水压条件下矿山法隧道主体结构的受力特征

Mechanical Characteristics of Main Structure of Mining Tunnel under Water Pressure

为探明水压条件下矿山法隧道主体结构的受力特征,采用模型试验研究高水压条件下衬砌的力学行为、结构与围岩、地下水相互作用关系及结构破坏模式.研制了马蹄形断面非均布水压-土压加载装置,模拟大断面隧道衬砌主体结构在不同水压与土压共同作用下的力学行为.研究表明:弯矩沿衬砌周向总体上呈蝴蝶形分布,轴力呈近似椭圆形分布;土压力增大使结构弯矩、轴力、最大变形量和偏心距均增大;侧压系数增大使结构弯矩不同程度地减小,而使轴力增大;水压增大使衬砌轴力迅速增大,而弯矩增大较慢;高速铁路隧道衬砌结构承受的极限水压不宜超过500 kPa.

In order to probe into the mechanical characteristics of main structure of a mining tunnel under the action of water pressure, model tests were carried out for investigating the mechanical characteristics of tunnel, the interaction between lining and strata and the failure modes of the structure were researched. Non-uniform water pressure-soil pressure device for a horseshoe-shaped tunnel section was designed. The mechanical characteristics of main structure subjected to water pressure and soil pressure were simulated experimentally. The reserach result demonstrates that moment has a butterfly-shaped distribution along lining perimeter, and the distribution of axial force appears as an ellipse. With the raise of soil pressure, bending moment, axial force, deformation, and eccentricity of lining increase. The increase of lateral pressure coefficient will lead to the reductions of bending moment and axial force. In addition, water pressure will influence the axial force of lining sharply and bending moment gradually. Consequently, limited water pressure is less than 500 kPa.