深基坑施工与紧邻隧道相互影响研究

Study on Effect of a Deep Excavation Construction on the Adjacent Tunnel

以某紧邻地铁隧道的深基坑工程为例,通过数值模拟建立深基坑-隧道三维模型,研究深基坑施工对紧邻隧道的影响,明确了考虑运营地铁荷载的必要性。研究表明:①地下连续墙的水平位移随着基坑深度迅速增大,在基坑深度一半处达到峰值,地铁运营期基坑施工引起的隧道和基坑变形明显大于非运营期;②基坑和隧道变形随着基坑与隧道间的水平距离的增大逐渐减小,且这种影响也越来越小;③当隧道底部与基坑底部一致时,隧道拱底隆起位移最大,并随着隧道底部远离基坑底部逐渐减小。当隧道处于地下连续墙埋深中部时,即地下连续墙最大水平位移处,地下连续墙和隧道影响最为显著。

In this paper,a deep foundation excavation project adjacent to the subway tunnel is taken as an example,and the three-dimensional model of the deep excavation near the existing tunnel is established by the numerical simulation software to study the influence of deep excavation construction on the adjacent tunnel.Throughout the comparative analysis,the need of considering the operative subway load is further clarified,and the deformation relationships in the excavation and the existing subway tunnel are evaluated in the paper.The results show that the deformation of the existing tunnel induced by the deep excavation construction in subway operative period is significantly greater than that in non-operative period;With the increase of the horizontal distance between the excavated area and the tunnel,the deformation of the deep excavation supporting structure and the tunnel gradually decreases,and the influence is smaller and smaller;When the tunnel is in the middle portion of the diaphragm wall,that is,the maximum horizontal displacement of the diaphragm wall,the influence of the diaphragm wall and the tunnel is the most significant.