武都西隧道底鼓机理及防治措施研究

Study on Mechanism and Prevention Measures of Floor Heave in Wuduxi Tunnel

基于武都西隧道穿越高地应力软弱围岩段发生底鼓、挤压变形的特点,研究了隧道底鼓的形成机理,在分析隧道底板稳定性的基础上,推导出隧道底板产生压曲破坏时的临界荷载表达式,进一步研究了隧道底鼓防治措施。研究结果表明:1武都西隧道发生底鼓的主要原因在于力学及物理方面,其底鼓形式分别为挤压流动性底鼓、膨胀性底鼓。2根据薄板临界平衡理论可得隧道底板压曲微分方程,解得临界荷载表达式,可对隧道底板稳定性进行分析,为底鼓防治措施提供理论依据。3采用"可让式支护+锚注加固"的综合防治措施,可有效控制隧道底鼓。

Based on the floor heave and extrusion deformation characteristic of soft rock and high ground stress in Wuduxi tunnel,we study on the formation mechanism of floor heave,and based on analyzing the floor stabilization,we derive the critical load expression of floor flexural failure,further analyzing the prevention measures of floor heave.The results show that：①The main reasons of Wuduxi tunnel floor heave are mechanical and physical mechanism,and the forms are squeeze flow heave and expansibility heave.②According to the thin plate critical equilibrium theory,we can get flexural differential equation and the critical load expression.The result provide the theoretical basis for the floor heave prevention measures.③Using the prevention measures of yielding support and bolt grouting reinforcement, we can control the floor heave efficiently.