基坑加固对既有下卧隧道变形影响研究  

Study on the Effect of Pit Reinforcement on the Deformation of Existing Underpass Tunnels

作　　者：伍敏 Wu Min(China Railway Construction Port and Harbour Bureau Group Company Limited Fourth Engineering Branch Company,Chongqing 401220)

机构地区：[1]中国铁建港航局集团有限公司第四工程分公司,重庆401220

出　　处：《江西建材》2024年第6期217-220,共4页

摘　　要：为保障地基的稳固,对基坑工程软土地基进行加固处理是常见的措施,而基坑加固对既有下卧隧道的影响却少有研究。为了探明基坑加固对既有的下卧隧道的竖向变形影响,文中选取了满堂加固、裙边加固、抽条加固三种典型的坑底加固形式,对基坑底部进行不同高度的加固。试验结果表明,这三种加固形式均对抑制隧道的隆起变形有良好的效果,满堂加固效果最优;当加固高度超过一定值时,坑底加固对隧道的隆起变形的抑制效果会转变为促进隧道的沉降变形;基坑施工过程中支护桩施工对隧道的变形影响最大,同时其也是基坑施工过程中隧道变形最大的阶段,基坑施工时应特别关注支护桩施工阶段;下卧隧道竖向变形主要受坑底隆起变形的影响。Reinforcement of soft ground is a very common measure to ensure the stability of the foundation in pit engineering,while the effect of pit reinforcement on the existing undercrossing tunnels is rarely studied at present.In order to investigate the effect of pit reinforcement on the vertical deformation of the existing undercrossing tunnel,three typical forms of pit bottom reinforcement,namely,full-top reinforcement,skirt reinforcement,and drawbar reinforcement,were selected to reinforce the bottom of the pit at different heights.The test results show that:these three forms of reinforcement have good effect on the suppression of tunnel bulging deformation,and the full-tang reinforcement has the best effect;when the reinforcement height exceeds a certain value,the suppression effect of pit bottom reinforcement on the tunnel bulging de-formation will be changed to the promotion of the tunnel settlement deformation;the support piles construction has the greatest effect on the de-formation of the tunnel in the process of pit construction,and at the same time,it is the largest deformation of the tunnel in the process of pit construction,and it should pay special attention to the support piles construction during the construction of pit.Special attention should be paid to the supporting pile construction stage during the pit construction;The vertical deformation of the undercropping tunnel is mainly affected by the deformation of the pit floor uplift.

关 键 词：基坑加固 下卧隧道 竖向变形 

分 类 号：U4577[建筑科学—桥梁与隧道工程]