Analysis Of Dynamic Stress Paths In Semi-circular Canyon Induced By Seismic Waves

The effect of local terrain on the seismic effect has been confirmed in the seismic records and post-earthquake investigations at home and abroad.Research on the local irregular terrain has always been a topic of concern in geotechnical engineering,soil dynamics and seismic engineering.The amplifying effect of irregular terrain on the surface of the earth as a macroscopic phenomenon is essentially the scattering and dynamic stress concentration of seismic waves.The theoretical study of the problem of elastic wave scattering and dynamic stress concentration mainly considers the influence of different factors on the stress state,such as the geometric characteristics of the scatterers,physical parameters,the constitutive relation of the medium,whether or not they contain voids,whether they contain water,and dynamic load,Spectrum characteristics and so on.The dynamic stress path is an index that represents the dynamic characteristics of the soil.With the soil unit as the research object,half of the difference between the vertical stress and the horizontal stress is selected as the abscissa,and the shear stress is selected as the ordinate to draw the curve.It is called dynamic stress path.Different dynamic stress paths will affect the cumulative deformation of soil,the pore pressure development model of sand,the long-term cyclic resilience modulus of soft clay,and the shape of stress-strain hysteresis curve.The dynamic response and vehicle of the foundation of subsea structures are studied.The response of the ground under dynamic load and the response of the runway foundation under aircraft loads have been widely used.The main content of the paper are as follows:1.The dynamic stress path of the semi-infinite space under the incident elastic wave is studied.The effects of different ground parameters and seismic wave parameters?incidence angle,incident frequency,shear modulus,Poisson's ratio,depth?on the dynamic stress path of the soil are analyzed..2.A large arc model was established to study the analytical solution of the semi-circular hollow site under incident P-waves.The formulas for the calculation of soil stress and displacement were deduced,and the influence of semi-circular hollow sites on the amplitude of surface displacement was analyzed.Large arc model and numerical simulation results.3.A horizontal half-space model was established to study the analytical solution of the semi-circular hollow site under the incident P-wave.The formulas for calculating the stress and displacement of the soil were deduced.The results of horizontal half-space model and large arc model and numerical simulation were compared.4.A horizontal half-space model was established to study the analytical solution of the semi-circular hollow site under incident P-waves.The formulas for calculating the stress and displacement of the soil were deduced,and the horizontal half-space model,the large arc model,and the explicit finite-difference program FLAC^3D were compared.