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Home My WebLink AboutCDP 16-18; Rancho Paradiso; Grading Plan Review; 2017-06-05Geotechnical Exploration, Inc. SOIL AND FOUNDATION ENGINEERING e GROUNDWATER e ENGINEERING GEOLOGY 05 June 2017 Mr. Gary Barberio 4270 Clearview Drive Carlsbad, CA 92008 Job No. 15-10764 Subject: Grading Piao Review Barberio Residence 252 Normandy Lane Carlsbad, california Dear Mr. Barberio: As requested, we have reviewed the grading plans (4 sheets) for the subject property, undated, and prepared by Mr. Robert Sukup of The Sea Bright Company. The grading plans have been reviewed from a geotechnical engineering viewpoint to verify their adequate compliance with our recommendations presented in the "Report of Preliminary Geotechnical Investigation ... " for the subject site, dated May 19, 2015. After suggested corrections were made, it Is our opinion that the grading plans are in adequate conformance with the recommendations presented in our geotechnical investigation report dated May 19, 2015. Any soil compaction and grading at the site shall be as required by the City of Carlsbad and in accordance with our report. If you have any questions regarding this letter, please contact our office. Reference to our Job No.15-10764 will help expedite a response to your inquiry. Respectfully submitted, GEOTECHNICAL EXPLORATION, INC. ~ EtZ~ ~ 00 C) (',.J ~ c:-l Jaime A. Cerros, P.E. .-of u CT) R.C.E. 34422/G.E.2007 w ~ l.J... Senior Geotechnical Engineer ~ Cc: The Sea Bright Company MAA Architects 7420 TRADE STREET• SAN DIEGO, CA. 92121 • (858) 549-7222 • FAX: (858) 549-1604 e EMAIL: geotech@gel-sd.com f-z w (!) ~ / 0.. = 0 C __J I Jj !..!J : J .> ,,. liJ --0 ) C L z UJ :5 Geotechnical Exploration, Inc. son. AND FOUNDATION er«;JHEERJNG • GROUNDWATER • ENGI1EEIUHG GEOLOGY 09 June 2016 Mr. Gary Barberio 4270 Cle'arvlew Drive carlsbad,CA ·92008 Subject: ere11m1narv Grading Plan Review Barberio Residence 228 Normandy Lane Carlsbad, Callfomla Dear Mr. Barberio: Job No. 15-10764 As requested, we have reviewed an undated prellmlnary grading plan for the subject property prepared by Mr. ~obert Sukup of The Sea Bright Company. The plan was reviewed from a geotechnlcal engineering viewpoint to verify adequate compllence with our recommendations as presented In our \\Report of Preliminary Geotechnlcal Investigation" for the site, dated May 19, 2015. ' After review and discussions with Mr. Sukup, It Is our opinion that the plan adequately conforms to the recommendations presented In our report dated May 19, 2015. We understand that a final grading plan Is In progress. We should also review the · final plan, when completed, to verify compliance with our recommendations. Any soil compactJon and grading should be as required by the City of Carlsbad and In accordance with our report. If you have any questfons regarding this letter, please contact our office. Reference to our Job No. 15-10764 wlll help expedite a response to your Inquiry. Respectfully submitted, GEOT CHNICAL EXPLORATION, INC. Jaime A. Cerros, P.E. R.C.E. 34422/G.E. 200 Senior Geotechnical Engineer cc: The Sea Bright Company 7-i20 TRADE STREETIII ~_DIEGO, CA. 92121 • (858) 549-7222 e FAX: {858) 519-1604 • EMAIL: geotechOgekd.co Geotechnical Exploration, Inc. SOIL NfJ ~ EfGNEEROO • GlOllfONATER • eGNEBUHG GEOLOGY 19 May-2015 Mr. Gary.Barberio 4270 Cearvlew Dr1ve cartsbad, CA 92008 Job No. 15-10764 Subject: BIP9d Qf PnllmJoncv Gegbldlnlcal lnwstlqBtloo Barberio Residence 228 Normandy Lane carlsbad, catlfomla Dear Mr. Barberio: In accordance with your request, a representative of Geotechnlcal Explonltlon, :tnc. has visited the subject site and performed an evaluation of the soll conditions In the area of the proposed new structure. It Is our understanding that the site Is being developed to receive a new three-story slngle-famlly residence