Study On Disaster-Reducing Countermeasures Against Landslide And Dammed Lake And New Technology Of Bridge Construction In Kangding-Changdu Section Of Sichuan-Tibet Railway

In the west,where the terrain is complex and multi-seismic,the environment is relatively bad,and the landslide dammed lake and other disasters occur frequently,and the research is relatively weak.In order to ensure the safety of railway lines and transportation infrastructure to ensure the unimpeded life channel,the landslide event has become a key problem which hinders and constrains the construction of Sichuan-Tibet railway.The landslide-dammed lake disaster chain should have become prevention and control in line design stage.The line planning of Kangding-Changdu section of Sichuan-Tibet Railway will pass through the alpine region.But the low temperature in the alpine region and the short construction season in the whole year are the inevitable natural factors that hinder the local construction.Therefore,it is necessary to reduce the construction time of the site.The construction of the railway will face a lot of difficult problems,due to the limitations of time,this article only for the next two problems are analyzed.First,in this paper,a set of methods for assessing risk of landslide blocking is established,and the theoretical formula of each link is proposed.On this basis,taking the Desha landslide of Sichuan-Tibet Railway as an example,first,the model grid is processed by ANSYS finite element software and the three-dimensional landslide model is established by FLAC3D finite difference software.The purpose is to analyze the stability of the landslide,and to determine the quantity of the landslide in the river by calculating the volume.And then the empirical formula is used to calculate the slip distance,slope speed,the minimum amount of blocking,to predict the risk of blocking river in the case of large earthquakes.Finally,the recommended formula is used to calculate the width and flow of the fracture,the flow and the water level along the flood peak to estimate the influence range of the dammed lake,and line engineering for disaster reduction countermeasures are put forward in this paper.And,it not only can provide reference for the design of the line location and the layout of major projects in the study area,but also hope to promote the development of the technology of disaster chain reduction in mountain railway through case study.Then,in order to solve the problem of bridge construction in the alpine region construction,this paper analyzes and studies the international problems which are widely used in the high cold area to restrict the prefabricated concrete bridges.This paper proposes a new concept of Joints with headed bar details for bridge rapid construction.5 pieces of beam parameters with different joint specimens are made to carry out the test of flexural capacity,and the optimal parameters of the joints are obtained.And strut-and-tie model is taken for mechanical structural analysis of joints.It is of great significance to study the traffic construction in the alpine region and to guarantee the long-term safety of the precast concrete bridge in the rescue and disaster relief project.