Shaking Table Test Study on Seismic Acceleration Response of Ground Fissure Sites under Horizontal Seismic Action
Wang Qi-ya · Journal of the China Railway Society · 2015
Based on the background of ground fissure sites where the subway line 2crosses the ground fissure F6 and F′6in Xi'an,the seismic response experiment of ground fissure sites under horizontal seismic action was accomplished on the shaking table test system with a scale of 1:15.Seven different conditions of exciting acceleration peak of El Centro wave and Taft wave were respectively loaded on the shaking table experiment to measure the response acceleration of 6 measuring points on the top of ground fissure model with acceleration sensor.The experiment results proved that,triggered by El Centro wave,the amplification coefficients of response acceleration on the top of ground fissure sites model were all over 1.0.However,with the increment of exciting peak acceleration,the amplification coefficients of response acceleration were decreasing rapidly in the shape ofzwhen there was an inflection point and the excitation peak acceleration was equal to 300 gal.Furthermore,triggered by Taft wave,the amplification coefficients of response acceleration on the top of ground fissure sites model were all over 1.0.With the increment of exciting peak acceleration,the amplification coefficients were decreasing gradually when there was an inflection point and the excitation peak acceleration was equal to200 gal.Triggered by both El Centro wave and Taft wave,the amplification coefficients of response acceleration on the top of ground fissure sites model reduced with the increase of the exciting peak acceleration.However,the reducing rates and curve shapes varied with different exciting seismic waves.In the practice of engineering,structures should be avoided on the location ofyshaped wedgeyshaped between the ground fissures,or effective seismic control measures for construction structures should be adopted.