Loading...
HomeMy WebLinkAboutSubsoils Report for Foundation DesignPage I of14 't t"" Soil Investigation, Branded Rock Ranch, Gapfield'Go-rRd 209 " a.: -.r' , ti " GOODRICH ENGINEERM{G .fi r.r.c*;5i* '..! 't' Rex Goodrich. Plesident 23-38 Mor[uneut Road" Grafld Jtrirctio[ CO 815O7 e70-250-3358 rcx. gootlrich4S€t) gmai l.con't 'l'iebacks. (icology. I logy. I)ri I I ing-C'otrsult:rttt" s;Wa ouI"s.rr-tC-orrc cILockSocotcch(;n ciI [']n nccrulg RE: Soil Investigation, Branded Rock Ranch, Garfield Co Hwy 209' Debeque CO. (revised due to site conditions after open hole inspection). Nate, Per your request, Goodrich EngineeringLLC (GELLC) personnel completed a geotechnical subsurface study at the planned residence at Branded Rock Ranch approximately 20 miles northwest of Debeque CO. The location map is shown in Figures I and2. Test pit photos are shown in Figwes 3 and4- Two test pits were excavated to about 10 ft depth. Bedrock was not encountered. No groundwater was found. The purpose for the exploration pits was to visually inspect the subsurface and to collelt ;:ilruffir"# underlying soil for determination of the structural stability of the soils as a I Nate Porter Porter Homes Grand Junction, CO 81507 office@si norterhomes.com (e70\ 2ss-7077 Goodrich Engineering LLC 7 7 tbm2ypy/3t / darle Job 91-16 Oct13,2025 -lJ \ \ .-R E\l n t\l V) ==u ,$t[ S.ss\ .\ N tr a +Oct 16,2025 Page2 of14 Soil Investigation, Branded Rock Ranch, Garfield Co Rd 209 Figure 1. Location of Site. Northwest of Debeque, CO on Garfield Co Hwy 209. Figure 2. Detailed Site Location. Site is Northwest of Branded Rock Lodge. Two Test Pits Were Dug in Area Depicted in Yellow. Laboratory tests were performed on representative soil samples to determine their relative engineering properties. Samples were taken in a quasi-undisturbed manner using 2.S'inch Shelby tubes and as grab sampies. This letter contains general recommendations for the construction of a residential foundation but is not a foundation design and cannot be used as such. Geology/Soil/Rock Type: The soil consisted of sandy silty clay with rock fragments. Small amounts of sulfates exist but not enough to cause collapse upon dissolution' The rock strata in the canyon surrounding the building site consists of Green River Goodrich Engineering LLC Oct 16,2025 Page 3 of 14 Soil Investigation, Branded Rock Ranch, Garfield Co Rd 209 Formation. The strata are composed mostly of dolomitic marlstone that erodes into shale-like fragments of rock. Above the Green River Formation at the tops of the canyon there exists sandstone outcrops from the Uinta Fm. The silty clay will likely collapse (10% or more) upon wetting and loading. A graph of the 2 lab tests are shown in Figures 5 and 6. The soil is hard but contained smali open voids or vesicles. lt appears that when wetted and loaded the soil closes in on the voids. There was no tendency to swell. Groundwater was not encountered in either test pit. Groundwater fluctuation can be caused by seasonal precipitation and irrigation. The soil will provide a good substrate for the concrete foundation. Attention to details will be important during the soil preparations described below. Figure 3. Test Pit Locations. (above) West Test Pit, 10 ft Deep. The Colluvium is Composed of Material from the Green River Fm that Makes up the Ctiffs Surrounding the Vatley. It is Mostly Sandy Fragments of Rock and Silty Clay. (right) East Test Pit. Same Materials Found in Both Pits. Separation was About 50 ft. Goodrich Engineering LLC Oct 16,2425 Page 4 of 14 This site is located in an al fan that was Soil Investigation, Branded Rock Ranch, Garfield Co Rd 209 Figure 4. Photo of the Western Test Pit Dug to Approximately 10 ft. down thefrorn water to the is north Foun dation