Sensitivity Analysis Of Influencing Factors On Stability Of Submarine Energy Soil Slope

Submarine energy soil slope is a submarine slope containing natural gas hydrate(commonly known as "combustible ice").The reserves of natural gas hydrate is very large,just as to its widely distributed and high energy density.Natural gas hydrate is a new type of clean strategic alternative energy which has the most commercial development prospect in twenty-first Century.However,the natural gas hydrate is very harsh in the condition of high temperature and low temperature.Environmental changes and human engineering activities caused by a slight increase in the temperature or pressure release is likely to make the hydrate dissociation,which led to the submarine landslide.Submarine landslide is one of the marine geological disasters.It is not only a serious threat to the safe exploitation of combustible ice,but also can destroy the gas hydrate deposits,resulting in a large number of methane gas leak,and causing destruction of the seabed environment and greenhouse effect.There are many factors that affect the stability of the marine energy and soil slope,and they influence each other.Sensitivity analysis of influencing factors on the stability of submarine energy soil slope is important to effectively predict the instability of seabed energy and soil slope,and ensure the safe exploitation of natural gas hydrate.This article briefly analyzes the research status of the stability and sensiygttivity of the submarine slope.And on the basis of it,the following work has been done.1.This article briefly introduces the basic principle of finite element strength reduction method,the selection of yield criterion of rock and soil materials and the large nonlinear finite element software ABAQUS.And through an example calculation,we verify the feasibility of the finite element strength reduction method based on ABAQUS in slope engineering.2.The finite element model of the typical section of the submarine energy soil slope be established based on the relevant research data of a certain sea area in the South China Sea.According to the multi factors energy slope stability of seabed to determine the effect of the principle of orthogonal test of multi level combination,and by choosing the decomposition degree,depth,thickness,hydrate hydrate overlying water pressure of the 4 important factors affecting the submarine slope stability,we established the orthogonal matrix.3.Then,we use the ABAQUS finite element software to calculate the combination of the various factors in the orthogonal test matrix.And according to the calculation result,we get the corresponding factor level combination scheme,the stability safety factor of the seabed slope,the plastic zone,displacement and other information.We used orthogonal design range analysis method and variance analysis method to analyze the stability safety factor of the submarine slope under the influence factor level combination scheme of orthogonal test.And then we get the Sensitivity analysis results of influencing factors on stability of submarine energy soil slope4.The concept of natural gas hydrate in the critical depth is put forward,and the critical depth of hydrate in the ideal seabed slope model is studied.And the preliminary analysis results of the critical depth of hydrate are obtained by numerical simulation of the specific submarine slope.