摘要
研究目的:处于高水压富水区的隧道,由于地下水的渗流作用,对围岩结构产生了渗流体积力,从而改变了隧道开挖后次生应力状态,进而改变了隧道周围的非弹性变形区域,易发生塌方并引起突水事故。本文研究地下水渗流作用下隧道围岩的应力分布规律、塑性区和破裂区影响因素,以便为高水压富水区的隧道维护提供决策依据。研究结论:(1)考虑渗流体积力、岩体应变软化和扩容,以及侧压系数等重要因素,应用弹塑性力学理论,推导出二向不等压条件下考虑渗流、应变软化和扩容的圆形隧道围岩的应力和位移分布规律,给出了隧道围岩不同分区范围与孔隙水压力、岩体应变软化系数和扩容系数,以及侧压系数之间的关系。(2)孔隙水压力、侧压系数、岩体应变软化和扩容对隧道围岩破裂区的影响程度比对塑性区的影响程度明显。在考虑侧压系数时,渗流场、岩体应变软化和扩容特性沿不同方向对隧道塑性区和破裂区的影响表现出各向异性的特点。(3)本文研究结果可以为高水压富水区隧道围岩稳定性分析等方面提供理论依据,对高水压富水区隧道支护结构的设计以及预注浆范围的确定具有一定的工程实用意义。
Research purposes： In high water pressure area, the tunnel is easy to collapse and water inrush occurs because of groundwater seepage, which makes the secondary stress state of the excavated tunnel changed and thus the inelastic deformation area around the tunnel is altered. In this paper, stress distribution and factors that affected the plastic zone and the rupture zone of surrounding rock of the tunnel under ground water are analyzed to provide evidence of decision making for the maintenance of tunnel in high - pressure water - rich area. Research conclusions： （ 1 ） Taking into account seepage body force, strain softening of rock mass, dilatancy and lateral pressure coefficient, elastic - plastic mechanics theory is applied to derive distribution laws of stress and displacement of surrounding rock under two - dimension unequal pressure considering seepage, strain softening and dilatancy, and establish relationships between different partition range of surrounding rocks, pore water pressure, strain softening coefficient of rock mass, dilatancy factor and lateral pressure coefficient. （ 2 ） The results have shown that pore water pressure, lateral pressure coefficient, strain softening of rock mass and dilatancy have greater impact on the fractured zone than the plastic zone. Considering lateral pressure coefficient, the impact of seepage field , strain softening of rock mass and dilatancy on the plastic zone and the fractured zone of tunnel along the different directions show inhomogeneity. （3） The results provided a theoretical basis for the stability analysis on surrounding rock of tunnel in high water pressure area. And it is practical meaningful for underground engineering like supporting structure design of the tunnel in the high - pressure water - rich area and decision of the scope of the pre - grouting works.
出处
《铁道工程学报》
EI
北大核心
2013年第11期62-68,共7页
Journal of Railway Engineering Society
关键词
巷道围岩
渗流
二向不等压
扩容
软化
surrounding rock of tunnel
seepage
two - dimension unequal pressure
dilatancy
softening