Recommendations: If a small amount of movement can be tolerated the soil at this site should be suitable for a shallow foundation. (A spread-footing-type foundation (footing and stem-wall) or a slab-on' grade type foundation). As a general rule, it is recommended to elevate the foundation of the home as much as possible for drainage' Given the potential for a large amount of collapse, a 2-ft to 3-ft of over-excavation is recommended. The native soil is strong but requires removal and replacement with added moisture and compactive effort with heavy equipment to gain the strength increase. The native soil may be used as structural fill after removal and replacement with moisture density control' SwelVConsolidation testing was completed on two samples from the site. The first (Figure 5) is the soil in its native state with no change to moisture content or existing void ratio. This test indicates a of 1300 The second sample was the same soil but was moisture conditioned first, then compacted and then tested in the same manner. This sample demonstrated a laboratory bearing hi Goodrich Engineerin g LLC Qct 16,2425 Page 5 of 14 One-Oimensionol Consoldotion by ASTM D2435 - Melhod B Sumary Rcport ,s 0.m G. --,-_--G-'*_ -e -'-_e ---_ .g o6; 5 EIliI oro 015 020 lm Sb6:.9:l rm00 One-Dimensional Conso[dation by ASTM 02435 'Melhod B Sumary Reorl 40? 0.m +-.- -'__-G----- _.-+-___-o g 002 d E H t6 oor 0.6 0s 100 rm Stra:.?. p:f 1fi00 Soil Investigationo Branded Rock Ranch, Garfield Co Rd 209 Figure 5. Consolidation Test of the Native SoiI at 4 ft. Consolidation Occurred After the Wetting and Loading. Strength Gain was Low Indicating the Soil is Not Compacted well Insitu. Figure 6. Consolidation Swell Test of a Moisture Conditioned and Compacted Sample Recovered from a Depth of 4 Ft. Minimal Collapse Occurred after Wetting and Load. Bearing Capacify of this SamPle is About 4500 Psf. capacity of after allowing 2Vo settlement of approximately 4500 psf. This test is shown in Figure 6. The difference in performance of these two samples demonstrates the importance of proper Goodrich Engineering LLC Oct 16,2025 Page 6 of 14 Soil Investigation, Branded Rock Rancho Garfield Co Rd 209 compaction methods and that the native material will be adequate to use for structural fill. The lab tests are conducted on small samples and cannot reflect the open depositional structure of the native alluvial fan deposit. Therefore, the strengths for bearing capacity must be reduced to account for the o'scale'o loss in the sampling and testing. Once the soil is removed, the bottom of the excavation should be soaked thoroughly to allow moisture to penetrate as deeply as possible into the soil underlying the foundation. Allow the water to soak in and sit for several hours, at least. Afterwards, compact with heavy equipment (wheel rolled orheavy vibratory compactor). Finish the compaction after scarifuing and wetting. Then compact the native subgrade to at least 90% Modified Proctor' Two options for bearing capacity are given below. One for 3 ft of remove and replace and another for 2 ft of remove and replace. Both provide a robust foundation but at different design loads. 3-ft Over Excavation Option: Fill the footing area with 3 ft of structural fill (may be native or imported structural fill) compacted in 8-inch-thick lifts to 90o/o Modified Proctor. All structural fill shall be 3-inch-minus A schematic of the foundation template for the 3-ft remove and replace is shown in Figure 7a, The bearing capacity of this native but reconditioned soil structure compacted in the lab is approx. 