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1999-5970 G Street Address Category Serial # Name Description Plan ck. # Year ENGINEERING SERVICES DEPARTMENT C ity Of Capital Improvement Projects District Support Services Encinitas Field Operations Sand Replenishment/Stormwater Compliance Subdivision Engineering Traffic Engineering October 10, 2000 attn: Gerry H. Veal Rancho Santa Fe National Bank P.O. Box 2388 Rancho Santa Fe, CA 92067 Re: Tract 97 -100 "Double LL Ranch NW-1Y #2: Lot 2" Grading Permit 5970GI {3472 Cl Margarita / Margarita LLC A.P.N. 264- 241 -09 -00 Final release of security Permit 5970GI authorized earthwork, storm drainage, single driveway, and erosion control, all needed to build a single family dwelling within the named subdivision. Final Inspection has been completed to the satisfaction of the Field Operations Division. Therefore, release of the security deposit is merited. Assignment of Loan 4003012 -60, in the initial amount of $22,436.00 and since reduced to $5,609.00, has been cancelled by the Financial Services Manager and is hereby released in its entirety. The document original is enclosed. Should you have any questions or concerns, please contact Jeff Garami at (760) 633 -2780 or in writing, attention this Department. Sincerely, Greg Shields 4eslie Suelter Senior Civil Engineer cial Services Manager Field Operations Financial Services cc Leslie Suelter, Financial Services Manager Margarita LLC, Property Owner (point of delivery) enc PGS/ rtb/ jsg/f:grading/ginew /gi5970f.doc 1 TEL 760- 633 -2600 / FAX 760- 633 -2627 505 S. Vulcan AvcnL[C, Encinitas, California 92024 -3633 TDD -60- 633 -2700 41Q.' recycled paper PE 817 HYDROLOGY /HYDRAULICS REPORT FOR: ROBERT MUELLER CONSTRUCTION 415 SOUTH CEDROS, STE. 250 SOLANA BEACH, CA 92075 (619) 991 -4498 APRIL 16, 1999 PREPARED BY: PASCO ENGINEERING, INC. 535 NO. HIGHWAY 101, SUITE A SOLANA BEACH, CA 92075 (619) 259 -8212 QP 0 - 0 1 0 - A. p,,gs00���% 2 w N0.29577 rn °C Exp. 3/31/03 civic � cA��� °Q �✓ e 9� WAYNE PASO RCE 29 7 REGISTRATION EXPIRES TABLE OF CONTENTS I. INTRODUCTION ..... ..............................1 II. DISCUSSION ....... ..............................1 III. CONCLUSION ....... ..............................1 IV. HYDROLOGY CALCULATIONS .......................2 -8 V. HYDRAULICS ....... ...........................9 -12 VI. APPENDIX ......... ..........................13 -20 VII. EXHIBITS ......... ..........................21 -23 PE 817 I. INTRODUCTION THE PURPOSE OF THIS REPORT IS TO ADDRESS THE IMPACTS OF STORM WATER RUNOFF ON THE PROPOSED SINGLE FAMILY RESIDENCE GRADING PLAN FOR MR. ROBERT MUELLER, LOCATED AT THE NORTH END OF CALLS MARGARITE IN OLIVEHAIN. BASED ON THE INFORMATION AND CALCULATIONS CONTAINED HEREIN, RECOMMENDATIONS WILL BE MDE TO ADEQUATELY DESIGN AND SIZE A STORM DRAIN SYSTEM ADEQUATE TO INTERCEPT, CONTAIN AND CONVEY Qioo TO APPROPRIATE POINTS OF DISCHARGE. II. DISCUSSION THE SUBJECT PROPERTY IS KNOWN AS APN 264 - 241 -09, AND IS PHYSICALLY LOCATED AT THE NORTH END OF CALLE MARGARITE IN OLIVENHAIN. IT SITS WITHIN 50 -75 FEET HORIZONTALLY FROM A RIDGE LINE THAT DEFINES THE LIMIT OF THE DRAINAGE BASIN. REFER TO EXHIBITS "A" & "B" FOR THE LIMITS OF THE DRAINAGE BASIN, AND DESIGN NODE LOCATIONS USED IN THE HYDROLOGIC AND HYDRAULIC CALCULATIONS HEREIN. III. CONCLUSIONS IT IS THE PROFESSIONAL OPINION OF PASCO ENGINEERING THAT THE DRAINAGE SYSTEM AS DESIGNED AND DEPICTED ON THE CORRESPONDING GRADING PLAN WILL FUNCTION AS DESIGNED, AND IS ADEQUATE TO INTERCEPT, CONTAIN AND CONVEY Qloo TO THE DISCHARGE POINTS SHOWN ON THE ABOVE PLAN. —1— IV. HYDROLOGY CALCULATIONS -2- ********************************************* * * * * * * * * * * * * * * * * * * * * * * * * * * * * * ** RATIONAL METHOD HYDROLOGY COMPUTER PROGRAM PACKAGE Reference: SAN DIEGO COUNTY FLOOD CONTROL DISTRICT 1985,1981 HYDROLOGY MANUAL (c) Copyright 1982 -92 Advanced Engineering Software (aes) Ver. 1.3A Release Date: 3/06/92 License ID 1388 Analysis prepared by: Pasco Engineering, Inc. 535 North Highway 101, Suite A Solana Beach, CA 92075 Ph. (619)259 -8212 Fax. (619)259 -4812 * * * * * * * * * * * * * * * * * * * * * * * * ** DESCRIPTION OF STUDY * * * * * * * * * * * * * * * * * * * * * * * * ** * 100 YEAR HYDROLOGY ANALYSIS - MUELLER /CALLE MARGARITA * PE 817 * SEE EXHIBIT " A " FOR OFFSITE DRAINAGE AREA AND EXHIBIT * "B" FOR ONSITE DRAINAGE AREAS. * 4 -14 -99 MS ******************************************* * * * * * * * * * * * * * * * * * * * * * * * * * * * * * ** FILE NAME: 817.DAT TIME /DATE OF STUDY: 10: 2 4/15/1999 ---------------------------------------------------------------------------- USER SPECIFIED HYDROLOGY AND HYDRAULIC MODEL INFORMATION: ---------------------------------------------------------------------------- 1985 SAN DIEGO MANUAL CRITERIA USER SPECIFIED STORM EVENT(YEAR) = 100.00 6 -HOUR DURATION PRECIPITATION (INCHES) = 2.900 SPECIFIED MINIMUM PIPE SIZE(INCH) = 4.00 SPECIFIED PERCENT OF GRADIENTS(DECIMAL) TO USE FOR FRICTION SLOPE _ .95 SAN DIEGO HYDROLOGY MANUAL "C"- VALUES USED NOTE: ONLY PEAK CONFLUENCE VALUES CONSIDERED ********************************************* * * * * * * * * * * * * * * * * * * * * * * * * * * * * * ** FLOW PROCESS FROM NODE 1.00 TO NODE 2.00 IS CODE = 21 ---------------------------------------------------------------------------- >> >>> RATIONAL METHOD INITIAL SUBAREA ANALYSIS<< <<< ---------------------- -------------- SOIL CLASSIFICATION IS "D" RURAL DEVELOPMENT RUNOFF COEFFICIENT = .4500 INITIAL SUBAREA FLOW- LENGTH = 285.00 UPSTREAM ELEVATION = 335.00 DOWNSTREAM ELEVATION = 328.70 ELEVATION DIFFERENCE = 6.30 URBAN SUBAREA OVERLAND TIME OF FLOW(MINUTES) = 15.163 100 YEAR RAINFALL INTENSITY(INCH /HOUR) = 3.736 SUBAREA RUNOFF(CFS) _ .81 TOTAL AREA(ACRES) _ .48 TOTAL RUNOFF(CFS) _ .81 ********************************************* * * * * * * * * * * * * * * * * * * * * * * * * * * * * * ** FLOW PROCESS FROM NODE 2.00 TO NODE 5.00 IS CODE = 3 ----------------------------------------------------------------- - - - - -- >> >>> COMPUTE PIPEFLOW TRAVELTIME THRU SUBAREA<< <<< >> >>>USING COMPUTER - ESTIMATED PIPESIZE (NON- PRESSURE FLOW)<< <<< ----------------- - - - - -- DEPTH OF FLOW IN 6.0 INCH PIPE IS 3.7 INCHES PIPEFLOW VELOCITY(FEET /SEC.) = 6.4 UPSTREAM NODE ELEVATION = 326.70 DOWNSTREAM NODE ELEVATION = 322.00 FLOWLENGTH(FEET) = 125.00 MANNING'S N = .012 ESTIMATED PIPE DIAMETER(INCH) = 6.00 NUMBER OF PIPES = 1 PIPEFLOW THRU SUBAREA(CFS) _ .81 TRAVEL TIME(MIN.) _ .33 TC(MIN.) = 15.49 ********************************************* * * * * * * * * * * * * * * * * * * * * * * * * * * * * * ** FLOW PROCESS FROM NODE 2.00 TO NODE 5.00 IS CODE = 1 ---------------------------------------------------------------------------- >> >>>DESIGNATE INDEPENDENT STREAM FOR CONFLUENCE<< <<< ------------------ - - - --- TOTAL NUMBER OF STREAMS = 2 CONFLUENCE VALUES USED FOR INDEPENDENT STREAM 1 ARE: TIME OF CONCENTRATION(MIN.) = 15.49 RAINFALL INTENSITY(INCH /HR) = 3.68 TOTAL STREAM AREA(ACRES) _ .48 PEAK FLOW RATE(CFS) AT CONFLUENCE _ .81 ********************************************* * * * * * * * * * * * * * * * * * * * * * * * * * * * * * ** FLOW PROCESS FROM NODE 15.00 TO NODE 5.00 IS CODE = 21 ---------------------------------------------------------------------------- >> >>>RATIONAL METHOD INITIAL SUBAREA ANALYSIS<< <<< ---------------------- ----------- SOIL CLASSIFICATION IS "D" RURAL DEVELOPMENT RUNOFF COEFFICIENT = .4500 INITIAL SUBAREA FLOW - LENGTH = 160.00 UPSTREAM ELEVATION = 327.80 DOWNSTREAM ELEVATION = 322.00 ELEVATION DIFFERENCE = 5.80 URBAN SUBAREA OVERLAND TIME OF FLOW(MINUTES) = 9.634 *CAUTION: SUBAREA SLOPE EXCEEDS COUNTY NOMOGRAPH DEFINITION. EXTRAPOLATION OF NOMOGRAPH USED. 100 YEAR RAINFALL INTENSITY(INCH /HOUR) = 5.005 SUBAREA RUNOFF(CFS) _ .81 TOTAL AREA(ACRES) _ .36 TOTAL RUNOFF(CFS) _ .81 ********************************************* * * * * * * * * * * * * * * * * * * * * * * * * * * * * * ** FLOW PROCESS FROM NODE 15.00 TO NODE 5.00 IS CODE = 1 ---------------------------------------------------------------------------- >> >>>DESIGNATE