Retaining wall info - Laserfiche WebLink

Home Browse Search

Page � 2 taken near Wall 2. The hand auger boring extended to d pths ranging from about 2 to 5 feet below the ground surface. Hand auger boring HAP-1 encountered about 1 1/z feet cl y fill overlying about 21/z feet of granular fill underlain by native clay soils. Borings HAP-2 and H -3 encountered about 1 to 31/2 feet of clay or clayey sand fill overlying native clays. Hand auger boring HAP-4,taken"behind" Wa112 encou tered about 5 feet of clay fill. Hand auger borings HAP-5 and HAP-6 taken at the base of Wall 2 encountered about 3 feet of organic clay. Laboratory organic content test(s) of the clay resulted ' an average organic content of about 9 1/z percent which classifies the soil as"organic". A Log of Boring sheet for each boring is attached. Soil ata boundaries were estimated based on changes in the samples recovered and the auger cu 'ngs. The strata boundaries are only approximate and the boundaries will likely occur as gra ual rather than abrupt transitions. Strata boundaries should also be expected to vary away from th boring location. The approximate boring locations are shown on the S '1 Boring Location Sketch, attached. The sketch was prepared by HGTS using a "Certificate of Su ey" of the property prepared by Sathre- Bergquist, Inc. as a base. Groundwater Conditions Groundwater was not encou ered in the hand auger borings. We made water level measurements in the borings at the times an under the conditions stated on the boring logs. The period of observation was relatively short and uctuations in the groundwater level may occur due to rainfall, flooding, irrigation, spring thaw, drainage, and other seasonal and annual factors not evident at the time the observations were mad . Design drawings and specifications and construction planning should recognize the possibility of uctuations. Discussion Based on the results of the hand auger brings completed or Wa111, it appears that the boulder wall is supported on native clay soil or clay fill that was judge to be generally suitable for wall support. We observed a layer of granular soil in boring HAP-1 tak n"behind" Wall 1 but did not observe the granular layer in boring HAP-2 which was also taken be 'nd Wall 1. It appears imported sand was used as a drainage layer,although it appears inconsistent. Draintile was not observed day-lighting through the wal or encountered in the hand auger probes. Based on conversations with the contractor, draintile w s installed and routed through the yard, day-lighting near the pond. Based on conversations with the contractor, we underst d Wall 2 is going to be reconstructed to retain less than 4 feet,and therefore it will not require to e engineered. 1 3570 GROVE ORIVE �'�78! APLE GROVE, M1� 5531 1