磷石膏动残余变形特性试验研究

Experimental study on dynamic residual deformation characteristics of phosphogypsum

为分析云南某磷石膏库堆积坝在地震作用下的永久变形,采用英国GDS-DYNTTS型微机控制振动三轴试验系统对堆积坝料进行动力残余变形特性的试验研究。试验结果表明:同一固结比,当围压和动应力水平较低时,残余剪应变γ_(d)和残余体应变ε_(VI)与lg(1+N)在双对数坐标中能较好拟合;当围压和动应力水平较高时,试验开始阶段试验数据与拟合曲线会产生偏差,但是随着振次增加,实验曲线与拟合曲线能较好重合。此外,残余体应变斜率c;与剪应变γ_(d)拟合度较好,而C_(dr)/S_(1)^(2)与剪应变γ_(d)拟合关系较离散,通过改进沈珠江模型,调整应力水平指数,拟合关系离散程度大大减小。

In order to analyze the permanent deformation of the accumulation dam of a phosphogypsum reservoir in Yunnan under the action of earthquake,the British GDS-DYNTTS microcomputer-controlled vibration triaxial test system was used to test the dynamic residual deformation characteristics of the accumulation dam material.The test results show that with the same consolidation ratio,when the confining pressure and dynamic stress levels are low,the residual shear strain γ_(d) and the residual volume strain ε_(VI) and lg(1+N)can fit well in the double logarithmic coordinate.When the confining pressure and dynamic stress levels are high,there will be deviations between the test data and the fitted curve at the beginning of the test but as the vibration frequency increases,the experimental curve and the fitted curve can better coincide.In addition,the residual volume strain slope cvr and the shear strain γ_(d) have a good fit,while the fitting relationship between C_(dr)/S_(1)^(2)~2 and the shear strain γ_(d) is relatively discrete.By improving the Shen Zhujiang model and adjusting the stress level index,the degree of dispersion of the fitting relationship is greatly reduced.