INDEPENDENT STREAM FOR CONFLUENCE<< <<< >> >>>AND COMPUTE VARIOUS CONFLUENCED STREAM VALUES<< <<< ------------------- ---------------- TOTAL NUMBER OF STREAMS = 2 CONFLUENCE VALUES USED FOR INDEPENDENT STREAM 2 ARE: TIME OF CONCENTRATION(MIN.) = 9.63 RAINFALL INTENSITY(INCH /HR) = 5.00 TOTAL STREAM AREA(ACRES) _ .36 PEAK FLOW RATE(CFS) AT CONFLUENCE _ .81 r 6 ** CONFLUENCE DATA ** STREAM RUNOFF Tc INTENSITY AREA NUMBER (CFS) (MIN.) (INCH /HOUR) (ACRE) 1 .81 15.49 3.684 .48 2 .81 9.63 5.005 .36 RAINFALL INTENSITY AND TIME OF CONCENTRATION RATIO CONFLUENCE FORMULA USED FOR 2 STREAMS. ** PEAK FLOW RATE TABLE ** STREAM RUNOFF Tc INTENSITY NUMBER (CFS) (MIN.) (INCH /HOUR) 1 1.40 9.63 5.005 2 1.40 15.49 3.684 COMPUTED CONFLUENCE ESTIMATES ARE AS FOLLOWS: PEAK FLOW RATE(CFS) = 1.40 Tc(MIN.) = 9.63 TOTAL AREA(ACRES) _ .84 ********************************************* * * * * * * * * * * * * * * * * * * * * * * * * * * * * * ** FLOW PROCESS FROM NODE 3.00 TO NODE 4.00 IS CODE = 21 ---------------------------------------------------------------------------- >> >>>RATIONAL METHOD INITIAL SUBAREA ANALYSIS<< <<< --------------------- ------------ SOIL CLASSIFICATION IS "D" RURAL DEVELOPMENT RUNOFF COEFFICIENT = .4500 INITIAL SUBAREA FLOW- LENGTH = 240.00 UPSTREAM ELEVATION = 340.00 DOWNSTREAM ELEVATION = 327.00 ELEVATION DIFFERENCE = 13.00 URBAN SUBAREA OVERLAND TIME OF FLOW(MINUTES) = 10.321 *CAUTION: SUBAREA SLOPE EXCEEDS COUNTY NOMOGRAPH DEFINITION. EXTRAPOLATION OF NOMOGRAPH USED. 100 YEAR RAINFALL INTENSITY(INCH /HOUR) = 4.788 SUBAREA RUNOFF(CFS) _ .60 TOTAL AREA(ACRES) _ .28 TOTAL RUNOFF(CFS) _ .60 ********************************************* * * * * * * * * * * * * * * * * * * * * * * * * * * * * * ** FLOW PROCESS FROM NODE 15.00 TO NODE 16.00 IS CODE = 21 ---------------------------------------------------------------------------- >> >>>RATIONAL METHOD INITIAL SUBAREA ANALYSIS<< <<< ---------------------- ------------------ SOIL CLASSIFICATION IS "D" RURAL DEVELOPMENT RUNOFF COEFFICIENT = .4500 INITIAL SUBAREA FLOW - LENGTH = 190.00 UPSTREAM ELEVATION = 327.80 DOWNSTREAM ELEVATION = 323.80 ELEVATION DIFFERENCE = 4.00 URBAN SUBAREA OVERLAND TIME OF FLOW(MINUTES) = 12.584 100 YEAR RAINFALL INTENSITY(INCH /HOUR) = 4.213 SUBAREA RUNOFF(CFS) _ .59 TOTAL AREA(ACRES) _ .31 TOTAL RUNOFF(CFS) = 59 �D FLOW PROCESS FROM NODE 16.00 TO NODE 6.00 IS CODE = 3 ---------------------------------------------------------------------------- >> >>> COMPUTE PIPEFLOW TRAVELTIME THRU SUBAREA<< <<< >> >>>USING COMPUTER - ESTIMATED PIPESIZE (NON- PRESSURE FLOW)<< <<< DEPTH OF FLOW IN 6.0 INCH PIPE IS 2.9 INCHES PIPEFLOW VELOCITY(FEET /SEC.) = 6.2 UPSTREAM NODE ELEVATION = 320.20 DOWNSTREAM NODE ELEVATION = 312.60 FLOWLENGTH(FEET) = 180.00 MANNING'S N = .012 ESTIMATED PIPE DIAMETER(INCH) = 6.00 NUMBER OF PIPES = 1 PIPEFLOW THRU SUBAREA(CFS) _ .59 TRAVEL TIME(MIN.) _ .49 TC(MIN.) = 13.07 FLOW PROCESS FROM NODE 16.00 TO NODE 6.00 IS CODE = 1 ---------------------------------------------------------------------------- >> >>>DESIGNATE INDEPENDENT STREAM FOR CONFLUENCE<< <<< ------------------- - - ---- TOTAL NUMBER OF STREAMS = 2 CONFLUENCE VALUES USED FOR INDEPENDENT STREAM 1 ARE: TIME OF CONCENTRATION(MIN.) = 13.07 RAINFALL INTENSITY(INCH /HR) = 4.11 TOTAL STREAM AREA(ACRES) _ .31 PEAK FLOW RATE(CFS) AT CONFLUENCE _ .59 FLOW PROCESS FROM NODE 17.00 TO NODE 6.00 IS CODE = 21 ---------------------------------------------------------------------------- >> >>>RATIONAL METHOD INITIAL SUBAREA ANALYSIS<< <<< ---------------------- ---------- SOIL CLASSIFICATION IS "D" RURAL DEVELOPMENT RUNOFF COEFFICIENT = .4500 INITIAL SUBAREA FLOW- LENGTH = 125.00 UPSTREAM ELEVATION = 313.80 DOWNSTREAM ELEVATION = 312.30 ELEVATION DIFFERENCE = 1.50 URBAN SUBAREA OVERLAND TIME OF FLOW(MINUTES) = 12.310 100 YEAR RAINFALL INTENSITY(INCH /HOUR) = 4.273 SUBAREA RUNOFF(CFS) _ .23 TOTAL AREA(ACRES) _ .12 TOTAL RUNOFF(CFS) _ .23 FLOW PROCESS FROM NODE 17.00 TO NODE 6.00 IS CODE = 1 ---------------------------------------------------------------------------- >> >>>DESIGNATE INDEPENDENT STREAM FOR CONFLUENCE<< <<< >> >>>AND COMPUTE VARIOUS CONFLUENCED STREAM VALUES<< <<< --------------------- -------------------- TOTAL NUMBER OF STREAMS = 2 CONFLUENCE VALUES USED FOR INDEPENDENT STREAM 2 ARE: TIME OF CONCENTRATION(MIN.) = 12.31 RAINFALL INTENSITY(INCH /HR) = 4.27 TOTAL STREAM AREA(ACRES) _ .12 PEAK FLOW RATE(CFS) AT CONFLUENCE _ .23 ** CONFLUENCE DATA ** STREAM RUNOFF Tc INTENSITY AREA NUMBER (CFS) (MIN.) (INCH /HOUR) (ACRE) 1 .59 13.07 4.111 .31 2 .23 12.31 4.273 .12 RAINFALL INTENSITY AND TIME OF CONCENTRATION RATIO CONFLUENCE FORMULA USED FOR 2 STREAMS. ** PEAK FLOW RATE TABLE ** STREAM RUNOFF Tc INTENSITY NUMBER (CFS) (MIN.) (INCH /HOUR) 1 .80 12.31 4.273 2 .81 13.07 4.111 COMPUTED CONFLUENCE ESTIMATES ARE AS FOLLOWS: PEAK FLOW RATE(CFS) _ .81 Tc(MIN.) = 13.07 TOTAL AREA(ACRES) _ .43 ********************************************* * * * * * * * * * * * * * * * * * * * * * * * * * * * * * ** FLOW PROCESS FROM NODE 18.00 TO NODE 8.00 IS CODE = 21 ---------------------------------------------------------------------------- >> >>>RATIONAL METHOD INITIAL SUBAREA ANALYSIS<< <<< --------------------- ------------- SOIL CLASSIFICATION IS "D" RURAL DEVELOPMENT RUNOFF COEFFICIENT = .4500 INITIAL SUBAREA FLOW - LENGTH = 80.00 UPSTREAM ELEVATION = 313.80 DOWNSTREAM ELEVATION = 313.00 ELEVATION DIFFERENCE = .80 URBAN SUBAREA OVERLAND TIME OF FLOW(MINUTES) = 10.465 100 YEAR RAINFALL INTENSITY(INCH /HOUR) = 4.745 SUBAREA RUNOFF(CFS) _ .15 TOTAL AREA(ACRES) _ .07 TOTAL RUNOFF(CFS) _ .15 ********************************************* * * * * * * * * * * * * * * * * * * * * * * * * * * * * * ** FLOW PROCESS FROM NODE 17.00 TO NODE 7.00 IS CODE = 21 ---------------------------------------------------------------------- >> >>>RATIONAL METHOD INITIAL SUBAREA ANALYSIS<< <<< SOIL CLASSIFICATION IS "D" RURAL DEVELOPMENT RUNOFF COEFFICIENT = .4500 INITIAL SUBAREA FLOW - LENGTH = 120.00 UPSTREAM ELEVATION = 313.80 DOWNSTREAM ELEVATION = 312.60 ELEVATION DIFFERENCE = 1.20 URBAN SUBAREA OVERLAND TIME OF FLOW(MINUTES) = 12.817 100 YEAR RAINFALL INTENSITY(INCH /HOUR) = 4.163 SUBAREA RUNOFF(CFS) _ .22 TOTAL AREA(ACRES) _ .12 TOTAL RUNOFF(CFS) _ .22 END OF STUDY SUMMARY: PEAK FLOW RATE(CFS) _ .22 Tc(MIN.) = 12.82 8 TOTAL AREA(ACRES) .12 END OF RATIONAL METHOD ANALYSIS V. HYDRAULIC CALCULATIONS -9- Prepared by Pasco Engineering 04/15/1999 PE 817 �0 CALCULATE CAPACITY OF AREA DRAINS. FORMULA: Qcap = 3.0(P)(D ^1.5) / 2. DIVISION BY 2 ACCOUNTS FOR GRATE. MAXIMUM PERIMETER AVAIL HW GRATE FACTOR Q100 (CFS) P (FT) D (FT) 2* CAPACITY (CFS) INLET TYPE 0.81 4.00 1.00 2.00 6.00 12" x 12" NDS OR EQUAL 0.59 6.00 0.50 2.00 3.18 18" X 18" BROOKS CB THEREFORE, 18 "x18" BROOKS CATCH BASIN IS O.K. NODE 16 THEREFORE, 12 "x12" NDS AREA DRAIN IS O.K. NODE 2 l( ********************************************* * * * * * * * * * * * * * * * * * * * * * * * * * * * * * ** HYDRAULIC ELEMENTS - I PROGRAM PACKAGE (C) Copyright 1982 -92 Advanced Engineering Software (aes) Ver. 3.1A Release Date: 2/17/92 License ID 1388 Analysis prepared by: PASCO ENGINEERING, INC. 535 N. HIGHWAY 101, SUITE A SOLANA BEACH, CA. 92075 Ph: (619) 259 -8212 Fax: (619) 259 -4812 ---------------------------------------------------------------------------- TIME /DATE OF STUDY: 10:50 4/15/1999 * * * * * * * * * * * * * * * * * * * * * * * * ** DESCRIPTION OF STUDY * * * * * * * * * * * * * * * * * * * * * * * * ** * CHECK,&LOW VELOCITYXIN EARTHEN BROW DITCH AT NODE 2 * 4 -15 -99 MS * 100 YEAR STORM * * SEE EXHIBIT "B" FOR NODE LOCATIONS. * PE 817 ******************************************* * * * * * * * * * * * * * * * * * * * * * * * * * * * * * ** ********************************************* * * * * * * * * * * * * * * * * * * * * * * * * * * * * * ** >> >>PIPEFLOW HYDRAULIC INPUT INFORMATION<< << ----------------------------------------------------------------------- PIPE DIAMETER(FEET) = 2.000 PIPE SLOPE(FEET /FEET) _ .0200 PIPEFLOW(CFS) _ .81 