不同滑带角度滑坡作用下隧道衬砌结构受力特征

随着越来越多的隧道工程穿越滑坡区，滑坡与隧道相互作用过程的研究尤为重要. 为研究不同滑带角度滑坡对隧道衬砌结构受力的影响，以大（同）准（格尔）铁路南坪隧道为例，采用室内模型试验、数值模拟的方法，对0°、10°、20°、30°、40°、50°不同滑带角度条件下滑坡推力作用下隧道衬砌结构受力的影响特征及变化规律进行研究. 研究结果表明:滑带角度越小，隧道变形越大，作用在隧道衬砌结构上的弯矩、剪力及土压力越大，并在拱脚处出现最大值，形成隧道拱结构左右受力不对称特征，呈现偏压现象；通过计算隧道拱结构左右两侧的竖向偏压应力比显示，在拱肩位置且滑带为0时，偏压应力比为1.17，随着滑带角度的增大，隧道衬砌拱结构左右应力差越来越小，趋于平衡拱；在拱脚位置，偏压应力比随滑带角度的增大而逐渐增大，隧道衬砌拱结构左右两侧所受应力差越来越大，趋向于偏压隧道，最小偏压比和最大偏压比分别为1.08、1.87. 

Stress Characteristics of Tunnel Lining Structures Under Landslides with Different Angles of Sliding Zone

With more and more tunnel projects passing through landslide areas, research on the interaction between landslide and tunnel is particularly important. To better understand the influence of landslide with different angles of sliding zone on the stress of tunnel lining structure, taking the Nanping tunnel of Datong–Zhungeer railway as an example, laboratory model tests and numerical simulations were conducted to study the influence characteristics and variation rules of tunnel lining structure stress under different angles of sliding zone (namely 0°, 10°, 20°, 30°, 40° and 50°). The results show that the smaller the angle of sliding zone, the greater the tunnel deformation, and the greater the bending moment, shear force and earth pressure acting on the tunnel lining structure. Moreover, the maximum stress appears at the arch foot, and the forces on the left and right tunnel arch structure are asymmetric, showing a phenomenon of bias pressure. The calculation of the vertical bias stress ratio of the left and right sides of the tunnel arch structure shows that at the arch shoulder position, when the angle of sliding zone is 0, the bias stress ratio is 1.17. As the angle of sliding zone increases, the difference between the left and right stresses of the tunnel lining arch structure is getting smaller and smaller, tending to balance around the arch; but at the arch foot position, the bias stress ratio gradually increases with the increase of the angle of sliding zone. The stress difference between the left and right sides of the tunnel lining linebreak left="0.7" right="1.3"/> arch structure becomes larger and larger. For the bias tunnel, the minimum bias ratio is 1.08 and the maximum bias ratio is 1.87.