Analysis And Modeling Of Spatial Variation Characteristics Of Engineering Ground Motion Field Strength Parameters

The spatial variation of ground motion needs to be taken into account in the seismic analysis of long and large Structural engineering such as dams and long-span bridges.The study of spatial variation of seismic motion is often described from the perspective of spatial correlation of seismic motion.Based on this,this study takes the SMART-1 array as the research object,analyzes the spatial variation characteristics and modeling of engineering seismic field strength parameters,compares the laws of model parameters and factors affecting magnitude and epicenter distance under different intensity index components.The main research content and results are as follows:Firstly,the correlation between the direction and strength parameters of ground motion records was analyzed in different plane coordinate systems.Using the measured data of five earthquakes recorded by the SMART-1 array,the original recorded east-west and north-south ground motions were adjusted to parallel and perpendicular to the epicenter site direction.The peak acceleration and response spectrum acceleration of the ground motions were calculated,and a multiple linear regression model for the ground motion intensity index was established and significance testing was conducted.The results indicate that compared to the EW-NS direction earthquake,the intensity correlation between the epicenter site direction earthquake is more significant,which can better reflect the spatial distribution pattern of earthquake intensity indicators.Afterwards,analyze the seismic motion in the epicenter site direction.Using spatial position as the independent variable and using binary regression analysis method,linear regression models and logarithmic linear regression models were established for peak acceleration and response spectral acceleration,respectively.The model parameters related to radial distance and tangential distance were identified.The residual calculation results of the model indicate that the linear regression model has the best fit with the spatial distribution of real earthquake intensity indicators.Finally,the correlation function of the real ground motion intensity parameters was calculated,and a correlation function parameter model for peak acceleration and response spectrum acceleration was established.The model parameters for three different distances were identified,and the relationship between the model parameters and earthquake parameters such as magnitude and epicenter distance was analyzed.The results indicate that as the magnitude and epicenter distance increase,the model parameters gradually decrease.The results of this study can be used for seismic disaster prevention analysis of urban lifeline systems such as road networks and pipeline networks,providing seismic input strength basis and reference for damage simulation and seismic reliability calculation of lifeline systems.