MANNINGS FRICTION FACTOR = .030000 CRITICAL -DEPTH FLOW INFORMATION: ------------------------------------------------------------- CRITICAL DEPTH(FEET) _ .31 CRITICAL FLOW AREA(SQUARE FEET) _ .309 CRITICAL FLOW TOP- WIDTH(FEET) = 1.446 CRITICAL FLOW PRESSURE + MOMENTUM(POUNDS) = 6.60 CRITICAL FLOW VELOCITY(FEET /SEC.) = 2.622 CRITICAL FLOW VELOCITY HEAD(FEET) _ .11 CRITICAL FLOW HYDRAULIC DEPTH(FEET) _ .21 CRITICAL FLOW SPECIFIC ENERGY(FEET) _ .42 NORMAL -DEPTH FLOW INFORMATION: ------------------------------------------------------------------- NORMAL DEPTH(FEET) _ .33 FLOW AREA(SQUARE FEET) _ .34 FLOW TOP- WIDTH(FEET) = 1.481 FLOW PRESSURE + MOMENTUM(POUNDS) = 6.65 -5- FLOW VELOCITY (FEET /SEC. ) = 2.409 FLOW VELOCITY HEAD(FEET) _ .090 HYDRAULIC DEPTH(FEET) _ .23 FROUDE NUMBER = .891 SPECIFIC ENERGY(FEET) - .42 I -7 1Z TABLE I -6 - ALLOWABLE VELOCITIES FOR ERODIBLE LININGS Earth - No Vegetation* Maximum Allowable Velocities Type of Lining lear Water Carrying g Fine Silts Water Carrying Water Sand & Gravel (Colloidal) fps fps fps a. Fine sand (noncolloidal) 1.5 2.5 1.5 b. Sandy loam (noncolloidal) 1.75 2.5 j6 - 2.0 C. Silt loam (noncolloidal) 2 3.0 2. d. Ordinary firm loam 2.5 3.5 2.25 e. Volcanic ash 2.5 3.5 2.0 f. Fine gravel 2.5 5.0 3.75 g. Stiff clay (very colloidal) 3.75 5.0 3.0 h. Graded, loam to cobbles (noncolloidal) 3.75 5.0 5.0 i. Graded, silt to cobbles (colloidal) 4.0 5.5 5.0 j. Alluvial silt (noncolloidal) 2.0 3.5 2.0 k. Alluvial silt (colloidal) 3.75 5.0 3.0 1. Coarse gravel (noncolloidal) 4.0 6.0 6.5 m. Cobble and shingle 5.0 5.5 6.5 n. Shale and hardpan 6.0 6.0 5.0 Earth with Vegetative Cover Slope Easily Erosion Type of Cover Range Eroded Resistant Soils Soils % fps fps 0 -5 6 8 a. Bermuda Grass sod 5 -10 5 7 10+ 4 6 b. Sod - forming grass such as Kentucky 0 -5 5 7 Blue Grass, Buffalo Grass, Smooth Brome, 5 -10 4 6 Red Top, Blue Gamma. 10+ 3 5 c. Grass mixture. This is not recom- mended for use on slopes steeper 0 -5 4 5 than 107 5 -10 3 4 d. Bunch grasses, vines, and similar open cover such as Lespedeza, Weeping Lovegrass, Ischaemum (yellow Bluestem), Kudzu, Alfalfa, Crabgrass, Sudan Grass. 0 -5 2 5 3.5 Annuals (for temporary use). Not recom- mended for use on slopes steeper than 5 %. 'Recommended in 1926 by Special Committee on Irrigation Research ASCE. ----' - 5 /NC E « cSulAt Q��, B�eow 2 > 1 rc tel 7D VI. APPENDIX -13- 0 '•_ v �' I n I i i- cv • �D E m,e• 6L1 `..' i _ M eQZ cm Lo z Li 0 C . CD CN i _ �• z CN C w 1 Uj \ • u 1\ v+ M w C3 w < x r ` < a w r< y N M A Cs7 < _ p v is OZ F I U u Q a 4 a O F — -- I I I o — 9 y H Cl N t+1 U1 4 a Q o Z LL _J c I �1' < V M C Q O O I w `" c _ L ? ~ i p < O O Lu O u F v N Q v 1 Q= p cc [� OO I Y. O w J O H U p lL r w I r I � N J u w 4 w II —A -7 1 1 r3 CD cm o� u , LZI CIO �* 1�• � c �. , f •, ^ I � . I G .; - 1 r l l �_ 'rte ._ © cr C:) < 0 U >' U z ° LLJ a G C] V) i a N O � U u 111 O CL C) w o _ U v — V1 O V 1- C-- o �> Z C p M< s O_ O M, a a O W J — H DOU_ I w < o z H N 1 V u L TABLE 2 RUNOFF COEFFICIENTS (RATIONAL METHOD) DEVELOPED AREAS (URBAN) Coeffi C Land Use Soil Group (1) Residential: A B C D Single Family .40 .45 ,50 .55 Multi -Units .45 .50 .60 .70 Mobile homes .45 .50 .55 .65 Rural (lots greater than 1/2 acre) .30 .35 .40 .45 Commercial ( 80% Impervious • 70 .75 .80 .85 Industrial (2) .80 $ 90`/ Impervious 5 .90 •95 NOTES: ()) Soil Group mans are available at the offices of the Department of Public Works. (2 )Where actual conditions deviate significantly from the tabulated impervious- ness values of 80% or 90%, the values given for coefficient C, may be revised by multiplying 80% or 90% by the ratio of actual imperviousness to the tabulated imperviousness. However, in no case shall the final coefficient be less than 0.50. For example: Consider commercial property on D soil,group. Actual imperviousness = 50% Tabulated imperviousness = 80% Revised C = 50 x 0.85 = 0.53 80 IV -A -9 APPENDIX IX -B Rev. 5/81 TABLE 11 . -- INTERPRETATIONS FOR LAND MANAGENIFN' ! [Numerals indicate soil properties or qualities that affect erodibility. Numeral 1 refers surface layer texture; 9 to depth to hard rock, or a h to slope; 2 to ardpan, or any layer that restricts permeability; 16 to grade of structure in the surface layer. Absence of rating means no valid interpretations can be made] Map Soil Limitations for symbol Hydro- Erodibility conversion logic from brush to group grass AcG Acid igneous rock land--------- -- ---- ----------------------------------- D Severe 1 - - - -- AtC Altamont clay, 5 to 9 percent slopes________ _______ ______ Severe. AtD ltamont clay, 9 to 15 percent slopes_________ _________ D Slight- - - - -__ Slight. 1/ AtD2 Altamont clay, 9 to 15 percent slopes, eroded -------------- D Slight ------- Slight. 11 D Slight- - -- - -- Slight. 1/ AtE ltamont clay, 1S to 30 percent slopes ------------------- D Moderate 'AtE2 Altamont clay, 15 to 30 percent slopes, ero e -- 1 - -- Slight. 1/ '- " - - --- ----- o erase -- D Severe 1 - - - -- hf tF Altamont clay, 30 to SO percent slopes --- - - - - -- -- ' --- Mo dg a 1 derate 1/ AuC Anderson very gravelly sandy loam, S to 9 percent A slopes. Severe 16 - - -- Slight. AuF Anderson very gravelly sandy loam, 9 to 45 percent A slopes. Severe 16 - - -- Moderate. 2 / AvC Arlington coarse sandy loam, 2 to 9 percent slopes- - - - - -- C Severe 16 - - -- AwC Auld clay, 5 to 9 percent slopes------- ---- -- ------- - - - - -- D Slight - - -- - -- Slight. --- --- -- - - -- Slight. AwD Auld clay, 9 to 15 percent slopes ----- - -____ g ht. AyE Auld stony clay, 9 to 30 percent slopes_______ ___________ D Slight- - - - - -- Slight. BaG Badland_______ __ ___________________ D Moderate 1 - -- Slight. --------------- - - - - - -- D Severe 1 - -- -- BbE Bancas stony loam, 5 to 30 percent slopes ----- - - - -__ Severe. C Severe 16 - - -- Moderate. BbE2 Bancas stony loam, 5 to 30 percent slopes, eroded -------- BbG Bancas stony loam, 30 to 65 percent slopes --------------- C Severe 16 - - -- Moderate. Severe 1 - - - -- Moderate. B G2 Bancas stony loam, 30 to 6S percent slopes, eroded------ - BeE Blasingame loam, 9 to 30 percent slopes ----- - - - - --- - C Severe 1- - - -- Moderate. D Severe 16 - - -- Slight. BgE Blasingame stony loam, 9 to 30 percent slopes p D Severe 16 - - -- Moderate. BgF Blasingame stony loam, 30 to 50 percent slopes----- - - - - -- D Severe 1 - - - -- B1C Bonsall sandy loam, 2 to 9 percent slopes--------- -- ----- D Moderate. slopes, eroded-- - - - - -_ Severe 9 -____ Slight. B1C2 Bonsall sandy loam, 2 to 9 percent B1D2 Bonsall sandy loam, 9 to 15 percent slopes, eroded- - - - - -- D Severe 9 - - - -- Slight. BmC Bonsall sandy loam, thick surface, 2 to 9 percent D Severe 9 -- - -- Slight. slopes. Moderate 2 - -- Slight. BnB Bonsall - Fallbrook sandy loams, 2 to 5 percent slopes: Bonsall--------------- Fallbrook -------------------------------------------- D Severe 9 - - - -- Slight. BoC Boomer loam, 2 to 9 percent slopes------- -- ----- -- --- - --- C Severe 9 - - - -- Slight. BoE Boomer loam, 9 to 30 percent slopes_____ ______ ___ __ _____ C Moderate 2 - -- Slight. BrE Boomer stony loam, 9 to 30 percent slopes_______ _________ Moderate 1 - -- Slight. C BrG Boomer stony loam, 30 to 65 percent slopes_______ ________ C Moderate 1 - -- Slight. BsC Bosanko clay, 2 to 9 percent slopes---------- - -- --- Severe 1 --- -- Moderate. BsD Bosanko clay, 9 to 15 percent slopes --------- D Moderate 16 -- Slight. 1/ - - -" " -' ---- D Moderate 16 -- Slight. 11 BsE Bosanko clay, 1S to 30 percent slopes -------------------- D Moderate 1 - -- Slight. 1/ BtC Bosanko stony clay, 5 to 9 percent slopes------ -- ----- D BuB Bull Trail sandy loam, 2 to S percent slopes------- ------ C Moderate 16 -- Slight. 3/ BuC Bull Trail sandy loam, 5 to 9 percent slopes------- ------ C Severe 16 - - -- Slight. 4/ BuD2 Bull Trail sandy loam, 9 to 15 percent slopes, eroded - - -- Severe 16 - - -- Slight. 4/ BuE2 Bull Trail sandy loam, 15 to 30 percent slopes, eroded - -- C Severe 16 - - -- Slight. 