Research On The Mechanical Properties Of Segment And Joint Waterproof Of Large Diameter Underwater Shield Tunnel

With the increasing number of underwater tunnel constructions, shield method has become the mainstream ways for its good quality, high security, strong adaptability, etc, which is moving forward in the directions of large cross section, long distance and high speed construction. Because of a short time application and lack of experience, many problems exist in the segment design and the structure waterproof of underwater shield tunnel.Taking the Nanjing Weisanlu Yangzi River shield tunnel as the background, this article uses the M-K model to make strcture calculation under the typical cross sections of two kinds of segement plans; then the analysis of joint-open question is carried on; finally considering the domestic and foreign experience, some proposals on the joint waterproof are put forward.Main work and fruits are as follows:Firstly, referring to the related research situation, M-K model is sleeted to design the segment.Secondly, through the strcture calculation, it can be found that the smaller cap block is, the more non-uniform the structure stress is. The ratio of horizontal load and vertical load on the structure is defined as "coefficient of lateral pressure load", the relationship between deformation and internal force of segment ring from the perspective of the size of the lateral pressure coefficient is given.Thirdly, through the analysis of joint-open, it can be found that the cap block's position affects the value and the position of joint-open, and also the number of the outside opened joint.Finally, some appropriate recommendations are put forward on the design and construction of the joint waterproof.