软岩隧道掌子面玻璃纤维锚杆加固参数研究

新意法的核心思想是通过调节超前核心土的强度和刚度来控制围岩变形。通过数值计算方法模拟掌子面玻璃纤维锚杆加固参数(加固长度、搭接长度、加固范围)在软岩隧道变形中的作用,得出软岩隧道的变形规律。结果表明:(1)加固超前核心土能有效控制隧道变形;(2)根据隧道预收敛变形可以确定锚杆长度,根据掌子面失稳机理和破裂面的深度可以确定锚杆最小搭接长度;(3)在隧道变形允许情况下,可以对掌子面加固范围进行优化,仅加固掌子面中心部位。

Study on Reinforcement Parameters of Fiber Glass Anchor Bar at Soft-rock Tunnel Face

The core idea of ADECO-RS is that the deformation of rock mass is controlled by adjusting the core soil strength and stiffness. The function of face reinforcement parameters( the reinforcing length,the lap length and reinforcing region) on the deformation of soft-rock tunnel by numerical simulation is employed to find out the deformation rule of soft-rock tunnel. The results show that( 1) the reinforcement of the core rock at tunnel face has significant effect on the tunnel deformation response;( 2) the reinforcing length of the anchor bar is defined by the pre-convergence of tunnel,the lap length of the anchor bar is defined by the instability mechanism of the tunnel face and the depth of the breaking crosssection;( 3) the reinforcing region of the anchor bar at the tunnel face can be optimized and only the center of the tunnel face is reinforced once allowable tunnel deformation is maintained.