Prediction And Control Method For Subway Shield Tunnel Approaching Cross Adjacent Structure

Having many advantages such as short construction schedule, slight influence on surface traffic, easy to control quality and good at waterproof quality etc., shield method played an important role in the development of the underground space in the 21 centruy. Because of the restriction of geology condition and construction craft, the shield constuction still can't avoid to disturb the environment and change the ground stess as well as displacement. If the displacement oversteps the guideposts, the metro and the adjacent structure will be in danger and cause a series of environment problems likes to structure sloping and warping. So prediction and control for subway sheild tunnel approaching cross adjacent structure is valuable both for academia and application.Based on the ChengDu Metro and Shen Zhen Metro, numerical simulation and model test are used to prove up the disturbed mechanism of environment , predict and control the disturbance of the adjacent structure adduring the constructon process. The main work has been done is as follows:1. Mechanism and development process of ground settlement and adjacent structure caused by subway shield construction were analyzed, and the environment guideposts as well as control method were discussed.2. Adopted 3D-FEM to carry on numerical simulation about some sheild tunnel approaching projects of railway foundation, rigid isolated-foundation, walk-through, pile foundation, existing tunnels etc. Predicted the influence regulation about adjacent sturcture during sheild tunnel constraction. Judged the safety of the structure by guideposts, also analyzed the control method purposively.3. A concept of the sheild-ground-structure system was proposed. Based on choosing the parameter which can evidently infuence the result of the test, the similarity law about the sheild-ground-structure system was got through using dimensional analysis method. And then the laboratorialmodel test was carried out.4. The universal law of the adjacent structure displacement and endogen force during the dynamic shield construction process was got by analyzed the data of the model test. The influence of jacking force, mucking earth rate, advance rate, injecked packing ratio to the ground and adjacent structure was studied. Based on the similarity theory, both of the text data and numerical simulation date were compared.