堆石料动力残余变形特性试验研究

Experimental Study on the Dynamic Residual Deformation Property of Rock-fill Materials

通过大型动三轴试验,对某水电站土石坝主堆石料的动力残余变形特性进行了试验研究,并结合数据探讨了沈珠江模型的适用性。分析表明沈珠江残余变形模型计算结果与实际结果有时存在较大偏差,不能很好地描述较高动应力情形下的动力残余变形全过程曲线。充分考虑振次和动应力比对残余变形的影响,对沈珠江模型进行了改进,使残余变形与振次的关系更符合实际。不同动应力和围压下堆石料的残余变形实测值和模型计算值对比表明,改进模型对残余体应变和残余剪应变均能较好地拟合。

The dynamic residual deformation property of rock-fill materials of an earth-rock dam was investigated through large-scale dynamic triaxial test.The applicability of Shen Zhujiang＇s residual deformation model was also discussed.The test results indicate that sometimes conspicuous deviation exists between the results of Shen Zhujiang＇s model and the actual data,which suggests that Shen Zhujiang＇s model sometimes cannot describe the entire process curve of dynamic residual deformation accurately under high dynamic stress.The influence of cyclic number and dynamic stress ratio on residual deformation was considered to modify the model proposed by Shen Zhujiang,in the purpose that the relationship between residual deformation and cyclic number could be more consistent with practice.The comparison between measured value and calculated value of residual deformation of rock-fill materials under different dynamic stresses and confining pressures shows that the modified model could accurately fit the residual volumetric strain and residual shear strain.