14-0725 (SFD) Geotechnical UpdateSladden Engineering
45090 Golf Center Parkway, Suite F, Indio, CA 92201 (760) 863-0713 Fax (760) 863-0847
6782 Stanton Avenue, Suite A, Buena Park, CA 90621 (714) 523.0952 Fax (714) 523-1369
450 Egan Avenue, Beaumont, CA 91723 (951) 845-7743 Fax (951) 845-8863
800 E. Florida Avenue, Hemet. CA 92543 (951) 766-8777 Fax (951) 766-8778
May 27, 2014 Project No. 544-14127
14-05-211
29th Street Citrus Project, LLC
699 Indian Trail
Palm Springs, California 92264
Project: Proposed Custom Residence
50-685 Breva Court
Tract 32068 — Lot 6
La Quinta, California
Subject: Foundation and Grading Plan Review
Ref: Geotechnical Update prepared by Sladden Engineering dated May 27, 2014; Project
No. 544-14127, Report No. 14-05-210
As requested, we have reviewed the Precise Grading Plan prepared by JHA Engineering, Inc.
along with the Foundation Plans and Details prepared by Gouvis Engineering. The plans
reviewed were prepared for the custom residence to be constructed at 50-685 Breva Court within
the Citrus Course development in the City of La Quinta, California. Based on our review, it is
our opinion that the recommendations provided in the above referenced Geotechnical Update
and the previous geotechnical reports have been properly incorporated into these plans.
If you have questions regarding this memo or the above referenced report, please contact the
undersigned.
Respectfully submitted,
SLADDEN ENGINEEI;
Brett L. Anderson ~� ANDERSON
EF No. C45389
Principal Engineer � EP. 9130/14
CIVIL
ENGINEERING
Letter/gvm
Copies: 4 / 29th Street Citrus Project, LLC
March.3, 2006 -4- Project No. 544-06184
06-03-215
1997 UNIFORM BUILDING CODE INFORMATION
The International Conference of Building Officials 1997 Uniform Building Code contains
substantial revisions and additions to the earthquake engineering section in Chapter 16.
Concepts contained in the updated code that will be relevant to construction of the proposed
structures are summarized below.
Ground shaking is expected to be the primary hazard most likely to affect the site, based upon
proximity to significant faults capable of generating large earthquakes. Major fault zones
considered to be most likely to create strong ground shaking at the site are listed below.
Fault Zone
Approximate Distance
From Site
Fault Type
(1997 UBC)
San Andreas
10.3 km
A
San Jacinto
32.0 km
A
Based on our field observations and understanding of local geologic conditions, the soil profile
type judged applicable to this site is So, generally described as stiff or dense soil. The site is
located within UBC Seismic Zone 4. The following table presents additional coefficients and
factors relevant to seismic mitigation for new construction upon adoption of the 1997 code.
Sladden Engineering
Near -Source
Near -Source
Seismic
Seismic
Seismic
Acceleration
Velocity
