HomeMy WebLinkAboutCT 72-34; RANCHO LA CUESTA; GEOLOGIC GRADING REPORT; 1976-10-14•
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FINAL ENGINEERING GEOLOGIC AND
SOIL ENGINEERING GRADING, REPORT
Tract 72-,34, Lots ,16-19 (Unit 1) and
Lots 91-98 and 130-133 (Unit 11),
In the City of Carlsbad, California
", M~n; ~It "7
for
Newport Shores Builders
October 14, 1976
Pacific Soils Engineering, Inc •
Irvine, California
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PACIFIC SOILS ENGINEERING, INC.
17921 SKY PARK CI RCLE (SUITE G) I RVINE, CALIF. 9~707
TELEPHONE: (714) 557-9450
Newport Shores Sui Iders
P.O. Box A
Huntington Beach, CA 92648
Attention:
Subject:
Gentlemen:
Mr. Mike Jager
Final Eng,ineering Geologic Grading Report;
Tract 72-34, Lots 16-19 (Unit 1) and Lots
91-98 and 130-133 (Unit II), in the City of
Carlsbad, California
L.A. COUNTY OFFICE
1492 w. 240th Street
Harbor City, Ca. 907~0
(213) 325-72.72 or 775-6771
VENTURA COUNTY OFFICE
post Office !:lox 75
Thousand Qaks, Ca. 91360
. (213) 889-9919
(805) 495-65i3
Ot.tober 14, 1976
Work Order
100236-A
This final geologic report for the subject tract is submitted in accordance with the
requirements .of'the City of Carlsbad. Geologic data are plotted on the p.lan included
with the companion Proj-ect Grading Report ~
A buttress fiJI was required for support of fhe cut slope at the rear (eost) of Lot 16.
Based on our inspection of geologic conditions of the site, the subject lots are satisfactory
for the intended use from a geologic point of view.
Respectfully submitted,
PACIFIC SOILS ENGINEERING, INC. Revi ewed by:
6~t, 0. )lill;;-
REX P. KElTER, Vice President
Dist: {10} Addressee
REl:RPK/vll
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PACIFIC SOILS ENGINEERING, INC.
17921 SKY PARK CIRCLE (SUITE ~) IRVINE, CALIF. 92707
TELEPHONE: (714) 557-9450
Newport Shores Builders
P.O. Box A
Huntington Beach, CA 92648
Attention: :
Subject:
Reference:
Gentlemen: '
Mr. Mike Jager
Project Soil Engineering Grading Report;
Tract 72-34, Lots 16:'19 (Unit I), and
Lots 91-98 and 130-133 (Unit II), in
the City of Carlsbad, California
Preliminary Soil Engineeririg and Engineering
Geologic Report and' Engineering Geologic
and Soil Engineering Review of Grading
Plan for Tract No. 72-34, dated July 5,
1974, by Pacific Soils Engineering, Inc.
(W.O. 100236).
L.A. COUNTY OFFICE .
1402 W. 240th Street
Harbor City, Ca. 90710
(213) 325-7272 or 775-67.71
VENTURA COUNTY OFFICE
Post OJfice !'lox 75
Thousand Oaks, Ca. 91360
(213) 889-9919
(!lOS) 495-6513
October 14, 1916
Work Order
100236-A
This report presents soil engineering data and test results pertaining to the placement of
compacted earth fi II on the subject property. Foundati~n criteria are a Iso included
in this report for the subject residential lots 16-19, inclusive; 9l-98,inclusive; and
130-133, inclusive.
All fills, cuts or processing of original ground under the purview of this teport.~a.ve been
completed under our inspection or accepted by this firm, and are incompliance wrth
F .H.A. criteria and the Grading Code of the City of Carlsbad, Cqlifornia .• All work
under our purview was accomplished in accordance with the IIEarthquake SpecHicationsll
,
contained in the above~refernced j'nvestigafion report.
