开采扰动土体微观结构变异规律

Microstructure variation of disturbed soil in subsidence area

以开采扰动土体作为研究对象,进行室内模拟试验。采用KH-3000VD数字式三维视频显微系统,采集不同扰动状态下土体的微观图像,研究开采扰动对地基土体微观结构参数的影响规律。研究结果表明:土体在侧向卸载扰动条件下,颗粒分布分维随着侧向卸载扰动程度的不断增大而有所减小,并且颗粒分布分维数变化程度并不大;孔隙比随着侧向卸载扰动程度的增加有所增大,且孔隙比变化较小;土体在侧向加载扰动条件下,颗粒分布分维随着侧向加载扰动程度增大而减小;孔隙比随着侧向加载扰动程度的增大有所增大,且孔隙比变化程度较大。

Taking disturbed soil in subsidence area as the research object,indoor simulation test was conducted.A digital three-dimensional video micro system of KH-3000VD was used to collect micro images of soil in different disturbed states.The influence law of microstructure parameter when foundation soil is disturbed was studied.The results show that when soil is under lateral unloading disturbed conditions,with the increase of the lateral unloading disturbance degree,the fractal dimension of grain distribution decreases,and it changes little;the void ratio increases,and it changes little too;when soil is under lateral loading disturbed conditions,with the increase of lateral loading disturbance degree,the fractal dimension of grain distribution decreases,the void ratio increases,and void ratio fluctuates greater.