考虑含水率的红砂岩蠕变力学特性试验研究

Experimental study on creep mechanical properties of red sandstone considering water content

为揭示不同含水状态下红砂岩的蠕变力学特性,以0%、1.25%、3.16%和5.38%4种含水率为控制条件,开展三轴压缩蠕变试验。分析蠕变试验结果,探究不同含水条件下红砂岩应变特征、蠕变速率和长期强度的变化规律。研究发现:1)红砂岩在水和应力的作用下表现出3阶段蠕变行为,高含水率岩石在更少加载等级下发生蠕变破坏;2)红砂岩蠕变应变远大于瞬时应变,水的作用促进瞬时和蠕变应变的增长;3)含水率的升高对初始和极限加速蠕变速率的增大起到促进作用;4)红砂岩在4种含水率下的长期强度分别为22.86、21.91、16.27和10.74 MPa,长期强度随含水率的升高而逐渐降低。研究成果可为红砂岩蠕变特性研究及港口地基长期稳定性分析提供参考。

In order to reveal the creep mechanical properties of red sandstone under different water content conditions,we carry out triaxial compression creep tests under the control conditions of 0%,1.25%,3.16% and 5.38% water content,and analyze the creep test results to explore the strain characteristics,creep rate and long-term strength of red sandstone under different water bearing conditions.It is found that:1)Red sandstone shows three-stage creep behavior under the action of water and stress,and creep failure occurs in rocks with high water content under less loading levels;2)The creep strain of red sandstone is much larger than the instantaneous strain,and the action of water promotes the growth of instantaneous and creep strain;3)The increase of moisture content promotes the increase of initial and ultimate accelerated creep rate;4)The long-term strength of red sandstone under four water contents is 22.86,21.91,16.27 and 10.74 MPa respectively.The long-term strength decreases gradually with the increase of water content.The research results may serve as reference for the study of creep characteristics of red sandstone and the long-term stability analysis of port foundation.