盾构隧道施工对短桩基—框架结构的影响  

Influence of Shield Tunnel Construction on Short Pile Foundation-Frame Structure

作　　者：周冠南[1] 周顺华[1] 王春凯[1] 宋天田[1] 

机构地区：[1]同济大学道路与交通工程教育部重点实验室,上海200331

出　　处：《中国铁道科学》2009年第4期51-57,共7页China Railway Science

基　　金：中铁十三局科研项目(ZT13J2GS-CDDT004)

摘　　要：以成都地铁1号线盾构隧道近距离穿越某短桩基—框架结构为背景,采用Mohr-Coulomb弹塑性屈服准则,建立有限元数值模型,研究盾构穿越施工对桩基和框架结构的影响。研究结果表明:采用荷载转移措施可减小隧道上方的荷载和结构变形,有效保护建筑结构;盾构掘进对框架结构的边跨梁影响较大、对中跨梁影响较小,梁的最大正弯矩在二层右边跨梁的跨中,最大负弯矩在二层右边跨梁的右端头位置,柱的最大正弯矩在隧道右侧最远处的柱与二层右边跨梁刚接的位置;盾构从桩端下方穿越使隧道正上方及两侧的3根桩的轴力减小,两侧桩体下部向隧道方向产生挠曲变形,正上方桩体发生整体位移;距隧道较远处的桩发生刚性倾斜,桩轴力增大。监测数据表明,盾构穿越施工对桩基影响较小,荷载转移措施达到预期效果。Taking the shield tunnel passing closely through certain short pile foundation-frame structure in Chengdu Metro Line 1 for background, the finite element numerical model is established by using Mohr-Coulomb elastic-plastic yield criterion to study the influence of the shield tunneling construction on the frame structure and pile foundation. Results indicate that the load transition can reduce the load and structure deformation above the tunnel and effectively protect the building structure. The impact of shield tunneling on the side span beams of the frame structure is greater but little effect on the middle span beam. The maximum positive moment of the beam is located at the mid-span of the right span beam on the second layer. The maximum negative moment is located at the right end of the right span beam on the second lay- er. The maximum positive moment of the column is located at the rigid joint between the right span beam on the second layer and the right side column farthest from the tunnel. The axial force of the three piles of the upper and two sides of the tunnel will be decreased due to the shield tunnel excavating under the pile toe. The bottom parts of both sides＇ piles will generate flexural deformation toward the direction of tunnel, while the upper pile will generate integral displacement. The pile, which is farther to the tunnel, will incline rigidly and its axial force will increase. The monitoring data show that the shield tunneling con- struction has less influence on the pile foundation and the measures for load transition have achieved the desired effect.

关 键 词：盾构隧道 桩基础 框架结构 荷载转移 数值模拟 

分 类 号：U455.43[建筑科学—桥梁与隧道工程] U452.13[交通运输工程—道路与铁道工程]