土-地下结构界面层效应试验研究  

Experimental study of the soil-underground structure interfacial layer effect

作　　者：夏红春[1,2] 周国庆[1] 杜泽超[2] 

机构地区：[1]中国矿业大学深部岩土力学与地下工程国家重点实验室,江苏徐州221008 [2]聊城大学建筑工程学院,山东聊城252059

出　　处：《中国矿业大学学报》2011年第6期846-851,共6页Journal of China University of Mining & Technology

基　　金：国家自然科学基金项目(50974117);国家科技支撑计划项目(2006BAB16B01)

摘　　要：用粗糙钢板模拟地下结构面,利用DRS-1型超高压直残剪试验系统,研究了不同法向应力条件下福建标准中砂与地下结构接触面及界面层的剪切力学特性.结果表明:随着法向应力的改变,界面层内土体的力学特性发生明显变化.在相对低应力条件下,接触面及界面层内土体的剪切应力-剪切位移曲线均呈现出应变软化特性,但界面层内土体的抗剪强度高于接触面处的抗剪强度,发生明显的"界面层强化效应";反之,在相对高应力条件下,将发生"界面层弱化效应",即界面层内土体的抗剪强度低于接触面处的抗剪强度,接触面及界面层内土体的剪切应力-剪切位移曲线均呈现出应变硬化特性.利用"界面层效应因子"可以衡量界面层效应的类型及其强弱化程度.The DRS-1 high normal stress residual shear apparatus was used to study Fujian standard medium sand.An underground structure in the sand was simulated with a rough steel plate.The direct shear characteristics at the interface between the sand and the structure were studied at different normal stresses.It was observed that the mechanical characteristics at the interfacial layer change with changes in the normal stress.At a relatively low normal stress the stress-strain curves of soil at the interface show strain softening.In this case the shear strength of soil in the interfacial layer is higher than for the soil against the structure.On the contrary,at high normal stress levels there is an attenuation effect at the interface and the shear strength of soil in the interfacial region is lower than what is seen for soil against the structure.Under these conditions the stress-strain curves show strain hardening.An interfacial effect factor,Le,was introduced to estimate the magnitude of this interfacial layer effect.

关 键 词：土 地下结构 法向应力 界面层 界面层效应 

分 类 号：TU459[建筑科学—岩土工程]