摘要
Abstract
The surrounding rock mechanical properties of the water-rich soft rock tunnel are severely degraded by water,which greatly reduces the stability of the tunnel.Therefore,clarifying the softening characteristics of the mechanical properties of the surrounding rock when encountering water and revealing the stability control mechanism of the surrounding rock of the water-rich tunnel have important guiding significance for the design of support structures.Therefore,the paper first establishes a time-dependent evolution model for the mechanical properties of soft surrounding rocks by statistically analyzing the variation of rock mechanical properties with water content and time.At the same time,based on the three-dimensional spatial mechanical effects of soft rock tunnel excavation and the theory of elastic-plastic mechanics,an elastic-plastic calculation model for the mechanical properties of soft rock tunnel surrounding rock considering the coupling effect of soft rock water softening time effect and tunnel construction spatial effect was established.Finally,through parameter analysis,the spatiotemporal evolution law of the stress displacement field of soft surrounding rock was clarified,and the stability control mechanism of the surrounding rock of the water rich soft rock tunnel was revealed.In a short period of time,the rock mechanical properties of the soft and weak surrounding rock in the rich water area deteriorate severely,and the deformation and plastic zone range of the surrounding rock increase rapidly after excavation.Therefore,in order to ensure the stability of the unsupported section of the tunnel,the initial support structure is quickly applied after excavation to avoid instability of the surrounding rock in the unsupported section due to long construction time.关键词
富水隧道/软弱围岩/力学特性/时效模式/稳定性控制Key words
water-rich tunnel/soft surrounding rock/mechanical properties/timely mode/stability control分类
天文与地球科学