4/ C Severe 16- - -- Slight. CaB Calpine coarse sandy loam, 2 to 5 percent slopes --- - - - -__ 4/ CaC Calpine coarse sandy loam, S to 9 percent slopes --------- B Moderate 2 - -- Slight. 4/ CaC2 Calpine coarse sandy loam, 5 to 9 percent slopes, B Moderate 2 - -- Slight. 4/ eroded. B Moderate 2 - -- Slight. 4/ See footnotes at end of table. 32 TABLE 11 . -- INTERPRI TATIONS FOR LAND tlkNAGEi�11iN'I'-- Cont:inucd 1CJ Limitations for Map Soil Hydro- Erodibility conversion S ymbol logic from brush to group grass IInG Holland stony fine sandy loam, 30 to 60 percent C Severe 1 - - - -- Moderate. slopes. HCC 11olland fine sandy loam, deep, 2 to 9 percent C Severe 16 - - -- Slight. slopes. IIrC Huerhuero loam, 2 to 9 percent slopes------------- - - - - -- D Severe 9 - - - -- Slight. HrC2 Huerhuero loam, 5 to 9 percent slopes, eroded --------- D Severe 9 - - - -- Slight. HrD Huerhuero loam, 9 to 15 percent slopes------------ - - - - -- D Severe 9 - - - -- Slight. HrD2 Huerhuero loam, 9 to 15 percent slopes, eroded----- - - - - -- D Severe 9 - - - -- Slight. HrE2 Huerhuero loam, 15 to 30 percent slopes, eroded---- - - - - -- D Severe 9 - - - -- Slight. lluC Iuerhuero -Urban land complex, 2 to 9 percent slopes: Huerhuero - - - - - -- D Urban land - - - - -- D WE Huerhuero -Urban land complex, 9 to 30 percent slopes: Huerhuero - - - - -- D Urban land ---------------------------------------- InA Indio silt loam, 0 to 2 percent slopes------------- - - - - -- C Severe 16 InB Indio silt loam, 2 to S percent slopes------------- - - - - -- C Severe 16 IoA Indio silt loam, saline, 0 to 2 percent slopes----- - - - - -- C Severe 16 IsA Indio silt loam, dark variant - - - - -- C Severe 16 KcC Kitchen Creek loamy coarse sand, S to 9 percent B Severe 2 - - - -- Slight. 4/ slopes. — KcD2 Kitchen Creek loamy coarse sand, 9 to 1S percent B Severe 2 - - - -- Slight. 4/ slopes, eroded. — LaE2 La Posta loamy coarse sand, 5 to 30 percent slopes, A Severe 2 - - - -- Slight. 4/ eroded. — LaE3 La Posta loamy coarse sand, S to 30 percent slopes, A Severe 2 - - - -- Severe. 41 severely eroded. — LcE La Posta rocky loamy coarse sand, S to 30 percent A Severe 2 - - - -- Moderate. 4/ slopes. — LcE2 La Posta rocky loamy coarse sand, 5 to 30 percent A Severe 2 - - - -- Moderate. 4/ slopes, eroded. — LcF2 La Posta rocky loamy coarse sand, 30 to 50 percent A Severe 1 - - - -- Moderate. 4/ slopes, eroded. — WE I.a Posta- Sheephead complex, 9 to 30 percent slopes: La Posta - - - - -- A Severe 2 - - - -- Moderate. 4/ Sheephead-------------------------------------- - - - - -- C Severe 2 - - - -- Moderate. 4/ LdG La Posta - Sheephead complex, 30 to 6S percent slopes: — La Posta - - - - -- A Severe 1 - - - -- Moderate. 41 Sheephead--------------------------------------- - - - - -- C Severe 1 - - - -- Moderate. 4 / LeC Las Flores loamy fine sand, 2 to 9 percent slopes--- - - - - -- D Severe 2 - - - -- Slight. Le C2 Las Flores loamy fine sand, S to 9 percent slopes, D Severe 2 - - - -- Slight. roded. LeD Las Flores loamy fine sand, 9 to 15 percent slopes-- - - - - -- D Severe 2 - - - -- Slight. Le D2 Las Flores loamy fine sand, 9 to 15 percent slopes, D Severe 2 - - - -- Slight. eroded. LeE Las Flores loamy fine sand, 15 to 30 percent slopes- - - - - -- D Severe 2 - - - -- Slight. LeE2 Las Flores loamy fine sand, 1S to 30 percent slopes, D Severe 2 - - - -- Slight. eroded. LeE3 Las Flores loamy fine sand, 9 to 30 percent slopes, D Severe 2 - - - -- Severe. severely eroded. LfC Las Flores -Urban land complex, 2 to 9 percent slopes: LasFlores - - - - -- D Urban land ---------------- - - -------- ------------ - -- - -- D See footnotes at end of table. 35 w ti FN y ✓ h 4 y SnG w ExG , r t " d � •`x v r+ r �` d ,;5 1 #3 � r 9 . � t 4. e a 1 �tt ae `SY`',i. t; a a,$'t+}jrr�-"! 4 .� c� s ' � • a ' ik' , � .cr - :k t " .,t�+�$�e� `, r ,. k 7 '�ra t 1 Y := + -, swat , >✓<„' 4 r } • i, p7� °yk nw 7 �HfC d > � "� L ���� � � �� �" yy1 � 64 � r r FIrp2 � � , x x .. X/ a t �• •r � , , }` .`ti I�,,.�.. S ' ' - �. 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V ivo Z 6l a Jim A"Im =American Geotechnical ' Protecting Your Future FINAL REPORT OF TESTING ' AND OBSERVATION SERVICES DURING GRADING ' LOT 2 - CALLE MARGARITA OLIVENHAIN, CALIFORNIA 1 PREPARED FOR: RMCI DEVELOPMENT 1 ' FILE NO. 22183.01 SEPTEMBER 28, 1999 1 1 1 1 ' 22725 Old Canal Road, Yorba Linda, CA 92887 (714) 685 -3900 (800) 275 -4436 FAX (714) 685 -3909 5764 Pacific Center Boulevard, Suite 112, San Diego, CA 92121 (619) 450 -4040 FAX (619) 457 -0814 =American Geotechnical ' Protecting Your Future ' September 28, 1999 File No. 22183.01 ' Mr. Bob Mueller RMCI DEVELOPMENT 514 Via De La Valle, Suite 210 ' Solana Beach, California 92075 Subject: FINAL REPORT OF TESTING AND OBSERVATION SERVICES DURING SITE GRADING Lot 2 - Calle Margarita Olivenhain, California ' Reference: "Preliminary Geotechnical Study, Calle Margarita Development, Lot 2 - Calle Margarita, Olivenhain, California," prepared by American Geotechnical, dated ' April b, 1999. ' Dear Mr. Mueller: Pursuant to your request, American Geotechnical has provided geotechnical services in the ' form of observation and testing during grading for the subject property. Our field services were performed during the period of August." 1, 1999 through September 8, 1999. ' Based on the results of the testing and observations, it is our opinion the grading has been completed in general conformance with the recommendations provided in the referenced preliminary geotechnical report and intentions of this office. ' We appreciate the opportunity to be of service. If you should have any questions, please do not hesitate to contact us. ' Sincerely, p;WFES,q/ ' AMERICAN GEOTE � T.,�,q �9F cc NO. CAF ?387 m Exp. gaol Eetred T. Marsh �l °'FCH14%co Associate Engineer OPCALV*F - I ' G.E. 2387 ETM: kr ' Distribution: Mr. Bob Mueller - (4) 22725 Old Canal Road, Yorba Linda, CA 92887 (714) 685 -3900 (800) 275 -4436 FAX (714) 685 -3909 5764 Pacific Center Boulevard, Suite 112, San Diego, CA 92121 (619) 450 -4040 FAX (619) 457 -0814 ' File No. 22183.01 September 28, 1999 American Geotechnical ' Page 1 ' 1.0 INTRODUCTION ' 1.1 GENERAL This report presents the results of our observations and testing during site grading of Lot 2 - ' Calle Margarita in the Olivenhain area of San Diego County, California. The project grading plans were prepared by Pasco Engineering, and are entitled Grading Plan for Lot 2, Map No, 13566 Calle Margarita. The project soil report is referenced above. ' 1.2 SCOPE OF SERVICES The scope of services performed during grading included the following: • Observing the grading operation, including the removal of loose topsoil and unsuitable material, and the keyway excavations for site slopes. ' • Performing in -place density tests in fill placed and compacted during site grading. ' • Performing laboratory tests for evaluating the relative compaction, expansion potential ' and other engineering characteristics of soil encountered and /or used for fill. ' • Providing consultation during grading. ' • Performing additional geologic and engineering analysis for the proposed project. ' Preparation of this final grading report. II' ' File No. 22183.01 September 28, 1999 M American Geotechnical ' Page 2 ' 2.0 SITE PREPARATION AND GRADING ' 2.1 PREPARATION AND REMOVALS During the grading operations, a representative from American Geotechnical made periodic observations and performed compaction testing as recommended in the preliminary report. Initially, the site was cleared of vegetation. After the clearing operation, topsoils, colluvium, alluvium and undocumented fills were removed to firm natural ground within the area of the proposed site improvements. The limits of this removal extended beyond the limits of ' proposed improvements, as delineated on the site grading plan. ' 2.2 FILL PLACEMENT Following completion of the removals, fill soils derived from on -site excavations were then moisture conditioned, placed and compacted in thin layers until the design elevations were obtained. In general, on -site fill materials consisted of greenish -brown to dark brown Sandy ' Clay and Olive gray to Gray Brown Silty Sand. ' During the grading operation, compaction procedures were observed and in -place density tests were performed to evaluate the relative compaction of the fill material. The in -place density tests were performed in general conformance with ASTM D -1556 (sand cone). The results of the in -place density and moisture content tests are summarized on Table 1. The ' approximate locations of the in -place density tests are shown on Figure 1. In g eneral, the in- place density test results indicate that fill soil, where tested, has a relative compaction of at ' least 90 percent per ASTM D -1557. Any failed areas were re- worked and re- tested until they ' met or exceeded the 90 percent relative compaction requirement. Laboratory tests were performed on samples of material used for fill to evaluate moisture - density relationships, expansion characteristics, optimum moisture content and maximum dry ' density. The results of the laboratory tests are summarized in Tables 2 and 3. 