2000-6519 G
Street Address
-7
Category Serial #
0-,fig RXMIA)
Name Description
Plan ck. # Year
Geotechnic s
AMENEfthm.- Incorporated
Principals:
Anthony F. Belfast
Michael P. Imbriglio
W. Lee Vanderhurst
July 5, 2000
i
Mr. Chad Lake Project No. 0614-001-00
2307 Terraza Ribera Document No. 0-0618
Carlsbad, California 92009
SUBJECT: GRADING PLAN REVIEW AND REPORT UPDATE
Proposed Single Family Residence, Colony Terrace
PD 2, Lot 28 8 POR, Encinitas, California
REFERENCES: Geotechnics Incorporated. 1998. Geotechnical Investigation, Proposed
Residential construction, 1.1 Acre Lot, Colony Terrace, Encinitas,
California, Project No. 0398-001-01, Document No. 8-0096, April 8.
Wayne Stutzman Engineering & Land Surveying. Undated. Grading and-
Erosion Control Plans for Lake Residence, PD 2. Lot 28 8 Por.
Dear Mr. Lake:
At your request, we have reviewed the proposed grading plans, referenced above, which you have
provided to us. In addition, we have reviewed the referenced geotechnical report, prepared by
Geotechnics Incorported, which provides recommendations for the geotechnical aspects of site
development.
In our opinion, the referenced geotechnical report adequately addresses the site conditions and
should remain suitable as the design document. In addition, the grading plan reviewed adequately
incorporate the intent of the recommendations provided in the geotechnical report. However, the
planned grading extends over a larger area than previously anticipated during preparation of the
geotechnical report. This will result in remedial grading to mitigate conditions created by the
grading. These are summarized as follows.
The building pad for the structure will result in a cut/fill transition within the building area. To
decrease the likelihood of distress due to the different settlement characteristics of the formational
material and the fill, the building area should be overexcavated as recommended in Section 8.2.3
of the geotechnical report. This will likely involve the excavation of up to seven feet of formational
material in the building area, and its replacement as a compacted fill.
9245 Activity Rd., Ste. 103 • San Diego, California 92126
Phone (858) 536-1000 • Fax (858) 536-8311
MR. CHAD LAKE PROJECT NO. 0614-001-00
JULY 5, 2000 DOCUMENT NO. 0-0618
PAGE 2
The two lower pads are likely to be in an area of relatively deep colluvial soils, which we have
found to be compressible. All of the colluvium in areas to be graded or improved should be
removed to expose formational material, and fills keyed and benched into the formational material
as recommended in the geotechnical report. Because construction in this area was not anticipated
during preparation of the geotechnical report, only one boring was made in the area of the lower
slope, and about 20 feet of colluvium was found. The depth of colluvium over the areas of the pool
pad and the garden pad may vary from this, and the variation is not known at this time. This can
be determined during grading, based on field observations. It should be realized that the colluvium
depths will impact development costs, and it may be desirable to more accurately determine the
depth of colluvium to determine your grading costs. The additional excavations can be done by
your grading contractor, or by a geotechnical consultant.
Please call at your convenience if you should have any questions regarding this correspondence.
We appreciate this opportunity to be of continued service.
GEOTECHNICS INCORPORATED
Anthony F. Belfast, P.E. 40333
Principal
okOFESS/O
G 'w C040333 N-+ Z
w m
d Exp. -3~
- L'IV11.
9xF OF CALIFOPa
Geotechnics Incorporated
Geotechnics
Incorporated
' Principals:
Anthony F. Belfast
Michael P. Imbriglio
W. Lee Vanderhurst
I
GEOTECHNICAL INVESTIGATION
' PROPOSED RESIDENTIAL CONSTRUCTION
1.1 ACRE LOT, COLONY TERRACE
OLIVENHAIN
ENCINITAS, CALIFORNIA
I
I
prepared for:
' Mr. Steve Gregory
742 Genevieve Street, Suite F
Solana Beach, California 92075
I
I by.
GEOTECHNICS INCORPORATED
I Project No. 0398-001-01
Document No. 8-0096
I
April 8, 1998
I
9245 Activity Rd., Ste. 103 • San Diego, California 92126
Phone(858)536-1000 • Fax(858)536-8311
Geotechnics
Incorporated
Principals:
Anthony F. Belfast
Michael P. Imbriglio
W. Lee Vanderhurst
April 8 1998
I Mr. Steve Gregory Project No. 0398-001-01
742 Genevieve Street, Suite F Doc. #8-0096
Solana Beach, California 92075
SUBJECT: REPORT OF GEOTECHNICAL INVESTIGATION
Proposed Residential Construction
1.1 Acre Lot, Colony Terrace
I Olivenhain
Encinitas, California
Dear Mr. Gregory:
In accordance with your request, we have completed a geotechnical investigation for the proposed
residential construction in the Olivenhain community. In general summary, the proposed residential
development of the site are feasible from a geotechnical standpoint. Our conclusions and
recommendations regarding site conditions, earthwork construction, and design of structures, are
presented in the attached report.
We appreciate this opportunity to provide professional services. If you have any questions or
comments regarding this report or the services provided, please do not hesitate to contact us.
I
Respectfully submitted,
GEOTECHNICS INCORPORATED
I Anthony F. Belfast, P.E.
Principal
AFB/kws
Distribution: (4) Addressee
I
9245 Activity Rd., Ste. 103 • San Diego, California 92126
I Phone(858)536-1000 • Fax(858)536-8311
GEOTECHNICAL INVESTIGATION
PROPOSED RESIDENTIAL CONSTRUCTION
1.1 ACRE LOT, COLONY TERRACE
OLIVENHAIN
ENCINITAS, CALIFORNIA
TABLE OF CONTENTS
' 1.0 INTRODUCTION ........................................................1
' 2.0 PURPOSE AND SCOPE OF WORK 1
3.0 SITE DESCRIPTION 2
' 4.0 PROPOSED DEVELOPMENT 2
' 5.0 GEOLOGY AND SUBSURFACE CONDITIONS 2
5.1 Delmar Formation 3
5.2 Undifferentiated Topsoil/Colluvium 3
I 5.3 Groundwater ................................................3
6.0 GEOLOGIC HAZARDS AND SEISMICITY 4
I ~ 6.1 Geologic Hazards 4
6.2 Seismicity .4
7.0 CONCLUSIONS 5
8.0 RECOMMENDATIONS ...................................................6
8.1 Plan Review ................................................6
8.2 Earthwork and Grading 6
8.2.1 General 6
8.2.2 Site Preparation for Building and Fill Areas 7
8.2.3 Cut/Fill Transitions 7
8.2.4 Site Preparation for Driveway 7
8.2.5 Excavation and Grading Observation 8
I 8.2.6 Fill Compaction 8
8.3 Surface Drainage ............................................9
8.4 Slope Stability 9
I 8.5 Foundation Recommendations 10
8.6 On-Grade Slabs 11
8.7 Expansive Soils 12
I 8.8 Reactive Soils 12
8.9 Earth Retaining Structures . . . . . . • • . • . . . . • . . . • . . . . . . . . . . . . . . . 12
I 9.0 LIMITATIONS OF INVESTIGATION 13
I Geotechnics Incorporated
I
GEOTECHNICAL INVESTIGATION
I PROPOSED RESIDENTIAL CONSTRUCTION
1.1 ACRE LOT, COLONY TERRACE
OLIVENHAIN
I ENCINITAS, CALIFORNIA
1.0 INTRODUCTION
In accordance with your request, we have completed our geotechnical investigation for the planned
I residence, located on Colony Terrace in the community of Olivenhain, California. The following
report presents our findings, conclusions, and recommendations of our geotechnical investigation
for the planned development.
This investigation was conducted in accordance with the authorization of the Mr. Steve Gregory.
I The scope of services provided during this investigation were consistent with those outlined in our
Proposal No. 7-221, dated December 2, 1997.
I
2.0 PURPOSE AND SCOPE OF WORK
I The purpose of our investigation was to evaluate existing geotechnical conditions at the site as they
relate to the proposed residential construction, and to make recommendations regarding foundation
I design parameters, retaining wall design, and site preparation and grading. The recommendations
contained herein are based on a surface reconnaissance, subsurface exploration, laboratory
I testing, and professional experience in the general site area. Design values may include
presumptive parameters based on professional judgement. Our scope of work was limited to:
2.1 Review of available literature related to general geologic conditions.
I 2.2 A visual reconnaissance of the site, geologic mapping of exposures, and drilling of two
large diameter borings. Bulk and undisturbed samples of the various soil types were
I collected for laboratory testing.
