Research On Mechanical Characteristics Of Reinforcement Measures For Talus Slope On Sichuan-tibet Railway

With the steady progress of the Sichuan-Tibet Railway construction,the problem of reinforcement of talus slopes along the line has been increasingly prominent.Talus slopes belong to frozen landform.Under the action of freezing and weathering,the rocks are continuously disintegrated and broken,and are constantly accumulated on the surface of the slope.Although it can maintain its own stability under natural conditions,it has a greater risk of instability under the effects of artificial excavation,earthquakes,freezing and thawing.Traditional reinforcement and support solutions such as retaining walls cannot effectively reinforce talus slopes,and even the dilemma of "digging and sliding" occurs.There is an urgent need to propose a reinforcement program suitable for talus slopes.This paper considers the shortcomings of traditional reinforcement measures,and combines the characteristics of the talus slope itself,and proposes a joint reinforcement plan of micro steel pipe piles + anchored SNS nets.First,using micro-steel piles to pre-reinforce the slope excavation,and then using anchored SNS nets on the slope during the excavation process to improve the stability of the whole process.The full text adopts theoretical analysis,numerical simulation and research methods combined with actual work points to study the reinforcement effect and force characteristics of the above-mentioned reinforcement measures.The theoretical analysis part mainly summarizes the characteristics of the talus slope and reinforcement measures,and analyzes and derives the calculation method of the force of the micro steel pipe pile and the anchored SNS net and the stability calculation method of the talus slope.In the numerical simulation part,firstly,through different settings of the layout of reinforcement measures,the optimal solution in the layout method is found and the necessity of joint reinforcement is proved.Secondly,the effectiveness of the reinforcement scheme under different rock content conditions is verified,and the corresponding reinforcement effect and the force characteristics of the reinforcement measures are studied.Finally,it is verified whether the reinforcement measures can maintain its own stability and slope stability under the influence of the two adverse geological effects of freeze-thaw and earthquake,and the reinforcement effect and force characteristics of the reinforcement measures under the influence are studied.Combined with the actual work point,by using the real data of the actual work point,and combining with the modeling form in the numerical simulation part,the application design and numerical simulation analysis research are carried out.The actual geotechnical data of the construction site adopts the real data of the talus slope construction site at the entrance of the Kangding Tunnel,and the reinforcement effect of the reinforcement scheme under the action of manual excavation and earthquake is discussed,which provides a guidance for subsequent research.