1920 MERRILL CREEK PKY 2018-01-01 MF Import

��„ �� uy w�v iv�c� aicrttcn ��n�ittu�IlUfV I'H7l NU, LUti tSifb 9S3U Y� UJ . _ • .... �... 5ierra Construcdon Services, Inc. SyANiVONF�bVILSON,lNG Atln: Mr. Gcocge Constantine ' March 18, 1994 Page 3 primary modes of failun of this material. Slumping or global instability is ruely sccn in outwash. Outwa�h could continue to erode and retrcat, which could cause the overlying till and till-like soils to slab off, or along the tce of the slope the nx.ession of the outwash bluffs could trigger failunes in the flll and colluvium and perhaps impact the proposed development. 3. Golluvium. The Hkcly mode of faiture within colluvium is a planar, shallow (sucGcial) slide, and not mtational, decp-scated (global) instability. Pailure would likely occur in periods of heavy rainfall or during situations where water is introduced into the slope from ovedand flow, dawnspouts, brolaen utility Ilnes, and other means. Inslabfllty could also occur as a result of ground mwements associated with an earthquake. Failure within colluvium wnuld not likely impact the propose�l development on the upper plateau, because the development will be founded on $11- like soils. 4. Landslide DeRqsits and Fill. This is also suggested by othcr documents indicating end•dumped flll on the site. CutxenAy, the ezisting flll slopes are thought to be marginally stable. This is supported by the following obsenations: 1) these soils are in a loose stale, 2) 8l1 soils to the south pf the slte have failed on slopes as steep a9 or flatter than portions of the site, 3) there is evidence of a possible scarp along the alope, as shown on Figure 1, 4) 1,S�I:1V to 1.75H:IV are near the aegle of reposo of dumped fill, S) stumps and debris were obscrved in the fill, 6) there is evidence of c�eep within the flll. The likely mode of failure with 811 is also a planar, shallow slidq which would tend to occur during heavy rainfall or during a seismic event As in colluvlum, failu� would not likely impact the proposed upslope development, but it could impact the p�nperty below CONCLUSiONS AND RECOM ENUATIONS Based on the tesults of our ezplontions and studics and our discussions with lhe design team, it is our opinion that the site is suitabie for developmcnt and construction of the proposed facilities. Our major iecommendations in mgard to the alope aro summadzed below: ► In our opinion, development of the site as planned ahould not create a hazacd to the subject pmperty ptrnidod the recommendattons in this report ate followed. Additlonally, it is our opinion that devclopment will not adversely affcct the Fast slope or result in a decrease in the stabiliry of tlu slope. Instead, collecting and controiling surface w.�ter upslope, as part of site development, ttnd preventing its flvw over the slope should decrease the rate of futun slope erosion. AddiNonally, W-6693-01