城市浅埋矩形隧道减震层厚度对减震效果的影响分析*

为研究减震层厚度对减震效果的影响，以某城市浅埋双连拱矩形隧道工程为例，利用数值模拟软件ABAQUS对比分析50,100,150 mm 3种厚度减震层的减震效果。结果表明:施设50 mm厚减震层时，边墙收敛减小14.90%，最大、最小主应力最大值分别减小13.96%和9.59%，最大剪应力减小3.22%，最小安全系数最小提高23.13%；施设100 mm厚减震层时，边墙收敛减小6.63%，最大、最小主应力分别减小14.70%和11.90%，最大剪应力减小4.56%，最小安全系数最小提高41.39%；施设150 mm厚减震层时，边墙收敛减小4.65%，最大、最小主应力最大值减小幅度较大，其中最小主应力最大值减小了14.03%，最大剪应力减小6.17%，最小安全系数最小提高42.72%；施设100 mm厚减震层优于50 mm和150 mm厚减震层。研究成果可为城市浅埋双连拱矩形隧道的减震设计提供参考。

Analysis on influence of thickness of shock absorption layer on shock absorption effect of urban shallow buried rectangular tunnel

In order to study the influence of the thickness of the shock absorbing layer on the shock absorbing effect,taking a shallow buried double arch rectangular tunnel project in a city as an example,the numerical simulation software ABAQUS was used to compare and analyze the shock absorbing effect of three kinds of shock absorbing layers with the thickness of 50,100 and 150 mm.The results showed that when applying the shock absorption layer with the thickness of 50 mm,the side wall convergence decreased by 14.90%,the maximum of maximum and minimum principal stress decreased by 13.96% and 9.59%,respectively,the maximum shear stress decreased by 3.22%,and the minimum safety factor increased by 23.13% at least;When applying the shock absorption layer with the thickness of 100 mm,the side wall convergence decreased by 6.63%,the maximum of maximum and minimum principal stress decreased by 14.70% and 11.90%,respectively,the maximum shear stress decreased by 4.56%,and the minimum safety factor increased by 41.39% at least.When applying the shock absorption layer with the thickness of 150mm,the side wall convergence decreases by 4.65%, and the maximum of maximum and minimum principal stresses decrease by a large margin, among which the maximum minimum principal stresses decrease by 14.03%,the maximum shear stress decreased by 6.17%,and the minimum safety factor increased by 42.72% at least.The shock absorption layer with the thickness of 100 mm was better than those with the thickness of 50 mm and 150 mm.The research results can provide reference for the shock absorption design of urban shallow buried double arch rectangular tunnels.