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Specifications c C'G/ West Coast Geotech, Inc. • GEOTECHNICAL CONSULTANTS • June 21, 2004 W -1878 Diversified Construction 12439 SW 22 " Avenue Lake Oswego, OR 97035 Attn: Mr. Tom Clarke GEOTECHNICAL SERVICES (BOULDER WALL DESIGN REPORT) • BEVLAND OFFICE BUILDING WEST TIGARD, OREGON Gentlemen, In general accordance with our proposal of June 17, 2004, and your authorization of the same day, West Coast Geotech, Inc., is pleased to provide you with geotechnical design recommendations concerning the proposed boulder retaining walls for the above - referenced project that is generally located northwest of the intersection of SW Beveland Road and SW 72 Avenue in Tigard, Oregon. Any discussion of subsurface soil conditions that may be contained herein is not based on any actual site - specific test pits or borings since neither test pits nor borings were conducted for this project. Hence, we will make assumptions about the subsurface soil conditions in order to provide you with geotechnical design recommendations for the boulder wall design only. The subsurface soil conditions will need to be verified during construction in order to validate our geotechnical design recommendations. This report was prepared for your use in the design of the subject facility and should be made available for information on factual data only. This report should not be used for contractual purposes as a warranty of interpreted subsurface conditions • discussed herein, if any. SITE AND PROJECT INFORMATION We understand that the proposed project consists of the design and construction of two boulder walls (more or less, on the periphery of the property with an overall maximum height of 8 feet, more or less) in order to create a more level lot. One of the boulder walls will retain native cut P.O. Box 388 West Linn, Oregon 97068 503/655 -2347 FAX 503/655 -0642 Diversified Construction June 21, 2004 Page 2 while the other boulder wall will retain fill for a level parking lot, based on our telephone conversation with your Excavator on June 1, 2004. If our understanding of the project is substantially different than what we have presented in the previous paragraph, please bring" the new information to our attention as soon as possible so that we can determine if our recommendations require modification. BOULDER WALL DESIGN RECOMMENDATIONS General We have not conducted any surveying or determined any elevations; hence, we will rely on you and/or your Excavator to provide the control necessary in determining elevations, boulder wall heights and slopes. If any of these variables are significantly different (as measured by you and/or your Excavator) than what is presented herein within this report, then it is your responsibility to bring the matter(s) to our attention. Boulder Walls We recommend that 1 -1/2 ton angular boulders with a typical size of 3 to 4 feet in diameter, more or less, be used for the boulder wall planned for this project and should be selectively placed to fit "snugly" with surrounding, adjacent boulders. The attached figure(s) at the end of this report shall be used in constructing the boulder walls for this project and shall be used in conjuction with this report and not as a separate item(s): O Figure 1 for the 0 to 6 -foot tall, more or less, boulder wall (and, includes a level backslope behind the boulder wall), ® Figure 2 for the 6 to 8 -foot tall, more or less, boulder wall (and, includes a level backslope behind the boulder wall). If grading plans change and/or if the boulder wall height changes, we recommend that we be allowed to review the changes and modify any or all recommendations contained within this report. Diversified Construction June 21, 2004 Page 3 A copy of our boulder wall design calculations is provided in Appendix A for the fires provided. In general, we attempted to rely on the following factors of safety, more or less, in our design calculations: • Factor of Safety Against Sliding (Primary and Most Important Variable, in our opinion, for boulder wall design) 1:4 `minimum 1.5 or greater, preferred, • Factor of Safety Against Overturning (Secondary) — 2, minimum • Factor of Safety for Average Allowable Bearing Pressure (Secondary) — 3, minimum, • We also attempted to check the maximum toe pressure, more or Less, to determine if the maximum toe pressure exceeded what we believe was the ultimate bearing pressure (although, this check is not determined to be a critical factor for boulder wall design as this check is for critical for concrete wall design, in our opinion, because the stones do yield since the stones are essentially blocks), • The same can be said for determining the presence of negative contact pressure at the toe. Stones do yield, hence the check for determining the presence of negative contact pressure at the toe is not critically important, in our opinion, for boulder wall design. Hence, we may allow negative toe pressure to be present in our boulder wall design and do not allow this check to govern the design of the boulder wall. Our design also assume that a spoil's trench does not exist in front of the boulder wall. If your Excavator plans to borrow inorganic soil and replace the over - excavation with spoil's /organic soils in the general proximity of the proposed boulder wall locations, we recommend that we be allowed to evaluate the effect on the design of the boulder walls due to such grading/borrowing. Our design assumes that the native soils adjacent to the boulder walls generally consist of firm, approved, fine- grained silts capable of supporting an allowable bearing pressure of 2,000 psf (average). If any fill is placed in the vicinity of the boulder walls, we assume that the fills have been or will be placed, compacted and tested in lifts to dry densities of at least 95 percent of the standard Proctor maximum dry density (ASTM D698) beginning upon an approved, firm, native subgrade (reasonably level and properly benched, as necessary) capable of supporting an allowable bearing pressure of 2,000 psf (average). The fill shall consist of approved, inorganic • onsite fine - grained soils that does not contain organic or deleterious debris nor substantially containing clay or over -sized material such that compaction cannot be adequately achieved and/or tested using a nuclear densometer. Our design assumes that the excavated soils at the native, cut slopes generally consist of firm, inorganic silt/clayey silts with an approximate unit weight of 120 pcf and an intemal friction Diversified Construction June 21, 2004 Page 4 angle of 34 degrees and an allowable bearing pressure of 2,000 