I 2.3 Laboratory testing of samples collected in the field to classify the soil for aid in
determining engineering properties.
l 2.4 Engineering analysis of field and laboratory data to develop our conclusions and
recommendations.
I 2.5 Preparation of this report.
I
Geotechnics Incorporated
Mr. Steve Gregory Project No. 0398-001-01
April 8, 1998 Doc. #8-0096
Page 2
3.0 SITE DESCRIPTION
The subject ro ertis on the i
subject property p y t west side of Manchester Avenue, in the community of Olivenhain,
in the city of Encinitas, California. Access to the lot is from Colony Terrace, a private street. The
site consists of an apparently undeveloped 1.1 acre rectangular lot, with an old (pre 1953) house
on the south side, Colony Terrace on the north, portions of a cemetery and driveway on the west
and a residential lot on the east (see Location Map, Figure 1). Topographically, the area consists
of gentle to moderate slope to the east, and is located within an area of subdued knolls and ridges.
I Above the site and to the west is an abrupt sandstone ridge, with erosion rills typical of the Torrey
Sandstone. The surface of the site appears to have been disced or tilled to control vegetation,
however no other signs of agricultural use or grading were observed. The 1953 stereo graphic-pair
aerial photographs indicate that the site has not changed significantly since that time. Site
drainage by sheet flow is directed to the northeast.
4.0 PROPOSED DEVELOPMENT
The proposed development will include a single family residence, with associated driveway. No
plans are available at this time, however, we understand that the structure will be located on the
western elevated portion of the site. It is anticipated that some grading will be required to produce
a level building pad, due to the sloping site. We assume the anticipated loads for the structures
will be typical for light, wood-framed construction.
5.0 GEOLOGY AND SUBSURFACE CONDITIONS
The site is located within the coastal plain of the Peninsular Range Geomorphic Province. The
I coastal plain consists typically of subdued landforms underlain by sedimentary formations. Based
on our subsurface investigation and literature review, the site is underlain primarily by the Eocene
-age Delmar Formation. An irregular thickness of colluvium was encountered in the eastern portion
of the site, with a thickness of 21 feet overlying the Delmar Formation. Topsoil on the site is a
I relatively thin zone of loose soil that was tilled, and covers the site. Adjacent to the west property
boundary of the site is a relatively steep bluff that consists of the Torrey Sandstone. The bluff is
characterized by erosion rills and steep slopes.
The borings were advanced to a maximum depth of 74 feet below existing grade. The approximate
locations of the borings are shown on the Site Plan, Plate 1. Logs describing the subsurface
I Geotechnics Incorporated
PEGASO
Sf% L `d E{I f
' LrA rtlsA- CL PµRIE.-A3 1 g rNjl qS _ I /1~ [ .v~'~ V ( ~O ~rpq _ VGp,SUtU' El i
f05 1
2 'EC* M M6 1rlt Lff H \aB~ 'rf
~ VN 0.
p I gb
Ba va a uui 1t s s y'Y 6/ 0 Sr
Q N I3 tx.A~+` = 3J3 ,J,_ ..rN n.`p sa
~ ~ 1 ~J 9y EL rA°° r
G,y AVD OE E5 ADNL3~ TAEGAM / / I 100 I• /
DR ms
iYGLEN qp p tTAF ~RD •UDD % / l egoo
TREE a I • I.. 0 N~
Dal A ° /TF 8
onr ~
1400 NIU PERNILL DR '~1 ~ .
. ~ ~ P t~~ O I v ~ ~
NYAN ~;:,1 9 S Q 6
w ,8'/*/ ~p~ ''q09 1 dl
~Di 5 ]Bili z T, y lP ~ ~°n
DR ~ ~ppDA g
o p-.
C5 I ..lo Y tiP O ACA D,
°
00
= LN a BPANO
CT 24 11 p~ Oy AB00 •°o ; .-si.., `IA DE Coll,
? ~O
CREST g ELI JO
'
I c W a ~S,~rr~ ~I'i roo LA ,r COAO ~cLF CLLR ~q f
J X KID r
W DR w •`I .--a! AVfN10 5300 ',fix'" i
B
~~1lLlA5 LIS
7600 I I g 9 f / ~kAV[ LLAS
I/ f^C pVENIDA QOSA
3 .la T° / ~ ~sr tip a~ t s~
S
TA I d CV` lVP tp5 EL SECIP SCL~.O {
:TY
J
'd ~0P V300 \ ~ AC ° O
- ~ xo~go0 E CL 1 0F1 AOR \
FAY I7-A t~ 2
\ r° II N,O?Y %fl` S LA GLDR1 A !q SENCII
1
25
1 w o0 600`i 6~c^~ E CIEL~rO P~'
~-Am ELIJO CDOV
COUNTY:PA b
_ SERERq~' '~F'J.
ECOLOGICAL E
o
v ~fotA Goa DA DEL
-sSARTF NIALGA BOSOUf 5 $ CALIADA
d
goo 0SFL REN lP ST~ 1~ >r_ 1 SP p1 * I- , , L
k14 AB6bC0 CIE'~dl 5700
. t ~/H g~• SpV'Sp EST LLA wri p y CTDRIA o Y' 'rte t I f~ 5~ P
,p x.Q I SANt s $ $i SSN r0 q, R P'1T° rS Q4,
c(•, 3 RIGR00 CT
lNQtt 5 1~
wr. Mvr cri EXfafffVE CDLWE ate rt! f( PUER A .
Sr' P p 3AV vATRt to ml b TERESA y l L
s ~ ~p LICIA $ rr a 4yr 4 ~ ~ ~
p
< ~p HELENA `R4 c~' r a uia
Is w ~
n r Gs LnMS SN(TAP E n RAS a Q~
..3 c CDU r3 J
-36 fL COLWTUr
c•~.~ $ , b~ 3 3 A. PE RWL .~+N'f "~y 17 •Fg,P T, t . o q¢W ' .
Cf1VAT DR yIMIBRFS ~-t yT
IAR80 : GBRTA BR I + - 5
r U~
IS 1 1 DP. 1500 r q i~ ire
1
f m s _ ° S dj ~i
of SPNE fzH z5 1 11 :lB,ll. a I s6wrurr 0p ECHO HILL . •JC
ML g29N _ H2/23 ;lA a L 4BIq LN p ~ n
D 7135 tiP ~q
LA I I Cy y t' `0f, r~ q Pi
3OBRINA LytBC r t\~ I 1~~'
fADEMY DR ! 0 ~P r lGNA i t3 SODD 6 tNP zV' z w oi v Pt JI+11as r "^"'~1`
I NDIA 6 9 D I t HlGrl l~ I LN _ p er.. R i s ICI A% DEL
tX (VISTA NY y' a N j .r--~~ .W'Y ky~ 'S
~i CENEN IEVE ST • e SIL Me ~ ~ Ba A. s f y A:' w
14111111111~1 G LOCATION MAP PROJECT NO. 0398-001-01
eo t e c hn i c s Terrace Residence DOC. #$-0096'1
Incorporated Colony
Mr. Steve Gregory FIGURE 1
I •
Mr. Steve Gregory Project No. 0398-001-01
I April 8, 1998 Doc. #8-0096
Page 3
I
conditions encountered are given in the figures of Appendix B. A description of the subsurface
conditions and the specific units observed during drilling follows.
I 5.1 Delmar Formation
The Delmar Formation is believed to underlie the entire site, with near surface exposures
on the elevated western portion of the site. Colluvium covers the formation on the lower
eastern portion of the site. As observed on site, the formation ranges from a clayey
sandstone (SP) that is fine to medium grained, to a claystone (CL) that has low plasticity.
The formational materials are primarily light green in color, dense to very dense or hard,
and moist to wet. Groundwater was observed in the formation in Boring 1 at approximately
54 feet below the surface grade.
5.2 Undifferentiated Topsoil/Colluvium
Undifferentiated topsoil and/or colluvium material was observed to mantle the Delmar
Formation, with a thickness of ranging from approximately 1 to 21 feet. At higher elevations
of the site, a relatively thin layer of topsoil mantles the Delmar Formation. However, at the
eastern and lower area, the combined thickness of topsoil and colluvium is relatively deep.