Coefficient
Coefficient
Source
Factor, No
Factor, Nv
C,
C"
San Andreas
1.0
1.2
0.44 Na
0.64 Nv
San Jacinto
1.0
1.0
0.44 Na
0.64 N�
Sladden Engineering
' 1 r
MAY 3 0 2014
WINDOW WORKSHEET
Ci
DATE: 1
5/13/2014
BY:
ROY EADS
TEMPLE _ CITRUS LOT 61�11124EVISED
50685 BREVA, LA QUINTA
05/28/2014 - BY ROY AS PER ROBERT'S 5/27 EMAIL
OVERHANG
SIDEFIN
REFERENCE
WINDOW DESCRIPTION
WALL
TOTAL
WINDOW SIZE
TYPE
FRAME
DBL
CLEAR
U
SHGC
HZ
DIST
LEFT RIGHT LEFT DIST RT
DIST INVOICE
#
#
SF
W' W" H' H"
SINGLE
OBSCURE
FACTOR
PRO1
ABOVE
EXT FROM EXT
FROM LINE ITEM
WINDOWS
'
1
FRONT PDR
1
4.5
1
6
3 0
SH
VINYL
DBL
CLR
0.32
0.22
500-1
2
FRONT BR2-1
4
17.5
2
6
7 0
FX ARCH
VINYL
DBL
CLR
0.34
0.22
400-1
3
FRONT BR2-2
4
24.0
3
0
8 0
FX ARCH
VINYL
DBL
CLR
0.31
0.22
600-1
4
FRONT BR2-3
4
17.5
2
6
7 0
FX ARCH
VINYL
DBL
CLR
0.34
0.22
400-1
5
FRONT BA2
4
15.0
3
0
5 0
SH
. VINYL
DBL
CLR
0.33
0.20
700-1
6
RT CLOS UP -1
5
2.3
1
6
1 6
FX
VINYL
DBL
CLR
0.30
0.20
1600-1
7
RT CLOS UP -2
5
2.3
1
6
1 6
FX
VINYL
DBL
CLR
0.30
0.20
1600-1
8
RT CLOS UP -3
5
2.3
1
6
1 6
FX
VINYL
DBL
CLR
0.30
0.20
1600-1
9
RT MBA CLRST 1
5
7.5
5
0
1 6
XO
VINYL
DBL
CLR
0.29
0.18
1700-1
10
RT MBA CLRST 2
5
7.5
5
0
1 6
XO
VINYL
DBL
CLR
0.29
0.18
1700-1
11
RT MBA CLRST 3
5
7.5
5
0
1 6
XO
VINYL
DBL
CLR
0.29
0.18
1700-1
12
REAR MB SGD
7
144.0
16
0
9 0
SGD
MTL
DBL
CLR
0.42
0.23
8
4
4
10.0
10
13
REAR MB CLRST 1
7
23.5
7
10
3 0
FX CLRST
VINYL
DBL
CLR
0.30
0.20
8
0
4
10.0
1000-1
14
REAR MB CLRST 2
7
23.5
7
10
3 0
FX CLRST
VINYL
DBL
CLR
0.30
0.20
8
0
10
10.0
1000-1
15
LT MB FR DOOR
8
27.0
3
0
9 0
FR DR
MTL
DBL
CLR
0.75
0.19
25
4
8.0
4.0
20.0
4.0
11
16
REAR GRT RM SGD
9
180.0
20
0
9 0
SGD
MTL
DBL
CLR
0.42
0.23
19'.5
4
10.0
10.0
9.0 4.0 9.0
2.0
12
17
REAR GRT CLRST 1
9
29.5
9
10
3 0
FX CLRST
I VINYL
DBL
CLR
0.30
0.20
19.5
0
10.0
10.0
9.0 4.0 9.0
2.0 1100-1
18
REAR GRT CLRST 2
9
29.5
9
10
3 0
FX CLRST
VINYL
DBL
CLR
0.30
0.20
19.5
0
10.0
10.0
9.0 4.0 9.0
2.0 1100-1
19
REAR NOOK FD
11
22.5
2
6
9 0
FR DR
MTL
DBL
CLR
0.75
0.19
9
4
10.0
10.0
13
20
REAR NOOK -1
11
21.3
2
fi
R f,
FX
MTI
DRI_
CLR
0.75
0.19
9
4
10.0
10.0
15
21
REAR NOOK -2
11
21.3
2
6
8 6
FX
MTL
DBL
CLR
0.75
0.19
9
4
10.0
10.0
15
22
IREAR NOOK -3
11
21.3
2
6
8 6
FX
MTL
DBL
CLR
0.75
0.19
9
4
10.0
10.0
15
23
REAR NOOK FD -2
11
22.5
2
6
9 0
FR DR
MTL
DBL
CLR
0.75
0.19
9
4
10.0
10.0
14
24
REAR NOOK CLRST 1
11
7.5
2
6
3 0
FX CLRST
VINYL
DBL
CLR
0.30 '
0.20
9
0
10.0
10.0
1300-1
25
REAR NOOK CLRST 2
11
7.5
2
6
3 0
FX CLRST
VINYL
DBL
CLR
0.30
0.20
9
0
10.0
10.0
1300-1
26
REAR NOOK CLRST 3
11
7.5
2
6
3 0
FX CLRST
VINYL
DBL
CLR
0.30
020
9
0
10.0
10.0
1300-1
27
REAR NOOK CLRST 4
11
7.5
2
6
3 01
FX CLRST
VINYL
DBL
CLR
0.30
0.20
9
0
10.0
10.0
1300-1
28
REAR NOOK CLRST 5
11
7.5
2
.6
3 0
FX CLRST
VINYL
DBL
CLR
0.30
0.20
9
0
10.0
10.0
1300-1
29
REAR DIN SGD
it
144.0
16
0
9 0
SGD
MTL
DBL
CLR
0.42
0.23
8
4
10
3.0
16
30
REAR DIN CLRST 1.