psf (average) with a friction factor of 0.5. Site visit(s) during excavation and construction of the boulder walls are strongly advised to confirm the subsurface soil conditions in order to validate the boulder wall designs contained herein. Our design also assumes that the boulder retaining wall will not be surcharged by the presence of nearby elevated footings and/or concrete slabs /Sport's Courts. If any of these type structures fall within the zone of influence behind the boulder wall(s), say, within an imaginary slope of 1H:1V from the inside bottom edge of the boulder wall excavation to the outside edge of any footings and/or concrete slabs /Sport's Courts, then we recommend that we be allowed to consider the effect of surcharges on the boulder wall. In addition, a nonwoven geotextile may also be recommended to separate the fine - grained soils from the drainrock on the faces of the temporary cut/fill slopes for those critical areas where footings and/or concrete slabs /Sport's Courts may be present within the boulder wall's zone of influence. We recommend that we be allowed to consider these aspects in detail for any footings /slabs in near proximity to the boulder walls. The same recommendations in the previous paragraph should be considered for any traffic surcharges that may be present above the boulder retaining wall if trucks /cars are present within the boulder wall's zone of influence. Boulder Row Construction The bottom row of stones should be embedded approximately 1 foot, more or less, below lowest adjacent grade which should be taken as the final grade on the outside portion of the wall. The subgrade should be excavated using a smooth bucket trackhoe, if at all possible unless hard rock conditions prevail at subgrade levels, and should be sloped inward and downward slightly (say, less than five degrees from horizontal) in order to aid to the overall stability of the boulder wall. The lowest level of stones should be founded on firm, native, approved, inorganic, suitable subgrade after all the unsuitable fill/topsoil, if any, has been satisfactorily removed or upon engineered fill that has been satisfactorily placed, compacted and tested in lifts beginning on an approved native subgrade. Bench cuts should be excavated in terraced areas where fills will be • placed. The purpose of bench cuts is to "key -in" the new engineered fill to the native soils in order to promote stability. A relatively clean, uniform crushed drain -type rock (on the order of 2 to 4- inches in typical diameter with little, if any, fines) should be used to help "seat" the boulder stones in place and to backfill between the existing boulder wall and the reinforced section of new boulders. Where Diversified Construction Pa topsoil is 10 be 1)10Ced Over the drcIIIII"Oek. inv such topsoil IS planned. We recommend that a 11011\v0Vell :00ote.\111e SLICh aS M1011 141N. or eillliV..der)1, 1.1e pILICed 10 Sepa1010 (11 - 0)111 - 0CI■ 1 . 1•0111 (he lOpsoil, \Ve also recommend thai a perforated drain 0-inch ADS Draup2uard or siin 1 kn dralllpipe) be 000sidcr0,.1 ror cinhecinkimi thc dimilyuck noor th b o r th d r;1 1 n hi: 2t hdiiid Fh Walk. ho pw 01 ilk: drainpipe is 10 collect any intercepted and•or shallow round■vater flow and transport the collected water to 0 suitable St01 disposal area. The drainpipe should be properlv sloped to allow IF the How or the collected water, Otherwise, water seepa nino now throuell 1110 boulder wall and saturate the low elc\ :Mons on the downhill side ot the 1)ou1d00 - the O•ners/Contractor shou ld be made aware that althow2.11 boulders are often used to construct w•alls 10 support slopes and retain there SOH is rsornc risk associated wiln the t IL ihe boulders do not nt wHI (or -him t), siond too verttictil ;Ai py2. th,:iv will he a risk that a bcnilder(s) can dislodge and fall 011 the wall and cause damaye downhill of the boulder wall. The better that the boulders Pit with each other (and incorporatiw2. an inward slope 01 the Imulder (!lirill: construction). the lower the daft:Jct. however, 11101 will :110:100 he some risl; fallin boulders 110 matter how v. the houlders (it (es)ecially ditrin:ri record earthquakes). 111'AIITATIONS 11 is rciaininic.indal citiLtlik control he e. durin the preparation and construction 01 boulder walls and boulder wall terraces. Boulder walls should be constructed ho evcricncl Boulder \Vail Subcontractors. We slroriLtly recommend that site visits he conducted 1:iy the Geotechnical himineer. on a part-tirne, as-called basis, to observe the condition 011110 sub.Jrrade at (he boulder \\ h.,0tition :!lei anon and also duriwt-!, boulder wall construction. A noal silo visit should he conducted alter completion 0 the boulder wall. Uthery, Ise. without the 01(0 0101)5 FCCOIllilleildCd. our desien nine he invaliddice,ated and/or we will not he able to write, a final letter that addresses compliance with our recommendations. I so required by the Cii v. there 10 a substantial lapse of time between tile suhmission of this report and the start t d work • at the site, if conditions have changed due to natural causes of construction operations at or adjacent to the site, or if the basic project scheme is significantly modified from that assumed, it is recommended that this report be reviewed to determine the applicability of the conclusions and recommendations considering the changed conditions and time lapse. • Diversified Construction June 21, 2004 Page 6 Unanticipated soil conditions are commonly encountered and cannot be fully determined merely by producing a boulder wall design report without any field explorations. The actual subsurface conditions may be significantly different than what is assumed herein in this letter report. Such unexpected conditions frequently require that additional expenditures be made to attain a - properly constructed project: Therefore - a° contingency fund is to- accommodate such potential extra cost. Be advised that the Local Governing Agency may sometimes require additional geotechnical or other studies in order to approve the project as part of the planning approval/building permitting process. Our Boulder Wall Design Report(s) does not guarantee that the project will be approved by the Local Governing Agency without these additional studies, if required by the Local Governing Agency, being performed. Expenses incurred in reliance upon our Report(s) prior to final approval of the Local Governing Agency are the exclusive responsibility of the Client. In no event shall West Coast Geotech, Inc., be responsible for any delays in approval which are not exclusively caused by West Coast Geotech, Inc.. We trust