1717 ENGLAND AVE 2016-01-01 MF Import

� January 20, 2004 , HWA Project No. 2003-150-21 T100 e consists primarily of granular soils which have been�lacially overridden and are therefore ve.ry dense. 1 DAMAGE ' The west wall of the house has settled several inches. Severel level surveys have been made of various aspects of the house. We perfocmed a level survey of the interior floor ' and have shown the resulu in Figure 3. It appeazs the entire westem wall has settled, and the settlement has extended back about 8 feet on the north wall and 12 feet on the south wall. ' HWA checked the fooring depths in shallow excavallons at one location on the north wall and at the northwest comer. At both locations the stem wall plus footing was about 30 � inches high,most of which was below grade. Ted Newlander made measurements and drew a profile looking south of the entire south wall. That profile is included as Attachment 1. � GEOTECHNICAL EXPLORATIONS ' l o find the cause of the settlement HWA advanced 11 hand holes usitig several different +.ypes of hand operated drilling equipment over a period of several weeks. All holes � encountered approximately the same conditions: loose, weathered,soil and fill nver dense granulaz soil. The fill wa:.primarily granular in nature but also contained some organics and fine grained inclusions. It was generally very loose to loose. tThere was an abrupt change from the loose fill to the dense native(soil that has not been disturbed since its deposition)granular soil. The depth from the ground surface to this � break varied from 1 to 10.5 feet. We termed this as the depth to bearing surface(DTB3) and have shown the values on Figure 4. Generally, the native layer was faund to be medium to fine sand but there were larger grain sizes also. We made Dynamic Cone [ Penetrometer (DCP)measa*ements near the top of the dense material. Th�DCP is a 1/2- � inch diameter rod with a 3/4-inch diameter cone on the bottom. It is driven into the � ground with a 10-pound hammer dropping 20 inches per blow. The number of blows required to drive the cone 12 inches is approximately equal to the Standard Penetration Test"N"value commonly used in foundation design. The DCP values ranged from 31 to � 59 as shown on Figure 4. They would be expected to be higher at deeper depths. Based on this, we expect the bearing layer to be very dense native sand and gravel. I No groundwater was encountered. Based on visual observations, the topography and the geology we do not expect any groundwater neaz the surface. � I � I Linde report final 1-20-0< 2 �A CiEO$CIENCES�NC. /