Research On Risk Assessment Method Of High And Steep Slope Against Risk Database And Application

With the implementation of major national strategic plans such as "the 13th Five-Year Plan" and "the Belt and Road" and so on,there are more and more transportation infrastructure projects such as railways and highways,along with many slope projects among the planning line.Due to complex natural terrain that a large number of mountainous hills exist in many areas,it brings a large number of high-steep slope engineering and safety problems,which results in serious accident losses.The development of mountainous roads,the surrounding geographical environment being very complicated,so countless high-steep slopes formed by excavation.Because the increasing influence factors of uncertainties,the risks are also increasing,which lead to scale of losses caused by risks is also increasing.Therefore,it is particularly important to identify and estimate the risk sources of high and steep slopes.However,the high slope formed by artificial participation has more risk factors than the natural slope,if the slope excavation disturbance project is slightly inadvertent,the rock and soil body is prone to lose balance,which lead to non-negligible results.In order to carry out risk assessment of high and steep slopes more objectively,comprehensively and quantitatively,this paper relies on the national key research and development plan sub-topic "Hazardous source identification and risk assessment of large complex tunnels and high and steep slopes"(2016YFC0802201-2)to promote risk assessment method and application research of high and steep slopes.The main research is as follows:1.Based on the data survey,the geological conditions and slope characteristics of 103 high-slope working sites on mountain roads were obtained.Based on the theory of accident causation in system safety engineering,the slope points in detail is examined by the risk information questionnaire,as well as some slopes were field-tested.Combined with relevant literature,normative documents,on-site investigations,expert consultations,and collating statistics on high-steep slope risk information.It is found that the development of rock mass joints,the excavation of layered rock mass slopes,and the alpine valleys are the sources of risk factors for high and steep slopes that need attention after analysis.2.The BN risk identification method for high and steep slopes is proposed,and the dynamic load threshold division around the slope is established based on the distance range.The index system of existing normative documents is improved.After the layered analysis of the high-steep slope risk causes,based on the existing risk information,combined with the analysis of the risk database,the geometrical dimensions,geological conditions and periphery of the slope section are defined by internal and external factors.The first-level indicators,mainly environmental,natural predisposing factors and data integrity as well as specific secondary indicators.3.A risk assessment method for high and steep slopes with quantitative and qualitative supplements is formed.The high-steep slope risk assessment model established by the risk matrix method and the index system method is combined.Moreover,the preliminary risk assessment index system table of high and steep slopes under the objective conditions.The special risk assessment index system of excavation construction measures are determined.4.Considering the complexity of risk assessment in geotechnical engineering and the uncertainties of slope construction process,based on MATLAB and database information,the importance ranking method and analytic hierarchy process under rough set theory are utilized to comprehensively determine the weight value to obtain preliminary and special risk assessment level.The analysis of the risk of a high-steep slope in Lishui City shows that the risk of the project is high under given conditions,and relevant control measures should be taken during the excavation construction period to improve the risk warning.