Study On Seismic Behavior Of Urban Underground Utility Tunnel Corridor With FRP Bars

The underground utility tunnel is a kind of shallow buried underground space structure.It plays a highly intensive role that contains water pipes,gas pipelines,communication cables and other kinds of municipal pipelines.Nowadays,the corrosion problem is very serious.In some areas of China,the soil and surrounding rock environment are bad,the underground utility tunnel is co-erosting in soil,groundwater and affecting by the long-term dynamic load.After a period of time,it causes serious corrosion of steel bars and instability or destruction of underground structure.Experts research Fiber Reinforced Polymer(FRP)material with good corrosion resistance to replace the steel bars in the structure.However,FRP bars reduce earthquake resistance ability for underground structure as main reinforced function.Therefore,this paper research seismic response and the seismic capacity analysis of underground utility tunnel with FRP bars under numerical simulation of ABAQUS finite element software,and it gives some relevant suggestions.Firstly,beginning part elaborates the material properties and development status of FRP bars,and systematically analyzes the seismic response characteristics of the underground utility tunnel based on the seismic research experiences in China and other countries.Then,the part introduces the method steps of ABAQUS finite element software to achieve the seismic analysis of underground utility tunnel and some theoretical foundations involved.Secondly,in the numerical simulation,the second part finishes the establishment of the structure-soil mode,boundary condition verification,modal analysis and seismic response of the model is analyzed.The underground utility tunnel with FRP bars is established and calculated by using the displacement input form of seismic load.The dynamic response results of the structure are obtained by analyzing the concrete structure and the FRP reinforced steel cage respectively,and compared with the utility tunnel with steel bars and mixed reinforcement so that obtained the conclusions of different types' seismic resistance.Finally,according to the results of dynamic response of the underground utility tunnel with FRP bars,it is concluded that the structure has a good seismic capacity.In view of the characteristics of the underground utility tunnel structures are shallowly buried,the last part put forward the seismic design suggestions of the Shallow-buried utility tunnel structure.