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. October 14, 1976
Work Order 100236-A
Page Two
Completed work has been reviewed and is considered suitable for the construction now
planned. All slopes are considered grossly and surficially stable and will remqin so under
normal conditions.
Compaction test results are presented in Table I, and·approximate locations of tests are
sJiown on the enclosed grading plan (3 sheets). Also shown on the plan are locations of
tests taken i.n adjacent areas. These test results wi II be submitted in future grading reports,
as these areas are completed, or have been submitted in previousreporfs.
laboratory Standard: ASTM:D 1557-70T
% Swel/*
Soil Type
Opt. Mois.
(%)
Max. Dry Density
(Ibs ./cu .ft .) 650psf ASCE
D -Clayey Sand 12.5 118.0 0.1 ND
E'" Clayey Sand 13.0 115.5 NO 8
F-Clayey Sand 15.0 .113 .. 0 0.0 ND
G -Sand 15.0 108.5 ND ND
H -Clayey Sand 15.5 1 U.5 ND 4
I -Sand 13.0 117.0 NO NO
J -Clayey Sand 13.0 116.5 ND ND
*Swell tests were remolded in a one-i~ch high ring to 90 percent relative compaction
utilizing material at optimum moisture for samples to he surchQrged at 650 psf. Samples
were inundated for 24-hours and then amount of swell was recorded. ASCE denotes in
accordance with ASCE Expansion Index Test. ND denotes not determined.
1. Prior to the placement of compacted fill, the exposed natural surface was scarified,
wtJtered as necessary and compacted in-place, suitable to receive fill. Where
necessary, alluvial materials in canyon swale bottoms were removed to either in-
place bedrock, or competent natural soils.
2. Fill consisf.ing of the above soils types was thenplaced in thin lifts" watered as
PACIFIC SOR!..S ENGINEERING. INC.
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October 14, 1976
Work Order 100236-A
Page Three
3.
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7.
ne~essary and compacted in-place to a minimum of 90 percent of the laboratory
standard' utilizing tractor-drawn sheepsfoot type rollers and heavy earth moving
equipment. Each fi II was treated in a like manner.
Fill placed on slope gradients steeper 'than 5-horizontal to I-vertical was keyed
and benched into bedrock. The upper soils were stripped and/or benched out on
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the shallower slopes in such a manner that all compacted fill is in contact with
intact bedrock or competent soi Is.
All removals and excavating for canyon cleanouts, and processing in preparing
fill areas were inspected and approved by this fi~'s representative prior to
placement of any fill.
Compaction tests. were taken for each one to two feet of fill placed.. The maximum
vertical depth of Fi.!I placed is on the order of 20 feet on Lot 16.
Lots 91-98, inclusive, and 130-133, inclusive, are in cut, and confain no compacted
fiU. Random compaction tests performed at the finished cut grade indicate a
suitable compact finished. pad.
Based upon preliminary investigation and geologic inspection during grading, a
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15-foot base width cOl1'!pacted buttre~s fi II was recommended and constructed for
support of the (proposed cut at the rear (east) of Lot 16. The location and
approximate limits of this stabilization fill is shown on the enclosed plan,.
PACIFIC SOILS ENGINEERIN~, INC.
===="==-"=-"~,~,,,=,,~,~--------~--~----~------------,,,,,--,,,,,--------------------------------------
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October 14, 1976
Work Order l00236-A
Page Four
8. . The cut portion of the transitional lot was overexcavated to a depth of 30-inches
and replac'ed as a compacted fill to provide uniform bearing conditions. This
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was accomplished on Lot 16 as indicated with a "C" on the enclosed plan.
9. Fill slopes were backroHed as they were brought to grade at approxim<;Jfe four-foot
intervals. At the completion of fill placement, the slope was u'niformly compacted
by track-rolling and fininshed by cutting and trimming back to the compacted
core. Slope tests were made after completion of trimming. All slope densificatkm;
has been completed and the slopes are considered stable under normal conditions.
