层状围岩隧道受力特征分析及支护参数确定

当隧道在层状围岩中通过时，根据隧道轴线方向与岩层的空间关系不同，往往引起偏压等问题，从而使支护受偏压荷载。目前《公路隧道设计规范》中建议的隧道复合式衬砌设计参数主要针对普遍地质情况，而对于层状岩体中的公路隧道支护参数没有具体规定。采用数值分析的方法，建立相应的计算模型，系统分析了不同倾角情况及隧道轴线与岩层走向不同夹角下层状岩体隧道的受力特征，提出了不对称支护参数设计理念，并初步确定了不同岩层倾角下隧道的支护参数。

Analysis of the Stress Characteristics of a Layered-Surround-Rock Tunnel and the Determination of Supporting Parameters for It

When a tunnel goes through the stratified rock mass, problems such as the unsymmetrical loading often arise from the axial direction of the tunnel being different from the spatial relations of the rock layer; which frequently results in the support- ing structure being loaded by uneven loads. At present,the composite lining design parameters of the tunnel prescribed in the Highway Tunnel Design Specifications apply only to the common geological conditions, but there are still no specific design pa- rameters presented for highway tunnels in stratified surrounding rock. In the light of the method of numerical analysis, a corre- sponding computational model is established and the stress characteristics in the conditions of different inclinations and different angles between the tunnel axis and the strike of the rock layer are analyzed in the paper, on the basis of which the new design concept with unsymmetrical support parameters is put forward,with different supporting parameters for tunnels of different inclinations primarily determined.