仰拱曲率对浅埋大断面隧道衬砌结构承载力的影响研究

Study on Effect of Inverted Arch Curvature on Bearing Capacity of Lining Structure for Shallow Buried Large-section Tunnel

摘要:

仰拱曲率对三车道大断面隧道的承载能力影响较大，分别从二次衬砌弯矩、轴力及安全系数等方面对仰拱曲率对三车道大断面隧道的承载能力进行定量分析。研究结果表明：过渡圆弧半径与仰拱半径的比值R*存在临界值，当仰拱曲率在临界值以下时，弯矩和安全系数变化相对较大，当仰拱曲率超过临界值时，弯矩和安全系数变化相对较小；结构越趋于圆形，安全系数越大，承载力越高。

Abstract:

The inverted arch curvature has a great influence on the bearing capacity of three-lane large-section tunnel. The effect of the inverted arch curvature on the bearing capacity of three-lane large-section tunnel is quantitatively analyzed from the aspects of secondary lining bending moment, axial force and safety factor. The study results show that the ratio R* of the transition arc radius to the inverted arch radius has a critical value. When the inverted arch curvature is below the critical value, the bending moment and safety factor change relatively large, and when the inverted arch curvature exceeds the critical value, the change of bending moment and safety factor is relatively small. The more circular the structure becomes, the greater the safety factor is and the higher the bearing capacity is.