中文摘要：

通过对-6℃的冻结兰州黄土在1～15 MPa的围压范围内进行一系列的三轴试验,分析其变形和强度特性.研究发现,随着围压的增大,冻结兰州黄土的初始切线模量近似线性增大,当围压大于11 MPa时又随围压的增大近似线性减小,其应力-应变曲线既有应变软化又有应变硬化特征.根据Hoek-Brown强度准则及包络线理论,建立冻结兰州黄土的非线性强度准则,以描述冻土强度随围压非线性变化的现象.

英文摘要：

In order to study the deformation and strength behaviors of Lanzhou frozen loess,a series of triaxial compression tests have been conducted under confining pressure varying from 1MPa to 15 MPa at-6 ℃.The results show that the approximate linear of initial tangent modulus increases with the increase of confining pressure while it decreases when the confining pressure is more than 11 MPa,and the shape of the stress-strain curve presents both strain hardening and strain softening.Meanwhile,the nonlinear strength criterion is built based on Hoek-Brown strength criterion and the envelope theory to reflect the nonlinear relationship between strength and confining pressure.