1 ' Legend a Approximate location of compaction test ' ®- Graded elevations taken from grading plan no. 13586 Calls Margarita prepared by Pat ' American Compaction Geotechnical Call F.N. 22183.0 1 ' File No. 22183.01 September 28, 1999 American Geotechnical ' Page 3 ' 3.0 FOUNDATION RECOMMENDATIONS ' 3.1 GENERAL The following foundation recommendations are provided in consideration of the soil conditions encountered during site grading. The recommendations given below should supersede those previously issued in our referenced report. All other recommendations given t in the referenced geotechnical report still apply. Changes or additions which have been made to the original recommendations are presented below. 3.2 FOUNDATION DESIGN PARAMETERS ' It is understood that a post- tensioned slab and foundation system is planned for the subject site. In the referenced report, various alternatives were given consisting of things such as removing all expansive soil encountered, utilizing a heavily reinforced structural slab /foundation system or selective grading to lower the expansion potential of soils used near ' pad elevation. During the grading operation, it was chosen to blend on -site soil, to the extent possible, and to re- evaluate the expansion potential within the building pad area. The results of expansion testing performed near pad elevation indicates that the prevailing ' subgrade soil near pad elevation has a high expansion potential. Because oft this, the post - ' tensioned slab /foundation system should be designed to resist the effects of expansive soil influence. As discussed in the referenced geotechnical report, the designer should consider ' the effects of expansive soil "edge lift" and "center lift" as well as structural loading criteria. The post- tensioned slabs should be designed by a structural engineer experienced in the design of post- tensioned slabs -on -grade and should be designed in accordance with the latest edition of the Post - Tensioning Institute (PTI) - Design and Construction of Post - Tensioned ' Slabs -on- Ground. The following parameters can be used for design of the post- tensioned slab: ' Minimum Perimeter Foundation Embedment = 36 in. • Allowable Soil Bearing Pressure (gauow) = 1500 psf • Slab - Subgrade Friction Coefficient (g) = 0.30 ' File No. 22183.01 September 28, 1999 American Geotechnical ' Page 4 ' Edge Lift Design • Edge Moisture Variation (em) = 3 ft. • Estimated Differential Swell (Ym) = 2.5 in. Center Lift Design • Edge Moisture Variation (em) = 6 ff. • Estimated Differential Swell (Ym) = 4.5 in. ' It should be noted that the design method developed and presented in the PTI manual for slabs -on- ground is based solely upon climate controlled soil conditions and is deemed invalid ' therein when influenced to any significant degree by other conditions. Some of the conditions mentioned consist of things such as adverse drainage, vegetation, bare soil areas, planter ' beds adjacent foundations, among others. ' It cannot be emphasized enough the importance of proper design and maintenance of landscaping, irrigation systems, and other site improvements and /or alterations in close ' proximity to the slab /foundation system. Even using the parameters given above for design of the slab /foundation system, many non - climatic factors exist which are beyond the control of ' the geotechnical consultant and the designer which could influence the slab /foundation system. Some of these factors and suggestions which are included in the PTI manual and have been included in Appendix A at the end of the report. 3.3 ALLOWABLE FOUNDATION /SLAB DEFORMATION Work performed in -house (Day 1990 and Marsh, Thoeny 1999) and by other professional sources of outside research indicates that distress, for residential structures, generally occurs to ' the superstructure when angular distortion exceeds 1:300, or in other words, 0.6" of vertical deformation over a 15' horizontal distance. The structural design, at a minimum, should ' provide a slab /foundation system stiff enough to accommodate these tolerances with a factor -of- safety applied. The structural design should also take into affect the type of building ' materials to be used (i.e., sensitive wall coverings, pre -fab roof trusses, etc.) which may limit slab deformations to even more restrictive criteria. r File No. 22183.01 September 28, 1999 M American Geotechnical Page 5 I 3.4 SUBGRADE TREATMENT To help mitigate expansive soil influence, we recommend that the slab subgrade be ' presoaked to at least 4% above optimum moisture content prior to placement of slab concrete. We recommend that the depth of pre- soaking extend as deep as practically possible. ' The interior slabs should be underlain by a minimum of two (2) inches of clean sand, underlain by a moisture membrane such as visqueen. The visqueen should be a minimum of 10 mil thick ' and should provide a continuous vapor barrier sealed at all splices and around pipes. A five inch thick open graded gravel base should be placed below the visqueen to provide a r capillary break. To help protect the visqueen from punctures during placement, it is recommended that a filter fabric such as Mirafi 140N be placed between the crushed rock and visqueen. 3.5 SITE CONCRETE Experience and research has shown that concrete with a high water /cement ratio can ' experience problems such as excessive shrinkage cracking, moisture intrusion, and high vapor emissions, among other things. Generally speaking, the higher the water /cement ratio, the higher the porosity and permeability of the concrete, and the lower the strength. Concrete designed for minimum compressive strengths on the order of 2000 -2500 psi can oftentimes have excessive levels of mixing water and correspondingly a high water /cement ratio. ' Consideration should be given to using the lowest possible water /cement ratio while still maintaining workability. If necessary, water reducing agents can be used to increase workability. It is recommended that concrete used for footings and slab areas have a minimum compressive strength of 3,000 psi with a maximum water /cement ratio of 0.50. All steel and concrete materials, details, placement procedures, and curing should be performed strictly in accordance with ACI specifications and guidelines. The slab design by the structural engineer and /or architect should consider shrinkage of the concrete to limit cracking to the slab and overlying floor coverings. File No. 22183.01 September 28, 1999 M American Geotechnical Page b 3.6 REINFORCEMENT PLACEMENT Care should be taken when placing foundation and slab reinforcement. Placement details ' should be in conformance with ACI specifications. Unless otherwise specified by the structural engineer, continuous footing reinforcement should be placed in the upper and lower 1/3 i portions of the foundation's sections. The bottom foundation steel should not be closer than three inches to the underlying excavation. Slab reinforcement should be placed in a positive t fashion between the midpoint and upper 1/3 portion of the slab section. ' "Lifting" slab steel into place following concrete placement is not recommended. If the contractor elects to "liff" the reinforcement into position following concrete placement, the ' owner should consider verifying steel placement by coring of the slab areas. These recommendations apply to interior or exterior concrete. 