【作者】 张军；

【导师】 杨庚宇； 赵少飞； 李俊伟；

【作者基本信息】 华北科技学院 ， 安全工程（专业学位）， 2018， 硕士

【摘要】 盾构施工是目前在地铁及隧道开挖应用最广泛的一种手段,尤其对于软土地层穿越建筑物具有其他施工方法没有的优点,但地铁盾构隧道施工的时候是在地层中进行的,在盾构机的推动过程中不可避免会对周围邻近的土层产生影响从而导致土层上方建筑物发生变形,造成安全事故。同时目前大部分地铁盾构施工需要穿越建筑群,本文把建筑物、土层及盾构机作为有机整体,通过盾构隧道施工过程中对周围土层产生扰动的机理进行分析,探讨了邻近土层发生扰动的原因,同时分析了盾构隧道施工侧穿时建筑物之间的相互作用。有限元数值模拟是目前岩土工程领域分析地铁盾构隧道施工引起周围环境变形的一种实用有效的方法,本文整理了前人在这方面的研究,并同时把隧道开挖的机理进行了进一步的推导;采用天津地铁一号线东延线盾构区间侧穿两栋相似邻近公寓楼为工程背景,运用有限元软件MIDAS/GTS,充分考虑土体材料的非线性、盾构机对地层的作用、地层与管片之间的作用、管片外压(注浆压力)、地层损失及掘进压力(土压力)等主要因素建立有限元三维模型,对地铁盾构隧道施工掘进过程进行动态仿真模拟,得出盾构机开挖过程中邻近土层的变形规律,变形结果趋势与实测值吻合较好;以侧穿两栋相邻公寓楼为研究对象,在隧道-土体-结构有限元模型中分析了盾构隧道穿越时邻近建筑物之间的相互作用,得出盾构隧道施工侧穿时邻近建筑物之间距离大小对建筑变形量的影响,当盾构邻近双建筑物影响净距与隧道深度之比比值约为1时,隧道工作面首先遇到的建筑物的最大局部倾斜值、最大沉降量及最大扭转量为最小值,而当比值偏离1.0时,这三个变形量均增大明显。同时对建筑物在此过程中的安全稳定性作出了评估,为此后相似工程提供借鉴。更多还原

【Abstract】 At present shield construction is the most widely used method in subway and tunnel excavation,for soft soil,it has unique advantage methods for crossing buildings.However,the construction of subway shield tunnels is carried out in the stratum,In the process of shield machine driving,it will inevitably affect the adjacent soil layer,resulting in deformation of buildings above the soil layer and causing safety accidents.At the same time,most of the subway shield construction need to pass through the buildings.This article considers the building,soil layer and shield machine as an organic whole,analyzes the mechanism of the disturbance of the surrounding soil layer during the construction of the shield tunnel.The disturbance reasons about the adjacent soil.The interaction about between the buildings and the stratum between the buildings when the side of the shield tunnel was installed.Finite element numerical simulation is a practical and effective method in the field of geotechnical engineering to analyze the deformation of surrounding environment caused by shield tunnel construction.This article collates the previous research in this arera,at the same time the excavation mechanism of the tunnel is further deduced.The twin similar adjacent apartment buildings are used as the engineering background in the shield section of the East Extension Line of Tianjin Metro Line 1.The finite element software Midas/GTS is used to fully consider the nonlinearity of soil material,the action of shield machine on stratum,the action between stratum and segment,the pressure of grouting outside segment,the loss of formation and the pressure of tunneling(earth pressure),etc.in a 3-D finite element model.The dynamic simulation of tunneling process of shield tunneling is carried out,and the deformation law of adjacent soil layer in the excavation process of shield machine is obtained.The trend of the deformation results is fitted well with the measured value.The interaction between adjacent apartment buildings is analyzed when the shield tunnel side crossed in the tunnel-soil-structure finite element model.The relationship between adajiacent buildings at different locations during the construction of the shield tunnel is considered.It is found that the ratio of the net distance between the twin buildings to the depth of the tunnel axis has obvious influence on values of the settlememt,the loacal tilt and the tosion in the proceding building.When the ratio is about equal to 1.0,all of the values are achieving their minum values.The safety and stability of the buildings during the process are evaluated.For this reason,similar projects can be used for reference.更多还原