侧向粉喷桩变刚度处治桥头跳车效果研究  

The Effects of Lateral Powder-jet Piles with Variable Stiffness Treating Bridge Head Jumping

作　　者：涂义亮 方忠 徐建强[3] 柴贺军[3] 李海平[3] Tu Yiliang;Fang Zhong;Xu Jianqiang;Chai Hejun;Li Haiping(State Key Laboratory of Mountain Bridge and Tunnel Engineering,Chongqing Jiaotong University,Chongqing,400074,P.R.China;School of Civil Engineering,Chongqing Jiaotong University,Chongqing,400074,P.R.China;China Merchants Chongqing Communications Research&Design Institute Co.Ltd.,Chongqing,400067,P.R.China)

机构地区：[1]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 [2]重庆交通大学土木工程学院,重庆400074 [3]招商局重庆交通科研设计院有限公司,重庆400067

出　　处：《地下空间与工程学报》2021年第4期1201-1208,共8页Chinese Journal of Underground Space and Engineering

基　　金：国家自然科学基金(51808083);重庆市基础研究与前沿探索项目(cstc2018jcyjAX0491);中国博士后科学基金(2020M673110);重庆市教委科学技术研究项目(KJQN201800713)。

摘　　要：为了解决因软土路基不均匀沉降引起的桥头跳车问题,依托G15沈海高速八字桥段工程,提出了侧向粉喷桩变刚度非开挖处治方案,首先采用二维数值模拟得出粉喷桩不同处治深度的影响规律,然后采用三维数值模拟对设计方案进行了分析验证。结果表明:沉降主要发生在淤泥层,随着粉喷桩处治深度的增加,沉降控制效果逐渐变好,当桩长为42 m时,处治深度贯穿整个淤泥层,沉降控制效果最好;侧向粉喷桩较好地约束了路基土体的侧向水平位移,与周围土体形成的复合路基的竖向刚度得到增强,因而在路基沉降控制中能够发挥作用;通过对桥头段进行粉喷桩变刚度处治,使得沉降坡度减小,沿线路方向沉降呈现渐变效果,有效地缓解了桥头跳车问题。In order to solve the problem of bumping at bridge head caused by uneven settlement of soft roadbed,based on section bazi bridge of G15 Shenhai expressway,the trenchless treatment scheme of lateral powder jet pile with variable stiffness is proposed. Firstly,the influence law of different treatment depths of lateral powder jet pile was obtained by two-dimensional numerical simulation,and then the design scheme was analyzed and verified by three-dimensional numerical simulation. The results show that the settlement mainly occurs in the silt layer. With the increase of the depth of the powder sprayed pile treatment,the settlement control effect gradually becomes better.When the pile length is 42 m,the treatment depth runs through the entire mud layer,and the settlement control effect is the best. The lateral powder sprayed piles better restrain the lateral horizontal displacement of the subgrade soil,and the vertical stiffness of the composite subgrade formed with the surrounding soil is enhanced,so it can play a role in the control of the subgrade settlement. Stiffness treatment reduces the settlement slope,and the settlement along the line shows a gradual effect,effectively alleviating the problem of bridge head jump.

关 键 词：桥头跳车 侧向粉喷桩 数值模拟 变刚度 沉降 

分 类 号：U416.1[交通运输工程—道路与铁道工程]