隧道穿越方式对地表建筑物变形影响的数值分析

Numerical analysis of deformation influence of tunnel crossing types on ground building

以某地铁隧道穿越地表建筑的工程项目为依托,通过隧道不同穿越角度和偏心比条件下的数值仿真计算,分析隧道穿越方式对地表建筑基础及结构变形形态的影响。计算结果表明:隧道以不同角度和偏心比条件穿越时,地表建筑基础的沉降过程和分布形态差异明显。随着穿越角度的减少,建筑基础沉降最大增幅达37.3%,基础最大沉降位置偏移,沉降分布形态由对称分布逐渐向单侧倾斜,横向相邻柱基沉降差迅速增大,纵向相邻柱基沉降差变化较小;建筑物倾斜值增加明显,最大增幅约10倍。随着隧道偏心比的增大,即隧道逐渐偏离建筑中心,一侧基础沉降增大,最大增幅1.64倍,另一侧基础沉降减少,最大降幅1.24倍,基础最大沉降位置由建筑中心转向侧墙,沉降分布形态由对称分布向单侧倾斜,横向相邻柱基沉降差基本不变,纵向相邻柱基沉降差明显增大,最不利情况出现在偏心比为0.8时。偏心比的改变对建筑物横向倾斜影响较大,对建筑纵向倾斜影响较小。

Based on the project of a metro tunnel passing through ground building, a 3D elastic-plastic computational model was established. Numerical calculation of different conditions of tunnel crossing angle and eccentricity ratio were carried out, and the regularities distribution of the building foundation settlement and the structure deformation was analyzed. The results show that foundation deformation process and distribution are obviously different when the tunnelpasses through the building with different crossing types and eccentricity ratios. With the decrease of crossing angle, the settlement of foundation rises by 37.3% at most, and the surface settlement of foundation changes from symmetrical distribution to lateral flit, and the differential settlement of adjacent plinth increases obviously. Tilt displacements of building increase significantly at different crossing angles, and it can rise 10 times at most. With the increase of eccentricity ratio, the settlement of one side foundation rises 1.64 times, and the other side declines 1.24 times. The surface settlement of foundation changes from symmetrical distribution to lateral tilt, and the transverse differential settlement of adjacent plinth remains the same, while the longitudinal differential settlement increases obviously. The most unfavorable condition appears in the eccentricity ratio of 0.8. The influence of lateral tilt of the building is greater than vertical tilt with the change of eccentricity ratio.