The Study Of The Application Of The Laminated Primary Support Arch-Cover Method In The Field Of Large Span Subway Station In Qingdao

This study bases on the research on Structural Design and Risk Control Technology of the Large Span pile-less Underground Station.The author uses ABAQUS to establish a series of finite element models to make a contrast between the Laminated Primary Support Arch-Cover Method and the Double Side Wall method.The study also takes the design processes of the Xujiamaidao Subway Station and Qingjiang Road Station into consideration and finally summarizes surveillance data of the Xujiamaidao Subway Station to make contrast with the finite element computing results.The finite element analysis uses the way of Controlling Variables and set the Ratio of Each Kinds of Different Rocks on the Cross Section as the only argument,and calculates the inner force values in the primary supports and second linings under every single case of different arguments.Finally,this study determines the applicable conditions of the Laminated Primary Support Arch-Cover Method,and makes suggestions to the construction of the subway station using Shallow Buried Tunnelling method.The main works and achievements in this study are as follows:(1)In the areas such as Qingdao and Dalian,the micro-weathered rocks is shallow buried,the characteristics of the geosphere here is the hard rock contacts the soft soil directly,and the lots of subway stations here are constructed by the Shallow Buried Tunnelling Method.The paper firstly makes a collection of some specific subsurface excavation subway stations which are built by the Laminated Primary Support Arch-Cover Method and the Double Side Wall method.(2)Relying on the preliminary design of the actual engineering of Neimenggu Road Station,the author collected Geological Survey Report here and determined the geological characteristics of the region.Based on the theory of rock mechanics and soil mechanics,the paper analyzes the characteristics of the rock and the Developing condition of rock joint zone in the area to be built to the station.(3)In the research,two sets of finite elements models are built to take the Laminated Primary Support Arch-Cover Method and the Double Side Wall method into comparison,each set of finite element consists of a series of models in which have a single argument.The finite element analysis demonstrate a contrast of the stresses and strains in the primary supports and the second linings built by the Laminated Primary Support Arch-Cover Method and the Double Side Wall method.The research also compares the Land subsidence curves coursed by the above two methods to finally prove the applicability of the Laminated Primary Support Arch-Cover Method in the areas where the hard rocks are shallow buried and the hard rock contacts the soft soil directly.(4)There are some jointed cracks in the rock mass where the Neimenggu Road station to be built.So the paper combines with the geological parameters provided by the geological survey report,and builds another two finite element models with Constitutive Model of Jointed Element provided by ABAQUS to explore the effects of different reinforcement methods when the constructing passes the jointed area.Among so many different reinforcement methods,the Anchor Rod Retaining Wall method and the Support Piles method are two of the most commonly used methods.The author writes a series of python scripts in ABAQUS to make the parameter analysis with the Anchor Rod Retaining Wall method and the Support Piles method,and finally proves the Support Piles method is more effective than the Anchor Rod Retaining Wall method when using the Laminated Primary Support Arch-Cover Method to build subway stations among jointed areas.(5)The research compares the supporting structure and the Surrounding Rock conditions of the Neimenggu Station and the Xujiamaidao Station in Qingdao district.After summing up the similarity of the two station,the paper determines the in-situ monitoring data from the Xujiamaidao Station has guiding significance on the construction of the Neimenggu Road Station,and finally puts forward reasonable proposals on arch-building procedure of the Laminated Primary Support Arch-Cover Method.