Abstract:Research purposes: With the infrastructure construction in China getting better and better gradually, the new-built high-speed railway often has to crass the existing structures. When the subgrade of high-speed railway has tocross the existing subway, the correct evaluation of the impact of the train vibration on the metro and the roadbed structure is important. Taking the pile-slab structure subgrade of the Shanghai-Hangzhou Passenger Dedicated Line crossing shallow subway engineering as an example,this paper studies the dynamic response characteristics of the pile-slab structure and the subway tunnels under the train operation.
Research conclusions: The pile-slab structure-foundation-subway numerical model was built to make the dynamic simulation analysis and study the dynamic response characteristics of the system under the condition of loading on two coaches on the single track. The results showed: (1)With increase of train speed, the acceleration of the measured point increased Linearly, the dynamic stress increased exponentially and the dynamic displacement decreased linearly. (2)The dynamic response caused by the excited force decayed quickly through the bearing plate, the joists, the pile foundation and the soil around the pile, so the dynamic response to the subway lining structure was very small. (3)Under the effect of train excited force, the peak value of the subway increased linearly with increase of the train running speed, and the maximum value was about 0.96 cm/s and it satisfied the specification requirement. (4)The three-dimensional dynamic simulation result was very close to the real tested value. So the dynamic numerical model is reliable for making the dynamic analysis of the pile-slab structure-foundation-subway system and is feasible for studying the dynamic characteristics of the pile-slab structure and evaluating the safety of the subway structure under the effect of the excited force of train.
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