路堤挡墙与预应力管桩连接方法现场试验研究

发布时间：2018-11-07 07:39

【摘要】：采用预应力管桩(PHC)作为路基挡土墙基础,可发挥PHC桩质量保证率高、抗压性能好的优势,挡土墙承担水平荷载的要求也给PHC桩基础与基底的连接模式提出了问题。依托广东广清高速公路扩建工程进行现场试验,研究PHC桩基础分别采用有盖板的垫层式和无盖板的嵌入式承连挡土墙基底模式的作用机制。研究表明:垫层式与嵌入式连接的PHC基础桩间土均承担主要荷载,嵌入式连接外桩与桩间土应力比更大,是垫层式两倍左右,嵌入式内、外桩承载力发挥率差别更加明显;垫层式连接基础不能阻止墙体发生偏转,嵌入式连接通过桩体的约束作用控制墙体保持位置状态稳定;垫层式与嵌入式连接的挡墙受力主要表现为底板底面沿路基方向承受拉应力,在垂直路基方向底板底面未出现零压力区;两种连接模式墙体水平位移差别不大,桩间土是承担水平荷载的主体。
[Abstract]:The use of prestressed pipe pile (PHC) as the foundation of subgrade retaining wall can bring into play the advantages of high quality assurance rate and good compressive performance of PHC pile. The requirement of retaining wall to bear horizontal load also raises the problem of connection mode between PHC pile foundation and foundation. Based on the field test of Guangdong Guangqing Expressway extension project, the mechanism of PHC pile foundation with cushion type with cover plate and embedded retaining wall with no cover plate is studied. The results show that the soil of PHC foundation bearing the main load, the stress ratio between the embedded pile and the pile is larger than that of the cushion type, and the difference of bearing capacity ratio between the embedded pile and the embedded pile is more obvious. The cushion type connection foundation can not prevent the wall deflection, the embedded connection controls the wall to keep the position stable through the restraint action of the pile body. The bearing force of the cushion and embedded retaining wall is that the bottom face of the bottom plate is subjected to tensile stress along the road foundation direction, and there is no zero pressure zone on the bottom surface of the bottom plate in the vertical direction of the roadbed. There is little difference in horizontal displacement between the two connecting modes, and the soil between piles is the main body bearing horizontal load.
【作者单位】：河海大学岩土力学与堤坝工程教育部重点实验室;河海大学道路与铁道工程研究所;河海大学岩土工程科学研究所;上海理工大学环境与建筑学院;
【基金】：广东省交通运输厅科技计划项目(No.2011-02-021)
【分类号】：U417.1

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