The topsoil and colluvium was observed to be 21 feet in thickness in Boring 1. The
colluvium is interpreted to have been deposited on an eroded surface of the Delmar
Formation, with the likely source being the Torrey Sandstone west of the site. The
deposition of relatively thick colluvium has been associated with the friable characteristics
of the Torrey Sandstone in other locations of the geomorphic area. The colluvial materials
generally consists of a light green to yellow silty sand (SM), to clean sand (SP), that is fine
grained, nonplastic, and moist. The material was observed to be moist, loose to medium
dense, and mottled with orange staining. The contact with the underlying Delmar Formation
was inclined approximately 32 degrees to the east.
5.3 Groundwater
Groundwater was observed in Boring 1 at approximately 54 feet below existing grade, with
relatively heavy seepage into the boring. This groundwater elevation corresponds roughly
with the elevation of the creek adjacent to Manchester Avenue, a few hundred feet east of
the site. Groundwater is not anticipated to occur within the improvement areas of the site.
Geotechnics Incorporated
Mr. Steve Gregory Project No. 0398-001-01
I April 8, 1998 Doc. #8-0096
Page 4
I
However, changes in rainfall or site drainage could produce seepage or locally perched
groundwater conditions within the soil or bedrock underlying the site. It should be
recognized that excessive irrigation on residential sites is the most frequent cause of
I localized seepage and perched groundwater conditions. Since the prediction of the location
of such conditions is not possible, they are typically mitigated if and when they occur.
6.0 GEOLOGIC HAZARDS AND SEISMICITY
6.1 Geologic Hazards
The subject site is not located within an area previously known for significant geologic
hazards. No landslides nor deep-seated bedrock failures were noted in our investigation.
No faulting has been mapped or observed within the project site. Ground-breaking due to
active faulting is considered to have a low potential, due to the distance of the site from
known active faults. Since no shallow groundwater was observed, the potential for
I liquefaction at the site is considered remote.
6.2 Seismicity
The subject site is located approximately 6 miles east of the offshore trace of the Rose
I Canyon fault zone. The Rose Canyon fault zone has recently been upgraded to active
status, and is considered capable of a maximum probable earthquake of magnitude 6.4
I (DMG, 1992). The Rose Canyon fault zone governs design considerations due to its active
status, and relative proximity to the site. The estimated peak site ground acceleration for
an event centered on the Rose Canyon fault zone is 0.298. Design of structures should
I comply with the requirements of the governing jurisdictions, building codes and standard
practices of the Association of Structural Engineers of California.
I
I
l
Geotechnics Incorporated
I
Mr. Steve Gregory Project No. 0398-001-01
I April 8, 1998 Doc. #8-0096
Page 5
7.0 CONCLUSIONS
I No geotechnical conditions were apparent during the investigation which would preclude the
proposed development. However, some geotechnical factors exist which require consideration.
• There are no known active faults underlying the project site. The most likely seismic
I hazards at the site would be associated with significant ground shaking from an event
centered within the nearby Rose Canyon Fault Zone. The effects of ground accelerations
I from earthquakes are typically addressed by structural design of buildings in accordance
` with established procedures of the Uniform Building Code.
I • Evidence of existing slope instabilities, or landslides, were not encountered during this
investigation. However, proposed graded slopes should be constructed at recommended
gradients and protected from surface water flow and/or seepage that can result in surficial
slope failures and erosion.
I • The site is underlain at depth by the Delmar Formation covered with a variable depth of
undifferentiated topsoil and/or colluvium. The topsoil and colluvium is not considered
suitable, in its present state, for the support of fill or structural loads because of the potential
for adverse settlement. Consequently, in all building and improvement areas, this material
I should be excavated to expose undisturbed Delmar Formation, and then replaced as a
compacted fill. Removal depths can vary significantly,-based on the depths encountered
in our borings. If the planned residence area is located at the higher elevations of the site,
I it is anticipated the topsoil/colluvium with be shallow (about 1 to 3 feet deep).
I • The on-site soils include moderately expansive clays, that are located in the Delmar
Formation. The expansive clays are inter-bedded with less expansive sandstone portions
of the Delmar Formation. The topsoil and colluvium are typically sandy and not expansive.
Structures and concrete flatwork that is constructed on expansive clay soils may require
I extra reinforcement to resist the expansion forces. Non-expansive soils may be used as
a cap to reduce the reinforcement and soil movement.
• It is our understanding that the residence will be constructed on the elevated west side of
the site, and will likely include some grading to produce a flat building pad. If the grading
I produces a cut/fill transition under the structure, over-excavation of the cut portion is
I Geotechnics Incorporated
Mr. Steve Gregory Project No. 0398-001-01
April 8, 1998 Doc. #8-0096
Page 6
recommended to reduce differential settlement across the structure. This would produce
' a building pad that is underlain by a relatively uniform depth of fill.
f • Much of the material at the site is suitable for re-use in compacted fills. However,
vegetation and debris are considered deleterious and unsuitable for use in compacted fills
on site. These materials should be disposed off site.
8.0 RECOMMENDATIONS
' The remainder of this report presents recommendations in detail. These recommendations are
based on empirical and analytical methods typical of the standard of practice in southern California.
If these recommendations appear not to cover any specific feature of the project, please contact
' our office for additions or revisions to the recommendations.
8.1 Plan Review
It is recommended that foundation and grading plans be reviewed by Geotechnics
Incorporated prior to plan finalization.
' 8.2 Earthwork and Grading
r The following site preparation recommendations should be considered subject to revision
` based on conditions observed by the geotechnical consultant during grading operations.
The limits of all remedial grading operations should be accurately staked prior to
commencing removals. The bottom of all excavations should be observed by the
geotechnical consultant.
8.2.1 General
I Clearing of the existing site should include the removal of deleterious materials from
all areas to receive new structures or fill. Deleterious materials should not be used
in site fills. Deleterious materials include buried pipes and structures, construction
debris, and any soil containing vegetation. Subsurface utilities that will be
I
I Geotechnics Incorporated
Mn Steve Gregory Project No. 0398-001-01
April 8, 1998 Doc. #8-0096
Page 7
abandoned should be excavated and removed, and the trenches backfilled and
compacted as discussed in Section 8.6.
8.2.2 Site Preparation for Building and Fill Areas: In all areas where buildings or
any settlement-sensitive structures are planned or where any fill is to be placed,
topsoil and colluvium soil should be excavated to expose undisturbed formational
I material. Removals should include the area within five feet of the structure's
perimeter. The stockpiled soil that is free of deleterious materials should then be
' moisture conditioned, and compacted to at least 90 percent of the maximum density
as determined by ASTM D1557.
' 8.2.3 Cut/Fill Transitions: The proposed residential structure should not cross a
transition from fill to formational material. If the planned grading will create this
condition, we recommend that the cut portion of a building pad be over-excavated
below finish grade to a depth of 3 feet, or to a depth of D/2, whichever is greater.
' The variable "D" in this case is equal to the greatest depth of fill underlying the
structure. Note that the over-excavation envelope should extend a minimum of 5
feet beyond the proposed building area. The over-excavated portion of the pad
should then be brought back to finish grade with compacted fill as discussed in
Section 8.6.
8.2.4 Site Preparation for Drivewa
y A driveway through the lower areas of the site
is expected to be over areas underlain by deep colluvium (in excess of 20 feet
deep). It may be impractical to fully remove and recompact this material to mitigate
the potential for settlement. However, it some settlement of the drive is acceptable,
partial removal of the colluvium is considered to be an acceptable alternative. We
recommended that at least five feet of the topsoil and colluvium and topsoil be
removed from below the driveway area. Provided no more than one to two feet of
fill will be added over the existing grade, we expect the total settlement to be less
than about 2 inches.
I
Geotechnics Incorporated
Mr. Steve Gregory Project No. 0398-001-01
April 8, 1998 Doc. #8-0096
Page 8
8.2.5 Excavation and Grading Observation
Foundation excavations and site grading excavations should be observed by
Geotechnics Incorporated. During grading, Geotechnics Incorporated should
provide observation and testing services continuously. Such observations are
considered essential to identify field conditions that differ from those anticipated by
the preliminary investigation, to adjust designs to actual field conditions, and to
determine that the grading is accomplished in general accordance with the
recommendations of this report. Recommendations presented in this report are
contingent upon Geotechnics Incorporated performing such services. Our
personnel should perform sufficient testing of fill during grading to support our
professional opinion as to compliance with compaction recommendations.
