Numerical Analysis Of Influence Of Excavation Of Foundation Pit On Side Shield Tunnel

The country is currently vigorously advocating and investing in the construction of subways in cities.However,due to the limitation of urban space,large-scale foundation pit excavation works in neighboring subway tunnels are ubiquitous,and subway tunnels require high deformation control.Small deformations may cause cracks in subway tunnel segments and affect their normal operation.At the same time,the requirements for deformation of the large foundation pit project itself are also very high.Therefore,combining these two aspects,the influence of foundation pit excavation on the side-built shield tunnel is studied.How to effectively control the deformation of the side tunnel under the condition of ensuring the normal excavation of the foundation pit becomes a very Necessary research topics.In view of this problem,this paper combines a large-scale foundation pit excavation project in Ningbo to study the influence of foundation pit excavation on the side-built shield tunnel,and carry out numerical simulation analysis.The ABAQUS modeling software is used to establish the 2D and 3D models of the actual project.At the same time,the data processing software such as origin and Excel is used to analyze and process the results.In the modeling,in order to better fit with the actual project,Moore is adopted.Coulomb and the modified Cambridge model modeled and analyzed the actual project,and compared which soil constitutive model is more in line with the engineering practice,providing more theoretical support and reference for the actual project,providing technical guidance for future tunnel construction..This topic is based on the ABAQUS numerical simulation method,based on the actual parameters and dimensions of a large excavation project in Ningbo,simulates the excavation process of the whole project under the premise of appropriate simplification,and analyzes the impact on the side subway tunnel.Comparing the simulation results with the monitoring data of the subway tunnel and foundation pit on site,it can be concluded that the Cambridge model is more suitable for practical engineering,and also provides some reference for other similar practical projects.