Research On The Displacement Characteristics Of Slurry Shield Traversing Across Flood Wall Under The Condition Of Ground Overload In Jungong Road Tunnel

In recent years, there are many tunnel projects that cross river home and abroad. As the excusive tool for tunnel construction, shield is wildly used in the city subway tunnel construction for its advantages on fast construction speed, little environmental inference and so on. During the progress of tunnel excavation, the shield will inevitably have disturbance on strata and break the formal balanced state which results to displacement and deformation of the surround strata and earth surface. In order to make a long-distance tunnel go ahead smoothly, it is inevitable to make measurement on surface settlement,soil horizontal displacement etc. Based on Gungong Road slurry tunnel project, through analyzing on theory, filed test and finite element method, mainly research on disturbance mechanism, disturbance discipline, inference scope and degree of the surround strata during the progress of excavation with large diameter slurry shield, the major works and results are as follows:(1) Establish FEM numerical simulation model, study the displacement characteristics of vibration load and ground overload. According to the results, the vertical displacement produced 100mm because of vibration load and ground overload. Suggestions the reasonable control measures to achieve good subsidence control effect.(2) Measurement on singleline construction surface settlement and soil horizontal displacement of slurry shield; analysis based on above mentioned different angles about disturbance mechanism. Slurry system shows uneven settlement, surrounding soil settlement slowly grows to be excessive, reasonable measures must be taken to control the settlement.(3) Measurement on doubleline construction surface settlement and soil horizontal displacement of slurry shield; analysis based on above mentioned different angles about disturbance mechanism. The different measuring holes in the settlement displacement, suffering the comprehensive influence of ground overload and shield thrusting; in terms of horizontal displacement,shield thrusting influence will far outweigh the ground overload influence.(4)Based on the in-situ data and the numerical simulation data, combining the construction parameters to analyse the relationship between the construction parameters and soil deformation.The main research is about different grouting pressure on soil vertical displacement, different incision pressure on the horizontal displacement. The results can provide important experience to similar projects.