with an attached two-car garage and associated Improvements. The new structure wlll utilize continuous and Isolated footings with conaete slab-on-grade. As part of our lnvestlgatlonr we observed and evaluated the shallow soil conditions at two locations within the proposed new bulldlng area. In addition, we reviewed the conceptual architectural plans by Ayala Archttecture, dated July 30, 2014, in accordance wJth the requirements of the City of Carlsbad. We should review tne foundation plans when avallable. The field work, conducted on May 8, 2015, consisted of excavating two hand- excavated test pits In the locatfon of the proposed new structure. The excavations revealed that the building site Is underlain by approximately 12 Inches of medium dense, silty sand flll/topsoll over medium dense to dense, silty -sand formatlonal 7420 TRADE STREETe SAN DIEGO, CA. 92121 e (85B) 549-7222 G OOC: (858) 549-1604 o EMAIL: ~ _) Barberio Property Carlsbad, Callfomla Job No. 15-10764 Pege2 materials. The on-Site soils are considered to have 8 low expansion potential with an Expansion Index of less thlln 50. Based upon our observation, probing of the on-site soils, It Is our opinion that the new foundations for the additions can be founded directly Into the existing mrtural ground materials. The surface flll/topsolls In the proposed bl4!dlng pad area should be removed and/or property compacted as part of site preparatlon under any new slab areas. The new flll should be compacted to at least 90 percent of Maximum Dry Density. The Maximum Dry Density of the soll has been determined per ASfM D1557-12. 1. It Is our opinion thm: the existing medium dense to dense formatlonal materials will provide adequate bearing strength for the proposed new structure foundations. New footings placed In the existing medium dense to dense natural soils or properly compacted fill solls can be designed for an allowable soll bear1ng capacity of 2,500 pounds per square foot (psf). We do recommend that the proposed footings and slabs be supported by formatlonal soils and/or properly compacted fill, and contain at least a nominal amount of reinforcing steel to reduce the separation of cracks should they occur. The allowable soll bearing capacity may be Increased one-third for structural design lndudlng seismic or wind loads. 2. The proposed footings should have a minimum depth of 18 inches and a width of at least 15 Inches, founded In the dense formatlonal material or properly compacted fills, A minimum of steel for continuous footings should Include at least two No. 4 bars continuous, with two bars 3 Inches from the bottom or the footing. \"--,, '-/ Barberio Property Carlsbad, Calffomla Job No. 15-10764 Page 3. 3. Site-specific seismic design a1terln to calculate the base shear needed for the design of the residential addition ere presented In the following table. The design criteria was obtained from the Callfomla Building Code (CBC) 2013 edition, and Is based on the distance to the dosest active fault and soil profile dassfffcatlon. 4. The proposed addition should be designed In accordance with Section 1613 of the 2013 CBC, which Incorporates by reference the ASCE 7-10 for seismic design and the followlng parameters should be utlllzed. We have determined the mapped spectral acceleration values for the site based on a latitude of 33.1644 degrees and longltude of 117.3545 degrees, utilizing a program titled •'Design Maps and Tools," provided by the USGS, which provides a solutfon for ASCE 7-10 (Section 1613 of the 2013 CBC) utillzJng digitized flies for the Spectral Acceleration mnps. In addition, we have assigned a Site Classification of D. The response parameters for design are presented in the following table. Toe design spectrum acceleration vs. Period T Is attached. S F F 0.448 1.033 1.552 s. The liquefaction of saturated sands during