| With the rapid development of traffic and economy in the west,various geological disasters threaten the safety of traffic operation in the west,such as collapse,debris slope,debris flow and landslide.Grain body slope is mainly composed of gravel,clastic particles together to form the slope,with loose structure,poor permeability resistance and low cohesive force by characteristics of the structural characteristics and stability,can be a tremendous impact on the retaining wall after buckling destruction,poses a serious threat to traffic safety,pedestrian.This paper takes the xinjiang tianshan road(G217)along the"dushanzi-kuqa"section as the research area,the road along the development of the grain body slope investigation statistics,the analysis of the distribution of grain body slope characteristics and instability mechanism;On the basis of investigation and research,the characteristics of the impact force of the baffle wall under the impact of granular material are studied by means of physical simulation test.By means of numerical simulation,the dynamic characteristics of the impact baffle wall are analyzed.Finally,the vulnerability of retaining wall was evaluated for 35 granular slope along tianshan highway.Through the above research,the paper mainly achieved the following results:(1)The development of grain in the studied area slope statistical investigation concluded that grain of tianshan road body slope is mainly distributed in the north tianshan area k610~k655 section,35 typically developed along the grain body slope,road length is about 8.71 kilometers,the distribution of grain body slope and topography,lithology,geological structure,slope to the relevant climate and atmosphere,causes the instability of the main factors for the earthquake,wind load,rainfall and the impact of the Rolling Stones.(2)Through the grain body impact retaining wall of physical simulation experiment analysis:different grading of grain body,start height,start thickness,impact Angle and the retaining wall structure has a significant effect on impact,stack height:1)the larger the particle size,the impact of the retaining wall is,the greater the stack height,the higher the retaining wall.The higher the starting height of the granule,the higher the accumulation height after the impact wall,and the increase of the power function of the impact force.The larger the starting thickness of the granule,the greater the power function of the impact force of the retaining wall,and the linear increase of the height of the wall in front of the retaining wall.The impact Angle of the granule on the retaining wall is larger,and the impact force of the retaining wall increases with power function,while the accumulation height is linearly reduced.The impact force of the baffle wall is obviously less than the linear retaining wall,which indicates that the impact force is related to the wall structure.6 from schottky retaining wall impacted by a projectile motion process,found that both the particles in the process of impact,friction and collision motion,mutual transformation between two kind of movement form will cause huge impact to the retaining wall,close contact between particles compared when you start,the movement is given priority to with friction between particles and chute movement;As particles continued downward movement,front started hitting the retaining wall,the whole fluid gradually stretched,loose contact between particles,flow thickness decreases,at this point is given priority to with the collision of particles movement;Finally,it is blocked by the retaining wall,and the contact between particles becomes compact,and the collision movement becomes frictional movement,which eventually accumulates in the front of the wall.(3)The dynamic characteristics of the impact wall are studied by numerical simulation:the impact wall is a continuous impact process,and the impact force at different height of the baffle is nonlinear with time,and the higher the height is,the less the impact force is.The baffle wall can divert the particles to both ends and increase the collision frequency between particles,resulting in energy loss.Therefore,the impact of the broken wall is smaller than that of the linear retaining wall.The particle shape has some influence on the impact force.When the slope is smaller,the impact force increases with the increase of the circle degree.As the slope increases,the effect of particle shape on impact force decreases.The study also found that the greater the slope,spread the impact of the granule on retaining wall due to the nonlinear change,the more obvious,this change related to soil arching effect:when the slope gradient is small,form small impact between particles and chute arch,at this time the impact of the retaining wall is smaller;When the slope of the slope is relatively large,there is a large impact arch between the particles and the retaining wall,and the impact force of the retaining wall is larger.(4)By the three dimensional scanner scan highway k628+500 slope of the tianshan mountains,through the three periods of scan data calculation,its average annual production scrap rate from the slope in September 2015 and September 2016known slope terrain line change the loss of the trailing edge thickness up to 1.12 m;According to the average annual production scrap rate established the numerical calculation model of slope,found that over a long period of time the upper slope rock mass weathering of gravel impact will continue to tumble retaining wall,by simulating the grit body impact overturning failure process of retaining wall can be seen,the grain body on the impact of the retaining wall is behind the retaining wall first piled up,stack height will be more and more high,even over the moving to the retaining wall of highway,the impact effect on the fall of the retaining wall is becoming more and more obvious;After the baffle is overthrown,the slope of the granule slope begins to slide,and then the upper particles will cause the lower particles to collapse along,buried roads.(5)In xinjiang G217 roads,the vulnerability assessment of the wall is carried out.Firstly,the impact force of the loose particle on the lower wall is calculated according to the subgrade specification:(?),then calculate the upsetting moment of the impact force against the wall:M_f=Fcos?×h,The anti-overturning moment of the retaining wall is calculated according to the anti-overturn calculation principle of the retaining wall:M_d?Gx+Fbsin?,Finally,the vulnerability model is established according to the vulnerability quantification evaluation model:(?),The quantization value of the baffle is calculated.To distinguish between high and low.It can be seen from the results that the retaining walls along xinjiang tianshan highway are less than high vulnerability,most of them are in moderate vulnerability,and they are distributed in the k610~k655 sections in the north tianshan area. |
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