Study on load reduction method of snow-covered corrugated steel shed hole at tunnel entrance in alpine region
The tunnel entrance section in alpine region is easily affected by snow load and rockfall.Using the existing long-span corrugated steel shed hole will cause large deformation and instability,which will affect the safety operation of the border highway.Therefore,based on the corrugated steel snow shed hole project at the entrance of a tunnel of a certain line,starting from the arch effect and load reduction mechanism of stiffened bridge,the three-dimensional corrugated steel shed hole models of 10 load reduction schemes were conducted by using finite element software,including EPS plate,EPS plate+reinforced snow,EPS plate+reinforced ice.The effect of each load reduction scheme on the stress of shed hole,shed hole deformation and snow cover pressure were studied.The stress deformation characteristics and load reduction effect of steel shed hole were compared and analyzed,and the optimal load reduction scheme was selected.The results show that after applying the load reduction material,the snow cover pressure above the shed hole is dispersed to different degrees on both sides of the shed hole,which reduce the force of the shed structure.With the increase of snow cover height,the effect of load reduction is more significant.Among them,the combined scheme of 30 cm EPS plate+reinforced ice has the best load reduction effect.The roof stress is redu ced by 32.72％and the roof displacement is reduced by 22.63％.In view of the load reduction problem of corrugated steel shed hole,it is recommended to adopt 30 cm EPS plate+reinforced snow scheme within 30 m of the tunnel entrance,and 30 cm EPS plate+reinforced ice scheme can be used for 30 m distance away from the tunnel entrance.
万方数据
维普
