Shaking Table Test on Composite Isolation System of High-speed Railway Station with Integrated Station-Bridge Structure

This paper investigated the seismic performance of a typical “Integrated Station-Bridge high-speed railway station structure with a composite isolation system. The influential mechanism of the structure with isolation system was analyzed based on shaking table tests, mainly investigating on the failure mode, acceleration response and displacement response. Besides, a parameter optimization method of isolation layer for long-span structures was proposed based on genetic algorithm to better enhance the isolation performance of the large-span structure. The research revealed that there was no obvious damage to the composite isolation system under the PGA = 0.82 g. The nature frequency of the structure with isolation system is only 12.5% of that of non-isolation structure. The first three natural vibration frequency of the structure with isolation system only reduce 3.4%, 3.2%, 6.14% after the PGA = 1.27 g, that of the non-isolation structure reduce by more than 20%. The acceleration amplification factor of each layer of composite isolation system is less than 1, in particular, that of truss is about 0.3. The displacement response and acceleration response of the structure with isolation system have been reduced by about 90%. The proposed optimization method of isolation layer parameters provides an important reference for the isolation design for high-speed railway stations.