盾构隧道掘进施工对邻近既有建筑的影响分析

Analysis on Influence of Shield Tunneling on Adjacent Existing Buildings

摘要:

盾构隧道掘进过程中，会对周围土体产生扰动和变形。当变形达到一定程度时，会危及邻近建筑物的正常使用。基于有限差分软件FLAC 3D建立三维数值计算模型，模拟不同临近距离和不同建筑层高工况下盾构隧道掘进对邻近既有建筑物的影响，选择既有建筑物沉降作为指标进行分析，对不同工况下既有建筑物的沉降变化曲线进行数据拟合，并与现场实际监测数据进行对比分析。研究结果表明：（1）不同临近距离工况下，随盾构掘进步数增大，建筑物的沉降逐渐增大。随临近距离增大，同一施工步下建筑物的沉降逐渐减小，沉降速率逐渐减小。（2）不同建筑层高工况下，随盾构掘进步数增大，建筑物的沉降逐渐增大。随建筑层高增大，同一施工步下建筑物的沉降先逐渐增大后逐渐减小。（3）盾构掘进过程中对邻近建筑物的主要影响区约为1.6倍隧道外径。研究成果可为类似盾构隧道掘进施工提供参考。

Abstract:

During shield tunneling, the surrounding soil will be disturbed and deformed. When the deformation reaches a certain degree, it will endanger the normal use of adjacent buildings. Based on the finite difference software FLAC3D, a three-dimensional numerical calculation model is established to simulate the impact of shield tunneling on adjacent existing buildings under the working conditions of different adjacent distances and different building storey heights. The settlement of existing buildings is selected as an index for analysis. The settlement change curve of existing buildings under different working conditions is fitted and compared with the field actual monitoring data. The research results show that under the working conditions of different adjacent distances, with the increase of shield tunneling progress, the settlement of existing buildings increases gradually. With the increase of the adjacent distance, the settlement of the building decreases gradually at the same construction step, and the settlement rate decreases gradually. The settlement of existing buildings increases gradually with the increase of shield tunneling progress under different storey height conditions; With the increase of the building height, the settlement of the building first increases and then decreases at the same construction step. The main influence area on adjacent buildings during shield tunneling is about 1.6 times the outer diameter of the tunnel. The research results can provide reference for similar shield tunneling constructions.