8.2.6 Fill Compaction
All fill and backfill to be placed in association with site development should be
accomplished at slightly over optimum moisture conditions and using equipment
that is capable of producing a uniformly compacted product. The minimum relative
compaction recommended for fill is 90 percent of maximum density based on ASTM
D1557. Sufficient observation and testing should be performed by Geotechnics
Incorporated so that an opinion can be rendered as to the compaction achieved.
Imported fill sources should be observed prior to hauling onto the site to determine
the suitability for use. Representative samples of imported materials and on site
soils should be tested by the geotechnical consultant in order to evaluate their
appropriate engineering properties for the planned use.
During grading operations, soil types other than those analyzed in the geotechnical
reports may be encountered by the contractor. The geotechnical consultant should
be notified to evaluate the suitability of these soils for use as fill and as finish grade
soils.
Geotechnics Incorporated
f Mr. Steve Gregory Project No. 0398-001-01
April 8, 1998 Doc. #8-0096
Page 9
I
8.3 Surface Drainage
Foundation and slab performance depends greatly on how well the runoff waters drain from
the site. This is true both during construction and over the entire life of the structure. The
ground surface around structures should be graded so that water flows rapidly away from
the structures without ponding. The surface gradient needed to achieve this depends on
the prevailing landscape. In general, we recommend that pavement and lawn areas within
five feet of buildings slope away at gradients of at least two percent. Densely vegetated
areas should have minimum gradients of at least five percent away from buildings in the
first five feet. Densely vegetated areas are considered those in which the planting type and
spacing is such that the flow of water is impeded.
Planters should be built so that water from them will not seep into the foundation, slab, or
pavement areas. Roof drainage should be channeled by pipe to storm drains, or discharge
at least 5 feet from building lines. Site irrigation should be limited to the minimum
necessary to sustain landscaping plants. Should excessive irrigation, surface water
intrusion, water line breaks, or unusually high rainfall occur, saturated zones or "perched"
groundwater may develop in the underlying soils.
8.4 Slope Stability
In general, cut and fill slopes should be inclined no steeper than 2:1 (horizontal to vertical).
Fill slopes should be constructed entirely over prepared bedrock. Where the existing ground
slopes greater than 5:1 (horizontal:vertical), it should be benched to produce a level area
to receive the fill. Benches should be wide enough to provide complete coverage by the
compaction equipment. At the base of planned fill slopes a key should be excavated into
formational materials, with a minimum width of 15 feet and a 2 foot inclination across the
width of the key, into the hillside. The fill key should be reviewed by Geotechnics
representative prior to the placement of fill soils.
Cut fill slopes of at least 10 feet in height should be stable with regard to deep-seated
failure with a factor of safety of 1.5 at the recommended inclination. The surficial slope
stability is dependant upon maintaining good site drainage. The site should be graded so
that water from the surrounding areas is not able to flow over the top of the slope.
Diversion structures should be provided where necessary. Surface runoff should be
Geotechnics Incorporated
Mr. Steve Gregory Project No. 0398-001-01
April 8, 1998 Doc. #8-0096
Page 10
r
confined to gunite-lined swales or other appropriate devices to reduce the potential for
erosion. It is recommended that slopes be planted with vegetation that will increase their
stability. Ice plant is generally not recommended. We recommend that vegetation include
' woody plants, along with ground cover. All plants should be adapted for growth in semi-arid
climates with little or no irrigation. A landscape architect should be consulted in order to
develop a specific planting palate suitable for slope stabilization.
All slopes are subject to some creep, whether the slopes are natural or man-made. Slope
creep is the very slow, down-slope movement of the near surface soil along the slope face.
The degree and depth of the movement is influenced by soil type and the moisture
conditions. This movement is typical in slopes and is not considered a hazard. However,
it may affect structures built on or near the slope face. We recommend that settlement-
sensitive improvements not be located within 5 feet of the top of the proposed slopes
I unless specific evaluation of the condition is conducted by the geotechnical consultant.
8.5 Foundation Recommendations
These recommendations are considered generally consistent with methods typically used
in Southern California. Other alternatives may be available. The foundation
recommendations herein should not be considered to preclude more restrictive criteria of
governing agencies or by the structural engineer. The design of the foundation system
should be performed by the project structural engineer, incorporating the geotechnical
parameters described in the following sections. The following design parameters assume
that foundations will bear entirely on either bedrock or compacted fill materials and consider
an expansion potential in the moderate range.
8.5.1 Shallow Foundations
Allowable Soil Bearing: 2,000 lbs/ft2 (allow a one-third increase for short-term
wind or seismic loads)
I Minimum Footing Width: 12 inches
Minimum Footing Depth: 18 inches below lowest adjacent soil grade
Minimum Reinforcement: Two no. 4 bars at both top and bottom in continuous
footings.
Geotechnics Incorporated
Mr. Steve Gregory Project No. 0398-001-01
April 8, 1998 Doc. #8-0096
Page 11
I
8.5.2 Lateral Resistance: Lateral loads against structures may be resisted by
friction between the bottoms of footings or slabs and the supporting soil. A
coefficient of friction of 0.30 is recommended. Alternatively, a passive pressure of
350 Ibs/ft3 is recommended for the portion of vertical foundation members
embedded into compacted fill. If friction and passive pressure are combined, the
passive pressure value should be reduced by one-third.
8.5.3 Slope Setback: Foundations constructed near slopes should be deepened
as necessary so that the minimum distance between the outside bottom edge of the
footing and the slope face is 8 feet.
8.5.4 Settlement: Settlement resulting from the bearing loads recommended are
not expected to exceed 1 inch and three-quarters inch, respectively, for total and
differential settlements across the length of the proposed structure.
8.6 On-Grade Slabs
8.6.1 Interior Slabs: Building slabs should be supported by either bedrock or
compacted fill, prepared as recommended above. Slabs should be designed for the
anticipated loading. If an elastic design is used, a modulus of subgrade reaction of
200 kips/ft3 should be suitable. We recommend that a 5'h inch thick slab be used,
and reinforced with at least no. 3 bars at 18 inches on center, each way, placed at
mid-height of the slab. In addition, quality control measures should be provided to
limit the water-cement ratio to ACI standards, and to properly cure the concrete.
8.6.2 Moisture Protection for Slabs: Concrete slabs constructed on soil ultimately
cause the moisture content to rise in the underlying soil. This results from
continued capillary rise and the termination of normal evapo-transpiration. Because
normal concrete is permeable, the moisture will eventually penetrate the slab.
Excessive moisture may cause mildewed carpets, lifting or discoloration of floor tile,
or similar problems. The amount of moisture transmitted through the slab can be
controlled by the use of various moisture barriers.
To decrease the likelihood of problems related to damp slabs, suitable moisture
protection measures should be used where moisture sensitive floor coverings or
Geotechnics Incorporated
Mr. Steve Gregory Project No. 0398-001-01
April 8, 1998 Doc. #8-0096
Page 12
other factors warrant. The commonly used moisture protection in southern
California consists of about two inches of clean sand covered by "visqueen" plastic
sheeting. In addition, two inches of sand are placed over the plastic to decrease
concrete curing problems associated with placing concrete directly on an
impermeable membrane. It has been our experience that such systems will
transmit from approximately 6 to 12 pounds of moisture per 1000 square feet per
I day. If this is excessive for the slab usage, we can provide additional alternatives
upon request.
8.6.3 Exterior Slabs: As a minimal recommendation, slabs should be at least 5
inches thick and should be reinforced with at least #3 rebars on 24 inch centers,
each way (or alternatively 6" x 6"-W2.9 x W2.9 WWF). Crack control joints should
be placed on a maximum spacing of 5 foot centers for sidewalks, and 10 foot
centers, each way, for exterior slabs.
I 8.7 Expansive Soils
The soils observed during our investigation consisted primarily of low plasticity clayey sands
(SC), and sandy clay (CL). Laboratory testing of representative samples indicate that the
clayey soils on site have a moderate expansion potential, based on Uniform Building Code
criteria. Figure C-4 in the appendix summarizes the expansion test results.
8.8 Reactive Soils
Based on our experience with similar conditions, the sulfate content of the on-site soil or
groundwater is sufficient to react adversely with normal cement. Consequently, we
recommend that Type II cement be used in all concrete which will be in contact with soil.
