考虑干湿循环效应的砂岩边坡稳定性研究

选取安徽某矿山具有典型代表性的砂岩进行了砂岩强度干湿循环室内试验, 对干湿循环作用下砂岩强度指标衰减的变化规律进行了初步探讨; 在此基础上, 结合砂岩干湿循环效应对砂岩边坡进行了稳定性分析。研究结果表明:随着干湿循环次数增加, 砂岩质量损失率、吸水率呈正相关关系, 这是导致岩石强度衰减的重要因素; 砂岩强度、弹性模量、粘聚力则呈负相关变化, 内摩擦角呈正相关关系, 无论曲线变化趋势是增大或者减小, 其变化幅度总是先大后小, 并最终会趋于稳定; 随着干湿循环次数增加, 边坡稳定性降低, 安全系数递减。研究结果可为相关边坡设计和防护的计算参数选取提供参考。

Impact of Cyclic Wetting and Drying on Stability of Sandstone Slope

The representative sandstone of a mine in Anhui Province was selected for the laboratory test on the sandstone strength after cycles of wetting and drying, for the purpose of a preliminary investigation on the strength attenuation rule for sandstone after cyclic wetting and drying effect. Based on that, stability of sandstone slope was analyzed with the cyclic wetting and drying effect taken into account. The research results showed that, with the increased cycles of wetting and drying, sandstone mass loss rate and water absorption rate showed a positive correlation, which was an important factor leading to the rock strength attenuation, the strength, elastic modulus and cohesion showed a negative correlation, while the internal friction angle was in a positive correlation. However, the variation curves, no matter up or down, always showed a declining trend in the amplitude and tends to be stable finally. With the wetting and  drying cycle increased, the slope stability was reduced, showing a progressive decrease in the safety coefficient. This research result can be of reference for the selection of calculation parameter in slope and protection design.