passing Percent Passing #4 100 99 #8 92 94 #16 62 76 #30 37 58 #50 18 44 #100 6 29 #200 2 17 Sample Number Boring No. 10 @ 3y2' Sieve Size Percent Passing #4 100 #8 100 #16 99 #30 97 #50 92 #100 61 #200 31 CWE 199.293.6 March 16, 2000 Plate No. 33 p dationConsr«MW WBB* I I 1 50 100 LOAD CHRISTIAN WHEELER. ENGINEERING BY: JOB. NUMBER: CHC 199.293 (II) DATE: 11-99 PLATE NUMBER: 34 r i f i i I_JLJLTI _i_nf 2250 - CHRISTIAN WHEELER Project Number: 199.293 (II) Sample Number: B-1 at 15' Date: NOV 1999 Plate No.: 35 c c c i r i i i 1 o. 8 0.1 CHRJSTIA.N WHEELER- ENGINEERING X 0 ~\ 5 51 .™1 > - . - — i^ \L \ V 1 I M — \ ~~---J ,OA: V i-aa. D( v \ —a Ei ^~ 5 s) BY: CHC JOB NUMBER: 199.293(11) 10 f DATE: 11-99 >0 * WM« t, 1( ^•B DO • ~- PLATE NUMBER: 36 i i i i i i 2375 2400 2425 2450 2500- 1 f 1 II f 1 2475 H <D in TIME IN MINUTES CHRISTIAN WHEELER Project Number. 199.293(11) Sample Numbec B-2 at 15' Date: NOV 1999 Plate No.: 37 MM «M . 0- m mm 4 MB mm 2- tt» — >-^ 3-& 1:i:ia Ml Or } cw 5- *ww r eL 1 L . r s-L I i T .1 L i W •*• CHRJSTIAN -WHEELER. •. ENGINEERING 0.5 ^s "^ -.*5= ^ . 1 IX^ *- 1 I « "**^^S. •- •» ,OA: *=t ^^•v •S^E D( &4 \. smt Kf V-»^ 5 •) ri BY: CHC JOB NUMBER: 199.293 (II) \ _!_, 10 l — ' C50 1 *L()0 DATE: 11-99 PLATE NUMBER: 3S 0 ,- 2- MM I -g "- IIts ,U -3 1_ s 1U ©Q _ 5- L : „6- rL 7.r 1 r s-i I I T 1 i .1 1 W ^ CHRISTIAN WHEELER ,. ENONEERING 0.5 1* ^ 1 L -• -» ,OAJD( "\ =» Kf x. 5 0 BY: CMC JOB NUMBER; 199.293 (II) _! LO i R 0 •-Ra - l( i )0 DATE: 11-99 PLATE NUMBER 39 MI ~r 0- «w m 1- 2- «•»Q -£ IIJ5 4-Nr »""* M c-W 5- iiE _0- rL r- r [ -r I ° T i **«»^ i .1 i T W 1 CHBJSTIAN WHEELER. ENGINEERINGT ^ s I S ^ *^ 0.5 V\ V V \\, \ 2=6 y \\ V y ^-^-^ £={ \\\ i •«= &tL. \\\ ~~. V JL_ \ = : , 1 5 LOAD (Kfs) BY: CMC JOB NUMBER: 199.293 (II) 1 1 0 I i ....,_. — '— - 50 r — t_ ~ 1C)0 DATE: 11-99 PLATE NUMBER: •40 II 11 I I 1 f 1 I I 1 II II 2525---- TIME IN MINUTES i i CHRISTIAN WliEELER Project Number: 199.293 (II) Sample Number B-2 at 50' Date: NOV 1999 Plate No.: w» r i ru °- r r ' rL 2- r .. x-N 3- E^*" dr 1 *L | 4- *or iC 3U 5_r r e SB** f 1 I 8- I I ] .1 L ^=: -i W J CHRJSTIAN WHEELER. i ENGINEERING "**>*.'x 0. •^ ^ 5 ^ ^ -^ 1 "\^V\ \. X\\\1 ^^ 1 I — ••• \\ \\\y ^^^. .OA: •• -^12 \ \ i^^B D( Ii — ii mrmm -^ A i•^.•^••L • I. • Jf \ \\ \ •— • Kf \\»N 5 8) 1 J BY: CMC JOB NUMBER: 199.293 (II) — 1 •i 0 c>0 " tL( «•• )0 - DATE: 11-99 PLATE NUMBER 42 I I I II II II f ! f J or Ivj ^r'm ^ N- oo II II II 2425 TIME IN MINUTES CHRISTIAN WHEELER (Project Number. 199.293 (II) Sample Number. B-2 at 60' Dare: NOV 1999 Plate No.: 43 I ] ] •» » 0- w _ 2- Mr m •g J * '.fi•i• i '***' W " rf 6- i » 71 8- 0.1 =s= HI CHFJSTIAN WHEELER. ENGINEERING =4 0. ^ 5 ~ h- ^^"V vXx \ V ^*^^^..::: 1 1 I »L \ X\ X\ ^*^^ X>A: K •\— \ *^i in D( I I \ \ \ ^"** Kf i*^ m \ \ 5 s) 4 BY: CMC JOB NUMBER: 199.293 (II) -3 i 5I 1 I 0 c>0 • ••L()0 DATE: 11-99 PLATE NUMBER: 44 TABLE I SUMMARY OF SETTLEMENT RESULTS AGUA HEDIONDA TRUNK SEWER DRAIN, CARLSBAD, CALIFORNIA BORING NUMBER 1 Soil Depth to Layer Classification Center (feet) CL 20.5 Layer Thickness (feet) 17 Initial Stress (psf) 1933 1 Final Stress (4'Fill/9fFffl) (psf) 2433/3058 TOTAL SETT! Laboratory Consolidation <%) 6.5 CEMENT = | Settlement [4'Fill/9'FilI) (inches) 1.3/2.6 1.3/2.6 Time to 92% Consolidation (days) 340 BORING NUMBER 2 | Soil Classification SC CL SC CL SC CL SC Depth to Layer Center (feet) 14 19 25 33.75 . 