Research And Application Of Loose Slope's Collapse Scale Under Earthquake

Collapse and landslide which are triggered by earthquake with the characteristics of wide distribution often occur under sliding rapidly one off mode, therefore,they have become an unneglectable secondary disaster in earthquake region. Just as disasters triggered by earthquake, the human can't avoid disasters of collapse and landslide under earthquake completely, but we can take positive and effective measures to reduce the disaster. Especially in recent years, with the process of urbanization accelerating in our country, large water conservancy and hydropower projects establishing, strategies of economic development transfer to western,the requirement of developing the research of forecasting disasters of collapse and landslide under earthquake is more urgent.Under earthquake , surface collapse often occurs when the loose slope is in the instability mode and the collapse size of loose medium slope is an important index in collapse hazards. The collapse size in collapse hazards is also a scientific question for future study, but there are few studies at home and abroad. The loose particle of slop body is chosen as research object in pseudo-static method framework. According to the balance principle of force, the simplified formulae in instability of critical state is derived under different effects of earthquake intensity in this paper. The simplified formulae was validated by the centrifugal model test result (according to the criterion of gravitational force similarity, its height attains 20.4m) which uses slope body floor as the experimental model. Taking real underground projects of Tongmai to 105 Maintenance in the project of the treatment and reconstruction of Sichuan-Tibet highway at highway section of National Road 318 as an example , this paper will carry out an explanation of application mode in this research method.The main work and conclusion is as follow: (1) Geotechnical centrifuge model tests were adopted to study the accumulation 's collapse under earthquake which is formed by uniform and non-uniform particles.(2) Adopting the traditional mechanics method to study the relation between friction coefficient and internal friction angle using PFC2D procedure , and study the accumulation 's internal friction angle is affected by grain diameter ,density, and gradation.(3) By changing the angle of the slope corresponding to different sizes of earthquake intensity, numerical simulations of the accumulation 's collapse could be realized in PFC2D procedure,and compare the difference between simulation results and results of geotechnical centrifuge model tests.(4) Having established a simplified formulae which is used to estimate the collapse 's volume of loose slope under earthquake by using pseudo-static method for principle. According to this simplified formulae, the collapse 's volume of loose slope of real underground projects of Tongmai to 105 Maintenance in the project of the treatment and reconstruction of Sichuan-Tibet highway at highway section has been calculated under large , middle, small earthquake.