3.7 FOOTING SETBACK FOR SLOPES Any footings near slopes should satisfy a minimum horizontal setback as indicated in the Uniform Building Code, Chapter 18, Figure 18 -1 -1. This distance should be measured from the lower leading edge of the footing to the slope face. For slopes ten (10) feet in height or less, a ' minimum setback of ten (10) feet is recommended unless special detailing is implemented. ' File No. 22183.01 September 28, 1999 M American Geotechnical Page 7 4.0 RETAINING WALLS ' Where retaining walls are planned, they should be designed utilizing the following design criteria: Restrained Walls (level backfill): At -Rest Soil Pressure ........................ .............................60 pcf e.f.p. ' Passive Soil Resistance .................. ............................200 pcf e.f.p. Cantilever Walls (level backfill): ' Active Soil Pressure ......................... .............................40 pcf e.f.p. Passive Soil Resistance .................. ............................200 pcf e.f.p. In order for these soil design parameters to be valid, all planned retaining walls should be ' designed with appropriate detailing including an adequate backdrain system and a clean, non - expansive backfill for a width of at least half the height of the retaining wall for level backfill conditions. For ascending slopes surcharge, the minimum width of compacted granular backfill should be increased to a value equivalent to the height of the wall, as a ' minimum. All retaining walls should be waterproofed from above the highest point of earth retained to the heel of the foundation. The architect should provide details for waterproofing including ' termination details and provisions for protecting the waterproofing. Each retainin g wall should ' be provided with an appropriate backdrain system designed by the project architect or civil engineer. It is recommended that the backdrain system extend to the heel of the foundation, ' and at least one foot below interior slab elevation (where applicable). Water collected in the backdrain system should ideally be recovered in a perforated PVC plastic pipe (perforations down) and directed to a suitable disposal area at two percent gradient unless otherwise specified by the project civil engineer. Retaining wall backfill should be placed in thin lifts (6-8 inches) and compacted b P Y ' mechanical means. Care should be taken not to utilize heavy compaction equipment in close proximity to the walls to help reduce the possibility of damage to the wall and an ' increase in the above recommended earth pressures. ' File No. 22183.01 September 28, 1999 M American Geotechnical Page 8 5.0 APPURTENANT STRUCTURE CONSTRUCTION The same guidelines for slab and footings would also pertain to design and construction of ' appurtenant structures, with the exception of exterior flatwork which do not usually necessitate the use of a visqueen moisture barrier. However, the recommendations for slab ' thickness and reinforcement, pre- soaking and other recommendations for exterior flatwork still pertain to help reduce the potential for cracking and separation. For moderate to highly expansive soil areas, exterior slabs should be a minimum of six inches thick and reinforced with #4 rebars at 16 inches on center each way. A 12 inch thickened edge is recommended along slab edges. Exterior slabs should be underlain by a five inch thick open graded gravel base. The slab should also have proper jointing incorporated into the design to control ' cracking. As with interior concrete, all steel and concrete materials, details, placement procedures and curing should be performed strictly in accordance with ACI specifications ' and guidelines. Special detailing may be necessary to limit unsightly cracking at structural interfaces, such as between foundations and adjacent slabs. As described in the referenced report, appurtenant ' structures placed near slope tops could creep over time in response to slope movement. Appurtenant structures should be kept as for away from slope tops as possible. Any footings ' near slopes should satisfy a minimum horizontal setback as indicated in the Uniform Building Code, Chapter 18, Figure 18 -1 -1. This distance should be measured from the lower leading edge of the footing to the slope face. For slopes ten (10) feet in height or less, a minimum setback of ten (10) feet is recommended unless special detailing is implemented. This might ' include structurally tying exterior slabs to the foundation or providing a thicker, heavily reinforced section. The actual details should be developed by the project architect and /or ' structural engineer. ' File No. 22183.01 September 28, 1999 M American Geotechnical ' Page 9 ' 6.0 SITE DRAINAGE Proper surface drainage should be incorporated into the design for the proposed project. ' Because of potential problems associated with poor drainage conditions, proper surface drainage should be maintained at all times. As a minimum, the following standard drainage ' guidelines are recommended and should be considered by the civil engineer during final plan preparation; a. Roof drains should be installed on all structures and tied via a "tight line" to a drain system that empties to a storm drain, terrace drain, or other suitable disposal area. ' b. Surface water should flow away from structures and slopes and be directed to suitable (maintained) disposal systems such as yard drains, drainage swales, street gutters, etc. ' Five percent drainage directed away from structures is recommended, and two percent minimum is recommended over soil areas. Planter areas adjacent the ' foundation are not recommended, unless the plants are self- contained with appropriate drainage outlets (i.e., drainage outlets tied via a "tight line" to a yard drain ' system). ' C. No drains should be allowed to empty adjacent foundations or over slopes. ' d. PVC Schedule 40 or equivalent is preferred for yard drains. A corrugated plastic yard drain is not recommended. II' ' File No. 22183.01 September 28, 1999 American Geotechnical ' Page 10 ' 7.0 ADDITIONAL TESTING AND CONSTRUCTION OBSERVATIONS We recommend that any excavations made during construction be reviewed by the ' geotechnical consultant. This would include excavations for site retaining walls, foundations, slabs, utility trenches or other improvements. It is also recommended that a member of our ' staff be present to test any fill being placed on -site. Additionally, slab subgrade preparation should be observed and tested as recommended by a member of our staff prior to the ' placement of forms, reinforcement or concrete. ' 8.0 LIMITATIONS This report has been prepared for the sole use and benefit of our client in accordance with ' generally accepted geologic and geotechnical engineering principles and practices. Subsurface conditions, and the accuracy of tests used to measure such conditions, can vary ' greatly with time. The intent of the report is to advise our client on geotechnical matters involving the proposed development. We are not responsible for any conclusions or ' recommendations made by others regarding the site without an opportunity to review such conclusions and recommendations and concur in writing. It should be understood that the geotechnical consulting provided and the contents of this ' report are not perfect. Any errors or omissions noted by any party reviewing this report, and /or ' any other geotechnical aspects of the project, should be reported to this office in a timely fashion. The client is the only party intended by this office to directly receive this advice. ' Subsequent use of this report