40.75 49.5 62 Layer Thickness (feet) 4 6 6 11.5 2.5 15 10 Initial Stress (psf) 1556 1846 2194 2702 3108 3615 4340 Final Stress (4'Fm/9'Fill) (psf) 2056/2681 2346/2971 2694/3319 3202/3827 3608/4233 4115/4740 4840/5465 TOTAL SETT) Laboratory Consolidation e/o) 4.7 5.5 1.5 5.5 2.0 5.4 4.5 LEMENT = • | Settlement [4'Fill/9'FiH (Inches) 0.3/0.5 0.4/0.8 0.1/0.2 0.6/1.1 0.04/0.1 0.5/1.1 0.3/0.5 2.3/4.3 Time to 92% Consolidation (days) 13 43 29 160 5 270 81 1 CWE 199.293.5 February 11,2000 Plate No. 45 TABLE! SUMMARY OF SETTLEMENT RESULTS AGUA HEDIONDA TRUNK SEWER DRAIN, CARLSBAD, CALIFORNIA BORING NUMBER 3 | Soil Depth to Layer Layer Classification SC CL SC CL SC Center (feet) 15.5 20.5 26 44.5 63 Thickness (feet) 7 3 8 29 8 Initial Stress (psf) 1643 1933 2252 3325 4398 Final Stress (4'Fi]l/9'Fill) (psf) 2143/2768 2433/3058 2752/3377 3825/4450 4898/5523 Laboratory Consolidation (%) 3.0 5.5 3.0 5.5 3.0 TOTAL SETTLEMENT = Settlement (4'Fffl/9'FilI) (inches) 0.3/0.6 0.2/0.4 0.3/0.5 1.2/2.4 0.1/0.3 | 2.1/4.2 | Time to 92% Consolidation (days) 40 11 52 2.7 yrs 52 BORING NUMBER 4 Soil Depth to Layer Layer Classification SC CL SC CL SC Center (feet) 14.5 19.75 26.75 47 65.5 Thickness (feet) 5 5.5 8.5 32 5 Initial Stress (psf) 1585 1890 2296 3470 4543 I Final Stress (4'FUl/9'Fill) (psf) 2085/2710 2390/3015 2796/3421 3970/4595 5043/5668 Laboratory Consolidation ( <%) 3.0 5.5 3.0 5.5 3.0 TOTAL SETTLEMENT = | Settlement 4'Fill/9lFill (inches) 0.2/0.4 0.4/0.7 0.3/0.5 1.2/2.6 0.1/0.2 2.2/4-4 Time to 92% Consolidation ) (days) 20 24 59 3.3 yrs 20 | CWE 199.293.5 February 11,2000 Plate No. 46 CWE 199.293.6 March 16. 2000 Appendix A. Page Al REFERENCES Anderson, J.G.; Rockwell, R.K. and Agnew, D.C., 1989, Past and Possible Future Earthquakes of Significance to the San Diego Region, Earthquake Spectra. Volume 5, No. 2,1989. Jennings, C.W., 1975, Fault Map of California, California Division of Mines and Geology, Map No. 1, Scale 1:750,000. California Division of Mines and Geology, 1998, Maps of Known Active Fault Near Source-Zones in California and Adjacent Portions of Nevada. Federal Emergency Management Agency, 1997, San Diego County, California and Incorporated Areas Flood Insurance Rate Map. Kern, P., 1989, Earthquakes and Faults in San Diego County, Pickle Press, 73 pp. Mualchin, L. and Jones, A.L., 1992, Peak Acceleration from Maximum Credible Earthquakes in California (Rock and Stiff-Soil Sites) California Division of Mines and Geology Open-File Report 92-1. Tan, S. S., and Kennedy, M.P., 1996, Geologic Map of the Oceanside, San Luis Rey, and San Marcos 7.5' Quadrangles, San Diego County, California, California Division of Mines and Geology, Open File Report 96-02. Wesnousky, S.G., 1986, "Earthquakes, Quaternary Faults, and Seismic Hazards in California", in Journal of Geophysical Research, Volume 91, No. B12, pp 12,587 to 12,631, November 1986. TOPOGRAPHIC MAPS County of San Diego, 1976, 200 Scale Map, Sheet 354-1683. United States Geological Survey, 1967, San Luis Rey 7.5' Quadrangle United States Geological Survey, 1975, San Luis Rey 7.5' Quadrangle CWE 199.293.6 March 16. 2000 Appendix A. Page A2 PHOTOGRAPHS Aerial FotoBank/Thomas Bros., Inc., Aerial Foto-Map Book, San Diego County, 1995, Sheet 1107, Scale: 1 inch = 2000 feet (approximate). San Diego County, 1928, Flights 30 D and 30E: Scale: 1 inch = 1000 feet (approximate). San Diego County, 1960, Flight 5, Photographs 74 and 75; Scale: 1 inch = 1000 feet (approximate). San Diego County, 1970, Flight 4, Photographs 18 and 19; Scale: 1 inch = 1000 feet (approximate). San Diego County, 1973, Flight 33, Photographs 16 and 17; Scale: 1 inch = 1000 feet (approximate). San Diego County, 1978, Flight 16B, Photographs 27 and 28; Scale: 1 inch = 1000 feet (approximate). San Diego County, 1983, Photographs 537 and 538; Scale: 1 inch = 2000 feet (approximate). San Diego County, 1989, Flight 1, Photograph 215; Scale: 1 inch = 2000 feet (approximate). CWE 199.293.6 March 16, 2000 Appendix B, Page Bl RECOMMENDED GRADING SPECIFICATIONS - GENERAL