小半径近距离盾构隧道侧穿高架桩基影响研究

Analysis on Influence of Minor Radius Short-distance Shield Tunnel Side Crossing Viaduct Pile Foundation

以上海市轨道交通某盾构区间隧道侧穿内环高架桥桩基为背景,通过有限元数值模拟,分析盾构隧道穿越施工引起的桩基竖向位移、水平位移及倾斜率。研究表明:使用有限元软件模拟盾构穿越施工,可以较好地得到盾构隧道穿越引起的邻近桥桩变形量,以及桩基变形变化趋势;计算结果结合现场实测数据对比表明,在采取可靠措施的前提下,盾构隧道施工引起的邻近桩基竖向变形、倾斜,在桩基变形允许范围内,满足高架桥正常运营要求;小半径盾构隧道施工,需严格控制地层损失率,避免纠偏量过大、过猛。

Taking a shield tunnel side crossing the viaduct pile foundation of the Inner Ring of Shanghai Metro as the background, and according to the finite element numerical simulation, the article analyzes the vertical displacement, the horizontal displacement and the inclination ratio of the pile foundation caused by the crossing construction of shield tunnel. The results show that the use of the finite element software to simulate the shield crossing construction can better achieve the deformation of the adjacent piles caused by shield tunneling, and the deformation and variation trend of pile foundation. The calculation results after comparison with the field test data show that the vertical deformation and the inclination of the adjacent pile foundation caused by the shield tunnel construction meet the normal operation requirements of viaduct within the allowance range of pile foundation deformation under the premise to take the reliable measures. It is required to strictly control loss ratio of stratum during the construction of minor radius shield tunnel in order to avoid too much and substantial rectification.