盾构隧道施工对邻近桥梁桩基的影响分析

Impact Analysis of Shield Tunnel Construction on Adjacent Bridge Pile Foundation

以深圳地铁7号线珠光站—龙井站区间盾构隧道下穿南坪快速龙珠大道跨线桥为依托,运用MIDAS GTS NX软件模拟了盾构掘进的全过程,得出了地面沉降和桩基倾角值;对施工时地面沉降进行预测,并与监测数据进行了对比,证明计算结果可靠。结果表明:地面沉降的理论计算最大值为8.5 mm,实际监测值为8.0 mm,误差为6.25%;桥梁桩基产生隧道横断面、隧道纵向方向的最大倾角分别为39.62″,39.2″,其倾角在盾构机穿过桥基30 m后趋于收敛稳定。

Relying on shield tunnel through Nanping Longzhu Avenue Overpass in Zhuguang Station-Longjing Station of Shenzhen Metro 7 Line,the Midas GTS NX software was adopted to simulate the whole process of shield tunneling,the surface subsidence and inclination of pile foundation were obtained. The surface subsidence during construction was predicted and compared with the monitoring data,which proved that the calculation results were reliable. The results show that the maximum theoretic surface subsidence was8. 5 mm,the practical monitoring data was 8. 0 mm,and the deviation was 6. 25 %. The maximum inclination of bridge pile foundation in the cross section and longitudinal direction were respectively 39. 62″ and 39. 2″.The inclination was tend to be stable after 30 m of shield tunneling through the bridge foundation.