循环荷载作用下土工格栅拉伸试验研究

Tensile experiments of geogrids under cyclic loading

为了了解土工格栅在动力荷载作用下的软化特性,采用应力控制的循环拉伸试验对土工格栅进行研究。试验中研究了在不同循环拉力、预拉力、加载频率下土工格栅的力学性能,着重研究了各个因素对土工格栅动应变及循环软化特性的影响。试验结果表明,随着循环次数、循环拉力、预拉力的增加,动应变增大;随着加载频率的增大,在相同循环次数下,动应变减小。随着循环次数、循环拉力、预拉力的增加,软化指数减小;随着加载频率的增大,相同循环软化指数逐渐减少。

In order to investigate the strain softening characteristics of geogrids under cyclic loading, the geogrids were researched using cyclic load-extension test under stress control. The test considered mechanical properties of geogrids at different cyclic tensions, pretensions and frequencies of cyclic loading; the influences of the dynamic strain and cyclic softening characteristics were studied emphatically for every factor. It is observed that the dynamic strain increases with the cyclic numbers, cyclic tension or pretension increases; the dynamic strain decreases with that the frequency becomes higher in same cyclic times. The softening index is reduced with the increases of cyclic numbers, cyclic tension or pretension; the softening index is reduced with that the frequency becomes higher in same cyclic times.