隧道开挖流体-固体耦合分析在复杂断裂岩体中的应用

Application of Fluid Solid Coupling Analysis of Tunnel Excavation in Complex Fractured Rock Mass

基于某隧道工程,通过建立模型,研究了隧道开挖流体-固体耦合分析在断裂岩体中的应用。结果表明,在左隧道开挖后,围岩应力分布特征改变明显,应力距离隧道边缘越远变化越小,在洞半径约6倍以外的岩体,应力分布特征恢复到初始应力状态。在隧道拱顶,有较大沉降位移产生,拱腰水平收敛位移较大,拱底隆起变形较大。位移离洞边缘越近,变形越大,离洞边缘越远变形越小,围岩位移基于隧道中线为对称轴呈对称分布。与应力场作用下的应力相比,耦合作用下临近隧道围岩的应力高出约0~2.4 MPa,拱底处的应力要高出0~0.89 MPa。在耦合作用下,隧道洞周位移要大于应力场下的位移,在地下水渗流过程中,应力场发生明显的变化。在渗流场和流固耦合作用下,隧道水头分布情况基本一致,渗流场受应力场影响较小。

In this paper,based on a tunnel project,through the establishment of model,the application of fluid solid coupling analysis of tunnel excavation in fractured rock mass is studied. The results show that,in the left after the tunnel excavation,the surrounding rock stress distribution characteristics change significantly,stress from the tunnel edge farther change smaller,rock mass in the hole radius is about 6 times than the stress distribution characteristics of return to the initial stress state. In the vault of the tunnel,there is a large settlement displacement,the horizontal convergence of the arch is greater,and the deformation of the arch bottom heave is larger. The nearer the displacement to the edge of the hole,the greater the deformation,the farther away from the hole edge,the smaller the deformation,and the displacement of the surrounding rock is symmetrical based on the symmetry of the tunnel centerline. Compared with the stress under the stress field,the stress of surrounding rock near the tunnel under the coupling action is about 0 ~ 2. 4 MPa higher,and the stress at the bottom of the arch is higher than 0 ~ 0. 89 MPa. Under the coupling action,the tunnel displacement is larger than the displacement under the stress field,and the stress field changes obviously during the groundwater seepage process. Under the action of seepage field and fluid structure interaction,the distribution of water head in tunnel is basically the same,and the seepage field is less affected by stress field.