轨道交通振动下南京片状细砂的有效应力路径及破坏模式  

Effective stress path and failure pattern of Nanjing fine sand with flake-shape structure under vibrating load of rail transit

作　　者：刘雪珠[1,2] 陈国兴[1] 

机构地区：[1]南京工业大学岩土工程研究所,南京210009 [2]江苏省岩土工程公司,南京210018

出　　处：《岩土力学》2010年第3期719-726,共8页Rock and Soil Mechanics

基　　金：江苏省自然科学基金重点项目(NoBK2006702);中国地震局地震工程与工程振动开放实验室基金(No2007A02);江苏省博士创新基金(2007)

摘　　要：以南京片状结构细砂为研究对象,采用英国WFI动静多功能三轴仪,研究了饱和南京片状结构细砂在列车振动荷载作用下静偏应力水平、循环应力比对其动力特性的影响;把振动孔压的发展与应力路径相联系,分析了循环荷载作用下不同阶段南京片状结构细砂所处的初始压密状态、压缩状态和膨胀状态的发生和发展过程;同时,根据静偏应力与循环偏应力的大小,视有无偏应力反向,南京片状结构细砂的破坏模式可分为循环活动性和塑性应变累积破坏,并对其循环活动性的机制进行了初步探讨。A series of dynamic behavior tests on Nanjing fine sand with flake-shaped structure are performed by using WFI cyclic triaxial apparatus made in England. The dynamic behaviors of Nanjing fine sand with flake-shaped structure under different static deviator stresses and cyclic stress ratios are studied. Through comparing the effective stress path under cyclic loading with static loading, the process of liquefaction of saturated flake-shaped structural Nangjing fine sand with the development of pore-water pressure, including initial compact state, compression state and dilative state, are investigated. In addition, according to different combinations of static deviator stresses and cyclic stresses, two kinds of failure patterns with deviator stress reversal or without deviator stress reversal are observed including cyclic mobility and failure of accumulation residual strain; and the mechanism of the cyclic mobility is investigated preliminarily.

关 键 词：轨道交通振动荷载 南京片状细砂 循环三轴试验 破坏模式 有效应力路径 

分 类 号：TU435[建筑科学—岩土工程]