通过控制砂粒粗细的方法自制不同孔隙度的圆形薄板试样，利用RSM−SY7基桩多跨孔超声波自动循测仪测量其孔隙度值并进行标记。利用自主研发的渗透试验装置，在DDL600电子万能试验机上进行中心受压圆形薄板试样弯曲变形过程中的渗透特性试验；研究孔隙度对圆形薄板试样轴向抗压强度、初始渗透率的影响及其对圆形薄板试样弯曲变形过程中轴向载荷与渗流量出现峰值时间差的影响，并研究圆形薄板试样弯曲变形过程中渗透率的变化规律。研究结果表明：不同孔隙度中心受压圆形薄板试样弯曲变形过程中，其渗透率均在整体上呈现先增大后减小的趋势；试样的孔隙度越大，其轴向载荷峰值Fmax、初始渗透率整体越趋于减小；当试样孔隙度较大时，其弯曲变形过程中轴向载荷F峰值先于流量Q峰值出现，反之，其流量Q峰值先于轴向载荷F峰值出现。%The circular thin plate specimens of different porosity were made by the method of controlling sand sizes. RSM−SY7 automatic ultrasonic measuring instrument with foundation piles and more cross-holes was used to measure and mark the values of porosity. Permeability test in the process of bend and deformation of thin circular plate specimens under axial compression was carried out by DDL600 electronic universal testing machine and self-developed infiltration testing device;the axial compressive strength and initial permeability of the circular thin plate specimens caused by porosity were investigated; time difference between axial load and peak of seepage flow caused by the porosity in deformation process of the circular thin plate bending specimen was explored;the permeability variation of circular thin plate specimens in the process of bending deflection was also studied. The results show that in the process of bending deflection of the circular thin plate, the permeability of the circular thin plate specimens in different porosities has a tendency of initial increase then decrease in general when the center of the circular thin plate specimens is compressed.The greater the porosity of the sample, the smaller the axial loadpeak value of Fmax and the initial permeability. When the porosity of the sample is becoming larger, the axial loadpeak value of Fmax emerges prior to the flow of Q peak. Conversely, the flow of Q peak emerges prior to the axial loadpeak value of Fmax.
展开▼
