硬石膏常规三轴压缩下强度和变形特性的试验研究  

Experimental investigation on strength and deformation properties of anhydrite under conventional triaxial compression

作　　者：郭印同[1] 杨春和[1] 

机构地区：[1]中国科学院武汉岩土力学研究所岩土力学与工程国家重点实验室,武汉430071

出　　处：《岩土力学》2010年第6期1776-1780,共5页Rock and Soil Mechanics

基　　金：国家重点基础研究发展计划(973)(No.2010CB226701);国家自然科学青年基金(No.50904062)

摘　　要：采用伺服刚性试验机对硬石膏进行了不同围压下的常规三轴试验,研究了硬石膏的强度和变形特性。结果表明,在低围压下硬石膏破坏方式为剪切破坏;在围压超过10MPa时,硬石膏表现出明显的塑性流动特性。观察试验后试样发现,在围压为18MPa时,硬石膏已经没有明显的破坏面,而是表现出明显的膨胀现象。硬石膏的峰值强度与围压近似成正比例关系。分析了峰值应变、弹性模量随围压的变化规律,其结果表明:随着围压的升高,硬石膏的的峰值应变与弹性模量均逐渐增加。根据三轴试验结果绘制了摩尔包络线,采用回归分析得到了强度准则和抗剪强度参数c、φ值,其研究结果可为地下工程提供参考与借鉴。Experiments were carried out to study the strength and deformation properties of anhydrite under conventional triaxial compression by servo-controlling testing machine. The experimental results indicated that failure surface was shear failure under low confining pressure; when the confining pressure up to 10 MPa,anhydrite behaves obvious plastic flow characteristic; under confining pressure of 18 MPa,these was no obvious failure surface ,that is shown volume expansion. It is approximately linear relationship between peak strength and confining pressure. The peak strain and elastic modulus varieties under different confining pressures were also analyzed. The results indicate that the peak strain and elastic modulus increase with confining pressure increase. Protracted Mohr circle envelope curve using triaxial compression results. Regression analysis strength criteria and shear strength parameters c、φ ,the presented results can be expected to provide useful references to the analysis of underground engineering.

关 键 词：硬石膏 三轴试验 强度特性 围压 应力-应变曲线 

分 类 号：TU452[建筑科学—岩土工程]