泥炭质地层盾构侧穿桥梁施工相互影响及控制措施研究  

Research on the Mutual Influence and Control Measures of Shield Tunnel Side-Crossing Bridge Construction in the Peaty Strata

作　　者：邓如勇 DENG Ruyong(China Railway Siyuan Group Southwest Survey and Design Co.Ltd.,Kunming Yunnan 650220,China)

机构地区：[1]中铁四院集团西南勘察设计有限公司,云南昆明650220

出　　处：《铁道建筑技术》2024年第12期96-101,共6页Railway Construction Technology

基　　金：中铁第四勘察设计院集团有限公司科技研发计划项目(KY2023065 S、2017K105)。

摘　　要：以昆明地铁5号线龙庆路站-白云路站区间盾构侧穿东二环高架石闸立交桥施工为背景,通过数值模拟研究不同地层应力释放率下区间隧道侧穿桥梁施工相互影响规律。结果表明:盾构侧穿桥梁施工的竖向卸载效应大于水平卸载效应,桥桩出现背离隧道径向变形,夹土变松散,实际工程中采取洞内注浆进行夹土加固非常必要;隧道与桩基净距对盾构侧穿桥梁施工影响显著,地层应力释放率在0.1~0.3时,桩身各区段相对变形量较小,桩基因偏心受压而发生桩基开裂及破坏的可能性不大;隧道侧穿桥梁施工扰动区域主要分布于隧道周边1~2D(D为隧道直径)范围,盾构侧穿桩基施工对桩基轴力的影响表现为盾构隧道拱顶以上桩基轴力“颈缩”,对桩基弯矩的影响主要表现为侧穿段隧道中心区域所对应桩基弯矩增大;随地层应力释放率增加,盾构侧穿桥梁最大倾斜出现位置会发生变化,倾斜度呈先减小后增大的变化趋势。计算结果显示,地层应力释放率控制在0.3以内时,可满足相关规范对桥梁变形控制限值要求。This paper takes the construction of the shield tunnel side-crossing east second ring elevated stone gate overpass between Longqing Road Station and Baiyun Road Station on Kunming Metro Line 5 as the background,and studies the interaction law of the shield tunnel side-crossing bridge construction under different strata stress release rates through numerical simulation.The results show that the vertical unloading effect of the shield tunnel side-crossing bridge construction is greater than the horizontal unloading effect.The bridge piles undergo radial deformation away from the tunnel,resulting in soil loosening between the piles and the tunnel.It is very necessary to apply grouting inside the tunnel for soil reinforcement in practical engineering.The distance between the tunnel and the bridge pile has a significant impact on the construction of shield tunnel side-crossing bridges.When the stress release rate of the stratum is 0.1~0.3,the relative deformation of each section of the pile body is relatively small,and the possibility of pile cracking and damage due to eccentric compression of the pile gene is relatively small.The influence disturbance of the shield tunnel side-crossing bridge construction is mainly distributed within the range of 1~2D(D is the tunnel diameter)around the tunnel.The impact of shield tunnel side-crossing pile on the axial force of the pile is mainly to cause the axial force of the pile above the arch of the shield tunnel to“shrink”,and the impact on the pile bending moment is mainly to increase the corresponding pile bending moment in the center area of the side-crossing section of the tunnel.As the stress release rate of the formation increases,the position of the maximum inclination of the shield tunnel side-crossing bridge will change,and the inclination will show a trend of first decreasing and then increasing.The calculation results show that when the stress release rate of the stratum controlled within 0.3,it can meet the requirements of relevant specifications for the allowab

关 键 词：盾构隧道 泥炭质地层 应力释放率 侧穿桥梁 数值计算 影响分析 

分 类 号：U455.43[建筑科学—桥梁与隧道工程] U458.1[交通运输工程—道路与铁道工程]