注浆压力作用下隧道围岩变形规律与安全控制

注浆是隧道围岩加固与涌水封堵的主要技术手段，当围岩较为破碎且自稳能力较差时，注浆过程中若采取了不合适的注浆压力，极易造成围岩大变形甚至塌方等次生灾害。基于渗流-应力耦合理论，选取典型隧道开挖断面，建立注浆作用下渗流场与应力场数学模型，运用COMSOL多物理场耦合软件分析注浆过程中注浆压力作用下隧道围岩的变形规律。结果表明，围岩等级为Ⅴ时，注浆过程中注浆压力不断向隧道周围地层中扩散与传递，渗流场、应力场分布随注浆孔深度增加呈现衰减趋势； 随着注浆压力的提高，应力发生急剧变化，并不断地向围岩深部转移； 注浆初期，围岩变形速率急剧上升，注浆后期围岩变形速率下降，且变形量趋于稳定。依托具体工程实例，提出了合理选择注浆压力的控制技术，保证了围岩的稳定和安全。

Deformation Regulation and Safety Control of Tunnel Surrounding Rocks Under Different Grouting Pressures

Large deformation and collapse may occur when irrational grouting pressure is used for reinforcement of tunnel surrounding rocks characterized by poor self stability. In this paper, typical tunnel excavation cross sections are chosen, and a mathematic model in which seepage field and stress field are considered under various grouting pressures is established. The deformation of tunnel surrounding rocks under different grouting pressures is analyzed by means of multi physical field coupling software COMSOL based on seepage stress coupling theory. The results of surrounding rocks Grade V show that: 1) The grouting pressure can be transmitted to surrounding rocks during grouting. 2) The stress field decreases with increasing length of grouting hole. 3) The stress significantly varies and passes to surrounding rocks. 4) The deformation speed of surrounding rocks rises rapidly in the primary phase and drops in later phase. In the end, the stability and safety of the surrounding rocks are guaranteed by using rational grouting pressure control technologies proposed in this paper, which can provide theoretical support and technical guidance for similar projects in the future.