公路工程

为探求树根桩加固高速公路岩溶地基的适宜性,选取典型岩溶地区路基进行现场载荷试验,获得树根桩单桩承载力特征值、桩间土地基承载力特征值及抗剪强度参数,并对加固后的岩溶地区路基进行施工填筑数值模拟分析。结果表明:现场载荷试验所得单桩承载力和复合地基承载力均满足工程设计要求;树根桩施工时的注浆液明提高桩间土的抗剪强度,粘聚力c提高1.75倍,内摩擦角φ提高1.45倍;数值模拟结果表明树根桩能有效加固软弱的岩溶路基,减小了岩溶地区路基的工后沉降变形。研究成果可为树根桩在高速公路岩溶路基地基处理中的应用提供参考和指导。

In order to seek for the suitability of strengthening expressway karst roadbed by root pile,the field loading test in typical karst roadbed area was selected.According to this test,the bearing capacity eigenvalue of single pile of root pile,the bearing capacity eigenvalue of foundation of soil between piles and the shear strength parameters was obtained.Meanwhile,the karst roadbed construction after being reinforced was analyzed by numerical simulation.The result shows that both the bearing capacity of single pile and the bearing capacity of composite foundation can meet the demand of engineering design.In the construction of root pile,the grouting fluid well increases the shear strength of soil between piles.The cohesion C and the internal friction angle φ increases by 1.75 times and 1.45 times.The result of numerical simulation shows that root pile can effectively reinforce the weak Karst roadbed and decrease the settlement deformation of Karst roadbed area.The research result can provide reference and guidance for the foundation treatment of expressway karst roadbed by root pile.