1.1
235
7
1.0
3 0
FX CLRST
VINYL
DRI_
CI_R
0.30
0.20
R
0
. . 1
3.0
1000-1
31
REAR DIN CLRST 2
11
23.5
7
10
3 0
FX CLRST
VINYL
DBL
CLR
0.30
0.20
8
0
10 1
10.0
1000-1
WINDOW WORKSHEET
DATE:
5/13/2014
BY:
ROY EADS
TEMPLE _ CITRUS LOT 6
REVISED 05/28/2014 - BY ROY AS PER ROBERT'S 5/27 EMAIL
50685 BREVA, LA QUINTA
OVERHANG SIDEFIN
REFERENCE
WINDOW DESCRIPTION
WALL
TOTAL
WINDOW SIZE
TYPE
FRAME
DBL
CLEAR
U
SHGC
HZ DIST LEFT RIGHT LEFT DIST RT
DIST INVOICE
#
#
SF
W' W" H' H"
SINGLE
OBSCURE
FACTOR
PROJ ABOVE EXT FROM EXT
FROM LINE ITEM
32 LT DIN CLRST 1
11
18.0
6
0
3 0
FX CLRST
VINYL
DBL
CLR
0.30
0.20
2 2 8 10.0
1800-1
33 LT DIN CLRST 2
11
18.0
6
0
3 '0
FX CLRST
VINYL
DBL
CLR
0.30
0.20
2 2 10 3.0
1800-1
34 LEFT BA3
14
6.0
2
0
3 0
SH
VINYL
DBL
CLR
0.33
0.20
1500-1
35 ILEFT BD3-1
14
30.0
5
0
6 0
SL
VINYL
DBL
CLR
0.33
0.20
1400-1
36 LEFT BD3-2
14
30.0
5
0
6 0
SH
VINYL
DBL
CLR
0.33
0.20
1400-1
37 LEFT BA4
16
6.0
4
0
1 6
SL
VINYL
DBL
CLR
0.29
0.18
800-1
38 LEFT BD4
16
48.0
8
0
6 0
SL
VINYL
DBL
CLR
0.33
0.20
900-1
39 RT GAR HALL -1
19
17.5
2
6
7 0
FX
VINYL
DBL
CLR
0.32
0.22
200-1
40 RT GAR HALL -2
19
17.5
2
6
7 0
FX
VWYL
DBL
CLR
0.35
0.22
300-1
41 FRONT LAU-1
20
3.0
1
0
3 0
SH
VINYL
DBL
CLR
0.32
0.22
500-1
42 FRONT LAU-2
20
3.0
1
0
3 0
SH
VINYL
DBL
CLR
0.32
0.22
500-1
TOTAL WINDOWS = SF
>>>
1099
TOTAL EXT WALL SURFACES = SF
>>>
4480
CFA SF
>>>
4238
WEST FACING SF
>>>
767
WWR%
>>>
24.5%
WEST FACING/TOTAL WINDOWS%
>>>
69.8%
WEST FACING/CFA RATIO
>>>
18.1%
FENESTRATION/CFA RATIO
>>>
25.9%
DOORS
1 ENTRY DOOR - ARCH
31.5
3
6
9 0
DOOR
SCWD
2 GARAGE/HALL
22.7
2
10
8 0
DOOR
SCWD
3
Sladden Engineering
45090 Golf Center Parkway, Suite F, Indio, CA 92201 (760) 863-0713 Fax (760) 863-0847
6782 Stanton Avenue, Suite A, Buena Park CA 90621 (714) 523-0952 Fax (714) 523-1369
450 Egan Avenue, Beaumont, CA 92223 (951) 845-7743 Fax (951) 845-8863
800 E. Florida Avenue, Hemet, CA. 92543 (951) 766-8777 Fax (951) 766-8778
May 27, 2014 Project No. 544-14127
14-05-210
2911, Street Citrus Project, LLC
699 Indian Trail
Palm Springs, California 92264
Subject: Geotechnical Update
Project: Proposed Custom Residence
Tract 32068 — Lot 6
50-685 Breva Court
The Citrus Course
La Quinta, California
Ref: Soil Engineering Report prepared by Buena Engineers, Inc. dated February 25,
1986; Report No. 86-02-271, job No. 16006-P2
Geotechnical Update prepared by Sladden Engineering dated March 13, 2006;
Project No. 54406184, Report No. 06-03-215
Rough Grading Report prepared by Sladden Engineering dated December 14, 2007;
Project No. 522-06184, Report No. 07-12-861
As requested, we have reviewed the referenced geotechnical reports as they relate to the design
and construction of the proposed custom residence. The project site (identified as Lot 6) is
located at 50-685 Breva Court within the Citrus Course development in the City of La Quinta,
California.
The previous geotechnical reports referenced above include recommendations for the design and
construction of the residential building foundations. Based upon our review of the referenced
reports and our recent site observations, it is our opinion that the recommendations included in
the above referenced reports remain applicable for the proposed custom residence.
Footings should extend at least 12 inches beneath lowest adjacent grade. Isolated square or
rectangular footings at least 2 feet square may be designed using an allowable bearing pressure
of 1700 pounds per square foot. Continuous footings at least 12 inches wide may be designed
using an allowable bearing pressure of 1200 pounds per square foot. Allowable increases of 200
psf for each additional 1 foot of width and 250 psf for each additional 6 inches of depth may be
utilized if desired. The maximum allowable bearing pressure should be 2500 psf. The allowable
bearing pressures are for dead and frequently applied live loads and may be increased by 1/3 to
resist wind, seismic or other transient loading.
May 27, 2014 -2- Project No. 544-14127
14-05-210
The recommendations made in the preceding paragraph are based on the assumption that all
footings will be supported by properly compacted engineered fill soil. Prior to the placement of
the reinforcing steel and concrete, we recommend that the footing excavations be inspected in
order to verify that they extend into the firm compacted soil and are free of loose and disturbed
materials.
Settlements may result from the anticipated foundation loads. These estimated ultimate
settlements are calculated to be a maximum of 1 inch when using the recommended bearing
pressure. As a practical matter, differential settlements between footings can be assumed as one-
half of the total settlement. These elastic settlements are expected to occur during construction.
Resistance to lateral loads may be provided by a combination of friction acting at the base of the
slabs or foundations and passive earth pressure along the sides of the foundations. A coefficient
of friction of 0.45 between soil and concrete may be used for dead load forces only. A passive
earth pressure of 275 pounds per square foot, per foot of depth, may be used along the sides of
footings that are placed against properly compacted native or approved import soil.