8.9 Earth Retaining Structures
Backfilling retaining wall with expansive soil can increase lateral pressures well beyond
normal active or at-rest pressures. We recommend that retaining walls be backfilled with
soil having and expansive index of 20 or less. The backfill area should include the zone
defined by a 1:1 sloping plane, back from the base of the wall. Cantilever retaining walls
should be designed for an active earth pressure approximated by an equivalent fluid
Geotechnics Incorporated
I
Mr. Steve Gregory Project No. 0398-001-01
April 8, 1998 Doc. #8-0096
Page 13
pressure of 35 Ibs/ft3. The active pressure should be used for walls free to yield at the top
at least 0.2 percent of the wall height. For walls restrained so that such movement is not
permitted, an equivalent fluid pressure of 55 Ibs/ft3 should be used, based on at-rest soil
conditions with level backfill. The above pressures do not consider any surcharge loads or
hydrostatic pressures. If these are applicable, they will increase the lateral pressures on
the wall and we should be contacted for additional recommendations. Walls should contain
an adequate subdrain to eliminate any hydrostatic forces.
I Retaining wall backfill should be compacted to at least 90 percent relative compaction,
based on ASTM D1557. Backfill should not be placed until walls have achieved adequate
structural strength. Heavy compaction equipment which could cause distress to walls
should not be used.
9.0 LIMITATIONS OF INVESTIGATION
This investigation was performed using the degree of care and skill ordinarily exercised, under
I similar circumstances, by reputable geotechnical consultants practicing in this or similar localities.
No other warranty, expressed or implied, is made as to the conclusions and professional opinions
included in this report. The samples taken and used for testing and the observations made are
believed representative of the project site; however, soil and geologic conditions can vary
significantly between borings. As in most projects, conditions Tevealed by excavation may be at
variance with preliminary findings. If this occurs, the changed conditions must be evaluated by the
geotechnical consultant and additional recommendations made, if warranted.
I This report is issued with the understanding that it is the responsibility of the owner, or of his
representative, to ensure that the information and recommendations contained herein are brought
to the attention of the necessary design consultants for the project and incorporated into the plans,
I and the necessary steps are taken to see that the contractors carry out such recommendations in
the field.
Geotechnics incorporated
1 1 •
Mr. Steve Gregory Project No. 0398-001-01
April 8, 1998 Doc. #8-0096
Page 14
The findings of this report are valid as of the present date. However, changes in the condition of
a property can occur with the passage of time, whether due to natural processes or the work of
man on this or adjacent properties. In addition, changes in applicable or appropriate standards of
practice may occur from legislation or the broadening of knowledge. Accordingly, the findings of
this report may be invalidated wholly or partially by changes outside our control. Therefore, this
report is subject to review and should not be relied upon after a period of three years.
GEOTECHNICS INCORPORATED
Anthony F. Belfast, P.E. 40333 Kenneth W. Shaw, C.E.G.1251
Principal Project Geologist
O QPp F ES SOON
NY F. eF q
KENNM
~A- ~yC 1 SHAW
y co 4 0333 941 m .12519 CERTM
„~<<
EXPOcps, GEOLOqST
* * ~R
CIV I\-
OF C AO
Geotechnics Incorporated
t
APPENDIX A
REFERENCES
American Society for Testing and Materials (1992). Annual Book ofASTM Standards, Section 4,
Construction, Volume 04.08 Soil and Rock, Dimension Stone; Geosynthetics, ASTM,
Philadelphia, PA, 1296 p.
Anderson, J. G. , Rockwell, T. K., Agnew, D. C. (1989). Past and Possible Future Earthquakes
of Significance to the San Diego Region, Earthquake Spectra, Vol. 5, No. 2. pp 299-335.
Bowles, J. E. (1982). Foundation Analysis and Design, 3rd ed.: New York, McGraw Hill, 816 p.
California Division of Mines and Geology (1975). Recommended Guidelines for Determining the
Maximum Credible and the Maximum Probable Earthquakes California Division of Mines
and Geology Notes, Number 43.
' California Department of Conservation, Division of Mines and Geology, (1992), Fault Rupture
' Hazard Zones in California, Alquist-Pdolo Special Studies Zone Act of 1972: California
Division of Mines and Geology, Special Publication 42
' California Division of Mines and Geology, (1987), Landslide Hazards in the Rancho Santa Fe
Quadrangle, San Diego County, California: California Division of Mines and Geology, Open
File Report 86-15 LA
California Division of Mines and Geology, (1986), Landslide Hazards in the Encinitas Quadrangle,
San Diego County, California: California Division of Mines and Geology, Open File Report
86-8 LA
California Department of Conservation, Division of Mines and Geology, (1993), The Rose Canyon
Fault Zone. Southern California: Division of Mines and Geology, Open File Report 93-02
I California Division of Mines and Geology, (1982), Recent Slope Failures, Ancient Landslides, and
Related Geology of the North-Central Coastal Area, San Diego County, California:
California Division of Mines and Geology, Open File Report 82-12 LA
I Geotechnics Incorporated (1997). Report of Geologic Hazard Reconnaissance, Proposed
Residential Construction, 1.1 Acre Lot, Colony Terrace Access, Olivenhain Area, Encinitas,
I California, Project No. 0398-001-00, Doc. #7-0623, October 15, 1997
Geotechnics Incorporated
International Conference of Building Officials (1991). Uniform Building Code (with California
' Amendments) Title 23.
' Jennings, C. W., (1994), Fault Map of California: California Department of Conservation, Division
of Mines and Geology, California Geologic Data Map Series, Map No. 6.
' United States Department of Agriculture, (1953), Aerial Photographs, flight line AXN-8M-13 and
-14, stereo graphic pair, April 11, 1953
' Wesnousky, S. G. (1986). Earthquakes, Quaternary Faults, and Seismic Hazard in California:
Journal of Geophysical Research, v. 91, no. B12, p. 12587-12631.
I
1
I
' Geotechnics Incorporated
1
APPENDIX B
FIELD EXPLORATION
Field exploration consisted of a visual and geologic reconnaissance of the site, and the drilling of
t exploratory borings. Two borings were conducted using a 30-inch diameter, bucket-auger drill rig.
The maximum depth of exploration was 74 feet. The approximate locations of the borings are
' shown on the Geotechnical Map, Plate 1. Logs describing the subsurface conditions encountered
are presented on the following Figures B-1 through B-4.
' Relatively undisturbed samples were collected from bucket auger borings using a 3-inch outside
diameter, ring lined sampler (modified California sampler). Ring samples were sealed in plastic
' bags, placed in rigid plastic containers, labeled, and returned to the laboratory for testing. The
drive weight for ring samples from the telescoping kelley bar was approximately 3500 pounds with
' a fall of 30 inches. For each sample, the number of blows needed to drive the sampler 12 inches
was recorded on the attached logs under "blows per ft." Bulk samples were also collected from
auger cuttings at selected intervals. Bulk samples are indicated on the boring logs with shading,
' whereas ring samples with vertical bars.
' The borings were located by visually estimating and pacing distances from landmarks shown on
the Site Plan. The locations shown should not be considered more accurate than is implied by
' the method of measurement used and the scale of the map. The lines designating the interface
between differing soil materials on the logs may be abrupt or gradational. Further, soil conditions
at locations between the borings may be substantially different from those at the specific locations
' explored. It should be recognized that the passage of time can result in changes in the soil
conditions reported in our logs.