that this letter -report is sufficient to meet your current needs. If you have any questions, please call at your convenience. Sincerely, P®04 WEST COAST GEOTECH, C. S� ®E & ®� ift Immo *. By l Y / 1 � r ( OBEGON Michael F. Schrieber, P.E. • o. 20, V341 (4 Geotechnical Engineer • .e,Vtee' President C:W1878.DOC SEE JUNE 21, 2004, LETTER FOR MISCELLANEOUS BOULDER WALL DESIGN AND GRADING RECOMMENDATIONS. FALL PROTECTION NOT SHOWN; HOWEVER, OWNER SHALL CONSIDER FALL PROTECTION FOR TALL BOULDER WALLS.. • Embed bottom row of boulders at least 1 foot below lowest adjacent grade. Bottom row should have a minimum boulder base width of 3 feet. Install geotextile over the drainrock blanket before placing topsoil, if any, over drainrock. Also, place geotextile up against � 1/4H:1V fine- grained soil cutbank if I C Rock I`__ L•�.!A 4 \ concrete slab /patio or LL 'Ai-'ig ' ��], '. pavement structure or footing �`i ; , ,; ` �, is adjacent to boulder wall. co r '�;�, ` ;, I 1 � „ � However, call Geotechnical O - .. -11 , 1 _4,),=. !' II ", 1 — I �,. Engineer first in order to , I W I : . ,. :� determine the effect of 0 1 ' J A surcharge on the boulder 1 411 wall. 1/4H:1V INSTALL 4 -INCH PERFORATED DRAIN PIPE WITHIN CRUSHEDROCK DRAIN BLANKET (MINIMUM 12 INCHES THICK) AND CONNECTPIPE TO STORM DISPOSAL SYSTEM NOTES: 1. USE 1 -1/2 TON STONES (ABOUT3 TO 4 FEET IN DIAMETER,NOT ROUND), 2. USE CRUSHED DRAIN ROCK(TYPICALSIZE OF 2 TO 4 -INCH, IN DIAMETER,WITH LITTLE, IF ANY, FINE SAND /SILT FRACTION), 3. EXCAVATEAND CREATE SLIGHT INWARD AND NOT TO SCALE DOWNWARD SLOPED BENCH(NOT GREATER THAN :'` " FIVE DEGREES FROM HORIZOMAL)` .. • ._. B �/ AND O YC � igard, Oregon � Jl� D1N . ' . IN FIRM; NATIVE "'� � "' -' "' `"` " ' " � "_ _ ~� � T �� . • SOIL BELOW TOPSOIUEXISTING FILL. CALL FOR SITE VISIT PRIOR TO PLACING FIRST ROW OF TYPICAL BOULDER WALL BOULDERS. CROSS- SECTION (0 to 6 -foot height) 4. SELECTBOULDERSTO FIT "SNUGLY ". BREAK COMPACTED FILUNATIVE SOIL ROUND BOULDERSTO CREATE FACES TO AID THE JUNE, 2004 W -1878 FITTING PROCESS. DO NOT BUILD BOULDER WALL WEST COAST GEOTECH, VERTICALLY. Geotechnical Consultants FIG. 1 West Linn, Oregon SEE JUNE 21, 2004, LETTER FOR MISCELLANEOUS BOULDER WALL DESIGN AND GRADING RECOMMENDATIONS. FALL PROTECTION NOT SHOWN; HOWEVER, . OWNER SHALL CONSIDER FALL PROTECTION FOR TALL BOULDER WALLS.. • Embed bottom row of boulders at least 1 foot below lowest adjacent grade. Bottom row should have a minimum boulder base width of 4 feet. Use two stones wide, if necessary, to obtain minimum boulder width. Install geotextile over the drainrock blanket before placing topsoil, if any, over 1/4H:1V drainrock. Also, place w WI Crushed Rock ‘lir e:A r geotextile up against • w `/ ,i � , ■ r �� fine- grained soil cutbank if c° 1 1■�1 ,;t`i1� j concrete slab /patio or � u ; j ; pavement structure or footing adjnt to b wall. � � i ':��'% % However, call Geotechnical : �ii�1 g. En is Engineer firstin order oulder to r. 1141,i1 � ' ` Is determine the effect of ma :. surcharge on the boulder 1/4H:1 V wall. INSTALL 4 -INCH PERFORATED DRAIN PIPE WITHIN CRUSHEDROCK DRAIN BLANKET (MINIMUM 12 INCHES THICK) AND CONNECTPIPE TO STORM DISPOSAL SYSTEM NOTES: 1. USE 1 -1/2 TON STONES (ABOUT3 TO 4 FEET IN DIAMETER, NOT ROUND), 2. USE CRUSHED DRAIN ROCK(TYPICALSIZE OF 2 TO 4 - INCH, IN DIAMETER, WITH LITTLE, IF ANY, FINE SAND /SILT FRACTION), . 3. EXCAVATE AND CREATE SLIGHT INWARD AND NOT TO SCALE .... -- BOWNWARD SEOPEDBENCH(NOT GREATER THAN BEVLANU OFFI'CE•BUILDING - 1 FIVE ' DEGREES °FROM`HORIZONTAL)'IN" NATIVE "" "" ` SOIL BELOW TOPSOIUEXISTING FILL. CALL FOR T Oregon SITE VISIT PRIOR TO PLACING FIRST ROW OF TYPICAL BOULDER WALL BOULDERS. CROSS - SECTION (7 to 8 -foot height) 4. SELECT BOULDERSTO FIT "SNUGLY ". BREAK COMPACTED FILUNATIVE SOIL ROUND BOULDERSTO CREATE FACES TO AID THE JUNE,2004 W -1878 FITTING PROCESS. DO NOT BUILD BOULDER WALL WEST COAST GEOTECH, VERTICALLY. Geotechnical Consultants FIG. 2 West Linn, Oregon APPENDIX A BOULDER WALL CALCULATIONS Boulder Wall Stability Calculations Pg 1 of 3 Project: Bevland Office 1 West Coast Geotech, Inc. Project Number: W -1878 • Date: 6/19/2004 ! 6 !Wall Height (feet) Figure 1: 0 to 6 feet Properties of Boulder Wall and Retained Soil 3 Boulder Diameter (feet) 1.25 Boulder Weight (tons) Number of Stones in Cross Section 1 Number of Stones in Bottom Row 1 Number of Stones in Second Row Number of Stones in Third Row Number of Stones in Fourth Row Number of Stones in Fifth Row Number of Stones in Sixth Row Weight of Crushed Rock Behind Wall Width of Crushed Rock Blanket (feet) Unit Weight of Crushed Rock (pcf) 22.66667 Wall /Soil Friction Angle (2/3)Intemal Friction Angle 0 Angle of Backslope (Degrees) Batter of Base ( x Hor.: 1 Vert.) Ka= 0.282715 34 Internal Friction Angle of Retained Soil (degrees) 120 Unit Weight of Retained Soil (pcf) 0.5 Coefficient of Friction at base of wall (mu) 6000 Ultimate Soil Bearing Pressure (psf) Surcharge !Total Surcharge Pressure (psf) Additional Horizontal Force on Wall Additional Horizontal Force (pounds) Height from bottom of wall to Horizontal Force (feet) 1.68767 FS(sliding) FS >1.5? Yes 35.62932 FS(overtuming) FS >2? Yes 2.55187 FS(toe soil bearing) FS >1? Yes 2351.217 Q(min) Q(min)>0? Yes 633.9993 Average Contact Pressure psf 9.463733 FS(ave. soil bearing) FS >3? Yes Boulder Wall Stability Calculations Pg 2 of 3 Project: Bevland Office 1 West Coast Geotech, Inc. Project Number: W -1878 Date: 6/19/2004 ( 6 (Wall Height (feet) Calculation Page #1 Weight Moment Row Height x x1 =x +d /2 Count? W1 W 1 *x1 5000 8161.122 6th row 16.5 0.727234 2.227234 0 0 0 5th row 13.5 0.595009 2.095009 0 0 0 4th row 10.5 0.462785 1.962785 0 0 0 3rd row 7.5 0.330561 1.830561 0 0 0 2nd row 4.5 0.198336 1.698336 1 2500 4245.841 Bottom 1.5 0.066112 1.566112 1 2500 3915.28 2.526117 Batter of WaII (deg) 0.044075 Row Height x x2 =x1 +d Count? W2 W2 *x2 0 0 6th row 16.5 0.727234 5.227234 0 0 0 5th row 13.5 0.595009 5.095009 0 0 0 4th row 10.5 0.462785 4.962785 0 0 0 3rd row 7.5 0.330561 4.830561 0 0 0 2nd row 4.5 0.198336 4.698336 0 0 0 Bottom 1.5 0.066112 4.566112 0 0 0 Row Height x x3 =x2 +d Count? W3 W3 *x3 0 0 6th row 16.5 0.727234 8.227234 0 0 0 5th row 13.5 0.595009 8.095009 0 0 0 4th row 10.5 0.462785 7.962785 0 0 0 3rd row 7.5 0.330561 7.830561 0 0 0 2nd row 4.5 0.198336 7.698336 0 0 0 Bottom 1.5 0.066112 7.566112 0 0 0 Row Height x x4 =x3 +d Count? W4 W4 *x4 0 0 6th row 16.5 0.727234 11.22723 0 0 0 5th row 13.5 0.595009 11.09501 0 0 0 4th row 10.5 0.462785 10.96279 0 0 0 3rd row 7.5 0.330561 10.83056 0 0 0 2nd row 4.5 0.198336 10.69834 0 0 0 Bottom 1.5 0.066112 10.56611 0 0 0 Row Height x x5 =x4 +d Count? W5 W5 *x5 0 0 6th row 16.5 0.727234 14.22723 0 0 0 5th row 13.5 0.595009 14.1)9501 0 ,,.::.. 