4J00 psf. Given that the native soil was especially weak and that we can only influense tlie streneth of the soil removed and the immediate base of the open hole" use a maximum bearing capacitv of 3000 psf for desien Use a minimum deadload of 500 psf if pssible. Figure 7a. Schematic of the Planned Foundation. Over-excavate 3 ft of Soil Then Scarify the Bottom of the Open Hole About 6-inches and Flood with Water. Allow to Soak in Several Hours Then Recompact Until Hard. Then Commence Filling the Open Hole with Structural Fill. f-inch Thick Lifts with Moisture Density Control. Concrete Foottitg atlve or Structnral to Scarlfy About % It aad Recompact rrith 90% Modifi ed Proctor. Final grade backfill (approx.) Existing grade (approx.) 3fl thick t/2ft thick Goodrich Engineerin g LLC Oct 16,2025 Page 7 of 14 Soil Investigation, Branded RockRanch, Garfield Co Rd 209 2-ft Over Excavation Ootion: Fitl the footing areawith.2 ft of structural fill (may be native or imported structural fill) compacted in 8-inch-thick liffs to90Yo ModifiedProctor. Al[ sfiuctural filI shall be 3-inch-minus. A schematic of the foundation template for the 2-ft remove and replace is shown in Figure 7b. The bearing capaorty of this native but reconditioned soil structure compacted in the lab is approx. {J00 psf. Given that the native soil was especially weak and that we can only influe4ce the strength of the soil removgd and the immediate base of the open hole. use a maximum bearins capacitv of 2500 psf for desien. Asgumine a footinq width of 30 inches. the load transferred to 2 ft below the concrete will be about 60% of the 2500 psf or about 1500 psf. Use a minimum deadload of 500 psf if possible. Figure 7b. Schematic of the Planned Foundation. Over-excavate 2 ft of Soil Then Scarify the Bottom of the Open Hole About 6-inches and Flood with Water. Allow to Soak in Several llours Then Recompact Until Hard. Then Commence Filling the Open Hole with Structural Fill. 8-inch Thick Lifts with Moisture Density Control. Excavation Observation: GELLC personnel should be contacted to observe the foundation soils after the excavation has been completed and prior to placing forms or concrete. The purpose of this is to observe the type and condition of the foundation soils throughout the excavation. If the soils are found to differ from those encountered in our exploration pit, or if they are unstable, additional recommendations may be required prior to construction of the Existing grade St€m Wall Concrete Footilrg or Structural Modlfied Scarify About %ft rrnd Recompact with 90% Modified Proctor' Final grade (approx.)(approx.) backfill 2fr thick u2ft thick Goodrich Engineerin g LLC Oct 16,2025 Page 8 ofl4 Soil Investigation, Branded Rock Ranch, Garfield Co Rd 209 foundations Surface Water and Groundwater: Foundatiqn drains are not required f-or this structure. For protection of the foundation, drains may be installed to collect excess surface and groundwater to divert this water away from the foundation of the house, garage, and other out- buildings. Example drawings of drains, foundation and downspout, are shown in Figures 8 through 11 along with instructions for construction and notes to the owner and contractor. The minimum gradient of the drains shall be lyo. Adequate site drainage should be provided in the foundation areas both during and after construction to prevent the ponding of water and the wetting or saturation of the subsurface soils. We recommend that the ground surface around the structures be graded so that surface water will be carried quickly away from the buildings. The minimum gradient within 10 feet of the buildings will depend on surface landscaping. We recommend that paved areas maintain a minimum gradient of 2%v and that landscaped areas maintain a minimum gradient of \Yo. It is further recommended that roof drain downspouts be carried at least 5 feet beyond all backfilled areas and discharged a minimum of 