can only be authorized by the client. Any transferring of information or other directed use by the client should be considered "advice by client.' ' Conclusions and recommendations presented herein are based upon observation and ' testing, the evaluation of technical information gathered, experience, and professional judgment. Other consultants could arrive at different conclusions and recommendations. ' Final decisions on matters presented are the responsibility of the client and /or the governing agencies. No warranties in any respect are made as to the performance of the project. ' File No, 22183.01 September 28, 1999 American Geotechnical ' Table 1 COMPACTION TEST SUMMARY TEST ELEVATION PERCENT DRY MAXIMUM RELATIVE SOIL NO. DATE 00 MOISTURE DENSITY DENSITY COMPACTION TYPE REMARKS ' (cf) cf) N 1 8/31/99 320.0 16.7 112.0 118.0 95 1 2 8/31/99 317.9 13.8 117.0 118.0 99 1 3 9/1/99 325.0 14.8 117.5 118.0 99 1 ' 4 9/2/99 320.0 15.2 108.3 118.0 92 1 SLOPEFACE 5 9/2/99 322.0 12.6 115.0 118.0 97 1 6 9/2/99 324.0 16.0 114.1 118.0 97 1 7 9/3/99 325.9 16.1 112.1 118.0 95 1 8 9/3/99 326.3 13.2 116.5 118.0 99 1 ' 9 9/7/99 328.0 14.9 110.4 118.0 94 1 FINISH GRADE 10 9/7/99 328.0 14.3 115.6 118.0 98 1 FINISH GRADE 11 9/8/99 301.5 17.5 110.3 118.0 93 1 ' 12 9/8/99 303.5 18.9 110.9 118.0 94 1 13 9/8/99 305.3 18.8 108.1 118.0 92 1 14 9/8/99 307.6 20.4 104.9 118.0 89 1 FAILED ' 15 9/8/99 307.6 20.9 109.0 118.0 92 1 RETEST OF #14 16 9/8/99 327.0 14.4 108.6 118.0 92 1 SLOPEFACE 1 17 9/8/99 311.4 19.4 107.2 118.0 91 1 SLOPEFACE ' 18 9/8/99 309.4 21.8 110.0 118.0 93 1 SLOPEFACE 19 9/8/99 313.5 19.1 109.7 118.0 93 1 20 9/8/99 314.0 20.6 11.4 118.0 94 1 FINISH GRADE ' 21 9/8/99 326.2 14.4 108.6 118.0 92 1 FINISH GRADE ' File No. 22183.01 September 28, 1999 American Geotechnical Table 2 LABORATORY DATA SUMMARY COMPACTION TEST SAMPLE Max Dry Optimum EXPANSION TEST LOCATION SOIL Density Moisture Expansion Expansion ' in feet TYPE (PCF) % Index Potential Stock -pile 50/50 Clayey 118.0 12.0 -- -- Mix SAND South Annex -- -- -- 110 HIGH ■ ■ ■ ■ ■ ■■ ■1111\ .. � ... . , .. sell 0 Wo ■ ■ ■ ■ ■ ■ ■ ■ ■ ■ ■ ■ ■ ■ ■ ■ ■ ■ ■ ■ ■ ■ ■ ■ \NOW \ MOISTURE— 11' September 1999 i File No. 22183.01 September 28, 1999 American Georechnical APPENDIX A The following Sections (3) and (4) are excerpts from: ' "Design and Construction of Post - Tensioned Slabs -On- Ground," second edition, published by Post - Tensioning Institute, dated 1996. 1 ' Once a value of e is selected, the VOLFLO strong evapotranspiration influences that tend computer prog ram can be used to estimate the in wetter ma to retard or reverse the moisture migration nitude the effects of trees beneath the slab. Slabs constructed 9 of ym including climates would have larger moisture variation and ders should ensure that calculations of e120. s ' distances during edge lift swelling due to the Designers i center lift moments based on values of e strong influence of the wetter environmment. � The value of e be used in structural design greater than 5 ft. should not be less than those ' calculations should be provided in the soils generated for the 5 ft. threshold. It should be investigation report submitted by the geotech- recognized that better accuracy than the near - nical est 0.5 ft. (e.g. 4.5 ft) is not warranted when engineer. An approximate procedure for evaluating the edge moisture variation distance estimating e from Fig A.3.4. on the basis of the Thornthwaite Moisture 3 Differential Soil Movement, ym :Also known a Index is presented in Appendix A.3, Figure () as Differential Swell, the amount of differential ' A.3.4. i ' During the development of the PTI design soil movement y to be expected depends procedure, banded curves were selected as upon a number of conditions, including the type aids to determine edge moisture variation dis- and amount of clay mineral, depth of clay lay - ers, uniformity of clay layers, the initial wet- tance, e in Figure A.3.4. r The lower lines of the bands were deter- ness, the depth of the active zone (depth of soil mined by back - calculation, using the PTI equa- suction variation), the velocity of moisture infil- tions applied to post- tensioned residential tration or evaporation as well as other less eas- t slabs that had been in place for up to 10 years, ily measured and controlled effects. Effects including wet and dry years, and which were which are more difficult to measure may performing satisfactorily. These slabs repre- include the type and amount of site post -con- ' sented sites with average conditions. Non cli- struction and pre- construction vegetation matic conditions such as vegetation, slope or cover, slope of the site, drainage conditions, poor drainage were not encountered. as downs or irrigation, substantial local water delivery such p ' outs leaking water supplies, and However, because of the uncertainty of p g applying these curves over different soil condi- others. If these site conditions have been cor tions, upper parallel band curves were select- reced so that soil moisture conditions are con ed. The permeability of the soil is one factor trolled by the climate alone, the amount of dif- which contributes to this uncertainty. On sites ferential movement may be estimated by a with more pervious soil, values closer to the geotechnical engineer. A procedure that may upper lines could be chosen. On sites with less be used by geotechnical engineers to evaluate ' pervious soil, values closer to the lower lines the climate - controlled differential soil move - could be selected. The banded curves repre- ment is presented in Appendix A.3. sented primarily climatic conditions and a It must be emphasized that the determination return weather pattern period of approximately of ym, and therefore the entire design method 10 years. presented herein, is based solely upon climate - Guidance on determining e values associ- controlled soil conditions and is invalid when ated with return period weather patterns up to influenced to any significant degree by other ' 50 years is provided in Lytton ' 7 . Slopes can conditions, including but not limited to those also affect the selection of the e value and mentioned above and expanded upon in the this relationship requires further study, see following Section 42(6)(4). ' Lytton8, "9. The design method is valid for y m values up to 1 In choosing the appropriate e value, the and including 4 in. For ym substantially over 4 in. designer is not limited to values within the band a different type of foundation design method, width. Severe non - climatic conditions could such as finite element, should be considered. require a value of e to be selected that is 4 Factors Not Related to Climate: The use of greater than the upper line value, to adequate- () an environmental indicator such as the ' ly reflect the particular site conditions. How- Thornthwaite Moisture Index as an aid in esti- ever, the selection of e greater than the upper mating the amount of shrink -swell that a soil line value must not be considered as an alter- 9 ate to permit substandard site preparation, will exhibit does not account for factors o ali- - n t particularly in the areas of grading, drainage ing soil movement that are not related to li and irrigation. mate. Factors not related to climate may 10 induce soil movements many times larger (f) Time of Construction. If the slab is cast at than those resulting from climatic influences the end of a lengthy dry period, it may alone. While it may be possible to quantify the experience greater uplift around the edges effects of many non - climatic factors, their when the soil becomes wetter at the con- ' presence or absence is often beyond the clusion of the dry period. Similarly, a slab direct control of the structural and /or geotech- cast at the end of a wet period, may experi- nical engineer. In general, an effective means ence greater drying around the edges dur- ' for mitigating non - climatic factors is to provide ing the subsequent period of dryness. detailed limitations on construction and use (g) Post - Construction. A number of Post- on the plans and /or contract documents. construction practices beyond the control Some designers and builders actually prepare of the design engineer can occur to cause ' "user's manuals" for the owners of homes on distress to structures founded on expan- expansive soils, with detailed guidelines on sive clay. Planting flower beds or shrubs irrigation, drainage, vegetation, slopes, and next to the foundation and keeping these ' other non - climatic factors which may affect areas flooded will generally cause a net the performance of the foundation. The major increase in soil moisture content and result factors influencing soil movement that are not in soil expansion around the foundation related to climate are: perimeter in that vicinity. Planting shade (a) Pre - Vegetation. Large individual trees, trees closer to the structure than a distance thickets or other vegetation requiring large equal to half the mature height of the tree amounts of moisture from the soil tend to will allow the tree roots to penetrate ' make the soil in the areas reached by their beneath the foundation and withdraw roots drier than adjacent areas. These moisture from the soil; the result will be a dessicated pockets have a much higher soil shrinkage in the region of the roots. potential for swelling than do the adjacent, Redirecting surface runoff channels or ' less dessicated areas. swales by the owner can result in improper (b) Fence Lines, Trails, and Tracks. These drainage as detailed above. To minimize surface features typically have the vege- movements in soils due to post- construc- ' tation worn away, leaving only bare or tion factors that are not climate related, the thinly covered strips which are much drier following home owners maintenance pro - than the soil on either side. Like the dessi- cedures are recommended: ' cated areas caused by pre- construction (i) Initial landscaping should be done vegetation, these areas will swell more on all sides adjacent to the foundation and than other areas. drainage away from the foundation should ' (c) Slopes. Slopes comprised of active be provided and maintained. expansive soil have a tendency to migrate (ii) Watering should be done in a uni- downhill as the soil experiences shrink- form, systematic manner as equally as swell cycles. possible on all sides of the foundation to (d) Cut and Fill Sections. Cut and fill keep the soil moist. Areas of soil that do sections will experience differential soil not have ground cover may require more movement because of variations of com- moisture as they are more susceptible to ' pacted densities. evaporation. Ponding or trapping of water (e) Drainage. If rainfall runoff is allowed to in localized areas adjacent to the founda- pond or collect adjacent to a structure tions can cause differential moisture levels ' built on expansive soil, the structure may in subsurface soils. be subjected to distress caused by the (iii) Studies have shown that trees soil beneath the structure swelling as a within 20 feet of foundations have caused direct result of increased soil moisture differential movements in foundations. ' content. Lot surfaces must be graded to These will require more water in periods of drain away from the structure. Excess extreme drought and in some cases a root runoff should not be collected and dis- injection system may be required to main- posed of by carrying a discharge pipe tain moisture equilibrium. beneath the structure. Care should also (iv) During extreme hot and dry peri- be taken with sewage and water utility ods, close observations should be made ' lines to ensure that leaks do not develop around foundations to insure that adequate beneath the slab. watering is being provided to keep soil ' 11 ' ma be a controlling factor for determining from separating or pulling back from Y g the foundation. minimum edge beam depth. For consisten- cy with the computer study used to develop (C) Structural Parameters this design method, the design must be ' (1) Slab Shape: The slab plan geometry is gener- limited to a constant beam depth for all ally fixed by functional and architectural beams in both directions. Different beam requirements. depths may, of course, be used in the as- ' (2) Applicable Structural Systems: The design built foundation (such as a deeper edge procedure presented herein can be used for beam), however, the design in that case ribbed foundations (consisting of a uniform must be based upon the smallest beam thickness slab with stiffening beams projecting depth used. In addition, the total beam ' from the bottom of the slab in both directions) depth h shall be in no case less than 12 ", and uniform thickness foundations (a solid and the beam must extend at least 7" slab with uniform thickness and no interior below the bottom of the slab ' stiffening beams). (h >_ t + 7 "). (iii) Stiffening Beam Width: The (a) Ribbed Foundations: width of stiffening beams b affects the soil bearing capacity, the (i) Stiffening Beam Spacing: For g p y' applied shear ribbed foundations, the location of stiffen- stress, and all section properties. To ing beams is dictated mainly by the config- insure the accuracy of equations for uration of the foundation system, the struc- applied service moments, shears, and ' tural design requirements, and the wall deflections (in which b does not appear), layout of the superstructure. Beam spac- the beam width used in section property ing S shall be a maximum of 17 feet. A calculations must be limited to a range of ' minimum beam spacing S of 6 feet shall be 8" to 14 ". Within this range the flexural used in the design of ribbed slabs, howev- design is virtually unaffected by the beam width. Beam widths less than 8" wide are er, the actual spacing may be less than ; that if desired. Additional beams may be impractical due to excavation considera- ' required where heavy loads are applied to tions. Beam widths greater than 14" may the foundation, as in the case of a fireplace be used if required for bearing, however, or an interior column. in that case a width of 14" shall be used in ' When beam spacings vary, the aver- section property calculations. Stiffening age spacing may be used for design beam widths most commonly found in unless the ratio between the largest and practice are 10" to 12 ". Observations of ' smallest spacing exceeds 1.5. In that case, numerous slabs built on soils with low the design spacing shall be 0.85 times the bearing values and using larger bearing largest spacing. areas (containing a portion of the slab in Corners of ribbed foundations require addition to the beam width) have shown ' special consideration. Bending moments satisfactory performance. are biaxial near corners, affected by both b Uniform Thickness Foundations: long and short direction bending. For foun- () To design a uniform thickness dations with widely spaced ribs, the line of foundation the designer ner must first design a maximum moment around a corner may g not cross a rib. Additional ribs, or a diago- ribbed foundation for moment, shear, and nal rib extending from the corner to the differential deflection, and then convert the intersection of the first orthogonal ribs, may ribbed foundation to a uniform thickness be advisable to insure proper performance foundation using a conversion equation. at corners. The original ribbed foundation must con- ' (ii) Stiffening Beam Depth: The form to all of the moment, shear, and differ - depth of stiffening beams h is usually the ential deflection requirements for ribbed controlling parameter in the structural foundations, including the limitations on ' design of ribbed foundations. Beam depth beam spacing, depth, and width listed is the structural parameter which most above in Sections 4.2(C)(2)(a)(i) through influences the moment capacity, shear (iii). The uniform thickness of this type of ' capacity, and deflections in the ribbed foundation should be limited to a minimum foundation. Frost depth, where applicable, of 7.5 ", unless a continuous stiffening ' 12