0 0 , . , . 4th row 10.5 0.462785 13.96279 0 0 0 .. 3rd row 7.5 0.330561 13.83056 0 0 0 2nd row 4.5 0.198336 13.69834 0 0 0 Bottom 1.5 0.066112 13.56611 0 0 0 Boulder Wall Stability Calculations Pg 3 of 3 Project: Bevland Office 1 West Coast Geotech, Inc. Project Number: W -1878 Date: 6/19/2004 I 6 'Wall Height (feet) Calculation Page #1 Weight Moment Row Height x x6 =x5 +d Count? W6 W6 *x6 0 0 6th row 16.5 0.727234 17.22723 0 0 0 5th row 13.5 0.595009 17.09501 0 0 0 4th row 10.5 0.462785 16.96279 0 0 0 3rd row 7.5 0.330561 16.83056 0 0 0 2nd row 4.5 0.198336 16.69834 0 0 0 Bottom 1.5 0.066112 16.56611 0 0 0 5000 Total Weight (Ib) 8161.122 Total Moment (lb -ft) 1666.667 Total Weight per lineal foot of wall (Ib) 1.632224 Centroid Distance from toe (feet) Xc 2 Centroid Distance for Active Pre. Yp 25.19278 Wall Friction Angle #DIV /0! Backslope Angle 0.282715 Coefficient of Friction Rankine 1.559193 1 1 0.687303 0.559193 0.440807 Active Pressure 610.6642 P(total) =0.5 * k * UN.WT * (H)A2 + Ps *k *H 235.3312 F(wall)= P(total)sin d 1901.998 N =W + F(wall) Sliding 950.9989 F(resisting) =N (mu) Ib 563.498 F(driving) = P(total)cos d Ib 1.68767 FS(sliding) Note: FS >1.5? Overturning 1221.328 0 0 5280.613 M(resisting)= Xc W cosw + (Base)P(total)sin d Ib -ft - 148.2098 M(applied)= [Yp[P( total ) - Pscosw- P(add)cosw] +Hcosw /2* Ib -ft Pscosw +h(add)cosw *P(add)cosw]cosd 35.62932 FS(overturning) Note: FS >2? Soil Bearing 2351.217 2:55187 FS(bearing)=Q(allowable)/Q(max) _ Note: FS >1? < • • - 1.354274 e=[M(applied) - M(resistin9)]/N`+ Base /2 feet _ .> , • 633.9993 contact pressure psf - 1083.218 Q(max) =(N /(base)) *(1 +6e /Base) 2351.217 Q(min) = (N/base)) *(1 -6e /Base) Note: Q(min)>0? Boulder Wall Stability Calculations Pg 1 of 3 Project: Bevland Office 1 West Coast Geotech, Inc. Project Number: W -1878 Date: 6/19/2004 I 8 Wall Height (feet) Figure 2: 7 to 8 feet Properties of Boulder Wall and Retained Soil • 3 Boulder Diameter (feet) 1.25 Boulder Weight (tons) Number of Stones in Cross Section 1 Number of Stones in Bottom Row 1 Number of Stones in Second Row 1 Number of Stones in Third Row Number of Stones in Fourth Row Number of Stones in Fifth Row Number of Stones in Sixth Row Weight of Crushed Rock Behind Wall Width of Crushed Rock Blanket (feet) Unit Weight of Crushed Rock (pcf) 22.66667 Wall/Soil Friction Angle (2 /3)Internal Friction Angle 0 Angle of Backslope (Degrees) Batter of Base ( x Hor.: 1 Vert.) Ka= 0.282715 34 Internal Friction Angle of Retained Soil (degrees) 120 Unit Weight of Retained Soil (pcf) 0.5 Coefficient of Friction at base of wall (mu) 6000 Ultimate Soil Bearing Pressure (psf) Surcharge (Total Surcharge Pressure (psf) Additional Horizontal Force on Wall Additional Horizontal Force (pounds) Height from bottom of wall to Horizontal Force (feet) 1.456599 FS(sliding) FS >1.5? No, but close enough 14.51199 FS(overturning) FS >2? Yes 3.555653 FS(toe soil bearing) FS >1? Yes 1687.454 Q(min) Q(min)>0? Yes 972.7889 Average Contact Pressure psf 6.167834 FS(ave. soil bearing) FS >3? Yes Boulder Wail Stability Calculations Pg 2 of 3 Project: Bevland Office 1 West Coast Geotech, Inc. Project Number: W -1878 Date: 6/19/2004 1 8 1Wall Height (feet) Calculation Page #1 Weight Moment Row Height x x1 =x +d /2 Count? W1 W1 *x1 7500 12737.52 6th row 16.5 0.727234 2.227234 0 0 0 5th row 13.5 0.595009 2.095009 0 0 0 4th row 10.5 0.462785 1.962785 0 0 0 3rd row 7.5 0.330561 1.830561 1 2500 4576.402 2nd row 4.5 0.198336 1.698336 1 2500 4245.841 Bottom 1.5 0.066112 1.566112 1 2500 3915.28 2.526117 Batter of Wall (deg) 0.044075 Row Height x x2 =x1 +d Count? W2 W2 *x2 0 0 6th row 16.5 0.727234 5.227234 0 0 0 5th row 13.5 0.595009 5.095009 0 0 0 4th row 10.5 0.462785 4.962785 0 0 0 3rd row 7.5 0.330561 4.830561 0 0 0 2nd row 4.5 0.198336 4.698336 0 0 0 Bottom 1.5 0.066112 4.566112 0 0 0 Row Height x x3 =x2 +d Count? W3 W3 *x3 0 0 6th row 16.5 0.727234 8.227234 0 0 0 5th row 13.5 0.595009 8.095009 0 0 0 4th row 10.5 0.462785 7.962785 0 0 0 3rd row 7.5 0.330561 7.830561 0 0 0 2nd row 4.5 0.198336 7.698336 0 0 0 Bottom 1.5 0.066112 7.566112 0 0 0 Row Height x x4 =x3 +d Count? W4 W4 *x4 0 0 6th row 16.5 0.727234 11.22723 0 0 0 5th row 13.5 0.595009 11.09501 0 0 0 4th row 10.5 0.462785 10.96279 0 0 0 3rd row 7.5 0.330561 10.83056 0 0 0 2nd row 4.5 0.198336 10.69834 0 0 0 Bottom 1.5 0.066112 10.56611 0 0 0 Row Height x x5 =x4 +d Count? W5 W5 *x5 0 0 6th row 16.5 0.727234 14.22723 0 0 0 • 5th row 13.5 0.595009 14.09501 . 0 . , U.:.:.:... 0 4th 'row: 10.5 0.462785 ` 13.96279 0 : . 0 -. 0 „ ,,.., • 3rd row 7.5 0.330561 13.83056 0 0 0 2nd row 4.5 0.198336 13.69834 0 0 0 Bottom 1.5 0.066112 13.56611 0 0 0 Boulder Wall Stability Calculations Pg 3 of 3 Project: Bevland Off ice 1 West Coast Geotech, Inc. Project Number: W -1878 Date: 6/19/2004 8 Wall Height (feet) Calculation Page #1 Weight Moment Row Height x x6 =x5 +d Count? W6 W6 *x6 0 0 6th row 16.5 0.727234 17.22723 0 0 0 5th row 13.5 0.595009 17.09501 0 0 0 4th row 10.5 0.462785 16.96279 0 0 0 3rd row 7.5 0.330561 16.83056 0 0 0 2nd row 4.5 0.198336 16.69834 0 0 0 Bottom 1.5 0.066112 16.56611 0 0 0 7500 Total Weight (Ib) 12737.52 Total Moment (Ib -ft) 2500 Total Weight per lineal foot of wall (Ib) 1.698336 Centroid Distance from toe (feet) Xc 2.666667 Centroid Distance for Active Pre. Yp 25.19278 Wall Friction Angle #DIV /0! Backslope Angle 0.282715 Coefficient of Friction Rankine 1.559193 1 1 0.687303 0.559193 0.440807 Active Pressure 1085.625 P(total) =0.5 * k * UN.WT * (H) ^2 + Ps *k *H 418.3666 F(wail)= P(total)sin d 2918.367 N =W + F(wall) Sliding 1459.183 F(resisting) =N (mu) Ib 1001.774 F(driving) = P(total)cos d Ib 1.456599 FS(sliding) Note: FS >1.5? Overturning 2895.001 0 0 5098.236 M(resisting)= Xc W cosw + (Base)P(total)sin d Ib -ft - 351.312 M(applied)= [Yp[P( total ) - Pscosw- P(add)cosw] +Hcosw /2* Ib -ft Pscosw +h(add)cosw *P(add)cosw]cosd 14.51199 FS(overturning) Note: FS >2? Soil Bearing 1687.454 1555653 FS (bearing)= Q(allowable)/Q(max) • Note: FS >t ? -- 0.367328 e= [M(applied) = M(iesisting)]/N + Base /2 feet 972.7889 contact pressure psf 258.1238 Q(max) =(N /(base)) *(1 +6e /Base) 1687.454 Q(min) =(N /base)) *(1 -6e /Base) Note: Q(min)>0? , S/Ta,o({- 6 1 C'G/ West Coast Geotech, Inc. GEOTECHNICAL CONSULTANTS June 21, 2004 W -1878 Diversified Construction 12439 SW 22 Avenue Lake Oswego, OR 97035 Attn: Mr. Tom Clarke GEOTECHNICAL SERVICES (BOULDER WALL DESIGN REPORT) BEVLAND OFFICE BUILDING WEST TIGARD, OREGON Gentlemen, In general accordance with our proposal of June 17, 2004, and your authorization of the same day, West Coast