The Analysis Of Slope Stability And Mechanism Of Reservoir Bank Collapse Near The Qianyao Zi Reservoir Bridge

A bridge named QianYaoZi reservoir is located in QianYaoZi reservoir of Inner Mongolia Helingeer County,The whole bridge cross over QianYaoZi reservoir,which is the important part of railway connected DaZhun railway and ShuoHuang railway. Qian Yao Zi reservoir begin to retain water in recent years,Which change the original engineering geological and hydrological conditions and lead to the slope structure line continue to retreat by reservoir water infiltration and wave erosion,Which is a threaten to the safe operation of QianYaoZi reservoir bridge.So,this paper tightly combine with these conditions include engineering geology,meteorology and hydrology, topographic features and so on to research the types of bank collapse, the mechanism of bank collapse, the evolution trend of bank collapse and the harm of various bank collapses to the bridge and the stability of bank slope in the natural state, the seismic load and groundwater under three conditions near the QianYao Zi reservoir bridge site area, Provide a basic judgement of slope protection measures bridge site selection and reinforcement engineering degree on the base of standard. The main research contents of this paper are as follows:(1) Getting hydrology geology,landform,formation lithology and other basic engineering data through data collection and field investigation near the QianYao Zi reservoir bridge. Through the three-dimensional elastic-plastic model analysis to determine the bridge site area of reservoir bank collapse mode,the mechanism of bank collapse,the trend of bank collapse and on the base of summing the division of the bank collapse type in the mountainous area.This paper summary that all kinds of types collapse of QianYao Zi reservoir bridge and determine which is a threaten to the safe operation of bridge by analyzing the relative position between 6# bridge pier and slope and combining with the scale of bank collapse if the slope is broken.(2) Through the three-dimensional elastic-plastic model analysis to determine the most dangerous section of slope. The discrete element model is established for the broken state and joint trend of the rock and soil body at the most dangerous section. Through calculation and analysis of slope sliding failure progressive failure process and has carried on the detailed description of the stability,which can provide a qualitative judgement method when the slope is unstable. Getting the state of nature, the seismic load and hydraulic effects under three conditions of slope displacement in the critical stable state, which can provide a quantitative judgement method.(3) This paper analyses the stability of the most dangerous section of the slope under the conditions of the natural state, the seismic load and the action of the hydraulic near the QianYaoZi reservoir bridge site area by combining with discrete element program based on continuous medium and the strength reduction theory. Whether the reservoir of the bridge slope brothel still need further reinforcement according to the recommended value of designated code for slope grade and slope safety coefficient.