It is our opinion that the remedial grading recommended in the referenced Soil Engineering
report and performed during the previous rough grading adequately address foundation support
concerns. The remedial grading included overexcavation of the surface soil within the building
area. The remedial grading is described in the referenced Rough Grading report. Additional
grading should be limited to moisture conditioning and recompaction the weathered surface soil.
Based on our field observations and understanding of local geologic conditions, the soil profile
type judged applicable to this site is So, generally described as stiff soil. The following presents
additional coefficients and factors relevant to seismic mitigation for new construction based upon
the 2013 California Building Code (CBC).
Sladden has reviewed the 2013 California Building Code (CBC) and summarized the current
seismic design parameters for the proposed structure. The seismic design category for a structure
may be determined in accordance with Section 1613 of the 2013 CBC or ASCE7. According to the
2013 CBC, Site Class D may be used to estimate design seismic loading for the proposed
structures. The 2013 CBC Seismic Design Parameters are summarized below.
Risk Category (Table 1.5-1): I/111111
Site Class (Table 1613.3.2): D
Ss (Figure 1613.3.1):1.50lg
St (Figure 1613.3.1): 0.689g
Fa (Table 1613.3.3(1)): 1.0
Fv (Table 1613.5.3(2)):1.5
Sms (Equation 16-37 IN X Ss)): 1.5018
Sm1 (Equation 16-38 (Fv X Si)): 1.034g
SDs (Equation 16-39 12/3 X Sms)): 1.001g
SDI (Equation 16-40 (2/3 X Smt)): 0.689g
Seismic Design Category: E
Sladden Engineering
May 27,2014' -3- Project No. 544-1.4127
14-05-210
We appreciate the opportunity to provide service to you on this project, if you have any
questions regarding this letter or the referenced reports please contact the undersigned.
Respectfully submitted,
SLADDEN ENGINEERING
Brett L. Anderson` for BRETf L.
Principal Engineer \J ,�; ANDERSONv, ty,, C45389
E=' EXp.913o114
IL
SER/gvm ENGINNEERING
s,�TF 0 CALF ?
Copies: 4 / 291h Street Citrus Project, LLC
Sladden Engineering
LA QUINA
5 L/
Pilease verify that soils reports contain all of the above information. In addition, to assure
continuity between'the investigation/reporting stage and the execution stage, please use
the following checklist to verify that the conclusions and recommendations in the report
cover all the required elements. Only then. can we be assured that the construction
documents address all of the site soil conditions.
La Quinta Geotechnical Report Checklist
Does the "Conclusions and Recommendations" section of the report address each of the
following criteria?
"Address" means:
(a) the criterion is considered significant and mitigation measure(s) noted, or;
(b) the criterion is considered insignificant and explicitly.so stated.
Yes No Criterion
0 ❑ Foundation criteria based upon bearing capacity of natural or compacted soil.
❑ Foundation criteria to mitigate the effects of expansive soils.
® Foundation criteria based upon bearing capacity -of natural or --compacted soil.
❑ Foundation criteria to mitigate the effects of liquefaction.
9Q ❑ Foundation criteria to mitigate the effects of seismically induced differential
settlement.
I ❑ Foundation criteria to mitigate the effects of long-term differential settlement.
❑ Foundation criteria to mitigate the effects of varying soil strength.
❑ Foundation criteria to mitigate expected total and differential settlemerit.
Any "No" answers to the above checklist should be noted as specific required
coh-ections.
-r
77-725 Enfield Lane, Suite 100, Palm Desert, CA 92211 (760) 772-3893 Fax (760) 772-3895
6782. Stanton Ave., Suite A, Buena Park, CA 90621 (714) 523-0952 Fax (714) 523-1369
450 Egan Avenue, Beaumont, CA 92223 (951) 845-7743 Fax (951) 845-8863
December 19, 2007
TMC Company, Inc.
23382 Madero, Suite F
Mission Viejo, California 92691
Attention: Mr. Trevor Murphy
Subject: Geotechnical Update
Project: Proposed 12 Lot Residential Subdivision
Breva Court south of Mandarina
Citrus Course - Avenue 52
La Quinta, California
Project No. 544-06184
07-12-866
Ref: Soil Engineering Report prepared by Buena Engineers, Inc. dated February 25,
1986; Report No. 86-02-271, Job No. 16006-P2
Geotechnical Update prepared by Sladden Engineering dated March 13, 2006;
Project No. 544-06184, Report No. 06-03-215
Rough Grading Report prepared by Sladden Engineering dated December 14,2007;
Project No. 522-06184, Report No. 07-12-861
As requested, we have reviewed the referenced geotechnical reports as they relate to the design
and construction of the proposed residential development. The project site is located on Breva
Court south of Mandarina within the Citrus Course development in the City of La Quinta,
California.
The previous soils reports referenced above include recommendations for the design and
construction of residential building foundations. Based upon our review of the referenced report
and our recent site observations, it is our opinion that the recommendations included in the
above referenced report remain applicable for the proposed residential development.