10 feet away from the structures. Proper discharge of roof drain downspouts may require the use of subsurface piping in some areas. Under no circumstances should a'dry well discharge' be used on this site, unless specifically cited by a Geotechnical Engineer. Planters,if any, should be constructed so that moisture is not allowed to seep into foundation areas or beneath slabs or pavements. The existing drainage on the site rnust either be maintained carefully or improved. We recommend that water be drained away from struchres as rapidly as possible and not be allowed to stand or pond near the building. We recommend that water removed from one building not be directed onto the backfill areas of adjacent buildings. We recommend that a hydrologist or drainage engineer experienced in this area be retained to complete a drainage plan for this site. Should an automatic lawn irrigation system be used on this site, we recommend that the sprinkler heads, irrigation piping and valves be installed no less than 5 feet from the buildings. In addition, these heads should be adjusted so that spray from the system does not fall onto the walls of the buildings and that such water does not excessively wet the backfill soils. It is recommended that lawn and landscaping inigation be limited, to prevent undesirable saturation of subsurface soils orbackfilled areas. Several methods of irrigation water control are possible, to include, but not limited to: Goodrich Engineering LLC Oct 16,2025 Page 9 ofl4 Soil Investigation, Branded Rock Ranchn Garfield Co Rd 209 r Metering the Irrigation water. r Sizing the irrigation distribution service piping to limit on-site water usage. r Encourageefficientlandscapingpractices. c Enforcing reasonable limits on the size ofhigh-water usage landscaping for each lot and any park areas. o Incorporating'xeriscaping' landscaping and irrigation techniques. A plastic membrane placed on any crawlspace gound surfaces may retainltrap excessive amounts of water beneath the membrane. If future moisture problems develop or are anticipated, the Foundation Design Engineer or the Geotechnical Engineer may require that the mernbrane be partially or completely removed from the crawlspace area. Provided all recommendations found herein pertaining to site surface drainage, grading and soil compaction are closely followed, a perimeter foundation drain would not be required. For fully finished basements, however, the use of a perimeter foundation drain Would significantly reduce potential moisture related problems which can arise from subsequent area development. BackfiIl: To reduce settlement and aid in keeping water from reaching beneath this building, all backfill around this building should be mechanically compacted to a minimum of 90o/o of its maximum modifi.ed proctor dry density (ASTM D-1557). The only exception to this would be the components of the perimeter foundation drain, if any. All backfill should be composed of the native soils and should not be placed by soaking, jetting, or puddling. A1l backfill placed in utitity trenches around this strucfule or below foundation walls should be mechanically compacted to a minimum of 90% of its maximum modified proctor dry density (ASTM D- 1557). These soils should be placed at a moisture content conducive to the required compaction (usually proctor optimum contentt2o/o). Cement Type: Type IT, Type I-II, or Type IT-V cement is recommended for all concrete in contact with the soils on this site. The sulfates at this location are not unusually high but do exist. CDOT concrete mixes (Class D structural concrete) are highly recommended including mitigation for ASR. Goodrich Engineerin g LLC Oct 16,2025 Page l0 of14 Soil Investigation, Branded Rock Ranchn Garfield Co Rd 