盾构施工对邻近浅基础框架结构影响的研究

Research on the influence of shield construction on the nearby shallow foundation frame structure

框架结构作为城市建筑一种常见形式,应用广泛。城市轨道交通隧道从城市密集区域穿过,不可避免地对邻近房屋造成安全影响,容易导致建筑发生倾斜、开裂甚至坍塌等事故。为了解隧道施工对沿线框架房屋的影响,运用有限元软件ANSYS建立三维有限元模型,对盾构法隧道侧穿通过某框架结构房屋进行数值模拟,并通过实测数据对其准确性进行验证。变化框架与隧道中线水平距离L和隧道埋深H分多种工况对盾构隧道施工对邻近框架结构变形及内力的影响进行分析。研究结果表明:数值模拟是研究隧道对邻近框架房屋影响的一种可靠方法,所得结果贴近实际情况;框架结构的沉降、倾斜及最大第一主应力均随着L或H的增大而递减,相较于H,框架房屋对于L的增加更为敏感;针对本案例地层条件,当L达到25 m或者H达到30 m时,隧道施工对框架结构房屋的影响已相对较小甚至可以忽略不计。

As a main structure form of urban buildings,frame structure has been widely used. Urban rail transit tunnel passes beneath or below some buildings,which can give security implications and even lead to building's leaning,cracking or collapse. To study the impact of tunnel construction on frame structure buildings,ANSYS has been used to establish a 3D finite element model. Firstly,the numerical simulation of shield tunneling through a frame structure has been carried out and the results have been verified by measured data. Then the influence of frame structures on the deformation and internal force of shield tunnel construction under different L(frame and tunnel centerline horizontal distance) and H(tunnel depth) have been analyzed. The conclusions are drawn as following: Numerical simulation is an affective method to study the influence of tunnel on nearby frame structure buildings and the results obtained are reliable. The settlement,inclination and maximum 1st principal stress of the frame are all decreased with the increase of L or H,and the frame structures are more sensitive to L compared to H. According to the soil conditions of this case,when L reaches 25 meters or H reaches 30 meters,the influence caused by tunnel construction is little and even can be ignored.