Formulation Of Regional Earthquake Response Spectrum Based On Random Vibration Theory

The design response spectrum used in the current seismic code is calculated and fitted based on a large number of strong earthquake recorded sample data in a large area.However,the input of structural ground motion is affected by parameters such as the source and epicenter distance,and is also affected by local site conditions.Therefore,the structural design response spectrum obtained from ground motions in a large area cannot accurately reflect the impact of site conditions in a small area on the response spectrum.In recent years,we has built a large number of seismic observation stations and obtained local ground motion samples.It is possible to construct a design response spectrum that more accurately reflects the characteristics of local ground motions by using these ground motion sample information and improve the seismic design level of structures in this region.This paper will study a method of constructing regional ground motion response spectrum based on random vibration theory.This method uses the stochastic process to simulate ground motion input,uses a small amount of ground motion samples in the area to establish a ground motion non-stationary random output model,and constructs a structural design response spectrum with clear probability by calculating the non-stationary response of the structure under earthquake for the seismic design of the structure in the area.The specific content of this article is as follows:(1)Based on random vibration theory,a method of constructing seismic response spectrum with a clear and probabilistic significance with a small amount of ground motion record sample data in the area as input is studied.The construction method of the probability model of the random process of ground motion,the calculation method of the extreme probability distribution of the non-stationary vibration response of the structure,and the construction method of the ground motion response spectrum with probabilistic significance are studied.These three related theoretical methods are combined into a complete set of regional ground motion response spectrum construction methods based on a small amount of monitored ground motion data.(2)Carried out the research on the specific implementation steps of the construction method of regional ground motion response spectrum based on random vibration theory,and carried out simulation example verification.Using artificial synthesis methods,ground motions satisfying ideal conditions are generated as sample data.Numerical simulation analysis verifies the regional ground motion response spectrum construction method based on random vibration theory proposed in this paper.This method has the unique advantage of obtaining accurate structural response spectra under the condition of a small amount of ground motion samples.(3)Carried out the application research of regional ground motion response spectrum construction method based on random vibration theory.The Los Angeles and San Diego areas in the United States and the Dali-Baoshan area in China are selected as examples.The regional ground motion response spectra of the above areas are calculated according to the method in this paper.The applicability of the method in the actual application process is verified by analyzing the calculation results of the calculation example.