209 Senate BilI 13 (CRS 6-6.5-101) Discussion: This residence is being constructed on foundation soils that do possess a "slight potential for expansion." We recommend that the owner receives a copy of this swnmary report on our soil analysis and site recommendations. Limitations: This report is issued with the understanding that it is the responsibtlity of the owner or his representative to ensure that the information and recommendations contained herein are brought to the attention of the architect and engineerfor the project and are incorporated into the plans. In addition, it is the ovtner's responsibility that the necessary steps are taken to see that the contractor and their subcontrqctors carry out these recommendations during construction. Thefindings of this report are valid as of the present date. However, changes in the conditions of a property can occur with the passage of time, whether they be due to natural processes or the worlcs of man on this or adjacent properties. In addition, changes in acceptable or appropriate standards may occur or may resultfrom legislation or the broadening of engineering lvtowledge. Accordingly, thefindings of this report may be invalid, wholly, or partially, by changes outside our control. Therefore, this report is subject to review and sltould not be relied upon after a period of 2 years. The recommendations of this report pertain only to the site investigated and assume that the soil conditions do not deviate from those described in this report. If any variations or undesirable conditions are encountered during construction or the proposed construction will dffirfrom that planned on the day of this report, GELLC should be notified so that supplemental recommendations can be provided, f appropriate. GELLC makes no wananty, either expressed or tmplied, as to thefindings, recommendations, specifications or professional advice, except that they were prepctred in accordance with generally accepted professional engineering practices in thefield of geotechnica I engine ering. Please contact me if you have any concerns or questions. Respectfully ll* e./t Rex Goodrich PE PG Goodrich Engineerin g LLC 970-2s0-33s8 www. goodrichengineering.net t, Goodrich Engineerin g LLC act16,2025 Page ll of14 Soil Investigation, Branded Rock Ranch, Garfield Co Rd 209 Figure 8. Example Downspout Drains to Carry Water Away from the Foundation. cnrncAl DRANAGE ZOI'[ 7f,1€ rHt r+iD'Dt 0t tHE ofldilAr ElrAvlroJ ultt (vaPrEs - yrN,[ul. s 6 fLEr fRov ou,rr,flc) ROoF SOL PF[P,{itD l' to t' oEtP tO Lr},OSU#e. usa top uifi ug ffi Fuxtt aidld l€Hsc^Pfrc' EffiAr€S frHil M'gnc{ AA4rf ffi: oolrfiscour--1 6ROIJll0 SLOpt ACfOSS L N0SC P?N6 rlr{osclPt F eP,c Bglrr tH cR{rr.ly'tulc}l CwER I I In 6 $ Z 6 I I I In tHE ilAttt sols ga-ow lHf 'crdnc^L oRANlcf ?ff.' ro a€ R!'roRX€O r CO|PACIX? FAe it u'{rur or r? AdlEs sorl 9 ci(nt!,Frl IH'CXNESSr I}_l r lfllt lHlCl(NESSTl=.-l STRUCTURAL FILL couPActFo 'D pt|lYtzt o 0 0 0 aoc o o;?'i i !i;r'i o ooi {ioa a o o ao ono a FILL TO EXTENO BENEATH . ALL FOUNDANON EIEMINI5-,wat€R sfFP 6€ rHE FO0iloAnON m 50t^5 oc o oo o o o o o. .t'...t.r.'.. r tt..a...a6 0 060 0 0 0aa SEE NO]ES o o o SXCIV tOJ o o ;;t;;r'i;'!'i;ot GEBTEXTILE FABRIC a such os Contech C-180 ,NST/AIL OFA,N AS REAJ'RFD AY EA'G'NFER. or Mirofi 500-X AS REOUIREDSEE NO]T.S FOR OETAILS. pRATNAGE / LANDSCAPINT CONCIPT 'No wA R TONF' BY FOI NNATION cn,ncAL mt6c tllE ltoD f tlJE oRrdxn txcAvAnoN uvtf SOlt PRIFIRED 5' to 8' OECP rO l,trrosclpE tFa}JrotEs *ltlJrN ll,E'cf,nc^[ oRlll?^GE Zoilr, foor Dorwspotrta ffidto stoPE rcposs t-/rltosf,8il6 lrr8 ilAn'rE SotS *1Ol{ tHtclAL DPTTINACE Zailatr$*m I MFACp A HHYUP OF I? INOIES II'E sc'L aAo<nu C',iPACIED 70 NIMYII€ -.'z ar 9ltr(l!ral Allr tFllt IHICXIIESS tL-l to af !