10. ~aterials encounterd in cut and utilized for compacted fHl ranged from non to
slightly expansive in nature.
A lot-by-Iot evaluation of t,he soil conditions were conducted, with the subject
resid~ntial lots being considered to be very low to low in expansion potential,
according to Table '29-C of the 1973 Uniform Building Code. Results of these
expansion tests are as follows:
Lot No.ls.
16-19
Soil Type*
F,G
I,J .
Expansion
Index**
46
Potential
Expansion***
Low
(%Sand, Silty, Clay)
'78 11 11
91-98 &130-133 NO Very Low 88 6 6
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Per tabulation (page 2) compaction test soil types, upper'three feet
As determined in gccordcmce with ASCE Expansion Potential Method
Per Table 29-C of the 1973 Uniform Building Code
Design criteria for foundation and slabs-on-grade for the subject lots, are included
in items 11 and 12 of this report.
PACIFIC SOILS EN~INEER!NG,J INC.
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October 14, 1976
Work Order 100236-A
Page Five
11. The following criteria should be u$ed in foundation design for the residential ;lots.
a) The recommended bearing value for both the interior and exterior footings is
1500 Ibs./sq.ft. having a minimum embedment depth of 12-,i,nches and
having a minimum width of 12-inches.
b) A lateral bearing value of 300 Ibs./sq.ft. per foot of depth of a maximum of
1500 Ibs./sq.ft. may be utilized. A lateral sliding coefficient of 0.40 may
be used in design •..
The above values may be increased one-third for short 'duration loads -such
as seismic and wind loads.
12. Footing and slab~on-grade reinforcement criteria
A su~mary of foundation requirements is presented on Plate A.
. a) Compacted fill lots 16-1,9, inclusive, are considered to be non-expansive
(very low), to slightly expansive (low) i-n nature and therefore the following
criteria should be used for design. . -.J; _
1) . Exterior footings for two-story structures shall have a' minimum
'embedment of 18-fnc hes be low grade.
Interior f~otings for two-story structures and all footings for a single-
story structure shall have a minimum embedment of 12-inches below grade._
Spread or isO'loted footings maybe used.
PACIFIC. SOILS ENGINEERING. INC.
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October 14, 1976
Work Order l00236-A
Page Six
/6-19 All continuous footings)shall be reinforced with two No.4 bars,
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one placed in the bottom of the footing and one in the top.
2) All slabs-on-grade in living areas shall be reinforced with a minimum
of six-inch by six-inch, No. 10 by No. 10 welded wire mesh or
equivalent positioned at the mi:d-height of the slabs;ol2 by 12, W2.8
by W2.8 welded wire mesh is considered equivalent reinforcement.
3) A minimum If lo-mil polyvinyl membrane is required under aU slabs:-
° on-grade in living areas. This membrane shall be covered by a minimum
of one-inch of sand to aid in curing of the concrete.
4) Slab subgrade for living areas and garage areas shall be moistened to
at least optimum moisture, to a depth of 12 inches, prior to placing
concrete.
5) No special treatment oLthe garage areas is require~i except that the
garage slab should have a positive separation from the stemowall.
b) Cut lots 91-98, inclusive, and 130-133, inclusive, are considered to be
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r:lon-ex~nsive (very low) in nature and the following criteria should be
used for design.
1) Exterior footings for two-story structures shall have a minimum embedment
of l8-inches below grade.
Inte'rior footings for two-story structures and all footings for a single
PACiFIC saiLS ENGINEERING, INC.
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October 14, 1976
Work Order 100236-A
Page Seven
'11-tJ&
/30·..(Ej ~
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story structure~shall have a minimum embedrpent of 12-inches below
grade. Spread or isoloated footings may be used.
2) All slabs-on-grade in living areas shall be reinforced wHh a minimum
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of six-inch by siX-inch, No. 10 by No. 10 welded wire mesh or equivalent
positioned at the mid-height of th~ slabs; 12 by 12, W2.8 by W2.8
welded wire mesh is considered equivalent reinforcement.