' Geotechnics Incorporated
' LO OF EXPLORATION BORING O. 1
Logged by KWS Date: 1128198
' Method of Drilling 30 Inch Bucket Auger Elevation: 245'
H U. -J J V e
a ? DESCRIPTION LAB TESTS
Uj a"
a 3 > z T
p
o m _3 o m o
TOPSOIL: Brown clayey sand (SC), fine grained, nonplastic, moist, soft
loose
2 Grain Size
' COLLUVIUM: Light green-yellow clayey sand, (SC) fine grained, mottled, Expansion
3 moist, loose to medium dense, with orange staining
4
1 103 19 Light green-yellow silty sand, (SM) fine grained, mottled color,
6 moist, medium dense, with orange staining
' 7
8
' 9
10
' 11 At 11' to 16': Irregular contact with inclusions of grey siltstone in
orange stained sand (SP), friable, moist, medium dense
12
' 13
14
' 15
2 100 9.2
16
' 17
18
' 19
20 Contact: N 40° E - 32° E
' DELMAR FORMATION: Light green claystone (CL), low plasticity, moist
22 hard, weathered with staining and sand inclusions
' 23
24
' 25 Grades to less weathered, some brown staining in green claystone
2 102 23
26
' 27
28
29
' Grades to siltstone and claystone, (MUCL), with fine sand, moist, hard
30
' PROJECT NO. 0398-001-01 GEOTECHNICS INCORPORATED FIGURE: B-1
' LO OF EXPLORATION BORING O. 1
Logged by KWS Date: 1128/98
' Method of Drilling 30 Inch Bucket Auger Elevation: 245'
h- U. -J J U e
W W d
' v a N N DESCRIPTION LAB TESTS
a. 3 > is p
O m G m p ~
' 31
32
' Light green silty and clayey sand (SM/SC), moist, dense, massive
33
34
' 35
36
' 37
38
' 39
40
' 5 106 18
41
42
' 43 At 43' becomes very dense, slow drilling
44
' 45
46 Light brown sand (SP) fine to medium grained, moist, dense, massive
' 47
48
' 49
50
t 51
52
' 53
54 Contact at 55' has heavy groundwater seepage, with light caving of sides
55
'
10 Li
ght green sand (SP) fine to medium grained, moist to wet, dense, massive
56
57
' 58
59
' 60
' 1PROJECT NO. 0398-001-01 GEOTECHNICS INCORPORATED FIGURE: B-2
' LO OF EXPLORATION BORING O. 1
Logged by KWS Date: 1128198
' Method of Drilling 30 Inch Bucket Auger Elevation: 245'
t- LL J J U e
W 1z
a N U) D DESCRIPTION LAB TESTS
a 3 > U)
Yi z
W m p
o m o~
' 61
62
' 63
64
' 65 Green clayey sand (SC), low plasticity, moist to wet, dense to very dense, massive
66
' 67
68
' 69
70
' 71
72
' 73
74
' 75 Total Depth 74 Feet
Groundwater at 54 Feet
76 Caving at 54 Feet
Backfilled 1/28/98
' 77
78
79
80
' 81
82
' 83
84
' 85
86
' 87
88
89
' 90
PROJECT NO. 0398-001-01 GEOTECHNICS INCORPORATED FIGURE: B-3
Amlkk
' Ldff OF EXPLORATION BORING O. 2
i Logged by KWS Date: 1128198
Method of Drilling 30 Inch Bucket Auger Elevation: 267'
W
h- U- J J LL a
W W d wW
' = a N DESCRIPTION LAB TESTS
a > -i z
W m o m c~
' rown clayey san tine grained, nonp as ic, moist, so
1 loose
Grain Size
2 DELMAR FORMATION: Light green clayey sand (SC), nonplastic, moist Expansion
' medium dense to dense Sulfate
3 3
Direct Shear
4
' 5
6
' 7
8
3 110 18
10 Light yellow-green silty sand (SM), nonplastic, fine to medium grained
' moist, medium dense to dense
11
12
' 13
14
Total Depth 13 Feet
' 15 No Groundwater
No Caving
16 Backfilled 1/28/98
17
18
19
20
21
22
23
24
25
26
27
28
29
30
PROJECT NO. 0398-001-01 GEOTECHNICS INCORPORATED FIGURE: B-4
li
' APPENDIX C
' LABORATORY TESTING
' Samples typical of the soils encountered were selected for laboratory testing. Testing was
performed in accordance with methods of ASTM or other,commonly accepted methods.
' Classification: Soils were classified visually according to the Unified Soil Classification System.
' Visual classification was supplemented by laboratory testing of selected samples and classification
in accordance with ASTM D2487-90.
' Particle Size Analysis: Particle size analyses were performed in accordance with ASTM D422-
63. The grain size distribution was used to determine presumptive strength parameters and to
' develop foundation design criteria. The results are provided in Figures C-1 and C-2.
Expansion Index: The expansion potential of a selected soil samples were characterized by
using the test method ASTM D 4829. Figure C-4 provides the results of the tests.
Sulfate Content: To assess their potential for reactivity with concrete, a representative sample
was tested for content of water-soluble sulfate minerals using CALTRANS method 417 (Part 1).
' The results are listed in Figure C-4.
' Direct Shear Test: The shear strength of the soil was assessed through a direct shear test
performed in accordance with ASTM D3080. The results are summarized on Figure C-3.
' Geotechnics incorporated
0
o
° CO
1 ° N ° p V
Z Z Z o o
J H H- x
' co O
W
CK =i m a M z U'
m U ° C LL
_a 1 z E
J ~ U U
a CL N
g o ~
a a
O
O
D
z }
v a g
' d J U
o co
v
2
' Z
o V C
' C 0-
V N O
J
O U. N U
y y v
C
`y co
' Q p L
E W J C
z V d ~
ooLO
~ ~ J O O
J
N z N vI
C ~ O
C%) O }
CD 0
>
S zz a a
Q U N
v ~ N
1
N
5
w °
~ J O
G a
W W V ~
' Cd
~ O
O
° W U
' LUz o
J W O
H
< Z U
O
W z J
U) 0 -i (L
o Q
' a d
a o <
N J
CL
' x
0
0 0 0 0 0 0 0 0 0 0 0
o rn ao n t0 LO Itt th N
r-
o
o
r-
O co N
O ~ ~
r
Z Z Z 09 9 Lu
-_j X 00
w 0)
o Z O
W U Z O G LL
W 0 U Z 6 CD
E
3 ~
a a 'n m o
a
Mir
o
0
0
Z
a g
E ~ U
Z
F- 0)
Q C O
~ J U ~ W
O LL c4
07 ~ ~ C
a O A
_ w j rn c
LL 2
vo,
J O O
c O
/7 1 co
N_ fn
N o
(D O
To C Z Q Q
U )m
U
v C7 co ~i
w
g
w v
0
c a v
w v
U co
iE: z
O G
U ~ O
^
• r•I n
° w U
U
co
fV
v ~
w O Q
zL v
w" Z° U
J
Q O CL
a
o a o
w a
x
O w
0
O rn o°o 0 c°n Lnn °v a N ° °
t
1 y 8000 ~
a ,
y 6000 , , ■
1 W
4000 ■ ■ ■
U) in ~ ■ EMN
2000 ■ ■o
1 soon ■s■ l
z o ■
1 0.0 2.0 4.0 6.0 8.0 10.0 12.0 14.0 16.0 18.0
STRAIN
' 8000
s
' 7000
• ULTIMATE SHEAR:
' 6000 ■ PEAK SHEAR:
' U.
5000
W
' X 4000
U)
Q
' = 3000
•
2000
1000
0 1000 2000 3000 4000 5000 6000 7000 8000
0 _I
NORMAL STRESS [PSF]
SAMPLE: B2 @ 3' PEAK ULTIMATE
DEL MAR FORMATION (TM Pale V
56 ° 25 °
olive fine grained clayey sandstone (SC) C. 2,400 PSF 800 PSF
IN-SITU AS-TESTED
{ STRAIN RATE: 10.0010 IN/MIN yd 109.2 PCF 109.2 PCF
1 (Sample was consolidated and drained) w, 14.6% 14.7%
I A _G e o t e c h n i c s DIRECT SHEAR TEST RESULTS Project No. 0398-001-01
I n c o rp o r a t e d Colony Terrace Document No. 8-0096
Mr. Steve Gregory FIGURE C-3
As~
i
EXPANSION TEST RESULTS
(ASTM D4829)
SAMPLE EXPANSION t1I
B-1 @ 2' 59
' B-2 @ 2' 45
UBC TABLE NO. 29-C, CLASSIFICATION OF EXPANSIVE SOIL
EXPANSION INDEX POTENTIAL EXPANSION
' 0-20 Very low
21-50 Low
' 51-90 Medium
91-130 High
Ahoyp 1.1n
' SULFATE
CONTENT TEST RESULTS
(Caltrans Test Method 417)
' SAMPLE SULFATE CONTENT
(PPM)
' B-2 @ 2 ft. < 200
'
Adft-
_G e o t e c h n i c s Laboratory Test Results Project No. 0398-001-01
Incorporated Gregory Residence Document No. 8-0096
k
Olivenhain, California Figure C-4
DF2#Mk I IMAGE STUDY
LAKE?--
F ES I DERJCE
F= "n I_MT 28 8 F='OFZ
(APN# 259-210-0900)
COLONY TERRACE
ENCINITAS, CA.
