大跨公路隧道初支钢拱架稳定性预测判别方法研究

Discussion on Forecasting the Stability of Steel Arch Frame with Large-span Road-tunnel

随着新奥法思想的引入,以型钢钢拱架锚喷支护为主的柔性支撑在大跨公路隧道中得到广泛运用,但由于缺乏对柔性支撑安全性预测的系统有效方法,新奥法理念很难真正实现,事故仍时有发生。本文通过对柔性支护钢拱架作用特点的研究,结合实际工程提出了钢拱架锚喷支护安全性预测判别方法,工程实例表明,该方法能基本显示开挖稳定性安全性级别,并反映初支内力变化规律,可为有效控制施工安全提供参考。

Since the NATM was introduced into China,flexible shoring with section steel is applied widely in the excavation of large span road tunnel.However,due to the lack of the stability forecasting method for flexible shoring,there are occasionally accidents.In this paper,the characteristic of flexible shoring with section steel are introduced firstly.Then,the stability forecasting method of flexible shoring is presented.According to the field testing,the method is reasonable for safety controlling and the stability levels of surrounding rock can be evaluated.The stress principle of primary-support can also be revealed.