旋喷桩复合地基变刚度处治桥头跳车效果  

Effects of jet grouting pile composite foundation with variable stiffness treating vehicle bump at bridge head

作　　者：涂义亮 王星驰 柴贺军[2] 徐建强[2] 李海平[2] 余佳玉[3] Tu Yiliang;Wang Xingchi;Chai Hejun;Xu Jianqiang;Li Haiping;Yu Jiayu(School of Civil Engineering,Chongqing Jiaotong University,Chongqing 400074,China;China Merchants Chongqing Communications Research and Design Institute Co.,Ltd.,Chongqing 400067,China;State Key Laboratory of Mountain Bridge and Tunnel Engineering,Chongqing Jiaotong University,Chongqing 400074,China)

机构地区：[1]重庆交通大学土木工程学院,重庆400074 [2]招商局重庆交通科研设计院有限公司,重庆400067 [3]重庆交通大学省部共建山区桥梁及隧道工程国家重点实验室,重庆400074

出　　处：《东南大学学报（自然科学版）》2021年第4期588-595,共8页Journal of Southeast University：Natural Science Edition

基　　金：国家自然科学基金资助项目(51808083);中国博士后科学基金资助项目(2020M673110);重庆市基础研究与前沿探索专项(重庆市自然科学基金)资助项目(cstc2018jcyjAX0491);重庆市教育委员会科学技术研究资助项目(KJQN201800713);重庆交通大学省部共建山区桥梁及隧道工程国家重点实验室开放基金资助项目(SKLBT-19-011);招商局重庆交通科研设计院有限公司自主创新课题资助项目(190828).

摘　　要：为解决软土路基桥头跳车问题,提出了旋喷桩复合地基变刚度非开挖处治技术.首先,采用二维数值模拟方法分析了桩长、桩径、桩间距、桩排数、注浆深度对处治效果的影响规律及敏感度,并基于此提出了处治方案;最后,采用三维数值模拟方法对该方案进行了分析验证.结果表明:桩长越长、桩径越大、桩间距越大、桩排数越多,沉降控制效果越好,但随着注浆深度的增大,沉降控制效果先提高后不变,且桩径、桩间距、桩排数、注浆深度存在最优值,分别为0.8m、2.0 m、2、5~8m;桩长敏感度为1.02,远大于其他参数敏感度,故采用渐变桩长实现变刚度.处治后,固结沉降被控制在内侧路基的范围,且沉降从桥头向道路延伸方向呈较好的渐变效果,有效缓解了桥头跳车现象.To solve the problem of vehicle bump at bridge head in soft soil subgrade,a no-excavation treatment technology for composite foundation using jet grouting pile with variable stiffness was proposed.First,the influences and the sensitivities of the pile length,the pile diameter,the pile spacing,the number of pile rows,and the grouting depth on the treatment effects were analyzed by two-dimensional numerical simulation method.Then,a treatment scheme was proposed.Finally,the three-dimensional numerical simulation method was used to analyze and verify the scheme.The results show that the longer the pile length,the larger the pile diameter,the larger the pile spacing and the more the pile rows,the better the settlement control effect.However,with the increase of the grouting depth,the settlement control effect first improves and then remains unchanged.And there are optimal values of the pile diameter,the pile spacing,the number of pile rows and the grouting depth,which are 0.8 m,2.0 m,2,and 5 m to 8 m,respectively.The sensitivity of the pile length is 1.02,much higher than that of other parameters.Thus,it is suggested to change the pile length to realize variable stiffness.After treatment,the consolidation settlement is controlled within the inner subgrade.And the settlement from the bridge head to the road extension direction shows a good gradual change effect,alleviating vehicle bump at bridge head.

关 键 词：桥头跳车 旋喷桩 复合地基 变刚度 处治效果 

分 类 号：U416[交通运输工程—道路与铁道工程]