earthquakes can be a major cause of damage to buildings. Liquefaction Is the process by which soils are transformed Into a viscous fluid that wlll flow es a liquid when unconfined. It <>CaJrs prtmalily In loose, saturated sands and sifts when they are sufficiently \ Barberio Property cartsbad, Callfomla Job No. 15-10764 Page4 shaken by an earthquake. Soft saturated clays can also deform during earthquakes and contribute to slgnlffcent settlement. On this site, the risk of llquefactlon of foundation materials due to seismic shaking Is considered to be remote due to the relatively shallow, medium dense fill solls, dense nature of the natural-ground material and the lack of a shallow static groundwater surface under the site. No soll liquefaction or soll strength loss Is anticipated to occur due to a seismic event. 6. Any new conaete slabs on-grade ( on properly compacted fill or dense fonnatlonal solls) should be a minimum of 4 Inches actual thickness and be reinforced with at least No. 3 steel bars on 18-lnch centers, In both directions, placed at mid-height In the slab. The Interior slab should be underfaln by a 15-mil vapor barrier (15-mll StegoWrap) placed directly on properly compacted subgrade. The sand base may be waived. We recommend that lsolatlon joints and sawcuts be Incorporated to at least one-fourth the thickness of the slab In any slab designs. The joints and ruts, ff properly placed, should reduce the potential for and help control floor slab aacklng. In no case, however, should control joints be spaced farther than 20 feet apart, or the width of the slab. Control joints should be placed within 12 hours after concrete placement as soon as concrete sets and no raveling of aggregate ocaJrs. Slabs spanning any existing loose solls and supported by perimeter deepened foundations should be d~ned as structural slabs. 7. Although no retaining walls are planned, the active earth pressure (to be utilized In the design of cantilever, non-restrained walls) should be based on an Equfvalent Fluld Weight of 38 pounds per ruble foot (for level backflll only) ' Barberio Property carlsbad, California Job No. 15-10764. Page 5 If on-site soils are used. Addltlonal loads applied within the potential failure block should be added to the active soll earth pressure by multlpfylng the vertical surcharge load by a 0.31 lateral earth pressure coefficient. For restrained wall conditions, we recommend an equivalent fluid weight of 59 pcf. Surdtarge loads on restrained walls may be converted to lateral pressures by muttlplyfng by a factor of 0.47. Should seismic soll Increment be required, the unrestrained walls with level bl!!lckflll should be designed for a b1angular pressure of 15 pcf, In addition to the regular static loading, with zero pressure at the top and the maximum pressure at the bottom of the wall. 8. The pass~e earth pressure of the encountered fill soils (to be used for design of shallow found8tfons and footings to resist the lateral forces) should be based on en Equfvalent Fluid Weight of 250 pcf. This passive earth pressure should only be considered valid for design ff the ground adjacent to the foundation structure Is essentially level for a distance of at least three times the total depth of the foundation and Is proJ)4;!rly compacted or dense natural sol!. An allowable Coeffldent of Friction of 0.35 times the dead load may be used between the bearing soils and concrete foundations, walls or floor slabs. 