风化砂岩公路隧道渗流-应力耦合数值模拟

Numerical simulation of seepage-stress coupling in weathered sandstone highway tunnel

以江西省宜春市宜遂高速公路风化砂岩高且隧道工程为例,利用有限元分析软件Midas/GTS三维模拟了高且隧道的施工和开挖过程,将所得结果与现场监测数据进行比较,研究了渗流-应力耦合对隧道稳定性的影响,比较了耦合与非耦合条件下隧道稳定性的变化。结果表明,在渗流-应力作用下,隧道稳定性受到明显影响,渗流主要发生在隧道仰拱和边墙处,各施工阶段断面孔隙水压力在拱底处最大,在拱顶处最小;对比非耦合条件,在耦合条件下隧道拱顶、拱底和水平收敛值均有所增加,孔隙水压力对不同岩性的隧道拱顶沉降有很大影响。

Taking the weathered sandstone Gaoqie tunnel project of Yisui Expressway in Yichun City,Jiangxi Province as example,the finite element analysis software Midas/GTS was used to simulate the construction and excavation process of the Gaoqie tunnel.The calculation results were compared with the field monitoring data.The influence of seepage-stress coupling on tunnel stability is studied,and the changes of tunnel stability under coupling and non-coupling conditions are compared.The results show that the stability of the tunnel is obviously affected by seepage-stress.The seepage mainly occurs at the inverted arch and side wall of the tunnel.The pore water pressure value of the section in each construction stage is the largest at the arch bottom and the smallest at the vault.Compared with the uncoupled condition,the vault,arch bottom and horizontal convergence value of the tunnel increase under the coupled condition,and the pore water pressure has a great influence on the vault settlement of tunnels with different lithology.