地应力作用下软弱层带的工程特性研究

分析了勘探平洞中软弱层带取样试验存在的问题 ,研究了软弱层带受开挖松弛的影响 ,并采用了一种有效控制开挖松弛的取样办法 ,使软弱层带试验成果能反映天然地应力下的工程特性。以金沙江某水电站坝址软弱夹层为例 ,研究了地应力与软弱层带物理力学参数的关系 ,揭示了地应力是控制软弱层带工程特性最活跃的因素 ,这对岩体工程的建设和稳定性分析有指导意义。

Study on engineering properties of weak layers under ground stresses

The problems existing in the present sampling method for weak layers in exploratory adits, are discussed in this paper. Because the weak layers are easily affected by the relaxation after the excavation of exploratory adits, the test results of samples taken from exploratory adits cannot reflect the engineering properties of weak layers under natural ground stress. But the stress relaxation effect on weak layers can be avoided effectively if a special sampling method in exploratory adits is adopted.Taking the intercalations of a certain dam site in Jinshajiang River as an example, the correlations between physical and mechanical indices and confining pressure indicate that ground stress is the most important environmental factor, which controls the engineering properties of weak layers. The confining pressure effect on weak layers has a realistic significance for the construction and stability assessment of rock mass projects too.