交通荷载下掺土煤矸石的永久应变特性

Permanent strain characteristics of coal gangue mixed with soil due to traffic load

借助DSZ-2型电磁振动三轴仪针对掺土煤矸石开展了一系列单向循环加载试验,以探究其在交通循环荷载作用下的轴向应变累积特性,重点考虑了循环动应力水平(CSR)与黏土掺量(w)对掺土煤矸石永久轴向应变的影响。试验结果表明,掺土煤矸石试样在不同CSR和w条件下,在循环加载过程中产生的永久轴向应变均随着循环次数的增加近似呈指数规律增长,而回弹应变基本保持恒定。通过回归分析,基于所有试样循环加载5000次后测定的永久轴向应变(ε_(a,5000)^(p))构建了ε_(a,5000)^(p)与CSR和w之间的定量关系,并通过进一步分析确定了黏土的最佳掺量为22%。

To explore the strain accumulation behavior of coal gangue samples mixed with clay soil,a series of one-way cyclic tests were conducted using DSZ-2 dynamic triaxial apparatus.The influence of cyclic dynamic stress level(CSR)and clay soil content(w)on the permanent axial strain of samples is mainly considered.The experimental results indicated that the permanent axial strain of the samples increases exponentially with the increasing cycle numbers under different CSR and w values,while the resilient strain basically keeps constant.Based on the measured permanent axial strain after 5000 cycles(ε_(a,5000)^(p)),the quantitative mathematical relationships betweenε_(a,5000)^(p)versus CSR and w values was established,through curve-fitting regression of the test data.Further analyses suggest that the optimum clay soil content is 22%.