摘要
为了研究隧道开挖过程中围岩在加卸载条件下的应力应变特性,采用TAW-2000微机控制岩石伺服压力试验机对辉绿岩进行了三轴加载和卸围压试验,通过分析岩石强度、体积变形在试验全过程中的变化规律及其与围压的关系,研究岩石的力学特性、变形特性及其破坏机理。结果表明,在卸载试验条件下,岩石在屈服破坏后,同样具有应变软化特性和破裂膨胀特性;同时,由于在卸载条件下应变能的释放,岩石应力力学特性受围压的影响表现得更为突出,其卸载岩性强度影响系数接近三轴加载岩性强度影响系数的两倍,与加载试验相比,卸载试验中岩石单轴抗压强度和三轴强度明显偏低。研究成果可为地下工程开挖过程中围岩受力变形特性研究提供参考。
In order to study the stress and strain properties and damage mechanism of underground rock engineering under loading and unloading,Triaxial loading test and unloading confining pressure test are conducted with the TAW-2000 microcomputer control servo rock compression testing machine.The results show that,plastic strain softening properties and volume expansion properties are displayed not only in loading,but also in unloading,and greatly influenced by confining pressure.At the same time,the influence coefficient of rock strength under unloading is twice under loading,and uniaxial compressive strength under unloading tests is obviously lower than under triaxial loading tests.The research results can provide the reference for studying the mechanics and deformation characteristics of underground rock engineering.
出处
《公路》
北大核心
2011年第5期131-136,共6页
Highway
关键词
岩石试验
应力应变特性
加卸载
体积应变
隧道工程
rock test
stress and strain properties
triaxial loading and unloading confining pressure
volumetric strain
tunnel engineering