PROVISIONS AGUA HEDIONDA TRUNK SEWER MAIN REACH SAHT IE CARLSBAD. CALIFORNIA GENERAL INTENT The intent of these specifications is to establish procedures for clearing, compacting natural ground, preparing areas to be filled, and placing and compacting fill soils to the lines and grades shown on the accepted plans. The recommendations contained in the preliminary geotechnical investigation report and/or the attached Special Provisions are a part of the Recommended Grading Specifications and shall supersede the provisions contained hereinafter in the case of conflict. These specifications shall only be used in conjunction with the geotechnical report for which they are a part. No deviation from these specifications will be allowed, except where specified in the geotechnical report or in other written communication signed by the Geotechnical Engineer. OBSERVATION AND TESTING Christian Wheeler Engineering shall be retained as the Geotechnical Engineer to observe and test die earthwork in accordance with these specifications. It will be necessary that the Geotechnical Engineer or his representative provide adequate observation so that he may provide his opinion as to whether or not die work was accomplished as specified. It shall be the responsibility of the contractor to assist the Geotechnical Engineer and to keep him appraised of work schedules, changes and new information and data so diat he may provide these opinions. In the event that any unusual conditions not covered by the special provisions or preliminary geotechnical report are encountered during the grading operations, the Geotechnical Engineer shall be contacted for further recommendations. If, in the opinion of the Geotechnical Engineer, substandard conditions are encountered, such as questionable or unsuitable soil, unacceptable moisture content, inadequate compaction, adverse weather, etc., construction should be stopped until the conditions are remedied or corrected or he shall recommend rejection of this work. Tests used to determine the degree of compaction should be performed in accordance with the following American Society for Testing and Materials test methods: CWE 199.293.6 March 16, 2000 Appendix B, Page B2 *MI *" Maximum Density & Optimum Moisture Content - ASTM D-1557-91 — Density of Soil In-Place - ASTM D-1556-90 or ASTM D-2922 •Mir „», All densities shall be expressed in terms of Relative Compaction as determined by the foregoing ASTM mi testing procedures. .*a\ PREPARATION OF AREAS TO RECEIVE FILL•*» *&» All vegetation, brush and debris derived from clearing operations shall be removed, and legally disposed of. w All areas disturbed by site grading should be left in a neat and finished appearance, free from unsightly debris. **»• ift*'After clearing or benching the natural ground, the areas to be filled shall be scarified to a depth of 12 inches, ~" brought to the proper moisture content, compacted and tested for the specified minimum degree of ** compaction. All loose soils in excess of 6 inches thick should be removed to firm natural ground which is *•» defined as natural soil which possesses an in-situ density of at least 90 percent of its maximum dry density. MMMf When the slope of the natural ground receiving fill exceeds 20 percent (5 horizontal units to 1 vertical unit), the original ground shall be stepped or benched. Benches shall be cut to a firm competent formational soil. The lower bench shall be at least 10 feet wide or 1-1/2 times the equipment width, whichever is greater, and shall be sloped back into the hillside at a gradient of not less than two (2) percent. All other benches should m**r be at least 6 feet wide. The horizontal portion of each bench shall be compacted prior