Geotech, Inc., is pleased to provide you with geotechnical design recommendations concerning the proposed boulder retaining walls for the above - referenced project that is generally located northwest of the intersection of SW Beveland Road and SW 72" Avenue in Tigard, Oregon. Any discussion of subsurface soil conditions that may be contained herein is not based on any actual site - specific test pits or borings since neither test pits nor borings were conducted for this project. Hence, we will make assumptions about the subsurface soil conditions in order to provide you with geotechnical design recommendations for the boulder wall design only. The subsurface soil conditions will need to be verified during construction in order to validate our geotechnical design recommendations. This report was prepared for your use in the design of the subject facility and should be made available for information on factual data only. This report should not be used for contractual purposes as a warranty of interpreted subsurface conditions discussed herein, if any. SITE AND PROJECT INFORMATION We understand that the proposed project consists of the design and construction of two boulder walls (more or less, on the periphery of the property with an overall maximum height of 8 feet, more or less) in order to create a more level lot. One of the boulder walls will retain native cut P.O. Box 388 West Linn, Oregon 97068 503/655 -2347 FAX 503/655 -0642 Diversified Construction June 21, 2004 Page 2 while the other boulder wall will retain fill for a level parking lot, based on our telephone conversation with your Excavator on June 1, 2004. If our understanding of the project is substantially different than what we have presented in the previous paragraph, please bring the new information to our attention as soon as possible so that we can determine if our recommendations require modification. BOULDER WALL DESIGN RECOMMENDATIONS General We have not conducted any surveying or determined any elevations; hence, we will rely on you and/or your Excavator to provide the control necessary in determining elevations, boulder wall heights and slopes. If any of these variables are significantly different (as measured by you and/or your Excavator) than what is presented herein within this report, then it is your responsibility to bring the matter(s) to our attention. Boulder Walls We recommend that 1 -1/2 ton angular boulders with a typical size of 3 to 4 feet in diameter, more or less, be used for the boulder wall planned for this project and should be selectively placed to fit "snugly" with surrounding, adjacent boulders. The attached figure(s) at the end of this report shall be used in constructing the boulder walls for this project and shall be used in conjuction with this report and not as a separate item(s): • Figure 1 for the 0 to 6 -foot tall, more or less, boulder wall (and, includes a level backslope behind the boulder wall), • Figure 2 for the 6 to 8 -foot tall, more or less, boulder wall (and, includes a level backslope behind the boulder wall). If grading plans change and/or if the boulder wall height changes, we recommend that we be allowed to review the changes and modify any or all recommendations contained within this report. Diversified Construction June 21, 2004 Page 3 A copy of our boulder wall design calculations is provided in Appendix A for the fires provided. In general, we attempted to rely on the following factors of safety, more or less, in our design calculations: ® Factor of Safety Against Sliding (Primary and Most Important Variable, in our opinion, for boulder wall design) 1:4 `minimum 1.5 or greater, tom)= SY' ,referred P ® Factor of Safety Against Overturning (Secondary) — 2, minimum O Factor of Safety for Average Allowable Bearing Pressure (Secondary) — 3, minimum, ® We also attempted to check the maximum toe pressure, more or less, to determine if the maximum toe pressure exceeded what we believe was the ultimate bearing pressure (although, this check is not determined to be a critical factor for boulder wall design as this check is for critical for concrete wall design, in our opinion, because the stones do yield since the stones are essentially blocks), B The same can be said for determining the presence of negative contact pressure at the toe. Stones do yield, hence the check for determining the presence of negative contact pressure at the toe is not critically important, in our opinion, for boulder wall design. Hence, we may allow negative toe pressure to be present in our boulder wall design and do not allow this check to govern the design of the boulder wall. Our design also assume that a spoil's trench does not exist in front of the boulder wall. If your Excavator plans to borrow inorganic soil and replace the over - excavation with spoil's /organic soils in the general proximity of the proposed boulder wall locations, we recommend that we be allowed to evaluate the effect on the design of the boulder walls due to such grading/borrowing. Our design assumes that the native soils adjacent to the boulder walls generally consist of firm, approved, fine- grained silts capable of supporting an allowable bearing pressure of 2,000 psf (average). If any fill is placed in the vicinity of the boulder walls, we assume that the fills have been or will be placed, compacted and tested in lifts to dry densities of at least 95 percent of the standard Proctor maximum dry density (ASTM D698) beginning upon an approved, firm, native subgrade (reasonably level and properly benched, as necessary) capable of supporting an allowable bearing pressure of 2,000 psf (average). The fill shall consist of approved, inorganic onsite fine - grained soils that does not contain organic or deleterious debris nor substantially containing clay or over -sized material such that compaction cannot be adequately achieved and/or tested using a nuclear densometer. Our design assumes that the excavated soils at the native, cut slopes generally consist of firm, inorganic silt/clayey silts with an approximate unit weight of 120 pcf and an intemal friction Diversified Construction June 21, 2004 Page 4 angle of 34 degrees and an allowable bearing pressure of 2,000 psf (average) with a friction factor of 0.5. Site visit(s) during excavation and construction of the boulder walls are strongly advised to confirm the subsurface soil conditions in order to validate the boulder wall designs contained herein. Our design also assumes that the boulder retaining wall will not be surcharged by the presence of nearby elevated footings and/or concrete slabs /Sport's Courts. If any of these type structures fall within the zone of