+,rtEP 6E Fr6S BE FA)NOANN fo F8 sdtS PVC oallHiGf,P'PE rnli" THTCKNESSI r STRUCruRAL FILLEXArVitAfi U'Ut_ooo0 000too coooao;?';; r';i.: i i tiil'i i ./ NLL TO EXTEND BENEATH ALL FOUNDANON FTEMTA/TS. sFE iroTEso o o oo o a c o . . ta... .. .ooa9 oao0;?'jifji..oo GEOTEXTII,E FABRiCsuch os Con*ech C-180 INSIAI ONA'N AS RSOUIRED 9Y ENdNETR.or Mlrofl 500-X AS REOI,JIREDsFf NOIES FOR DETAILS' DRAINAGI / LANDSCAPING CONCTPT 'NO WA R ZONE' BY FOU NI]ATION Goodrich Engineerin g LLC Oct 16,2425 Page 12 of 14 Soil Investigation, Branded RockRanch, Garfield Co Rd 209 Figure 9. Example Foundation Drains to Carry Water Away from the Foundation. \\ covP^cl€o AACKNIL TO TNE 'RAINEX:T\O JP AND FLAOF SI.AB oo o o o o o oo o o.O.O-O'o' o.O. ' 'O'O,O.O! SfRUCTURAL I'ILI. SANO or GRAWL FLOOR 0rS TAI'CE CNGINEER V;.o.'Drip !rrigotion' A'loscd ;n l4;s A'eo, 0o Not Peqglll)lq-lle-!1bto.e covPAcE0 BACKFILL co*PAcl{D AAC}<NLL -ALL Irr;qat:on Piping, Volves o"d so'inklers to be OulS|DE o'Vemb'4"e. o .; o oo o o ,; ?' .; :"; .; :' ,; .; 9'.; _ 8.o_8E .o .o. o'o oo .; ,;r OEEP'R IS BEIIEN.OEIPIR IS AEIIER, SPREAD FOOTING WAIL_ON:GRAQE NO STRUCIURALfILL or Non-PERMEABLE FILL oooo " , o o oo o o :' .;.;?'i?' PERMEA.ELE STRUCTURAL_fILL EXT[I',D UPPER VEVBRANE IO COLTECT SURFACE 9RAINACE STE \OTES GEOVEVBEA\E TO EX:E\D i.rP SrDi *JALL. l" 6" A80VE PVC rilP!:. :l^sa o' ieF\c.l GRADEDrc l-\Av.'ui-r' I sctlARCI. poss:bre Locotio., ROOF DRA|N prPt (So{id PVC). REOUiRED SURTACE COLLECiION PIPE BEDOED IN CRAVEL, WRAPPTD WITFI (Pe.forcied PVC). FILTTR FAgRIC. t,OW PIAST,C SILTY CLAY COVPACTEC PERVEABL:, CCi'4FACT:T) SA\D or 6RAVILLY SANt i zo oz)o IXir::.lDEc :c i,lr0!Ri. v;NG 'Bl DR0(iK' J B zo oz Jo l: G:OCO\,IPOS'T[ Sr-'ErlS o. VEi?iiCAL DRA'NS VAY LTE .JS:J. GEOV!.VBRANT SE' NOIES ;oo oi gRAi\ Priri sHoull 8E 8F.Ol/ d^iil il;: BASiul\l/Srf-v w^ii. )Rl:\ iV:rL i'i'{FoRM tlisT lr "J* ;:[,lreQAi!0 cvc P.Pf ClAili.J oe/ !O-1!,S .-- -- ,- ,taAPrti) tJr r'.' :i::Iil rA:ll c. DIEP MOISIURI BA&RIIR & AREA DRAINS- EELOW HiLLSIDE DRAINING IOWAB!- Goodrich Engineerin g LLC Oct 16,2025 Page 13 of14 Soit Investigation, Branded Rock Ranch, Garfield Co Rd 209 Figure L0. General Notes for Drains and Compaction. I . The drain trench to be located at the base and exterior limit of any structural fill or below the base of the exterior foundation's elements. Excavate any trenching as narrow as practical. Observe sloping or bracing, as required by the appropriate OSHA requirements. 2. The sides and bottom of the trench is to be smooth and must be graded to drain to "Daylighf' discharge or SumP. 3. The minimum trench and pipe gradient is to be lYo. If daylight discharge is not possible a sump and pump must be used. 4. A geomembrane barrier is to be placed on the foundation side extended away from the foundation and toward the drain. The geomembrane barrier is to be placed beneath the drain as a water channel and extend up 3 inches to 6 inches above the drainpipe. 5. All cut and graded earth surfaces in contact with the geomembrane to be smooth, free of pockets, no loose rocks and have no sharp projections or a protective geotextile or sand cushion layer must be installed between the soil and the geomembrane. 6. In non-traffic areas, the geomembrane is to be a polyethylene or equal and to have the following characteristics: Minimum thickness ASTM D-5199 0.5mm (6-mils). In traffic areas, the geomembrane is to be a 10-mil polyethylene or equal.'7. ett;oltris in the geomembrane shall be overlapped and glued with products and in zuch a manner that conforms to the manufacturer's recommendation. If glued joints are not used the membrane edges shall be overlapped a minimum of 32 inches (09.6 m). The overlaps shatt be shingled so the exposed edges face in the same directions as the flow of water drainage. 