加筋堆石料的动残余变形特性试验研究

Residual deformation behaviors of reinforced rock-fill materials

加筋措施在土石坝的抗震加固中得到了较为广泛的运用。采用高精度的大型动力三轴仪,对两河口土石坝加筋堆石料的动力残余变形特性进行了试验研究,探讨了围压、循环荷载条件及加筋间距等对堆石料动残余变形的影响。试验结果表明:在循环荷载作用下,加筋堆石料与素堆石料的残余变形的发展规律基本一致,但加筋后堆石料的残余变形变小,且随加筋层数增加残余变形的降低愈明显。因此,扩大加筋范围、减少加筋间距是减小地震永久变形,提高抗震稳定性的有效工程措施。还根据试验结果,初步探讨了加筋对动残余变形影响的机理。

The reinforcement technology is widely used in rock-fill dams in high seismic hazard zones.The evaluation of reinforcement on deformation and safety is concerned,and it is one of the major study objectives in rock-fill engineering.The residual deformation behaviors of reinforced rock-fill materials are experimentally studies by use of a triaxial apparatus.The effects of intervals of reinforcement layers,confining pressures and conditions of cyclic loading on the residual deformation are analyzed.The results show that reinforcement improves the residual deformation behaviors of rock-fill materials.Both the residual shear strain and the residual volumetric strain are deduced.Based on the test results,the mechanism of the influences of reinforcement on the residual deformation is proposed tentatively.