Laserfiche WebLink
based on the laboratory test results completed on samples of the natural soils and bedrock; as well as on remolded <br />samples of the proposed fill materials. <br />For this evaluation a unit weight (soil density) of 125 pcf, a cohesion value of 2,000 psf and a phi angle of 0 were used <br />for the underlying, natural bedrock materials. A unit weight (soil density) of 130 pcf, a cohesion value of 0 psf and an <br />effective phi angle of 34 were used for the natural clays underlying the proposed embankment; whereas, a unit weight <br />(soil density) of 125 pcf, a cohesion value of 900 psf and a phi angle of 0 were used for the remolded clays to be used <br />in construction of the embankment. <br />Based on our calculations and analysis, the minimum calculated theoretical factor of safety for a failure of the <br />maximum embankment downstream section will be 2.37 under static conditions. The minimum calculated theoretical <br />factor of safety for the maximum embankment section under seismic loading will be 1.98. <br />Based on these results, we believe that the embankments that are properly constructed to the above configurations and <br />are filled to the emergency spillway elevation should be stable and perform adequately. As noted in our previous <br />reports, we strongly recommend that a representative of NWCC observe the embankment construction to observe the <br />foundation and groundwater conditions during construction, as well as be on-site to test the compaction of the fill <br />materials placed in the embankment. <br />We appreciate the opportunity, be of professional service to you in this matter. If you have any questions regarding <br />this report, or if we can be 9fiuther service, please contact this office. <br />Sincerely, N pfC'?ST <br />NWC , INC. <br />Brian D. Len, <br />Job Number: 07-7556 <br />NWCC, Inc. <br />Page 2