to receiving fill as #pf*i specified herein for compacted natural ground. Ground slopes flatter than 20 percent shall be benched when considered necessary by the Geotechnical Engineer. *** Any abandoned buried structures encountered during grading operations must be totally removed. All *** underground utilities to be abandoned beneath any proposed structure should be removed from within 10 ** feet of the structure and properly capped off. The resulting depressions from the above described procedure m should be backfilled with acceptable soil that is compacted to the requirements of the Geotechnical Engineer. w, This includes, but is not limited to, septic tanks, fuel tanks, sewer lines or leach lines, storm drains and water ^ lines. Any buried structures or utilities not to be abandoned should be brought to the attention of the —m Geotechnical Engineer so that he may determine if any special recommendation will be necessary. CWE 199.293.6 March 16, 2000 Appendix B, Page B3 FILL MATERIAL Materials to be placed in the fill shall be approved by the Geotechnical Engineer and shall be free of organic matter and other deleterious substances. Granular soil shall contain sufficient fine material to fill the voids. The definition and disposition of oversized rocks and expansive or detrimental soils are covered in the geotechnical report or Special Provisions. Expansive soils, soils of poor gradation, or soils with low strength characteristics may be thoroughly mixed with other soils to provide satisfactory fill material, but only with the explicit consent of the Geotechnical Engineer. Any import material shall be approved by the Geotechnical Engineer before being brought to the site. PLACING AND COMPACTION OF FILL Approved fill material shall be placed in areas prepared to receive fill in layers not to exceed 6 inches in compacted thickness. Each layer shall have a uniform moisture content in the range that will allow the compaction effort to be efficiently applied to achieve the specified degree of compaction. Each layer shall be uniformly compacted to the specified minimum degree of compaction with equipment of adequate size to economically compact the layer. Compaction equipment should either be specifically designed for soil compaction or of proven reliability. The minimum degree of compaction to be achieved is specified in either the Special Provisions or the recommendations contained in the preliminary geotechnical investigation report. When the structural fill material includes rocks, no rocks will be allowed to nest and all voids must be carefully filled with soil such diat the minimum degree of compaction recommended in the Special Provisions is achieved. The maximum size and spacing of rock permitted in structural fills and in non- structural fills is discussed in the geotechnical report, when applicable. '. Field observation and compaction tests to estimate the degree of compaction of the fill will be taken by the Geotechnical Engineer or his representative. The location and frequency of the tests shall be at the Geotechnical Engineer's discretion. When the compaction test indicates that a particular layer is at less than the required degree of compaction, the layer shall be reworked to the satisfaction of the Geotechnical Engineer and until the desired relative compaction has been obtained. Fill slopes shall be compacted by means of sheepsfoot rollers or other suitable equipment. Compaction by sheepsfoot roller shall be at vertical intervals of not greater than four feet In addition, fill slopes at a ratio of two horizontal to one vertical or flatter, should be trackrolled. Steeper fill slopes shall be over-built and cut- CWE 199.293.6 March 16, 2000 