A minimum of lO-mii polyvinyl membrane is requi red under all 'slabs-
on-grade in living areas. This membrane shall be covered by a minimum.
of one~inch of sand to aid in curing of the concrete.
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'4) Slab subgrade for living areas and garage area,s shall be moistened to
at least optimum moisture, to a· depth of 12-inches, prior to placing
concrete •
5) No special treatment of the garage areas is requiredr except that the
garage slab should have a pcisiti·ve .separation from the stem wall.
13. Utility trench backfill should be accomplished in accordance with the prevailing
criteria of the City of Carlsbad.
PACIFIC SOILS ENGINEERING, INC.
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October 14, 1976
Work Order 100236-A
Page Eight
Respectfo!ly submitted,
PACIFIC SOILS ENGINEERING Reviewed by:
6LQ'l~
REX P. KETTER, Vice President .
Dist: (10) Addressee
AJJ:RPK/vl/
PACIFIC SOILS ENGINEERING. INC.
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October 14, 1976
Work Order 100236-A •
TABLE
EJ.ev. Relot-ive • Date of Test 'Test Moisture Dry Density Soil
Test No. Location (feet) (%) (I bs/ C\?-; ft. ) Comp.% Type
9/2/76 110* Manzanita 6Q.0 11.7 100.4 92.0 SC D
9/9/76 168 Lot 19 81.0 14,.3 107:,0 91.0 D • 9/17/76 270 Pentas Ct. 83.0 10.5 . 109.2 93.0 D
271 Lot 17 82.0 15.6 H2.0 -95.0 D
9/18/76 291 Lot 16 85.0 17.6 107.1 95.0 F
292 Lot 18 84.0 15.6 109.2 96.0 F
293 Lot 19 84.0 14.3 104.0 ·92.0 G
• 9/20/76 307 Lot 19 . 87..0 12.4-108.0 -92.0 D
308 Lot 17 85~0 14.3 112.5 95.0 D
9/21/76 314 Lot 17 88.0 14.3 . 107.3 9LO D
9/25/76-359 Lot 19 89.0 14.9 106.3 94.0 SC F
360 Lot 19 91.0 17.0 102.5 91.0 SC F I • 361 lot 18 87.0 15.6 105.0 93.0 SC F
362 Lot 18 90.0 17.6 104.8 93.0SC F
363 lot 17 91.0 13.6 107.0 95.0 SC F
364-Lot 17 94.0 14.3 110.0 97.0 F
366 Lot 16 88.0 19.0 102.0 94.0 E • 367 Lot 17 96.0 14.3 104.3 96.0 E
9/27/76 -383 Lot 16 102.5 14.9 103.1 91.0-SC 1=-
9/28/76 398 Lot 16 91.0 14.3 11 0.1 93:.0 D
399 Lot 16 94.0 11.7 112.0 95.0 D
405 Lot 16 108.0 1l.7 109.0 92.0 D '. 406 Lot 16 111.0 13.0 11 1'.8 95.0 -D
I 9/29/76 409 Lot 16 97.0 17.0 101.4 93.0 SC G
410 Lot 16 100.0 15.6 102.0 94.0 SC G
412 Lot 16 115.0 16.3 102.5 91.0 F
415 Lot 18 92.0 14.9 -106.2 94.0 F • 416 Lot 18 95.0 13.0 103.8 92.0 F
417 Lot 17 98.0 17.0 101.0 93.0 G
418 Lot 17 100.0 15.6 98.0 90.0 G
419 Lot 16 -102.0 17.6 102.6 ,95.0 'G
9/3,0/76 420 Lot 16 124.0 13.6 107.2 95.0 F
• 421 Lot 16 120.0 14.9 105.0 93.0 F
422 lot 17 102.0 13.0 102.5 94.0 G
10/1/76 439 Pentas Ct. 90.0 14.3 103.7 96.0 SC G
528 Lot 19 93.7 14.9 105.2 93~OSC F
529 Lot 18 97.9 16.3 103.5 92.0 st F
• -" PACIFIC SOILS ENGINEERING. INC.