9. Adequate measures should be taken to properly finish-grade the site after the new additions and other Improvements are In place. Drainage waters from this site and adjacent properties are to be directed away from perimeter foundations, floor slabs, and footings, onto the natural drainage direction for \ this area or Into properly designed and approved drainage fadlltles. Proper subsurface and surfzice drainage will help minimize the potential for waters to seek the level of the bearing soils under the foundations, footings, and floor ---, ) \\.. --/ Barberio Property Carlsbad, Callfomla Job No. 15-10764 Page6 slabs. Fallure to observe this recommendation couk:I result in undermining, differential settlement of the building foundation or other Improvements on the site, or moisture-related problems. It Is not within the scope of our services to provide quality control oversight for surface or subsurface drainage construction or retain Ing wall sealing and base of wall draf n ·construction. It Is the responsibility of the contractor and/or their retained construction fnspectlon service provider to provide proper sumice and subsurface drainage. 10. Due to the possible bulld-up of groundwater ( derived primarily from rainfall and Irrigation), excess moisture Is e common problem In below-grade stnJctures or behind retaining walls that may be planned. These problems are generally In the form of water seepage through walls, mineral staining, mlldew growth and high humidity. In order to minimize the potential for moisture-related problems to develop, proper cross ventilation and water- proofing must be provided for below-ground areas, In crawl spaces, and the backfill side of all structure retaining walls must be adequately waterproofed snd drained. Proper subdrafns end free-draining backwall material (such as gravel or geocomposlte drains sudt as Mlradraln 6000 or equivalent) should be !~lied behind all retaining walls on the subject project In addition to wall waterproofing. Geotet:hnlt:III Exploretlon, Inc. wlll assume no llablllty for damage to structures that Is attributable to poor drainage. Barberio Property· Car1sbad, callfomla Job No. 15-10764 Page 7 11. Planter areas and planter boxes should be sloped to drain away from the foundations, footings, and floor slabs. Planter boxes should be constructed with a dosed bottom and a subsurface drain, Installed In gravel, with the direction of subsurface and surface flow away from the foundations, footings, and floor slebs, to an adequate dralnege facility. The finish grade around the addition should drain away from the perimeter walls to help reduce or prevent water aca.imulatlon. Exterior slabs or rigid Improvements should also be built on property compectecl solls and be provided with concrete shrinkage reinforcement and adequately spaced joints. Geotechnkal Explaratlon, Znc. recommends that we be asked to verify the actual soil conditions revealed In footing excavations prior to ro·rm and steel reinforcement placement. Should you have any questions regarding this matter, please contact our office. Reference to our Job No. 15-10784 wf II help to expedite a response to your Inquiries. Respectfully submitted, Gl!OTECHNICAL EXPLORAnON, INC. ~ Senior Project Geologist Jaime A. Cerros, P.E. R.C.E. 34422/G.E. 2007 Senior Geotedlnlcal Englneet '" -VICINITY MAP l ~\< , ~I_4'J.y~ ~ Bros GuJde San Diego Counfy pg 1 T~ \_ Barberio Property 228 Normandy Lane Carlsbad, CA. Figure No. I Job No. 15-10764 '>.. ___ ' \ SURVEY PLAT SHOWIN6 THE Rel.LT5o OF A Fl!LO ~VEY OF LOT 37. M.Y 1762. 6f<NNLLE rNU:. ~. GA. Ot\TE OF Sl.«WY. '1~ I..EGEN) o SET 31',• lltON rt!'!: W/TAb ~ LS t0.67 SCALE: 1" = 20' 32 REFERENCE: TIIJB Plot Pllln -plffltfl9d ml' 111 ..,_ Sl»M:Y l'f..AT bf EltllrBr ,__, ~ m dlatl 7/fllfU MtllloaJ OIHll8 aid MWIL b 9 patblr9d by8EI. I ( appro>elmafe ) • I i : I • I • I 31 LEGEND ~ Approximate Locaflon HIL1 of Exploratory Handpit i I I I I I I I 1 I I I I I 36 : JCI ' ~~~! i;: GORfERI :..t l l I 30 PLOT PLAN 8ametb Propelty 228 Normandy Lane Cadsbed, C4. Rg,nNo. {I Job No. 16-10784 ffi t=:='rnc. ~ Alllr21116 ~) ~·----~·--------------------------------------------------------------- ,.. EQIJFt.lBl1' DIMENl!QI I TYPE! a= EXCAVATICW DATE LOOOED ... HandToofa 2' X 2' X 3' Hllndpll 6-8-11 SURFACE 8.EYATICW GROtN>WA1ERf SEEPAGE DEPTH I.COOB)&V :t 71' Mean lea Lnel Not Encountered JKH FELD~ l AND ~ H i! ts I I a.ASSIRCATION !I H ii H !I 11 I I i DEBCRFT10NN6' RBMK8 I Ii --~Mcaa,Cln) 8IL lY SAND, 1lll8-to meaur, -.