Laserfiche WebLink
C� <br />b <br />This section discusses the seismic slope stability requirements for the design of Module 1 <br />of LF -2 at FSL. The design criteria were developed to satisfy the requirements of Title <br />27 of the California Code of Regulations (CCR), which includes an evaluation of the <br />Maximum Probable Earthquake (MPE), site design acceleration, and representative <br />ground motions. The evaluation presented in this report meets the requirements of the <br />State regulations. <br />CCR Title 27 requires consideration of the MPE for Class III landfills. MPE is defined <br />by the California Division of Mines and Geology (CDMG) as "the earthquake that is <br />likely to occur in 100 years but it is not to be smaller than the largest historical <br />earthquake." For the stability evaluations of FSL, the MPE is evaluated for faults that <br />can impact the landfill site. <br />® Title 27 CCR Section 21750(f)(5)(D) requires that a dynamic factor of safety of 1.5 or <br />greater must be achieved for the critical slope, unless a more rigorous method of analysis <br />is used that provides a quantifiable estimate of movement. It should also be <br />demonstrated that the amount of movement predicted by said calculation could be <br />tolerated without jeopardizing the integrity of the landfill. <br />The current state of practice in California, for seismic design of landfills, is to perform <br />seismic response analyses to estimate the induced accelerations within critical landfill <br />cross-sections during the design earthquakes. Yield accelerations are determined from <br />pseudo -static limit equilibrium methods using the designed landfill configurations and <br />appropriate material strengths. If induced accelerations are larger than yield <br />accelerations, seismically induced permanent displacements are calculated along the <br />critical failure plane. Since this is a rigorous method of analysis, the use of a factor of <br />safety of 1.5 for dynamic stability is not applicable. Based on the RCRA Seismic Design <br />Guidance (U. S. EPA, 1995), a permanent displacement of less than 6 to 12 inches along <br />the critical failure plane is considered acceptable. <br />®\\SACRFPI\COMMON\sacDP12002\PR.1\PJ8\83\835608.2bz.doc EMCOWOWT, Inc. <br />Rev. 0, 07/31/02 <br />4-1 <br />