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S
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SC
October 14, 1976
Work Order 100236-A
530 Lot 17 104.0 15.6
531 Lot 16 104.6 14.3
532-5 tot 16 115.0 17.0
10/12/76 540-ng Lot 130 179.0 13.6
541-ng Lot 133 181.2 14.3
542-ng Lot 92 ll6.9 11. 1
.543-ng Lot 95 173.6 13.0
544-ng Lot 97 170.8 l2.4
Test in processed and compacted natural ground
Slope Test
Test in undisturbed natural ground
107.0
105.0
102 • .5
lO5~3
107.2
106.5
:108.4
'J 06.0
Indicates test by sand cone method; remaining tests by drive tube •
?5,.0 SC
93.0 'SC
91.0'
90.0 SC
92.0 SC
91.0 SC
93.0 SC
91.0 SC
Areas riot meeting minimum compaction requirements were re-worked and retested. Only
passing tests are shown in the above table.
PACIFIC !!JOILS ENGINEIi'lRING, INC.
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October 14, 1976
Work Order 100236-A •
TABLE II
Approximate
• Lot No. Depth (feet)
.16 20
17 19
18 14 • 19 10
91 Cut
92 Cut
• 93 Cut
94 Cut
95 'Cut
• '96 Cut.
97 Cut
98 Cut
130 Cut • 131 . Cl,It
132 Cut
133 Cut
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PACIFIC SOILS, Er\lGINEERING. IN~.
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PACIFIC SOILS ENGINEERING, !NC.
17921 SKY PARK CIRCLE (SUITE G) I RVINE, CALIF. 92714
TELE~HONE: (714) 557,9450
SUMMARY OF FOUNDATJONREQUIREMENTIQl:
TRACT NO 72-34 (j;;[/
Lot
16
17
T8
19
91
92
93
94,
95
96
97
98
130
1~1
132
133
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D-
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Go:-
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Work Order 100236-A
FOOT!I'-JG I FOOTi~'JG
Depth Reinf. ' Slab NIoist. D .r eprn Re,inf. SJab
Ext. Into Ext. Int. Reinf. Reg It. Loi' Ext. Int. Ext. Int. Re'inf.
A A D D G J
A A D D G J
A A D D ,G J .,
A A D -12 G J
A A If X X 1 G J
A A I X X J G J
A A \ X X I G J
A A II X X , G J
A A, t X X I G J
A A \ X X f G J
A A \X X I G J
A A Ix X I G J
A A .Ix X I G J
A A Ix X I G J . ,
'A A IX X t G J
A A IX X 1 G _L...
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LEGEND
12"; B -18"; C -24" below lowest adjacent grade
One (1) No. 4 rebar at top and one (1) at bottom
Two (2) No.4 rebars at top and two (2) at bottom
One (1) No. 5 rebar at top and one (1) at bottom
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Six (6) inch by six (6) inch -No.1 0 by No.1 0 welded wire mesh, or equivalent.
Six, (6) inch by six (6) inch -~o. 6 by No.6 welded wire mesh, or equival'ent. '
No. rebars, -inches on center both ways.
"Moist·
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A moisture content of optimum moisture required ,to a depth of 12-inches below slab subgrade
Presaturation ,of slab subgrade'required to 105 percent of optimum moisture to a depth of 12-inche
be!ow slab subgrade. " ,
Slab subgrade moisture to be verified by the soil engineer, prior to placement of visqueen and
r~inforcement. '
NO SPECIAL REQUIREMENT, . ".
Note: 1) Exterior footings for 2-story structures must have a minimum embedment of 18-inches
below grade.
2) Exterior footings for 3-story struCtures must have a minimum embedment of 24-inches
below grade; interiors, IS-inches below grade.
/ PLATE A