influence behind the boulder wall(s), say, within an imaginary slope of 1H:1V from the inside bottom edge of the boulder wall excavation to the outside edge of any footings and/or concrete slabs /Sport's Courts, then we recommend that we be allowed to consider the effect of surcharges on the boulder wall. In addition, a nonwoven geotextile may also be recommended to separate the fine - grained soils from the drainrock on the faces of the temporary cut/fill slopes for those critical areas where footings and/or concrete slabs /Sport's Courts may be present within the boulder wall's zone of influence. We recommend that we be allowed to consider these aspects in detail for any footings /slabs in near proximity to the boulder walls. The same recommendations in the previous paragraph should be considered for any traffic surcharges that may be present above the boulder retaining wall if trucks /cars are present within the boulder wall's zone of influence. Boulder Row Construction The bottom row of stones should be embedded approximately 1 foot, more or less, below lowest adjacent grade which should be taken as the final grade on the outside portion of the wall. The subgrade should be excavated using a smooth bucket trackhoe, if at all possible unless hard rock conditions prevail at subgrade levels, and should be sloped inward and downward slightly (say, less than five degrees from horizontal) in order to aid to the overall stability of the boulder wall. The lowest level of stones should be founded on firm, native, approved, inorganic, suitable subgrade after all the unsuitable fill/topsoil, if any, has been satisfactorily removed. or upon engineered fill that has been satisfactorily placed, compacted and tested in lifts beginning on an approved native subgrade. Bench cuts should be excavated in terraced areas where fills will be placed. The purpose of bench cuts is to "key -in" the new engineered fill to the native soils in order to promote stability. A relatively clean, uniform crushed drain -type rock (on the order of 2 to 4- inches in typical diameter with little, if any, fines) should be used to help "seat" the boulder stones in place and to backfill between the existing boulder wall and the reinforced section of new boulders. Where Diversified Construction topsoil is 10 be placed over the drainrock. i 1 any such topsoil is planned. we recommend that a nonwoven such as )ii':ti I4 0 equi \talent. be placed to separate Me drainrock rrom Me topsoil. We also recommend that a perforated drain (4-inch ADS DrainLgiard or similar drainpipe) 1 considered 1 embedment within the draintoeli; nemr tk bottom ()Idle drJin NH, 21 behind the \\ he purpose of the drainpipe is to collect any interecip0A1 istirlace tinckor shallow oround \Vatt'r now and 11211Sp011 the collected water LO a suitable storm•ater disposal area. The drainpipe should bo properly sloped to allow for the flow of the collected \vater. Other\vise. wiater mav klow 110 the boulder ',Ind saturate the lower elc\-,mons 00 the downhill side oldie hi:gilder The Owners/Contractor should be mad iware that althoutlh boulders are olten used to construct 0:t support slopes and retain rill. there still is sunk' risk associated with these It ihe H IJo clo not lit tor - knit teiliert 01 0111111 too vertical at slope, thi.tire he a risk that a houlder(s) C111 dIsiOd3le and 1111! 011 the ((:111 1111 CLIUSe dalil300 C10\1111 of Ilk' boulder wall. .1 he better that the 1)001(10(0 lit with each other (and incomoratilpa an inward slope of the boulder wall d1Iiiint2 construct ion), the lower the daiii_ter; there \\ 111 ilwti■i's he sino Mb): lallint.e boulders no 'natter how well 1110 boulders lit (especially duri102, record e It is tvcon that close quality control be ey,erersecl M1ti1100 the prepartgion t int] const ly)tilder walls and boulder terraces. Boulder walls should be consiructed hv i,...\,perienced Boulder \V"till ,Subcontractors. We stroll - recommend that site visits bc conducicci by the (i0ot0climic:11 E.iw,iik‘er. 011 Lt ptirt-0n10. t basis. 10 observe the condition olthe subieTade it the bouldel w till location tittei ancl tilso durin boulder wall consto A 1 siftt should be concluded aner completion (1) Pc boulder wall. Otherw 1110 site visits as recommended. our dcsiun may be invalidinet2,ated tind/or (00 will not be 711)10 to write 1 111111 lett€T that addresses compliance with our recommendatons. Iso required 1)y the 11 then!: is 71 •:;1.!1)Stiiii;:11 SU1)Il1IS51011 1 - ep0r1 and the stall of 1n:011 , 11 he site. if conditions have chauLted Inc to natural CW_ISCS or COYISH - Ili:6On °I:II:al ;11. 01 • adjacent 70 ilia Silo, 01" if the basic p1"01001 SChCMC IS SIL20111C11111V 1110dirlCd r1"0111 that assumed. 0 [LIS report he rc', iew ed 10 eLii the tipplicabilny oldie conclusions anti • recommendations considerin0 the chany conditions and time lapse. Diversified Construction June 21, 2004 Page 6 Unanticipated soil conditions are commonly encountered and cannot be fully determined merely by producing a boulder wall design report without any field explorations. The actual subsurface conditions may be significantly different than what is assumed herein in this letter report. Such unexpected conditions frequently require that additional expenditures be made to attain a --- constructed project: ::Therefore; - a° contingency fund is to- accommodate such potential extra cost. Be advised that the Local Governing Agency may sometimes require additional geotechnical or other studies in order to approve the project as part of the planning approval/building permitting process. Our Boulder Wall Design Report(s) does not guarantee that the project will be approved by the Local Governing Agency without these additional studies, if required by the Local Governing Agency, being performed. Expenses incurred in reliance upon our Report(s) prior to fmal approval of the Local Goveming Agency are the exclusive responsibility of the Client. In no event shall West Coast Geotech, Inc., be responsible for any delays in approval which are not exclusively caused by West Coast Geotech, Inc.. We trust that this letter -report is sufficient to meet your current needs. If you have any questions, please call at your convenience. Sincerely, a PROitt WEST COAST GEOTECH, C. A'� o t M g 14279P2 By ►'/ �' ( ORZGOw Michael F. Schrieber, P.E. � 1% 2 ( Q. Geotechnical Engineer • .9eHRt President C:W1878.DOC SEE JUNE 21, 2004, LETTER FOR MISCELLANEOUS BOULDER WALL DESIGN AND GRADING RECOMMENDATIONS. FALL PROTECTION NOT SHOWN; HOWEVER, OWNER SHALL CONSIDER FALL PROTECTION FOR TALL BOULDER WALLS.. Embed bottom row of boulders at least 1 foot below lowest adjacent grade. Bottom row should have a minimum boulder base width of 3 feet. Install geotextile over the drainrock blanket before placing topsoil, if any, over drainrock. Also, place geotextile up against 1/4H:1V fine- grained soil cutbank if w Crushed Rock I r ui± f concrete slab /patio or w ' ,■ � : pavement structure or footing j1► .