Research Of Pit Edge Top-Down Construction Technique For Large-Scale Deep Excavation

In the past the large-scale pit needs to be set up a huge support structure, it costs much money and time. When the supporting structure is removed, it is time-consuming and expensive. Pit border top-down construction method can solve environmental problems and meet the super-deep excavation deformation strict requirements for the support construction. Pit edge top-down construction method uses the pit edge body structure and saves much project cost. It will be a promising technique for deep excavation.Lots of domestic project examples are collected in this dissertation with detailed description on their over-all plan through which we can grasp the trend of this construction technique. This dissertation tries to make a prospect of pit edge top-down construction method.According to the unique characteristics of the pit edge top-down construction, this dissertation gives a lot of key nodes structural design and construction technique. It solves the problem of steel beam position to be through and local design of such structures as elevator hoistway or stair tunnel and one-column-multi-pile design and construction. It also gives a method of transferring horizontal force between retaining wall and body structure. In addition, this dissertation presents an operational support for beam reinforcement through changing the rigidity of structure.Combining the characteristics of pit edge top-down construction, this dissertation gives the improved two-dimensional elastic-plastic analysis idea of the deep excavation. Advanced analysis tools are applied on the project example for the level of support systems and excavation stages of shedding numerical analysis of the impact of the surrounding environment. This analysis idea can truly reflect the force, displacement in the process of pit border top-down construction.This dissertation makes three-dimensional analysis system applied on the pit edge top-down construction. The work includes summarization of all parts of the projects (retaining walls, shells, pillars, piles, etc.), and the probably effects in result...