8. A geosynthetic/composite clay liner may be substituted for the geomembrane. Confirm with the design engineer.g. A perforated plastic pipe (PVC) is to be enclosed within the geomembrane at the base of the trench. Flexible piping may be used if the backfrll is less than 5 ft deep or specifically approved by the design engineer. For critical applications, the use of flexible piping is not recommended' 10. The perfoiated plastic pipe is to be a minimum 3-inch diameter. But must be sized for the anticipated conditions if the length of perforated pipe run along gradient exceeds 200 ft. An additional perforated pipe is to be added in the trench or the pipe size increased to either 4 inch or 6-inch diameter. Confirm with the engineer. i 1. The plastic pipe must be graded to drain to the daylight discharge or a sump discharge at a minimum lo/o grade' 12. The perforated plastic pipe is to be protected from clogging. Such protection can be achieved by wrapping the pipe with a non-woven geotextile filter fabric (i.e., Amoco 4547,Contech C-50W, Mirafi l40N). 13. A permeable sand or gravel water drainage/collection medium is to be placed around and above the perforated pipe' This drainage collection medium to be compacted to at least 80% of maximum dry density, ASTM D- 1557- Place geotextile fabric at the top surface of the permeable sand or gravel medium to prevent clogging. 14. The permeable water drainage/collection medium must be protected from clogging. Protection may be wrapping the medium with a non-woven geotextile fabric such as Amoco 4547 , Corftech C-50W, Mirafi 140N (Burrito drain)' 15. All backfill cover over the sand or gravelly sand drain must be carefully placed and compacted . The backfill cover is to be placed in lifts and compacted to at least 85%o of maximum dry density ASTM D-l557. Additional compaction (min. 907o) is recommended for backfill over l8 inches above the drainpipe. 16. With the approval of the design engineer, either geocornposite drains, board drains, and edge drains may be substituted for portions of the drain shown in this drawing. 17. Required observations by the design engineer: a. Completion of trench and surface excavation/preparation, prior to membrane installation. (compaction testing) b. Perforated drainpipe or other products in place to include protection from clogging. c. Top of water drainage/collection medium. (may require soil compaction testing) d. Top and intermediate backfill (soil compaction testing) e. Final soil cover, surface graded and prior to final landscaping. Goodrich Engineerin g LLC Oct 16,2025 Page 14 of14 Soil Investigation, Branded Rock Rancho Garfield Co Rd 209 Figure 11. General Notes for the Structural Engineer and Notes to the Homeowner. Notes for the Structural Engineer: r House Plans (garage, etc) Must be Reviewed for Constructability by GE LLC Before Design Commences. No Basements Below Water Table or in Swelling Soil. o Open Excavation Inspection is Required . Top of Compacted Fill Inspection is Required r Foundation Drains lnspection Before Backfill Required (if installed) r Voided Stem Wall Inspection (void height when installed for micropiles) o Final Drainage (prior to occupation) r Do Not Route Plumbing, Elecffical, Etc Through the Void Beneath the Stem Wall (if void is used for swelling soil) Notes for the Homeowner: r Biannual Inspection of Down-Spout Drains is Recommended r Biannual Inspection of Foundation Drains is Recommended (when installed) . Annual Inspection of 12-inchvoid is Recommended (when installed). o Biannual Inspection of 6-inch Void is Recommended (when installed) o Biannual Inspection of Surface Water Drainage is Recommended (no ponding near the foundations) Goodrich Engineering LLC Oet 16,2025