大埋深粘土三轴高压卸载变形与强度特征

以取自山东巨野矿区埋深近 4 30～ 6 0 0m的深部粘土样为例 ,分析测试了土的常规物理力学性质参数。考虑该埋深土的天然应力水平及其在煤矿建井开挖中的卸载应力变化 ,在三轴伺服仪上 ,进行三向等压分别达 11MPa、12MPa、14MPa下的卸除围压、保持轴压的三轴高压卸载试验 ,分析了深部粘土三轴高压卸载变形和强度特点 ,得到了相关力学参数。成果丰富了土的高压卸载力学性研究 ,并为巨野矿区煤矿立井建设提供了工程地质基础参数

STUDY ON THE CHARACTERISTICS OF DEFORMATION AND STRENGTH OF A DEEP CLAY UNDER TRIAXIAL HIGH PRESSURE UNLOADING TEST

Taking the clay buried nearly 430-600 meters deep in Juye mine area of Shandong province as an example, the authors analyze the general physical and mechanical parameters of soil. Considering the in-situ stress level of the deep soil at such a depth and its unloading change during the excavation proceeding of the vertical shaft building in the coal mine area, a triaxial servo controlled system is used to carry out the triaxial high pressure unloading tests. The axial stress is kept constant while gradually unloading the confining pressure from 11 MPa, 12 MPa and 14 MPa isotropic stress state is proceeded. The deformation and strength of the deep clay under triaxial high pressure unloading test are then analyzed to obtain related mechanical parameters. The results enriches the studying of soil mechanical properties under high pressure unloading conditions, and provides the basic engineering geological parameters for the building of the vertical shafts in Juye coal mine area.