1/211~~
-REV. G//3-/00
S 114-1 ° o
~o,?,of ESSjp y9
STUT
E
PREPARED BY:
0% No. C 33598
Exp.6-30-OL z
~tv». mss'
Grading/ Land Division' EQ~
Improvement Plans Septic Systems pf Cam`
CAD Drafting
Wayne Stutzman Engineering
Civil Engineering & Land Surveying
WAYNE STUTZMAN
Property Line Location RCE #33598
Elevation Certificates 2441 Sacada Circle
Ph./Fax (760) 943-0509 Carlsbad, CA. 92009
I IV ]E> E x
I
PBS.
DRAINAGE LETTER O
DRAINAGE BASIN AREA AND 0100 1
GRATED INLETS CAPACITY 1,2
DRAIN PIPE CAPACITY 3
EARTHEN CHANNELS BASIN AREAS AND Q140'S 3A
EARTHEN CHANNELS VELOCITIES 3B
EARTHEN CHANNELS VELOCITY WORKSHEETS 3C,3D
ISOPLUVIALS 415
SOIL TYPE COEFFICIENT b
INTENSITY-DURATION CHART 7
DRAINAGE AREA MAP 8
DRAINAGE LETTER
WAYNE STUTZMAN ENGINEERING
2441 SACADA CIRCLE
CARLSBAD, CA. 92009
Ph./FAX (760) 943-0509
1/21/99
PROJECT: gaq. 6/13 I~
LAKE -6RE88R-'- RESIDENCE
PD 2 LOT 28 8 POR. APN# 259-210-0900
COLONY TERRACE
ENCINITAS, CA.
THE SUBJECT PROJECT IS A 1.1 ACRE VACANT LOT ON THE SOUTH SIDE OF
COLONY TERRACE, OFF MANCHESTER AVENUE. THE SITE SLOPES GENTLY TO
THE NORTHEAST. PROPOSED CONSTRUCTION CONSISTS OF A MUTLTI LEVEL,
SLAB ON GRADE HOUSE, WITH TERRACED LANDSCAPING ON THE HIGH,
SOUTHWEST PORTION OF THE LOT, AND A GARDEN PAD AT THE LOWER,
NORTHEAST CORNER OF THE LOT. PROPOSED OVERALL LOT CONFIGURATION
(DRAINAGE) WILL REMAIN UN-CHANGED WITH ALL ONSITE RUNOFF TOWARDS
THE NORTHEAST.
THANK Y
WAYN TUT MAN
RC 3359
gr°egor°y. 7. tr-
" P6rF- l
R~~ . ~ I t~ ~ oo w~ s
oN s ITS OQAI NAG CCU I N A~2EA A o
Zl. 1 ~ 0.73 x 30~-/43,5~0 = o. 3Z ~cE2~
~l U D
~ S l L T `rPE C7" CO N S e2 V AT lVi7-
T1 _ to
Q goo = G~ Z ioo =
c~~G(~ G PAG tiT` O
A _ ~ F rN L~Z"~
o.33" 4" ATE?lvM YA2C_ IDlzal J J _
Q CAP = (A) 5.37 (H _ x o,332 a
4 = -o
A= 0,.0.43 S,F,
DEPT-( o~ v~l4T~~
+ -
o~~~1TE Z" = 0,17
S1PLl fi`t' ~NrYSI) Fl t2
11 i<-l LE T !~-D O l STi26U TE7C) T14,2ou6rgov T
~AS1N.
t
PG E ~
G(C____!m LET _APAGI ~TY - coN T - -
1 _ PA t_-rY W t-ET
-:5) -5-7
TE
CAC -r`ee _ 12 ~ 50 G-r12~ 7- E-=7 ._.1_ E_L T._.
> 4 X71 221 ~ ~ LET
Circular Channel. Analysis & Design
Solved with Manning's Equation
Open Channel. Uniform flow
LA (GE
Wor° k:shieet Name: "RE&RRV- RES I DENC: E
Comment: GREGORY RESIDENCE. 1 /21 /99 014
Solve For Fill Flow Capacity
Given Input: Data:
Diameter.......... 0.33 ft
Slope 0.0100 ft/ft
Manni.ng's n....... 0.012
Discharge......... 0.20 cfs
Computed Results:
Full Flow Capac::i.ty..... 0.20 cfs
Full Flow Dep•t_h........ 0.33 ft
Veloci.ty.......... 2.35 fps
Flow Area......... 0.09 sf
Critical Depth 0.25 +t
Critical Slope.... 0.0114 ft/ft
Percent Full 100.00 %
Full Capacit.y..... 0.20 cfs
AMAX @.94D........ 0.22 cfs
Froude Number FULL.
FINED G~1P~lC(T~~ oF 0/q. PV F ~
7 4-
~vN SECZ~I ~Tt v xLVj A Lis 1 - PL_ 4N
FOB LO P~ 0 7 I ° ~p
CA 4 it PNJ G Ca 2°/o N>-
Open Channel Flow Module, Version 3.16 (c) 1990
Naest.ad Methods, Inc„ * 37 Brookside Rd * Waterbury, Ct 06708
A~2~A
4. S ~0-7~~ oz~43,S~o = 0-0-7 4c-2-
o,-7~ 7<z~q 56 d= e,d 4. C-r-
C-~ A f2
D F / f d d Q t do = Z r ot_
o-sue ~c 4-Z1 ~ ~ _
A 12~-~A - lbo = 2 3ZX D j = O. t Z GAS
A2 e - ion = 2.3Z, d,d = O-~7 ci=
r" 0 CD
14-
a
~l 9LOG lT
F~(/ r-- o P C 1~1
N TG-: C 1-EOV~l
G ~1 N lL 1~~ r~~v LT C,~ F- AP
G 1-1/a tit ~ L l 1~l q FLU ~ f ~ L ~I 1Ta---I sv-,1` ~ b
b N 13Q T 7-0 ~ f1 w C~) C-r 1.20 L,-) T4 b F:::
GT - I? A Nl A I-l of
~T-
Sc,c~ l~~ I3As1t~ DZ~~ Sd = Z~% = c~.Z~
~ ~ Val 01=z IC ~ N ~ ~ T
= 3. ~ FPS C ¢ FPS C-~nO~ c~
G 1-4 Q e
13~~11~1 D~ J ~o = l7 °(0 = d. 17
c::11. (arl~:ta y~.1.
C:) r') r'1 I°1 ~•1 r•1 r'1 i~i? :I. l..i r•1:i. ~f r rn ~f~ :i. {:a w PU E- 3 ~
W t::3 r° I•~: ~~s P•1 ~ ~ ~ ICI <::; rrr k:?? L... (11 G~: 1=t (1 E::3 :I: ICI x:)';:'
t.., {a m m e.? 1'•1
t:?) i. v r•1 :f. r•11.) (..('t:. )r) t:.
B(::)t:.t:.c:)(r) Wi.(::1t:.1°1» » » „ » tiC3 f t
t... 1 r I..i t V)
0 1. O d V)
r" i:7 C:) „ C)'7 'f
i (::3 (Y? 1::) l.!. 't`. ti::' (::I 1"l (•ii? ?iii l..l .I. 't:. Siii
F= :I. (:°,w c.) 1::) WI, t:i't:. I°;
W t:, t E, t:a P c::?!'° :'s. rll c t r° „ C:3 » .46 f •t:.
r°:i. t:.:i. ) } (i'31:7 t°. I-3 •f: t
t.,.
t::. f fi:. /
I'° a. •t.. a. (::31::3 t;:? » )
\ , 5 6 (f 1. r) w i 4 > S ut F:') r• r a •I. )
t::)raer'1 t'I°1<:1r•1r•3ci l c::)w lylt::)c::l(..(1.(;: , Vr^rr'; aca 1.99f:)
? <:1
l..f < , to < .I ca M F:a'l I°3 c:3 r:(r:~ :I: r'} t::: „ ?t °.;'7 X::(rr::) o k: s i. c_i e F:*' (J jh W a t:. t; _ to t..t r,y, „ C; •I::. 0 67
L -
I., P' z :I. (:i i21.1 i l I'1 I"r F=.' .I r=11"1 iel .L V (iii :I. Gii X.; r <i?i a. O f'1 v~ ,
C:) C:hIaI.-I r)( :I. In 1. f ciI,--m f :Lc:)w
1, N -f} ?
r')~.. ^ 1.._AIi+la:::~:I:l~l
c:) In W :i. cl t:. I°) . „ ~ „ . c) „ O O + t.
