11731 AIRPORT RD Geotech Report 2018-01-02 MF Import

06/18/2005 15:27 4257478561 GEOTECH PAGE 10 Lueia Development, LLC JN 05233 August 18,2005 paye g ins2ability. Please note that loose soil can cave suddenly and without waming. Excavation, foundation, and utility eontraetors should be made espedally aware of fhis potential danger. These recommendations may need to be modified if the area near the potentfal cuts has been disturhed in the past by utility installatan, or if setttement-senaitive utilkies are located nearby. All pertnanent cuts irrto native soil should be inclined no steeper than 2.5:1 (H:y. To reduce the potential for shallow sloughing, fill must be compacted to the face of these slopes. This can be accomplished by overbuilding the compacted flli and then trimming R back to its final inclination. Adequate compaction of the sbpe face is important for long-term stability and is necessary to prevent excessive settlement of patios, slabs, foundations, or other improvements that may be placed near the edge ot the slope. Water should not be allowed to flow uncorrtrolled over the top of any temporary or permanent slope, All permanently exposed sbpes should be seeded widl an appropriate species of vegetation to reduce erosion and improve the stability of the su�aal layer of soil. DRAlNAGE CONSlDERATIONS We recommend that Toundatlon drains be installed at the base ot all foundation and earth-retai�ing walis. These drains shouid be surrou�ded by at least 6 inches of 1-inch-minus, washed rock and then wrapped in non-vwven, geotextile fiker fabric(Mirafi 140N, Supae 4NP, or similar materiah. At its highest point, a perforeted pipe irwert should be at least 6 inches below the bottom Of a slab floor or the level of a erawl spaee, and it should be slopad for dreinage. All roof and surface water drains must be kept separete from the foundation drain system. A typical drdin detail is attached to this repoR as Plate '12. For the best long-tertn pertortnanee, perforated PVC pipe is recammended for all subsurface drains. Ground�vater was observed during our field work. If seepage is encountered in an excavation, it should be drained from the site by directing it through drainage ditches, perforated pipe, or French drains, or by pumping it from sumps interconnected by shallow connector trenches at the bottom of the exc�vation. The excavation and sfte should be greded ao that surface water is direded off the site and away trom the tops of slopes. W�ter ahould not be allowed to stand In any area where foundations, slabs, or pavements are to be canstructed. Fina1 site gradi�g in areas adjacent to buildings should alope away at least 2 percerrt, excapt where the area is paved. Surface draina should be provitletl where necessary to prevent ponding of water behind foundaHon or retaining walls. PA VEA/ENT AREAS The pavement seetion may be supported on a minimum 1 foot of granular struetural fill compaded to a minimum 95 percent density based on Modified Proctor (ASTM Test Designation D-155?). Because the sRe soils are silty and moisture sensitivp, we recommend that the pavemeM subgrade must be in a stable, non-yielding condition at the time af paving. Addfional granular structural fill and/or geotextile fabric may be needed to stabiliie soit, wet, or unstable areas. To evaluate pavement subgrade strength, we recommend that a proof roll be completed With a loaded dump truck immediately before paving. In most instanCes where unstable subgrade contlitions are encountered, an additional 12 inches of granular structural fill will stabitize the subgrede, excspt for very soft areas where additional fill could be required. The subgrade should be evaluated hy GEOTECH CONSU�TANTS,INC.