� ;, ;'', is adjacent to boulder wall. 1 Z ,,` i „1 However, call Geotechnical 1 Engineer first in order to I ,IL:: •.l. determine the effect of 0 1 ;'!Ii� surcharge on the boulder 4��' wall. i I — 1/4H:1V INSTALL 4 -INCH PERFORATED DRAIN PIPE WITHIN CRUSHEDROCK DRAIN BLANKET (MINIMUM 12 INCHES THICK) AND CONNECTPIPE TO STORM DISPOSAL SYSTEM NOTES: 1. USE 1 -1/2 TON STONES (ABOUT 3 TO 4 FEET IN DIAMETER,NOT ROUND), 2. USE CRUSHED DRAIN ROCK(TYPICALSIZE OF 2 TO 4 -INCH, IN DIAMETER,WITH LITTLE, IF ANY, FINE SAND /SILT FRACTION), 3. EXCAVATEAND CREATE SLIGHT INWARD AND NOT TO SCALE -- , DOWNWARD SLOPED BENCH(NOT GREATER THAN 'BEitL iND o YCE 'BUILD .' . s — ' '''- ” " 'FIVE DEGREES FROM HORIZONtAL)'IN'FIRM NATIVE `' -'' - . , _ . _., ___ SOIL BELOW TOPSOIUEXISTING FILL. CALL FOR Tigard, Oregon • SITE VISIT PRIOR TO PLACING FIRST ROW OF TYPICAL BOULDER WALL BOULDERS. CROSS -SECTION (0 to 6 -foot height) 4. SELECTBOULDERSTO FIT "SNUGLY ". BREAK COMPACTED FILL/NATIVE SOIL ROUND BOULDERSTO CREATE FACES TO AID THE JUNE, 2004 W -1878 FITTING PROCESS. DO NOT BUILD BOULDER WALL WEST COAST GEOTECH, VERTICALLY. Geotechnical Consultants FIG. 1 West Linn, Oregon • SEE JUNE 21, 2004, LETTER FOR MISCELLANEOUS BOULDER WALL DESIGN AND GRADING RECOMMENDATIONS. FALL PROTECTION NOT SHOWN; HOWEVER, OWNER SHALL CONSIDER FALL PROTECTION FOR TALL BOULDER WALLS.. Embed bottom row of boulders at (east 1 foot below lowest adjacent grade. Bottom row should have a minimum boulder base width of 4 feet. Use two stones wide, if necessary, to obtain minimum boulder width. Install geotextile over the drainrock blanket before placing topsoil, if any, over 1/4H:1 V drainrock. Also, place w Crushed Rock ��5E! ; �Fa r geotextile up against W ' /i�; ; ,!: A� fine- grained soil cutbank if �t, ;� = '� concrete slab /patio or co ��. �i '�i� �. ,; i j�:, pavement structure or footing 1 \ o ' - is a djacent to wall. Ii�.; .... .:�� H o, t` ;JI, l Engineer firstin boulder order to OVA 1Z det ermine call the effect of Geotechnical ir '' ° "�� surcharge on the boulder I 1 /4H:1V wall. INSTALL 4 -INCH PERFORATED DRAIN PIPE WITHIN CRUSHEDROCK DRAIN BLANKET (MINIMUM 12 INCHES THICK) AND CONNECT PIPE TO STORM DISPOSAL SYSTEM NOTES: 1. USE 1 -1/2 TON STONES (ABOUT3 TO 4 FEET IN DIAMETER, NOT ROUND), 2. USE CRUSHED DRAIN ROCK(TYPICALSIZE OF 2 TO 4-INCH, IN DIAMETER,WITH LITTLE, IF ANY, FINE SAND /SILT FRACTION), 3. EXCAVATEAND CREATE SLIGHT INWARD AND NOT TO SCALE —> -. BOWNWARD •:SkOPEDBENCH(NOTGREATER THAN , -. = B EVLAN OFFICE $UltDIN G " ' FIVE 'DEGREES'FROM'HORIZONTAL)"`IN "FIRM, NATIVE' ". " °"'•- ,__r. .. .:. ,...., A . ,. . ...� , , , .- ., ., SOIL BELOW TOPSOIUEXISTING FILL. CALL FOR Tigard, Oregon SITE VISIT PRIOR TO PLACING FIRST ROW OF TYPICAL BOULDER WALL BOULDERS. CROSS - SECTION (7 to 8 -foot height) 4. SELECTBOULDERSTO FIT "SNUGLY ". BREAK COMPACTED FILUNATIVE SOIL ROUND BOULDERSTO CREATE FACES TO AID THE JUNE,2004 W -1878 FITTING PROCESS. DO NOT BUILD BOULDER WALL WEST COAST GEOTECH, VERTICALLY. Geotechnical Consultants FIG. 2 West Linn. Oregon APPENDIX A BOULDER WALL CALCULATIONS Boulder Wall Stability Calculations Pg 1 of 3 Project: Bevland Office ( West Coast Geotech, Inc. Project Number: W -1878 Date: 6/19/2004 I 6 (Wall Height (feet) Figure 1: 0 to 6 feet Properties of Boulder Wall and Retained Soil 3 Boulder Diameter (feet) 1.25 Boulder Weight (tons) Number of Stones in Cross Section 1 Number of Stones in Bottom Row 1 Number of Stones in Second Row Number of Stones in Third Row Number of Stones in Fourth Row Number of Stones in Fifth Row Number of Stones in Sixth Row Weight of Crushed Rock Behind Wall Width of Crushed Rock Blanket (feet) Unit Weight of Crushed Rock (pcf) 22.66667 Wall /Soil Friction Angle (2/3)Intemal Friction Angle 0 Angle of Backslope (Degrees) Batter of Base ( x Hor.: 1 Vert.) Ka= 0.282715 34 Internal Friction Angle of Retained Soil (degrees) 120 Unit Weight of Retained Soil (pcf) 0.5 Coefficient of Friction at base of wall (mu) 6000 Ultimate Soil Bearing Pressure (psf) Surcharge (Total Surcharge Pressure (psf) Additional Horizontal Force on Wall Additional Horizontal Force (pounds) Height from bottom of wall to Horizontal Force (feet) 1.68767 FS(sliding) FS >1.5? Yes 35.62932 FS(overtuming) FS >2? Yes 2.55187 FS(toe soil bearing) FS >1? Yes 2351.217 Q(min) Q(min)>0? Yes 633.9993 Average Contact Pressure psf 9.463733 FS(ave. soil bearing) FS >3? Yes • Boulder Wall Stability Calculations Pg 2 of 3 Project: Bevland Office 1 West Coast Geotech, Inc. Project Number. W -1878 Date: 6/19/2004 ' 6 'Wall Height (feet) Calculation Page #1 Weight Moment Row Height x x1 =x +d /2 Count? W1 W 1''x1 5000 8161.122 • 6th row 16.5 0.727234 2.227234 0 0 0 5th row 13.5 0.595009 2.095009 0 0 0 _ 4th row 10.5 0.462785 1.962785 0 0 0 3rd row 7.5 0.330561 1.830561 0 0 0 2nd row 4.5 0.198336 1.698336 1 2500 4245.841 Bottom 1.5 0.066112 1.566112 1 2500 3915.28 2.526117 Batter of Wall (deg) 0.044075 Row Height x x2 =x1 +d Count? W2 W2 *x2 0 0 6th row 16.5 0.727234 5.227234 0 0 0 5th row 13.5 0.595009 5.095009 0 0 0 4th row 10.5 0.462785 4.962785 0 0 0 3rd row 7.5 0.330561 4.830561 0 0 0 2nd row 4.5 0.198336 4.698336 0 0 0 Bottom 1.5 0.066112 4.566112 0 0 0 Row Height x x3 =x2 +d Count? W3 W3*x3 0 0 6th row 16.5 0.727234 8.227234 0 0 0 5th row 13.5 0.595009 8.095009 0 0 0 4th row 10.5 0.462785 7.962785 0 0 0 3rd row 7.5 0.330561 7.830561 0 0 0 2nd row 4.5 0.198336 7.698336 0 0 0 Bottom 1.5 0.066112 7.566112 0 0 0 Row Height x x4 =x3 +d Count? W4 W4 *x4 0 0 6th row 16.5 0.727234 11.22723 0 0 0 5th row 13.5 0.595009 11.09501 0 0 0 4th row 10.5 0.462785 10.96279 0 0 0 3rd row 7.5 0.330561 10.83056 0 0 0 2nd row 4.5 0.198336 10.69834 0 0 0 Bottom 1.5 0.066112 10.56611 0 0 0 Row Height x x5 =x4 +d Count? W5 W5*x5 0 0 6th row 16.5 0.727234 14.22723 0 0 0 5th row , 13.5 0.595009:: 14:09501 0 :. - ...:..0 .. 0: • _.,...; , .. 