Footings should extend at least 12 inches beneath lowest adjacent grade. Isolated square or
rectangular footings at least 2 feet square may be designed using an allowable bearing pressure
of 1700 pounds per square foot. Continuous footings at least 12 inches wide may be designed
using an allowable bearing pressure of 1200 pounds per square foot. Allowable increases of 200
psf for each additional 1 foot of width and 250 psf for each additional 6 inches of depth may be
utilized if desired. The maximum allowable bearing pressure should be 2500 psf. The allowable
bearing pressures are for dead and frequently applied live loads and may be increased by 1/3 to
resist wind, seismic or other transient loading.
December 19, 2007 -2- Project No. 544-06184
07-12-866
The recommendations made in the preceding paragraph are based on the assumption that all
footings will be supported by properly compacted soils. Prior to the placement of the reinforcing
steel and concrete, we recommend that the footing excavations be inspected in order to verify
that they extend into the firm compacted soils and are free of loose and disturbed materials.
Settlements may result from the anticipated foundation loads. These estimated ultimate
settlements are calculated to be a maximum of 1 inch when using the recommended bearing
values. As a practical matter, differential settlements between footings can be assumed as one-
half of the total settlement. These elastic settlements are expected to occur during construction.
Resistance to lateral loads may be provided by a combination of friction acting at the base of the
slabs or foundations and passive earth pressure along the sides of the foundations. A coefficient
of friction of 0.45 between soil and concrete may be used for dead load forces only. A passive
earth pressure of 275 pounds per square foot, per foot of depth, may be used along the sides of
footings which are poured against properly compacted native or approved import soils.
Retaining walls may be required to accomplish the proposed construction. Cantilever retaining
walls may be designed using "active" pressures. Active pressures may be estimated using an
equivalent fluid weight of 35 pcf for native backfill soils with level free -draining backfill
conditions. For walls that are restrained, "at rest" pressures should be utilized in design. At rest
pressures may be estimated using an equivalent fluid weight of 55 pcf. Walls should be provided
with adequate drainage.
It is our opinion that the remedial grading recommended in the referenced Soil Engineering
report and performed during the previous rough grading adequately address foundation support
concerns. The remedial grading included overexcavation of the surface soil within the proposed
building areas. The remedial grading is described in the referenced Rough Grading report.
Additional grading should be limited to recompacting the weathered surface soil and the
placement of the remainder of the fill within pads that remain low.
Sladden Eneineerine
i
December 19, 2007 -3- Project No. 544-06184
07-12-866
It should be noted that the site is located within a seismically active area of Southern California
and it is likely that the proposed structures will experience strong ground shaking as a result of
an earthquake event along one of the faults in the region during the expected life of the
development. As a minimum, structures should be designed based upon Seismic Zone 4 design
criteria included in the 2001 CBC indicated on the attached data sheet.
We appreciate the opportunity to provide service to you on this project, if you have any
questions regarding this letter or the referenced reports please contact the undersigned.
Respectfully submitted,
SLADDEN ENGINEERING _
Brett L. Anderson
77
�0 t_' 453
Principal Engineer
M Exp
`- ;
\
SER/gl
Copies: 4/TMC Company, Inc.
Sladden En--ineeriniz
December 19, 2007 -4- Project No. 544-06184
07-12-866
2001 CALIFORNIA BUILDING CODE (CBC) INFORMATION
The International Conference of Building Officials 2001 CBC contains substantial revisions and
additions to the earthquake engineering section in Chapter 16. Concepts contained in the
updated code that will be relevant to construction of the proposed structures are summarized
below.
Ground shaking is expected to be the primary hazard most likely to affect the site, based upon
proximity to significant faults capable of generating large earthquakes. Major fault zones
considered to be most likely to create strong ground shaking at the site are listed below.
Fault Zone
Approximate Distance
From Site
Fault Type
(1997 UBC)
San Andreas
10.3 km
A
San Jacinto
32.0 km
A
Based on our field observations and understanding of local geologic conditions, the soil profile
type judged applicable to this site is So, generally described as stiff or dense soil. The site is
located within UBC Seismic Zone 4. The following table presents additional coefficients and
factors relevant to seismic mitigation for new construction upon adoption of the 1997 code.
.Claddnn F.nninavrino
Near -Source
Near -Source
Seismic
Seismic
Seismic
Acceleration
Velocity
Coefficient
Coefficient
Source
Factor, Na
Factor, N,,
C.
&
San Andreas
1.0
1.2
0.44 Na
0.64 N,
San Jacinto
1.0
1.0
0.44 N,
0.64 N�
.Claddnn F.nninavrino
Slaelden
Engineering
77-725 Enfleld Lane, Suite 100, Palm Desert, CA 92211 (760) 772-3893 Fax (760) 772-3895
6782 Stanton Ave., Suite A, Buena Park, CA 90621 (714) 523-0952 Fax (714) 523-1369
450 Egan Avenue, Beaumont, CA 92223 (951) 845-7743 Fax (951) 845-8863
December 14, 2007
TMC Company, Inc.
24-002 Via Fabricante, Suite 222
Mission Viejo, California 92691
Project: The Gold Reserve at the Citrus
12 Lot Residential Subdivision
Breva Court south of Mandarina
La Quinta, California
Subject: Report of Observations and Testing During Rough Grading
Project No. 522-06184
07-12-861
Summarized in this report are the results of in-place density tests performed at the subject site
during rough grading along with pertinent observations. The project site is located on Breva
Court south of Mandariria within the Citrus Course development in the City of La Quinta,
California.