Appendix B, Page B4 back to finish contours after the slope has been constructed. Slope compaction operations shall result in all fill material six or more inches inward from the finished face of the slope having a relative compaction of at least 90 percent of maximum dry density or the degree of compaction specified in the Special Provisions section of this specification. The compaction operation on the slopes shall be continued until the Geotechnical Engineer is of the opinion that the slopes will be surficially stable. Density tests in the slopes will be made by the Geotechnical Engineer during construction of the slopes to determine if the required compaction is being achieved. Where failing tests occur or other field problems arise, the Contractor will be notified that day of such conditions by written communication from the Geotechnical Engineer or his representative in the form of a daily field report. If the method of achieving the required slope compaction selected by the Contractor fails to produce the necessary results, the Contractor shall rework or rebuild such slopes until the required degree of compaction is obtained, at no cost to the Owner or Geotechnical Engineer. CUT SLOPES The Engineering Geologist shall inspect cut slopes excavated in rock or lithified formational material during the grading operations at intervals determined at his discretion. If any conditions not anticipated in the preliminary report such as perched water, seepage, lenticular or confined strata of a potentially adverse nature, unfavorably inclined bedding, joints or fault planes are encountered during grading, these conditions shall be analyzed by the Engineering Geologist and Geotechnical Engineer to determine if mitigating measures are necessary. Unless otherwise specified in the geotechnical report, no cut slopes shall be excavated higher or steeper than that allowed by the ordinances of the controlling governmental agency. ENGINEERING OBSERVATION Field observation by the Geotechnical Engineer or his representative shall be made during the filling and compaction operations so that he can express his opinion regarding the conformance of the grading with acceptable standards of practice. Neither the presence of the Geotechnical Engineer or his representative or the observation and testing shall release the Grading Contractor from his duty to compact all fill material to the specified degree of compaction. CWE 199.293.6 March 16, 2000 Appendix B, Page B5 SEASON LIMITS Fill shall not be placed during unfavorable weather conditions. When work is interrupted by heavy rain, filling operations shall not be resumed until the proper moisture content and density of the fill materials can be achieved. Damaged site conditions resulting from weather or acts of God shall be repaired before acceptance of work. RECOMMENDED GRADING SPECIFICATIONS - SPECIAL PROVISIONS RELATIVE COMPACTION: The minimum degree of compaction to be obtained in compacted natural ground, compacted fill, and compacted backfill shall be at least 90 percent. For street and parking lot subgrade, the upper six inches should be compacted to at least 95 percent relative compaction. EXPANSIVE SOILS: Detrimentally expansive soil is defined as clayey soil which has an expansion index of 50 or greater .when tested in accordance with the Uniform Building Code Standard 29-C. OVERSIZED MATERIAL: Oversized fill material is generally defined herein as rocks or lumps of soil over 6 inches in diameter. Oversized materials should not be placed in fill unless recommendations of placement of such material are provided by the Geotechnical Engineer. At least 40 percent of the fill soils shall pass through a No. 4 U.S. Standard Sieve.