1 4th row 10.5 0.462785 13.96279 0 0 0 _ 3rd row 7.5 0.330561 13.83056 0 0 0 2nd row 4.5 0.198336 13.69834 0 0 0 Bottom 1.5 0.066112 13.56611 0 0 0 • Boulder Wall Stability Calculations Pg 3 of 3 Project: Bevland Office 1 West Coast Geotech, Inc. Project Number: W -1878 Date: 6/19/2004 I 6 Wall Height (feet) Calculation Page #1 Weight Moment Row Height x x6 =x5 +d Count? W6 W6 *x6 0 0 6th row 16.5 0.727234 17.22723 0 0 0 • 5th row 13.5 0.595009 17.09501 0 0 0 4th row 10.5 0.462785 16.96279 0 0 0 3rd row 7.5 0.330561 16.83056 0 0 0 2nd row 4.5 0.198336 16.69834 0 0 0 Bottom 1.5 0.066112 16.56611 0 0 0 5000 Total Weight (Ib) 8161.122 Total Moment (Ib -ft) 1666.667 Total Weight per lineal foot of wall (Ib) 1.632224 Centroid Distance from toe (feet) Xc 2 Centroid Distance for Active Pre. Yp 25.19278 Wall Friction Angle #DIV /0! Backslope Angle 0.282715 Coefficient of Friction Rankine 1.559193 1 1 0.687303 0.559193 0.440807 Active Pressure 610.6642 P(total) =0.5 * k * UN.WT * (H)A2 + Ps *k *H 235.3312 F(wall)= P(total)sin d 1901.998 N =W + F(wall) Sliding 950.9989 F(resisting) =N (mu) Ib 563.498 F(driving) = P(total)cos d Ib 1.68767 FS(sliding) Note: FS >1.5? Overturning 1221.328 0 0 5280.613 M(resisting)= Xc W cosw + (Base)P(total)sin d Ib -ft - 148.2098 M(applied)= [Yp[P( total ) - Pscosw- P(add)cosw] +Hcosw /2* Ib -ft Pscosw +h(add )cosw *P(add )cosw]cosd 35.62932 FS(overturning) Note: FS >2? Soil Bearing 2351.217 2.55187 FS( bearing ) =Q( allowable •) / Q(max) Note: FS >1? 1.354274 e`[M (applied) - M(resisting)]/N + Base /2 feet 633.9993 contact pressure psf - 1083.218 Q(max) =(N /(base)) *(1 +6e /Base) 2351.217 Q(min) = (N/base)) *(1 -6e /Base) Note: Q(min)>0? • Boulder Wall Stability Calculations Pg 1 of 3 Project: Bevland Office ( West Coast Geotech, Inc. Project Number: W -1878 Date: 6/19/2004 I 8 (Wall Height (feet) Figure 2: 7 to 8 feet Properties of Boulder Wall and Retained Soil 3 Boulder Diameter (feet) 1.25 Boulder Weight (tons) Number of Stones in Cross Section 1 Number of Stones in Bottom Row 1 Number of Stones in Second Row 1 Number of Stones in Third Row Number of Stones in Fourth Row Number of Stones in Fifth Row Number of Stones in Sixth Row Weight of Crushed Rock Behind Wall Width of Crushed Rock Blanket (feet) Unit Weight of Crushed Rock (pcf) 22.66667 Wall/Soil Friction Angle (2 /3)Internal Friction Angle 0 Angle of Backslope (Degrees) Batter of Base ( x Hor.: 1 Vert.) Ka= 0.282715 34 Internal Friction Angle of Retained Soil (degrees) 120 Unit Weight of Retained Soil (pcf) 0.5 Coefficient of Friction at base of wall (mu) 6000 Ultimate Soil Bearing Pressure (psf) Surcharge ( Total Surcharge Pressure (psf) Additional Horizontal Force on Wall Additional Horizontal Force (pounds) Height from bottom of wall to Horizontal Force (feet) 1.456599 FS(sliding) FS >1.5? No, but close enough 14.51199 FS(overturning) FS >2? Yes 3.555653 FS(toe soil bearing) FS >1? Yes 1687.454 Q(min) Q(min)>0? Yes 972.7889 Average Contact Pressure psf 6.167834 FS(ave. soil bearing) FS >3? Yes Boulder Wall Stability Calculations Pg 2 of 3 Project: Bevland Office I West Coast Geotech, Inc. Project Number: W -1878 Date: 6/19/2004 ( 8 IWall Height (feet) Calculation Page #1 Weight Moment Row Height x x1 =x +d /2 Count? W1 W1 *x1 7500 12737.52 6th row 16.5 0.727234 2.227234 0 0 0 ' 5th row 13.5 0.595009 2.095009 0 0 0 4th row 10.5 0.462785 1.962785 0 0 0 3rd row 7.5 0.330561 1.830561 1 2500 4576.402 2nd row 4.5 0.198336 1.698336 1 2500 4245.841 Bottom 1.5 0.066112 1.566112 1 2500 3915.28 2.526117 Batter of Wall (deg) 0.044075 Row Height x x2 =x1 +d Count? W2 W2 *x2 0 0 6th row 16.5 0.727234 5.227234 0 0 0 5th row 13.5 0.595009 5:095009 0 0 0 4th row 10.5 0.462785 4.962785 0 0 0 3rd row 7.5 0.330561 4.830561 0 0 0 2nd row 4.5 0.198336 4.698336 0 0 0 Bottom 1.5 0.066112 4.566112 0 0 0 Row Height x x3 =x2 +d Count? W3 W3 *x3 0 0 6th row 16.5 0.727234 8.227234 0 0 0 5th row 13.5 0.595009 8.095009 0 0 0 4th row 10.5 0.462785 7.962785 0 0 0 3rd row 7.5 0.330561 7.830561 0 0 0 2nd row 4.5 0.198336 7.698336 0 0 0 Bottom 1.5 0.066112 7.566112 0 0 0 Row Height x x4 =x3 +d Count? W4 W4 *x4 0 0 6th row 16.5 0.727234 11.22723 0 0 0 5th row 13.5 0.595009 11.09501 0 0 0 4th row 10.5 0.462785 10.96279 0 0 0 3rd row 7.5 0.330561 10.83056 0 0 0 2nd row 4.5 0.198336 10.69834 0 0 0 Bottom 1.5 0.066112 10.56611 0 0 0 Row Height x x5 =x4 +d Count? W5 W5 *x5 0 0 6th row 16.5 0.727234 14.22723 0 0 0 5th row , 13.5 0.595009 14.09501. 0 , ,.:, O. :, .. -.: 0 ., .: , .... _. , 4th row 10.5 0.462785 13.96279 0 : . . 0 , . . 0,, ... ,.,._..,,, . 3rd row 7.5 0.330561 13.83056 0 0 0 2nd row 4.5 0.198336 13.69834 0 0 0 Bottom 1.5 0.066112 13.56611 0 0 0 Boulder Wall Stability Calculations Pg 3 of 3 Project: Bevland Office 1 West Coast Geotech, Inc. Project Number: W -1878 Date: 6/19/2004 8 Wall Height (feet) Calculation Page #1 Weight Moment Row Height x x6 =x5 +d Count? W6 W6 *x6 0 0 6th row 16.5 0.727234 17.22723 0 0 0 5th row 13.5 0.595009 17.09501 0 0 0 4th row 10.5 0.462785 16.96279 0 0 0 3rd row 7.5 0.330561 16.83056 0 0 0 2nd row 4.5 0.198336 16.69834 0 0 0 Bottom 1.5 0.066112 16.56611 0 0 0 7500 Total Weight (Ib) 12737.52 Total Moment (Ib -ft) 2500 Total Weight per lineal foot of wall (Ib) 1.698336 Centroid Distance from toe (feet) Xc 2.666667 Centroid Distance for Active Pre. Yp 25.19278 Wall Friction Angle #DIV /0! Backslope Angle 0.282715 Coefficient of Friction Rankine 1.559193 1 1 0.687303 0.559193 0.440807 Active Pressure 1085.625 P(total) =0.5 * k * UN.WT * (H) ^2 + Ps *k *H 418.3666 F(wall)= P(total)sin d 2918.367 N =W + F(wall) Sliding 1459.183 F(resisting) =N (mu) Ib 1001.774 F(driving) = P(total)cos d Ib 1.456599 FS(sliding) Note: FS >1.5? Overturning 2895.001 0 0 5098.236 M(resisting)= Xc W cosw + (Base)P(total)sin d Ib -ft - 351.312 M(applied)= [Yp[P( total ) - Pscosw- P(add)cosw] +Hcosw /2* Ib -ft Pscosw+h(add)cosw*P(add)cosw]cosd 14.51199 FS(overturning) Note: FS >2? Soil Bearing 1687.454 3.555653 FS (bearing)= Q(allowable) /Q(max)• Note: FS >'h ? - 0.367328 e= M a p p lied M resistin /N + Base /2 feet . 972.7889 contact pressure psf 258.1238 Q(max) =(N /(base)) *(1 +6e /Base) 1687.454 Q(min) =(N /base)) *(1 -6e /Base) Note: Q(min)>0? n O N ®` I S x x Kt x m D ".133 g O D • o P1 Z r g ® J ° N rn r § nx r - rn PN r rn 4 c, m O z I . 4 0 mxrn yN Z N D • r 47 yy D P E- - cn 1 _ II 8/3/04 BEVELAND OFFICE BUILDINGS SITE PERMIT #s S1T2004 -00015 & SIT2004 -00014 0- "Building & Designing Fine Living & Work Space Since 1988" 12439 S.W. 22nd Ave. • Lake Oswego, Oregon 97035 • Voice 503.293.1226 o Fax 503.293.1536 • www.diversifiedconst.com • CCB# 0103025 0 N X Cn > a m 6' -0 MIN. e . r r 2• -0" U) r 1 O z L J \ 02 Bo5O ON ® .r x Z. x f 0 � f � yxx „,4%S. N, rJ . f A y o4 D^ D co -4„8 - r g 0 N Z z m N • ... 4 % � r n D x ® mzC' orn mJ v ( > = N \ /n o -I-.1 0 1 O r• ...3 Z 0 0 > 41 .0.. u 1 8/3/04 = BEVELAND OFFICE BUILDINGS - SITE PERMIT #s SIT2004 -00015 & SIT2004 -00014 "Building & Designing Fine Living & Work Space Since 1988" 12439 S.W. 22nd Ave. • Lake Oswego, Oregon 97035 • Voice 503.293.1226 • Fax 503.293.1536 • www.diversifiedconst.com • CCB# 0103025