The building pad areas were overexcavated to a depth of at least 3 feet below natural grade or 4
feet below pad grade, whichever was deeper. The overexcavation extended at least 5 feet beyond
the building limits laterally. The exposed surface was moisture conditioned and compacted to a
minimum of 90 percent relative compaction. The previously removed soil was then placed in
thin lifts at near optimum moisture content and compacted to at least 90 percent relative
compaction. Lots 5 through 8 were left low and will be filled and completed at a later date.
Field testing was performed from June 6, 2006 through June 22, 2006. Testing indicates that a
minimum of 90 percent relative compaction was attained in the areas tested. The passing test
results indicate compliance with the project specifications at the tested locations and depths but
are no guarantee or warranty of the contractors work.
Field Tests: In-place moisture/density tests were performed using a nuclear density gauge in
accordance with test methods ASTM D 2922 and ASTM D 3017. A total of 43 density tests were
performed. The approximate test.locations are indicated by lot number and test results are
summarized on the attached data sheet.
December 14, 2007 -2- Project No. 522-06184
07-12-861
Laboratory Tests: The moisture -density relationships for the tested materials were determined in
the laboratory in accordance with test method ASTM D 1557-91.
AIlowable Bearing Pressures: The results of our investigation indicate that either conventional
shallow continuous footings or isolated pad footings that are supported upon properly
compacted soil may be expected to provide satisfactory support for the proposed residential
structures.
Footings should extend at least 12 inches beneath lowest adjacent grade. Isolated square or
rectangular footings at least 2 feet square may be designed using an allowable bearing pressure
of 2000 pounds per square foot. Continuous footings at least 12 inches wide may be designed
using an allowable bearing pressure of 1800 pounds per square foot. Allowable increases of 200
psf for each additional 1 foot of width and 250 psf for each additional 6 inches of depth may be
utilized if desired. The maximum allowable bearing pressure should be 2500 psf. The allowable
bearing pressures are for dead and frequently applied live loads and may be increased by 1/3 to
resist wind, seismic or other transient loading.
Care should be taken to see that bearing soil is not allowed to become saturated from the
ponding of rainwater or irrigation. Drainage from the building areas should be rapid and
complete. Prior to the placement of concrete, we recommend that the footing excavations be
inspected in order to verify. that they extend into compacted soil and are free of loose and
disturbed materials.
The bearing soils are non -expansive and fall within the "very low" expansion category in
accordance with Uniform Building Code (UBC) classification criteria.
If there are any questions regarding this report or the testing summarized herein, please contact
the undersigned.
Respectfully submitted
SLADDEN ENGINE NG
Brett L. Anderson
Principal Engineer
Grading/gl
Copies 4 /TMC Company, Inc.
Sladdeu Engineering
TEST RESULTS
.PROIEr,T NAME: Citrus - Gold Club
LOCATION: Breva Court Mandarina, LaQuinta, California
PROJECT NO: 522-06184
REPORT NO: 07-12-861
Test no
Date Tested
Location
Elevation
Dry Density
In place
YD moisture
in place
Relative
Compaction
Maximum
Density
Building Pads
1
6/7/2006
Per Plan
4' BPG
101.2
12.3
90
112
2
6/7/2006
Per Plan
4' BPG
103.5
10.1
92
112
3
6/7/2006
Per Plan
4' BPG
100.9
8.3
90
112
4
6/7/2006
Per Plan
4' BPG
103.1
9.0
92
112
5
6/7/2006
Lot 1
2' BPG
105.0
15.7
94
112
6
6/7/2006
Lot 1
2' BPG
102.1
15.9
91
112
7
6/7/2006
Lot 2
2' BPG
103.5
14.4
92
112
8
6/7/2006
Lot 2
2' BPG
100.8
