大断面矩形顶管减阻技术应用研究:以苏州综合管廊矩形顶管为例

以苏州城北路人民路段综合管廊矩形顶管工程为例,分析了影响矩形顶管顶进力的关键因素,提出了管节配重、管节涂蜡和管节注浆等综合减阻方法以降低管壁摩阻力。在管节内放置重物平衡管节所受周围泥浆的浮力;通过涂蜡和喷蜡使管壁光滑,降低管壁与周围介质的摩擦系数;选择合适的材料和配比配制适合地层的泥浆,调整注浆量和注浆压力,使管节周围形成完好的泥浆套。基于实测顶进力与理论计算值的对比分析表明,管壁单位面积摩阻力降低了40%左右,证实该综合减阻方法解决了人民路段矩形顶管顶进力过大的问题。

Application of drag reduction technology of large section rectangular pipe jacking:A case study of rectangular jacking of Suzhou comprehensive pipe rack

Based on the rectangular pipe jacking project of people′s section of Chengbei Road in Suzhou, we analyzed the key factors affecting the jacking force of rectangular pipe jacking, and proposed comprehensive drag reduction methods about pipe weight, wax and grouting to reduce the wall friction resistance. Weights were placed inside the pipe to balance the buoyancy of the mud around the pipe. The surface of the pipe was painted with much wax, thus reducing the friction coefficient between the wall and surrounding medium. Also, we chose suitable materials and proportion to prepare the mud appropriate for the ground, and adjusted the grouting amount and pressure so as to form a good "mud jacket" around the pipe. Finally, by comparing the measured jacking force with the theoretical calculation value, we found that the friction resistance per unit area of the pipe wall was reduced by about 40%, solving the problem of excessive jacking force of rectangular pipe jacking in people′s section.