高填方土体中隧道开挖对地表市政设施的影响

Influence of Tunnel Excavation in Deep Fill on Municipal Facilities

为研究在高填方土体中开挖隧道对地表道路、挡墙和通道等市政设施的影响,采用ANSYS软件建立模型,对隧道开挖引起的土体变形进行模拟计算。结果显示,隧道开挖将导致地表不均匀沉降并形成负曲率,造成道路沉陷、开裂,挡墙墙体开裂、倾斜,通道沉降等危害,路面竖向位移达14.96~44.83 cm,挡墙在竖向和水平向的沉降差分别达到26 cm和7.35cm,通道沉降量达33 cm。隧道开挖后的长期变形预测表明,填土体仍会产生一定变形,道路、挡墙及通道仍会产生一定的沉降和变形,但其变形速率减缓,趋于稳定。在施工过程中应禁止爆破作业,加强监测,并视病害程度采取预加固措施。

In order to evaluate the influence of excavation in deep fill on the municipal facilities such as surface roads,retaining walls and pavements,the ANSYS software was adopted to establish the numerical model of soil deformation. Results showed that the tunnel excavation would lead to the differential settlement of the surface and form negative curvatures. The roads would suffer from settlement and cracking. The retaining wall would be cracking and tilt,and the settlement of pavements would also take place. The numerical simulation results indicated that the vertical settlement of surface road was from 14. 96 cm to 44. 83 cm. The differential settlements at vertical and horizontal by the retaining wall were 26 cm and 7.35 cm respectively,and settlement of the pavement was 33 cm. Long-term forecast by ANSYS showed that the deep fill would still suffer some deformations after tunnel excavation resulting in settlement and other deformations of the surface roads,retaining wall and pavements,but the rate of deformations would decrease and tend to be stable. Blasting operation should be banned in the construction process,and monitoring should be strengthened to support the measures of pre-reinforcement.