富水区外水压力作用下隧道衬砌受力特性研究

Study on Stress Characteristics of Tunnel Lining Underthe Action of External Water Pressure in Water-rich Area

为保证富水区隧道衬砌选型经济合理,以明月山隧道为依托,采用荷载-结构法,通过数值模拟,研究了外水压力作用下普通衬砌和抗水压衬砌结构的受力特性及安全系数变化规律,分析了外水压力对衬砌内力的影响态势和程度,明确了适用于不同外水压力的衬砌方案。结果表明:穿越富水区隧道衬砌结构在外水压力作用下,拱脚与仰拱为衬砌结构薄弱区;仰拱厚度增加和仰拱半径减小能显著提高衬砌整体抗外水压能力;根据外水压力值选取合理的衬砌动态设计方案可实现富水区隧道衬砌精细化设计。

In order to ensure the economic and reasonable selection of tunnel lining in a water-rich area,this paper,based on the Mingyueshan tunnel,employed the load-structure method to study the stress characteristics and the safety factor variation law of ordinary lining and the water-resistant lining structure under external water pressure through numerical simulation.The influence trend and degree of external water pressure on the internal force of lining was analyzed,and the lining schemes suitable for different external water pressures were defined.The results showed that the arch foot and inverted arch are the weak areas of the lining structure under the action of external water pressure;The increase of inverted arch thickness and the decrease of inverted arch radius can significantly improve the overall anti-external water pressure capacity of the lining;According to the external water pressure value,a reasonable dynamic design scheme for the lining can be selected to realize the refined design of tunnel lining in a water-rich area.