Statistical Characteristics Of Shear Wave Velocity In Tianjin Area And Its Influences On Ground Motion Parameters

As a central city in China,a metropolis and economic center in the Bohai Rim region,Tianjin is a typical soft soil area around the Bohai Bay.Most of the area is located in the zoning map(GB18306-2015)seismic fortification octave area.The shear wave velocity is an important parameter to determine the site classification and influence the ground motion parameters of the surface design.Based on the relevant researches at domestic and abroad,this paper systematically collects and analyzes the shear wave velocity data of earthquakes in Tianjin,and studies the correlation between shear wave velocity and buried depth,the uncertainty of shear wave velocity and its impact on surface earthquakes.Research on the influence of dynamic parameters.The main research work completed is as follows: 1.Based on the measured data of shear wave velocity and buried depth in the earthquake safety assessment work of soft soil sites in Tianjin,an empirical model of shear wave velocity and soil depth is established,and the site is discussed.The effects of classification,soil type,and soil state,and verify the reliability of the obtained model;2.The ?2 test method was used to test the frequency distribution of shear wave velocity in Tianjin area.The eigenvalues of shear wave velocity in this region and the confidence levels of 95%,85%,and 75% upper and lower limits were obtained.3.Using the new generation of one-dimensional soil seismic analysis method proposed by Yuan Xiaoming's research team,SOILQUAKE preliminary studied the influence of the uncertainty of shear wave velocity on the surface peak acceleration and response spectrum parameters in Tianjin,and gave quantification evaluation results.