Investigation of the Effects of the Nortridge Earthquake of 17 January 1994 on Muncipial Solid Waste Landfills

9422161卡瓦赞健联邦法规要求，位于地震影响区的城市固体废物填埋场的设计应能抵御地震危险。废物库的地震响应是令人关注的，因为动态荷载可能会在垃圾、衬砌和覆盖系统、基础及其界面内产生相对运动。这些移动可能会损坏衬垫系统，导致密封性丧失，和/或扰乱渗滤液和气体收集系统的功能。关于垃圾填埋场在地震震动期间的性能，特别是关于用含有土工合成材料的复合衬垫系统建造的垃圾填埋场的抗震性能的现场数据相对缺乏。1994年的北岭地震提供了有关垃圾填埋场对强烈地震震动的反应的重要观测数据。发生强烈震动(基岩峰值加速度为0.2克至超过0.5克)的垃圾填埋场，包括两个采用土工合成衬垫系统的垃圾填埋场，研究小组在事件发生后立即进行了检查。这些垃圾填埋场都没有显示出任何严重不稳定的迹象，但有几个垃圾填埋场因破裂而遭到破坏。由于实验室评估废物材料的动态特性存在困难，这些现场观测为反算动态强度和变形特性提供了宝贵的机会。其中一个堆填区(OII)配备了测量纪念碑、倾斜仪和两个强震记录站。该项目的目标是：1.收集记录在1994年北岭地震中强烈摇晃的固体废物填埋场的地震性能的观测数据。2.整理现有的垃圾填埋场特性数据，包括垃圾填埋场特性(成分、龄期、容重、含水率、强度和剪切波速)和垃圾填埋场几何形状的特性。3.对五个重要的填埋场实例进行了初步的一维等效线性和非线性动力响应分析，以及OII填埋场的二维等效线性动力响应分析。进行拟静力极限平衡和Newmark类型的地震变形分析，以反算最小动强度值，并校准流行的抗震设计程序。***

9422161 Kavazanjian Federal regulations required that municipal solid waste landfills located in seismic impact zones be designed to resist earthquake hazards. The seismic response of waste repositories is of concern because dynamic loads may produce relative movements within the waste, liner and cover systems, foundation and their interfaces. These movements could damage the liner systems, with a consequent loss of sealing, and/or disrupt the function of the leachate and gas collection systems. There is a relative lack of field data regarding landfill performance during earthquake shaking, particularly with respect to seismic performance of waste fills constructed with composite liner systems containing geosynthetics. The 1994 Northridge Earthquake provides important observational data on the response of landfills to strong levels of earthquake shaking. Landfills which experienced strong levels of shaking (peak bedrock accelerations of 0.2 g to over 0.5g), including two with geosynthetic liner systems, were inspected by the research team immediately after the event. None of these landfills showed any signs of major instability, but several experienced damage due to cracking. Because of the difficulties associated with laboratory evaluation of the dynamic properties of waster materials, these field observations present an invaluable opportunity to back-calculate dynamic strength and deformation properties. One of the landfills (OII) is well instrumented with survey monuments, inclinometers and a pair of strong motion recording stations. The objectives of the project are to: 1. Gather observational data documenting the seismic performance of solid waste landfills strongly shaken by the 1994 Northridge earthquake. 2. Organize existing landfill characterization data, including characterization of the waste fill properties (composition, age, unit weight, moisture content, strength, and shear wave velocity) and landfill geometry. 3. Perform preliminary one-dimensional (1-D) equivalent linear and nonlinear dynamic response analyses of five important landfill case records and 2-D equivalent linear dynamic response analyses of the OII landfill. Perform pseudo-static limit equilibrium and Newmark-type seismic deformation analyses to back-calculate minimum dynamic strength values and to calibrate prevalent seismic design procedures. ***