13.9
90
112
9
6/7/2006
Lot 3
2' BPG
101.1
12.5
90
112
10
6/7/2006
Pad 1
4' BPG
102.8
14.7
92
112
11
6/7/2006
Pad 2
4' BPG
102.3
15.6
91
112
12
6/9/2006
Lot 12
4' BPG
101.1
11.8
90
112
13
6/9/2006
Lot 11
4' BPG
102.3
10.2
91
112
14
6/9/2006
Lot 10
4' BPG
100.4
9.4
90
112
15
6/9/2006
Lot 9
4' BPG
100.6
10.7
90
112
16
6/12/2006
Lot 10
4' BPG
103.3
15.2
92
112
17
6/12/2006
Lot 11
4' BPG
105.5
17.5
94
112
18
6/12/2006
Lot 12
4' BPG
111.2
14.1
99
112
19
6/12/2006
Lot 12
4' BPG
101.7
17.4
91
112
20
6/12/2006
Lot 12
2' BPG
102.7
13.3
92
112
21
6/12/2006
Lot 9
4' BPG
101.3
10.8
90
112
22
6/12/2006
Lot 10
4' BPG
102.2
14.2
91
112
23
6/12/2006
Lot 11
4' BPG
103.9
13.7
93
112
24
6/12/2006
Lot 9
2' BPG
107.7
15.8
96
112
25
6/12/2006
Lot 10
2' BPG
111.5
13.9
99
112
26
6/12/2006
Lot 11
2' BPG
103.8
14.7
93
112
27
6/12/2006
Lot 9
2' BPG
110.3
14.7
99
112
28
6/14/2006
Lot 9
4' BPG
105.6
14.3
94
112
29
6/14/2006
Lot 9
2' BPG
102.1
15.7
91
112
30
6/14/2006
Lot 9
2' BPG
102.7
15.2
92
112
31
6/14/2006
Lot 10
2' BPG
104.2
15.3
93
112
32
6/14/2006
Lot it
2' BPG
102.8
16.8
92
112
December 14, 2007 Sodden Engineering
.PROJE4T NAME: Citrus - Gold Club TEST RESULTS
LOCATION: Breva Court Mandarina, LaQuinta, California
PROJECT NO: 522-06184
REPORT NO: 07-12-861
Test no
Date Tested
Location
Elevation
Dry Density
in place
o Moisture
in place
Relative
compaction
Maximum
Density
Building Pads
33
6/16/2006
Lot 4
4' BPG
105.7
15.5
94
112
34
6/16/2006
Lot 4
4' BPG
105.6
17.0
94
112
35
6/16/2006
Lot 3
4' BPG
108.9
12.6
97
112
36
6/16/2006
Lot 3
4' BPG
106.4
11.1
95
112
37
6/21/2006
Lot 3
2' BPG
105.3
14.7
94
112
38
6/21/2006
Lot 3
2' BPG
104.5
12.8
93
112
39
6/21/2006
Lot 4
2' BPG
102.6
11.3
92
112
40
6/21/2006
Lot 4
2' BPG
105.1
12.9
94
112
41
6/21/2006
Lot 10
PG
105.3
10.5
94
112
42
6/21/2006
Lot 10
PG
103.2
12.4
92
112
43
6/21/2006
Lot 10
PG
102.6
11.3
92
112
44
6/21/2006
Lot 10
PG
107.3
9.6
96
112
45
6/21/2006
Lot 10
PG
109.9
11.3
98
112
46
6/21/2006
Lot 9
PG
112.0
10.4
100
112
47
6/21/2006
Lot 9
PG
104.5
11.7
93
112
48
6/21/2006
Lot 9
PG
105.2
8.9
94
112
49
6/21/2006
Lot 9
PG
106.1
9.7
95
112
50
6/21/2006
Lot 9
PG
103.1
9.4
92
112
51
6/21/2006
Lot 12
PG
103.0
9.5
92
112
52
6/21/2006
Lot 12
PG
106.6
11.7
95
112
53
6/21/2006
Lot 12
PG
107.7
8.5
96
112
54
6/21/2006
Lot 12
PG
104.5
12.8
93
112
55
6/21/2006
Lot 11
PG
107.4
11.0
96
112
56
6/21/2006
Lot 11
PG
102.8
15.4
92
112
57
6/21/2006
Lot 11
PG
103.6
12.8
93
112
58
6/21/2006
Lot 11
PG
102.5
10.8
92
112
59
6/21/2006
Lot 11
PG
104.9
11.8
94
112
60
6/22/2006
Lot 2
PG
103.4
15.0
92
112
61
6/22/2006
Lot 2
PG
107.9
10.5
96
112
62
6/22/2006
Lot 2
PG
108.4
8.3
97
112
63
6/22/2006
Lot 3
PG
101.0
14.8
90
112
64
6/22/2006
Lot 3
PG
102.6
8.6
92
112
65
6/22/2006
Lot 3
PG
111.2
9.2
99
112
66
6/22/2006
Lot 4
PG
102.3
12.5
91
112
67
6/22/2006
Lot 4
PG
103.4
12.2
92
112
68
6/22/2006
Lot 4
PG
100.8
12.7
90
112
December 14, 2007 Slodden Engineering
TEST RESULTS
,.PROJECT NAME: Citrus - Gold Club
LOCATION: Breva Court Mandarina, LaQuinta, California
131.8
PROJECT NO: 522-06184
REPORT NO: 07-12-861
Test no
Date Tested
Location
Elevation
DryDenslty
In place
%Moisture
in place
Relative
Compaction
Maximum
Density
Building Pads
69
6/22/2006
Lot 8
4' BPG
101.7
16.2
91
112
70
6/22/2006
Lot 8
4' BPG
106.0
13.8
95
112
71
6/22/2006
Lot 7
4' BPG
102.1
13.7
91
112
72
6/22/2006
Lot 7
4' BPG
100.8
14.7
90
112
73
6/22/2006
Lot 5
4' BPG
106.0
10.6
95
112
74
6/22/2006
Lot 5
4' BPG
106.1
13.7
95
112
75
6/22/2006
Lot 6
4' BPG
101.0
13.1
90
112
76
6/22/2006
Lot 6
4' BPG
100.4
15.4
90
112
BPG = Below Pad Grade
PG = Pad Grade
December 14, 2007 Siadden Engineering
,,
'* Sladden
Engineering
6782 Stanton Ave., Suite A, Buena Park, CA 90621 (714) 523-0952 Fax (714) 523-1369
39-725 Garand Ln., Suite G, Palm Desert, CA 92211 (760) 772-3893 Fax (760) 772-3895
March 13 2006
TMC Company, Inc.
