软土地区盾构穿越待改建老旧大堤的变形控制研究  

On Deformation Control for the Shield Passing through Old Embankment to Be Rebuilt in Soft Soil Area

作　　者：季昌[1] 王力 JI Chang;WANG Li(Shanghai Key Laboratory of Rail Infrastructure Durability and System Safety,Tongji University,Shanghai 201804;Hongrun Construction Group Co.,Ltd.,Shanghai 200235)

机构地区：[1]同济大学上海市轨道交通结构耐久与系统安全重点实验室,上海201804 [2]宏润建设集团股份有限公司,上海200235

出　　处：《现代隧道技术》2019年第3期108-117,共10页Modern Tunnelling Technology

摘　　要：针对国内深厚软土地区盾构下穿改扩建堤坝变形安全控制问题,文章依托上海某典型软土盾构隧道下穿待改扩建堤坝工程,通过对比不同加固方式确定了真空联合堆载预压加固法,现场实测了真空联合堆载预压加固堤坝期间地层变形和孔压变化规律以及盾构下穿期间改扩建堤坝表层变形和隧道自身变形。结果表明:采用真空联合堆载预压加固方法可较好地控制盾构下穿改扩建堤坝的施工风险,真空联合堆载预压法对常规埋深盾构隧道下方约2倍盾构直径范围内的软土有加固效果,双曲线经验法能较好预测软土地区老旧大堤预压加固作用下的地基沉降,盾构穿越预压加固的大堤引发的固结变形沉降较小。Regarding safety control of the shield passing through the old embankment to be rebuilt in deep soft soil area in Shanghai,a reinforcement method of vacuum combined with surcharge preloading was determined after comparing several reinforcement methods,the ground deformation was measured at site and pore pressure variation law was obtained during embankment reinforcement with vacuum combined with surcharge preloading,and the embankment surface deformation and tunnel deformation during shield construction underneath the embankment were also measured.The results show that:the risks of shield construction under the old embankment can be well managed;the soft soil within a scope of two times shield diameter beneath the shield tunnel with normal overburden can be reinforced with the method of vacuum combined surcharge preloading;hyperbolic empirical method can well predict the ground settlement of old embankment under the effect of preloading reinforcement;the solidification deformation induced by shield construction passing through pre-reinforced embankment is small.

关 键 词：盾构施工 软土地基 老旧大堤 真空联合堆载预压加固 变形控制 

分 类 号：U451[建筑科学—桥梁与隧道工程]