Seismic Response Analysis Of Submarine Slope

More offshore oil and gas exploration platforms and seabed infrastructure will be built in the south China sea as the construction of a "maritime power" speeds up and the implementation of the national strategy of "One Belt And One Road" construction is pushed forward.However,the southeast coastal area of China is located in the Pacific Ocean seismic belt.Earthquakes occur from time to time,and the strong earthquake will lead to the instability of the submarine slope,thus causing the destruction of offshore oil and gas platforms,submarine tunnels,submarine cables and other Marine engineering facilities.Up to now,due to the lack of submarine seismic observation record,there is little research on the seismic response of subsea ground sites,especially on the local subsea sites.In this paper,a multi-media coupling model of submarine slope is established.Based on the existing three media coupling system dynamic analysis finite element method and the ground motion input method of Haiti site,the finite element program for analyzing the seismic response of submarine slope under oblique incidence of seismic wave is compiled by using the method of numerical simulation,and the depth of sea water is studied The influence of incident angle of incident wave,porosity of saturated soil and height of submarine slope on seismic response of submarine slope.Combined with the research status of submarine landslide and the seismic response law of submarine slope,the induced factors of submarine landslide are analyzed,and the following conclusions are drawn:1.With the increase of sea water depth,the amplification coefficient of displacement peak increases,the hydrodynamic pressure at the foot of slope increases with the increase of incident frequency of incident wave,and the hydrodynamic pressure first increases and then decreases with the increase of sea water depth when P wave is incident.The effect of the variation of the depth of sea water on the amplification coefficient of displacement and the hydrodynamic pressure at the foot of slope is less than that of P wave.2.When P wave is incident,with the incident angle of incident wave increasing,the horizontal displacement amplification coefficient gradually increases,while the vertical displacement amplification coefficient first decreases and then increases.When the SV wave is incident,the amplification coefficient of the vertical displacement peakincreases with the incident angle of the incident wave,while the horizontal direction is opposite.The peak value of hydrodynamic pressure at the foot of slope decreases with the increase of incident angle of incident wave.3.With the increase of the porosity of the saturated soil,the amplification coefficient of the displacement of the submarine slope decreases gradually,and the peak value of the hydrodynamic pressure at the foot of the slope increases with the increase of the frequency of the incident wave.When the frequency of the incident wave is fixed,the peak value of the hydrodynamic pressure at the foot of the slope decreases with the increase of the porosity of the saturated soil.4.The amplification coefficient of displacement on the slope surface increases with the increase of slope height.When the frequency of incident wave is constant,the peak value of hydrodynamic pressure at the foot of slope decreases with the increase of the height of submarine slope.