24-002 Via Fabricante, Suite 222
Mission Viejo, California 92691
Attention: Mr. Trevor Murphy
Subject: Geotechnical Update
Project: Proposed 12 Lot Residential Subdivision
Breva Court south of Mandarina
Citrus Course - Avenue 52
La Quinta, California
Project No. 544-06184
06-03-215
Ref: Soil Engineering Report prepared by Buena Engineers, Inc. dated February 25,
1986, Report No. 86-02-271, Job No. 16006-P2
Rough Grading Report prepared by Buena Engineers, Inc. dated July 17, 1986, job
No. 16006-P1, Report No. 96-07-223
Final Report of Testing and Observations Performed During Grading prepared by
Buena Engineers, Inc. dated April 23, 1990, Job No. B -16006 -PI, Report No. 90-04-
789
As requested, we have reviewed the referenced soils reports as they relate to the design and
construction of the proposed residential development. The project site is located on Breva Court
south of Mandarina within the Citrus Course development in the City of La Quinta, California.
The referenced previous soils reports include recommendations for the design and construction
of residential building foundations. Based upon our review of the referenced reporst and our
recent site observations, it is our opinion that the recommendations included in the above
referenced report remain applicable for the proposed residential development.
Footings should extend at least 12 inches beneath lowest adjacent grade. Isolated square or
rectangular footings at least 2 feet square may be designed using an allowable bearing pressure
of 1700 pounds per square foot. Continuous footings at least 12 inches wide may be designed
using an allowable bearing pressure of 1200 pounds, per square foot. Allowable increases of 200
psf for each additional 1 foot of width and 250 psf for each additional 6 inches of depth may be
utilized if desired. The maximum allowable bearing pressure should be 2500 psf. The allowable
bearing pressures are for dead and frequently applied live loads and may be increased by 1/3 to
resist wind, seismic or other transient loading.
March 3, 2006 -2- Project No. 544-06184
06-03-215
The recommendations made in the preceding paragraph are based on the assumption that all
footings will be supported by properly compacted soils. Prior to the placement of the reinforcing
steel and concrete, we recommend that the footing excavations be inspected in order to verify
that they extend into the firm compacted soils and are free of loose and disturbed materials.
Settlements may result from the anticipated foundation loads. These estimated ultimate
settlements are calculated to be a maximum of 1 inch when using the recommended bearing
values. As a practical matter, differential settlements between footings can be assumed as one-
half of the total settlement. These elastic settlements are expected to occur during construction.
Resistance to lateral loads may be provided by a combination of friction acting at the base of the
slabs or foundations and passive earth pressure along the sides of the foundations. A coefficient
of friction of 0.45 between soil and concrete may be used for dead load forces only. A passive
earth pressure of 275 pounds per square foot, per foot of depth, may be used along the sides of
footings which are poured against properly compacted native or approved import soils.
Retaining walls may be required to accomplish the proposed construction. Cantilever retaining
walls may be designed using "active" pressures. Active pressures may be estimated using an
equivalent fluid weight of 35 pcf for native backfill soils with level free -draining backfill
conditions. For walls that are restrained, "at rest" pressures should be utilized in design. At rest
pressures may be estimated using an equivalent fluid weight of 55 pcf. Walls should be provided
with adequate drainage.
It is our opinion that the remedial grading recommended in the referenced Grading report
adequately address foundation support concerns. The remedial grading recommended at this
time should include overexcavation of the surface soils within the proposed building areas.
The building pad areas should be cleared of the existing pavement, underground utilities and
any surface vegetation prior to grading. In order to provide for firm and uniform foundation
support, we recommend overexcavation and recompaction throughout the building areas. The
building areas should be overexcavated to a depth of at least 3 feet below natural grade or 4 feet
below pad grade, whichever is deeper. The exposed surface should then be scarified, moisture
conditioned and compacted to a minimum of 90 percent relative compaction. The previously
removed soils and fill material may then be placed in thin lifts and compacted to at least 90
percent relative compaction.
It should be noted that the Site is located within a seismically active area of Southern California
and it is likely that the proposed structures will experience strong ground shaking as a result of
an earthquake event along one of the faults in the region during the expected life of the
development. As a minimum, structures should be designed based upon Seismic Zone 4 design
criteria included in the Uniform Building Code (UBC). The potential for liquefaction or other
geologic/seismic hazards occurring at the site is considered to be negligible.
Sladden Engineering
March 3, 2006 -3- Project No. 54406184
06-03-215
We appreciate the opportunity to provide service to you on this project, if you have any
questions regarding this letter or the referenced reports please contact the undersigned.
Respectfully submitted,
SLADDEN ENGINEET
Brett L. Andersod'
Principal Engineer
SER/Ih
T11
Exp.913010fi M
r
\s�yT crvi- Q
OF Ci -.1 ��C•'
Copies: 4f MC Company, Inc.
Sladden Engineering