安阳膨胀岩重塑样三轴加卸荷试验研究  

Experimental Research on Triaxial Remolding Expansive Rocks under Loading and Unloading Conditions in Anyang

作　　者：董艳华[1,2] 程壮[3,2] 赵二平[3,2] 

机构地区：[1]三峡大学水利与环境学院,湖北宜昌443002 [2]三峡大学三峡库区地质灾害教育部重点实验室,湖北宜昌443002 [3]三峡大学土木与建筑学院,湖北宜昌443002

出　　处：《中国农村水利水电》2012年第11期80-83,92,共5页China Rural Water and Hydropower

基　　金：国家自然科学基金资助项目(50909052);三峡大学2011年研究生科研创新基金资助项目(2011CX010)

摘　　要：对取自河南安阳不同深度处的膨胀岩重塑样进行了三轴加载和卸荷试验。结果表明:加载过程中,随着围压的增大,试样的应力应变曲线形态由应变软化型逐渐向应变硬化型转变,峰值强度以及残余强度随围压的增加呈线性增大。不同卸荷量卸荷时,试样的残余强度与卸荷量呈线性正相关,相关系数在0.9左右;峰值强度和弹性模量Eur与卸荷量呈线性负相关,相关系数在0.95左右。循环加卸荷过程中,试样表现出明显的应变软化性质,试样弹性模量Eur随着循环加卸荷次数的增加而增大,且增加幅度越来越小,最终增加幅度趋近于0,稳定弹性模量Eur比初始弹模增加10%左右。因此,在膨胀岩渠道开挖、蓄水及水位降落时,应该考虑其对膨胀岩渠道稳定性的影响。This paper studies the triaxial test on remolding expansive rock under loading and unloading conditions at different depths of Anyang. The experimental results demonstrate that during the loading process, the stress-strain curve shape of the test samples transform from strain-softening to strain-hardening gradually and the peak strength and residual strength increase linearly with the increase in confining pressure. When unloading weight changes, there is a positive linear relationship between the residual strength of the sample rock and unloading weight with the coefficient of correlation about 0.9, and a negative linear relationship between peak strength, elastic modulus of the sample rock and unloading weight with the coefficient of correlation about 0.95. And, if it is in cy-clic loading and unloading process, strain-softening phenomenon is obviously visible in sample rocks. With the increase in cyclic load- ing and unloading numbers, the elastic modulus decreases, the reduction rate becomes smaller and smaller and disappears in the end, and stable elastic modulus increases about 10% relative to primary. Therefore, the influence of unloading effect on the expansive rock slope stability should be considered in the excavation, storage and the drawdown process of the expansive rock canals.

关 键 词：膨胀岩 重塑样 加卸荷 强度 弹性模量 

分 类 号：TV6[水利工程—水利水电工程]