•--.., "1U1 tsM -some room. Medium denle. Dry. Light brown. -~8 FILU -TOPSOIL (CW) - 1 811-lY BAND, m.10 ...... ~-Pt4edlum SM d£l188 to denae. Damp. Red-brown. -. OLD PARAUC DEPOSITS (Qop~ --23% paeslng #200 sleYe. 8.0 134.!5 - 2-- - - -- 3-U. M -Bot1om@3' - - 4- I - I - I - i . ~ PERCHED WATER TABLE JOBNNrE Barberio t8J BULK BAG SAMPLE 8ITE 1..0CATD [) IN-Pl.A.CE SAMPLE 221 Nannendy Lana, Carllbad, CA • MODIFIED CALFORNIA SAMPLE JOBIUIBER REYEWED Fl'f LDRIJAC LOGNo. [!] NUCLEAR FIELD DENSITY TEST 15-10784 &;I HP-1 FWRENUMBER ml STANDARD PE~TION TEST Ila -... EQJIPMENT DIIENBION I TYPE OF EXCAVATION DATE I..OCD:D HandToola 2' X 2' X 3' Hudplt 6-8-16 IIIJU'ACE 8.EVAlJON ~SEEPAOEDEPTH LOOOEDBY :t 76' Mean 8N Lnel Nol EnccNml8red JKH FB.D DESCRIPT10N l Atl) ~ ~I @ ~x I Cl.ASSIFICA TION n n 11 i~ !I 11 I i i Ii Ii i DEBCRFT10H NfJ RSMRl(8 ((aalllz9, ~ ....... Coler) ~ mLTTMNU, to,-~--......,wnn 8M some roots. ,_.um denN. Dry. Ught brown. - PIW -TOPSOL (Qaf) - 1-~ -BL lY SAIi), Ina-to m -~-...... SM dense to denee. Damp. RecM>rown. - OLD PARAUC Dl!POSIT8 (Qapz,.J -\ -' 2- - - - 3- -Bottom@3' --- -. 4-. i - t - I - i ;• I ~ PERCHED WAlER TABLE JCEPW&: BarbtHlo ii=,-'7 181 BULK BAG SAMPLE ll1TE LOCA1DI I m IN-PLACE SAMPLE 228 Normandy l..me, Cllrlebad, CA ~ • MODIRED CALIFORNIA SAMPLE .KlB IIAIBER ~BY LDRIJAC LOONo. ' [!] , NUCLEAR FIELD DENSITY 'TEST 1~10714 -· --HP-2 FIGlR: NIJr4BER ~~ Im. I I. fil STANDARD PENETRATION TEST 11b .J / I \ / I ' i i j ! i ; 135 a\ , 'I\ , • 1 \ " \ 130 \ J \ \ • \ \ l \ ' 126 \ \ \ \ Scuce of Mmertal HP-1 aur \ l 8IL TY SAND (811), Bfd:brOWD \ ' Description of Malarial 1--\ l \. Tast:Method ASTII D16S7 llethod A ' \ ' ' \ 11& ' ' ' ' \ TEST RESULTS ~ ' 1 ' \. Maxfinun Dry Denaffy 134.S PCF 110 I\ \ ' Optimum Water Content _M. % ' \. 1 I\ \ " \. i 108 \. ' Expalefon Index (El) -- ' " r\. l l 1 \ ' \ Ii. ' \ 100 " \ .. Curves of 100% Seturetlon i\ '' \ for Specific Gravity Equal to: i\ I\ ' 2.80 ~ i\ ' \ \. \. 2.70 \. \ .. \. " 2.60 ' \ ' 90 ' \. ' ' ... \ i\ ' \ 1, ' " " 86 I'\ I\. ----. -------~ ' -" I\.. ' ... "'-' , .... ', ... 80 I\. " ... "'\ .... I'\.. "'\ -... I'\.. ' ' I',. 'f 76 !'\I 0 1) 16 20 ~ j D ~ 5 .c ) 46 WATER CONTENT,% ~GNndl~ MOISTURE-DENSrrY RELATIONSHIP 1rap1ordon, Inc. Figure Number: IV Job Name: Barberio Property Sle Location: 228 Normandy Lene, Certabed. c.A Job Number: 15-10784 · IIUSGS Design Maps Summary Report U1er-Spedfled Input Report Tltle 228 Normandy Lane, carlsbad Mon May 18, 2015 18:17:49 UTC Bulldlng Code Reference Document ASCE 7-10 Standard (which utilizes USGS hazard data available in 2008) Site CoordlnatN 33.1644°N, 117.3545°W Site Soll Classification Site Class D -"Stiff Soll" Risk Cat.gory I/II/III j ' 2ml ------... , 5IHIII USGS-Provlcled Output s. = 1.168 g S1 = 0.448 g s,,.s = 1.206 g s,,11 = o.696 g S09 = 0.804 g S01 = 0.464 g Vista 0 ...... EDI For Information on how the SS and Sl values above have been calculated from probablllstlc (risk-targeted) and deterministic ground motions In the direction of maximum horizontal response, please return to the appllcatlon and select the "2009 NEHRP" building code reference document. 'I -rl MCE11 Response Spectrum 1.4:il 1.30 1.17 1,04 0.'1 0.78 0.'5 0.52 O.:il9 O.:lS o.u 0.00 1'---t---t---t--t----t--.,..._~...._-+-~f---1 0.00 0.20 o.,o O.CO O.IIO 1.00 1.20 1.,0 l.CC 1.80 2.00 P.-lod, T (••c) 'I -I 0.,0 Design Response Spectrum 0.81 o.n o.n 0.54 0.'5 0.3' 0.:27 0.18 0.0, 0.00 +--+--~-+--+---+--+---+-'"""""f---+---1 0.00 0.:20 o.,o O.CO O.IIO 1.00 1.:20 1.,40 l.SO 1.80 2.00 Period, T (NC) For PGA,.., Tv Cu, and CR1 values, please view the detailed report. /