静动荷载下桩网结构路基模型试验研究

通过室内模型试验测试了桩网结构路基各部分在动静两种荷载下的桩-土应力、格栅拉力，研究了土拱效应的发展演化机制以及土工格栅拉膜效应的发展特点。试验结果表明：桩-土应力以及格栅拉力的分布都是路基横截面方向上大于其纵向延伸方向，这与路基的梯形截面设计相关；空间土拱效应要强于平面土拱效应，空间土拱效应的极限状态出现在桩-土应力比为3.8时，平面土拱效应的极限状态出现在桩-土应力比为2.2时；动荷载下土拱效应较静载有一定的衰减，且静载下土拱效应越强的部位在动载的下衰减程度越大，桩间土压力随振次的发展趋势类似N型，与桩顶土压力的变化趋势正好相反。

Model tests on geogrid reinforced pile supported embankment under static and dynamic loads

The pile-soil stress and grid tensile force of each part of the geogrid reinforced pile supported embankment were detected through laboratory model tests under both dynamic and static loads, and the development and evolution mechanism of soil arching effect and the development characteristics of geogrid stretching effect were studied. The test results show that the distributions of pile-soil stress and grid tension are greater in the transverse direction of the subgrade than that in longitudinal extension direction, which is related to the design of the trapezoidal section of the subgrade; the spatial soil arching effect is stronger than the planar soil arching effect, and the limit state of the spatial soil arching effect when the pile-soil stress ratio is 3.8, the limit state of the plane soil arching effect appears when the pile-soil stress ratio is 2.2; the soil arching effect under dynamic load has a certain extent attenuation comapated with under static load, position with stronger soil arching effect under static load has a greater attenuation degree under dynamic load, the development trend of the soil pressure between the piles with the vibration frequency is similar to the N-type, which is exactly the opposite of the change trend of the soil pressure on the top of the pile.