临时垫块支撑对沉管隧道结构受力影响的研究  

Influence of Temporary Cushion Block Support on the Structural Stress of Immersed Tunnels

作　　者：魏纲[1] 邢建见 苏勤卫 陆世杰 WEI Gang;XING Jianjian;SU Qinwei;LU Shijie(Department of Civil Engineering,Zhejiang University City College,Hangzhou 310015;College of Civil Engineering and Architecture,Zhejiang University,Hangzhou 310058;Wuhan Real Estate Development Co.Ltd.,Wuhan 430000)

机构地区：[1]浙江大学城市学院土木工程系,杭州310015 [2]浙江大学建筑工程学院,杭州310058 [3]金地集团武汉房地产开发有限公司,武汉430000

出　　处：《现代隧道技术》2018年第4期139-145,共7页Modern Tunnelling Technology

基　　金：国家自然科学基金项目(51178428);浙江省自然科学基金项目(LZ12E08001)

摘　　要：在软土地区施工沉管隧道时,在基础层下添加临时垫块会造成管段内壁开裂等不利影响。基于此,文章采用MIDAS GTS软件对沉管隧道有垫块支撑和无垫块支撑工况进行了数值分析,并将两者的理论值进行了对比分析。分析结果表明:与无垫块支撑工况相比,在有垫块支撑位置处的管段弯矩值增加了近1倍,表明设计配筋偏危险;临时垫块的设置会使管段出现支点效应,对其运营期的内力分布影响较大,同时该处结构上部受拉,易出现裂缝;提出的有垫块支撑情况下管节纵截面的修正计算模型,具有一定可靠性,可为将来沉管隧道结构设计提供理论依据。When a temporary cushion block is put under the foundation of an immersed tunnel in a soft soil area, cracks form in the inner wall of the element. A numerical analysis of an immersed tunnel with and without the support of a cushion block is conducted by Midas GTS software, and the theoretical values are compared. The results show that： 1） with the support of a cushion block, the bending moment is lx larger than that without a cushion block, indi- cating the designed reinforcement is unsafe; 2） there may be a fulcrum effect on the element when a temporary cushion block is implemented and the internal force distribution is affected greatly during operation, and it is prone to producing cracks due to the tensile force applied on the superstructure; and 3） the proposed modified calculation model for a segment section with a cushion block support is reliable and provides a theoretical basis for the structural design of immersed tunnels in the future.

关 键 词：沉管隧道 垫块支撑 MIDAS GTS软件 弯矩值 结构设计 

分 类 号：U451[建筑科学—桥梁与隧道工程] U459.5[交通运输工程—道路与铁道工程]