Research On The Development Characteristics And Prevention Of Rockfall Hazards Of Highway In Liaoning Province

Rockfall is a common geological Hazards phenomenon of Liaoning Province, especially, happens on mountain road slope. Through the statistics of the 964 road slopes of the county level or above, which have happened many times, and has not been treated or controlled, there are 532 road slopes which have happened collapse or rockfall, accounting for 55.19% of the total of highway geological Hazards. Therefore, the research on the development characteristics and prevention of rockfall hazards of highway in Liaoning Province has great significance.Based on the project of “the research and application on the prevention of slope hazards of highway in Liaoning Province”,and through the investigation data of the 1236 sections of the highway slope in Liaoning province and the statistics of the history of geological disasters reported by the road bureau, and the research and analysis on the relationship between the shape of the slopes, geological conditions, climate factors, surrounding environment, human activities and the distribution of rockfall. The paper focus on the formation conditions, predisposing factors and its classification of the rockfall hazards of highway in Liaoning Province. The research results are as follows:(1) The formation conditions of Liaoning Province highway slope rockfall include: slope angle, slope lithology, geological structure effect, slope structure; The predisposing factors of Liaoning Province highway slope rockfall include: precipitation, weathering, vibration, plants and animals, as well as humans.(2) According to the condition of the initial motion, rockfall of the ordinary slope in Liaoning Province divided into rotary rockfall, sliding rockfall and straight rockfall; According to the causes offormation, rockfall of the ordinary slope in Liaoning Province divided into dumped rockfall, undercut rockfall, slide collapsed rockfall, sliding rockfall, freefall rockfall, tension rockfall.(3) Factors to influence the movement of rockfall is discussed, for specific Liaoning Province highway slope determine corresponding rockfall movement speed, trajectory and the motion characteristics of the application, for the study of rockfall mitigation lay a theoretical support.(4) Based on the ideal model of ground bearing capacity and the theoretical basis of the energy theory on Prangtl logarithmic spiral line. In consideration of the condition of the soil unit weight, cohesion, internal friction angle and rockfall size effect etc., paper establish rockfall impact force calculation formula which is suitable to the assumption.(5) Rockfall impact force formula relates to a high frequency power problem, the calculation is more complicated, you can use dichotomy iterative calculations to solve the a rockfall impact force.(6) Through the comparison of the rockfall impact force calculation results and the previous studies of the impact test results, determine the amplification factor of the maximum impact force formula is 1.25. The formula of the maximum impact force in this paper is compared with that of the impact force calculation formula recommended by the Japanese road group and the Swiss Labiouse method, proving the formula to calculate the maximum of rockfall reliable, reasonable and practical.(7) Using the control variable method, analyze the influencing factors of rockfall impact force.(8) According to the actual situation of Tieling City of Liaoning Province, Shen Ping line from K92+380 to K92+730 on the left slope analysis of reasons for the formation of the rockfall hazard, analyze its rockfall movement characteristics and the slope rockfall impact characteristics, and put forward corresponding preventive measures. Calculate the rockfall impact force which maybe damage the cable underneath, pipelines and so on.(9) According to the actual situation of seven highway slopes in Benhuan Line of Benxi City Liaoning Province, analyze the rockfall movement characteristics and the slope rockfall impact characteristics, and put forward the corresponding preventive measures. And carries on the technical promotion.