I....e•:t. Si(:iF, 1.c)N•)„ (I.A. V)
Right. S] 1. { M°I ; V )
C: I..) r1 I) r') Fi' ,I. E):[ I::) Fi' „ • „ f: 1:.
C)„:1.6 f
r.:)m1::)I.,•t:.ecl F, <.->I..(1. t.
V ( :I. c: i, 't:. y 5C.) I-.)
Fw 1. n w '1' (')1::) W i. c:i t. I") „ „ „ O ~ Fa O f t.
WF;rl'.:'l (aca P r :i. rr)F? l'°. e; I'° . C> „ 6.4'1 f 't:.
C,r° :i. 'c i, 1) e 1::)'t:.1..) 1. f t.
t:
.t. caw J. ti r..: a L )
I°) c:a w I°'i c:) ca L.I :I. V r° :i c:) r) :1. e5 1. 99
I f is c: s:a t.::.k c:I h1 r I°) (::I s J. I..) c- X::r r° c:) k < J. c..1 k.:, R, ?F W <:a 'I-. F ! r" L:) i r...~
3-IX XI4H3ddtl S8/I Pasi~ L A ~L • P~~ -
N
> 1
r-
N
H
O > 'T1 v l-1 \
m-r rmo
NO ooac
> C 3
nny ornp
zirv -z-~-n
.0 a
o r-- 'on z
nz~ Nv
w
o 00 D .-t
O V1
Y > v z m
O --1 O
Gb ,A N o I I ~
O Ft
r='n O
C) n Z
-C 0
> a 'z q n -
Z n r
Px Z a
O
M
M o >
w H
Q ..ice z r ` , w~
~o( ~w 1 ti r
7 COO CD
r7l
IWO
p
a ~ / lam"' ~ i ~ j ~~•~•y ~ t~~
J =I . ~ c~'n , la ~ ~ "'rcn•- /rte ~ ~ ~ Cam' y
CID
L. ~
I / 1
15-
I F i ~j
z7 ~o
` I1 IA A.LU&%"VUY
emu, • • a
m
n
r
• N
-I
cz
-nocl)
rnq rmo
m Z w o> z
~ r
p N C-)
C n o m o
mo x- w -n
0 0.>> ro v, G o v,
N
~n> - - - - ooa
n > r-n z
p. o ~ Z N v
> >
o I -I o
- _..0~0~ I I I I I
-t
C) ^ n O
~n0 z
> F 3 z
Y
r
i xl ~ n
Ulf > v+ n I 3 _
r z C7 r^
> .Zr co
• R 'i m o
co I'd
.J p1 fS~ -C_ a•
r7l
_
- r
_ N L m a
10
rri
C= C.3 N
1 V o /r mss,,
n CD
~ mr
00 ai Oo r L,,,1,~ a +
L„ , ; . + -
WON SHT OF
CALL DATE CHKO DATE
STATION AREA REFERENCE I too
.057 (50 scale)
AREA x .918 (200 scale) - ACRES
91.8 (2000)
COEFFICIENT OF RUNOFF: C (consider probable development)
Developed Areas (Urban) Coefficient "C"
Land Use L T'i 1~E
Residential: A 8 C 0
Single Family .40 .45 .50 .55- • 5S
Multi-Units .45 .50 .60 .70-
Mobile Homes .45 .50 .55 .65-
Rural (lots greater than
1/2 acre) .30 .35 .40 .45-
Commercial (2)
80% Imperviious .70 .75 .80 .85-
Industrial (2) -
90% Impervious .80 .85 .90 .95-
- 0,55
C
CA -
TIME OF CONCENTRATION Tc •Tc,r11,g(0)] yes
(chart -1) Il H J
HI:Pt. H. Tc - Time in Hours
L - Distance In Miles
Lo.Pt. L. H - Height in Feet
*Add 10 minutes to computed
Tc - min hr time of concentration
(10 min. minimum)
RUNOFF: 0 I x CA
I - "/hr cis USE d - .CFS
X -M
110 - CA cis USE 010 - CFS
Reference: San Diego County Flood Control Design and Procedure Manual.
(1) Obtain soil type from Soils Conservation Service
q4mcm)iLy t7ncnesj IIOUP) )2~
r AA niutraaav S8/1 PaSTAaE
C b 'A of L w ie V, f ! r P t+ P r P
r I I I I I~ t t jl i~ 1 1 1 1 ! I 1
- -J I •1 is t 1 1 I t ~ 1' 117 111.
1 j j' 1 .1. . 1 .1 '1 ' •~1• _ _
till
CD or
~ t7 b 1-1 ►-t
- - _ n a n n
I •I I 11 I ill .j 1 I •ii - - , ~ 1 •I 7 1 rt •O
N 111' i.l I l L j 1 1 7 ul '
,.1i,. 7 t 1 i 1 I r I f! ►i rf -i
is. t.l. I OR
I 1 ! 1 . 1 1 1 0.1! N• b J1 N
fill
'Co
N N W W -P A tJ 1 to Q1 y
O to O to c, to O to O to O T3
(sayOU L) uO L4e4 id LOa-1d A nOH-g
x (n
A W N - O A to p.- W N O U
v v v v v 't? v v. v v J.
~ [D
•-•1 Cf n -p N Cf --I 'O O 0-0 e+ e+ e+ } O 3 -•-1 N '►1 n
n d 0% o 0 S S "S O ==M m a S .A -S r+
n Cr. --A a M O a Q (D a V. to O YD O J.
11 C 11 CD r+ N c+ :E e+ e+ C) e+ c --.C to S O
y n J• t"+ S fD N to tD a fD '"S O
t+ e+ O O M a fD tT to .P ct 7 N
* (D N (D o n J. 07. fD r+ a -S
G C3. 11 a O --m n O- -s S a% a~ a a rD
a Ol J. m '3 (A m e+-a •p ~ -0 a = J. a
D 11 O ..O • • to t-+ 'T 'S -S C1 'S c+ t•+ "a
C tT r+ O- (D tD r t--z O C.) fl) N a -fl
CD CD o 'S n n S 'S 0 r+
J. J. J. (D O J. J. J. CO fD a -O -1h J. J.
0 -0
1 tc to c a a
tT ? A S t+ c+ et t7 -S r+
= t1 a r+ a a = J. tD -1 t+ t+ M
(D as = CD V+ C+ m - cD a 3 o a. m -0 =
O to fD o o -S t+ a ~ to
C J. : a J. O J• tR
N c+ "C7 O O C 'S O fD m
O O fDl O
I 7 fD r+m t+
tZ
n v
(D + .S C (D
e+ r+ O N m C+
.S O c O -h -h -.1 (D
c+ "C -t7 a -O m e+ N C) O.
.+.jV ltT e+ a p O O O
• (D O A II ~j Ln (D -h fD
O a 7 bt n 7. O -S
9D 0 (D m
J -1
O f) (D c r O to c C S
3 J
Pt t) tT cm ON CD lic =3 -
J.
Ln d G n
v O Q ~ t .S a
fD CD fD O to O Q
C -h
O Jo 0 -+10 `0
C
rn
RE\!• I 14
co V"4
\ ~ a
\ \ 1( \ \ o-..,~,a O I,
-41
d \ `a
~ a
m
1 i
i III \ 1 \ \ \p~ \ ~ \Gp~ \ , \ \ \ \ \ F ii 1` I ~a i\\
14
\11 \ \
1
i
A 111 Q \
I ~II of \ S 1 \1 \ \ \ , \ ` j1. l \ x A
A CD
4
$Z\ I \ \ \ \ \ ,pro 0 U I
\ \ \
(<:D rr
SAIL TESTERS"
P.O. Box 1195
Lakeside, California 92040
September 14, 2000 (619) 443-0060
(619) 443-0933 Fax
Chad Lake
2307 Perraza Ribera
Carlsbad, California 92009
Subject: File No. 10058 ti
2 5
Transfer of Geotechnical Responsibiily
Proposed Residential Building Site
Colony Terrace
Encinitas, California
Dear Mr. Lake:
We have reviewed the Geotechnical Investigation dated April 8, 1998, by Geotechnics
Incorporated and agree with the recommendations therein. We are assuming
geotechnical responsibility for the preparation and placement of the fill during grading
per the previously referenced report.
If you have any questions, please do not hesitate to contact our office.
Respectfully submitted, Q~pffssl
o C.
o y
No. 21.650
* Exp. 9130/01
J eph C. Smyth, RCE 21650 sr CMV
qrF OF CA~~~
JCS/ss
NoText