原状黄土不同应力路径下强度指标差异性试验研究

An Experimental Study on Strength Index Difference of Undisturbed Loess under Various Stress Paths

针对西安地铁工程航天大道十字隧道原状黄土,进行了常规三轴与真三轴剪切试验,按照摩尔库伦准则整理了不同中主应力比b应力状态下试样强度线,对比分析了强度指标黏聚,力、摩擦角的变化区间。结合工程实践分析表明:土体强度指标参数受应力路径彰响显著,真三轴不同应力路径剪切试验能给实际工程复杂应力状态工况提供更合理的强度指标参数。

The normal triaxial and true triaxial shear tests were carried out for the undisturbed loess in the cross tunnel of Hangtian Avenue of Xi'an metro project.According to the Mohr Coulomb criterion,the strength lines of the specimens under different b-stress conditions were arranged,and the ranges of cohesion and friction angle were compared and analyzed.It could be concluded that Strength Index was significantly different from undisturbed loess under various stress paths.For complex stress state,more reasonable strength index value were applied by true triaxial shear tests under various stress paths.