Engineering Research Equipment Grant: Closed-Loop Cyclic Triaxial Testing System for Earthquake Engineering Research

一种声学系统， 横波和纵波速度 土壤样本中的测量结果 是在新罕布什尔州大学发展起来的。 该系统已被用于确定 声波与 传输特性和液化 沙中的阻力 该项目的目标是提高 一个现有的循环三轴土壤加载 设备，并提高速度 音响系统的运作。 目的是 为了确定该系统的能力， 研究粘土在 动态加载，具体而言： (1)残余孔隙水的生成 压力和孔隙压力变化 单个加载循环; (2)剪切模量退化和阈值 循环剪应变水平; (3)材料阻尼随循环载荷的演化 应变水平 这种新的测试系统有可能 提供关于失败的重要信息 建筑物的地基 土壤现象引起的地震 液化

An acoustic system capable of making accurate shear and compression-wave velocity measurements in soil specimens has been developed at the University of New Hampshire. This system has been used to determine the relationship between acoustic wave transmission characteristics and liquefaction resistance in sands. The objective of this project is to upgrade an existing cyclic triaxial soil loading device, and to increase the speed of operation of the acoustic system. The aim is to determine the capability of this system to investigate the behavior of clays under dynamic loading, specifically: (1) The generation of residual pore-water pressures and pore-pressure variation during individual loading cycles; (2) Shear modulus degradation and threshold levels of cyclic shear strain; (3) Evolution of material damping with cyclic strain level. This new testing system has the potential to yield important information on the failure of earth masses and building foundations during earthquakes due to the phenomenon of soil liquefaction.