人工岛岛壁抛填对桥梁结构影响及控制措施  

Influences of artificial island wall dumping on bridge structure and control measures

作　　者：张泽卫 邱昕奕 杨峰[2] 赵炼恒[2] ZHANG Zewei;QIU Xinyi;YANG Feng;ZHAO Lianheng(China Railway Tunnel Consultants Co.,Ltd.,Guangzhou,Guangdong 511458,China;School of Civil Engineering,Central South University,Changsha,Hunan 410075,China)

机构地区：[1]中铁隧道勘察设计研究院有限公司,广东广州511458 [2]中南大学土木工程学院,湖南长沙410075

出　　处：《公路交通科技》2025年第4期112-120,共9页Journal of Highway and Transportation Research and Development

摘　　要：【目标】针对人工岛岛壁抛填易诱发邻近桥梁下部结构侧偏问题,提出钢管桩围护+高压旋喷加固等主动保护与防护相结合的控制措施,评估控制措施的力学可靠性及变形控制效果。【方法】采用PLAXIS开展岛壁抛填全过程三维模拟分析,探究岛壁抛填引起既有桥梁的附加变形特征,并以墩台顶面水平位移、墩台差异沉降和桩基水平位移为主控指标,结合实际施工和现场监测数据验证控制措施的有效性。【结果】人工岛岛壁块石抛填导致桥梁承台产生差异沉降、桩基出现背离岛壁侧的位移,其中相邻墩台最大差异沉降1.9 mm,桥墩顶面最大水平位移0.76 mm,桩基顶部最大水平位移2.5 mm,均符合控制要求。现场监测结果显示岛壁抛填完成后桥墩最大水平位移在3.0 mm以内,小于水平位移5 mm的控制标准,满足高速公路桥梁正常运营要求。【结论】“先施作隔离钢管桩,再旋喷加固软弱土层,后分层对称抛填岛壁块石”的综合桥下筑岛施工方案,能有效减少土体的侧向位移和沉降,减小对邻近桩基的横向压力,保证岛壁下穿施工中既有桥梁的正常运营。本工程的成功实施丰富了海域既有高架桥梁条件下人工岛筑岛施工经验。[Objective]Aiming at the artificial island wall dumping easily inducing substructure lateral deviation of adjacent bridge,the control measures combining active-protection and protection were proposed,e.g.,steel pipe pile enclosure and high-pressure jet grouting reinforcement.The mechanical reliability and deformation control effect of control measures were evaluated.[Method]PLAXIS was used to carry out 3D simulation analysis on whole process of island wall dumping,and to explore the additional deformation characteristics of existing bridges caused by island wall dumping.The horizontal displacement of pier top surface,differential settlement of pier,and abutment and horizontal displacement of pile foundation were taken as the main control indicators.The effectiveness of control measures was verified by using actual construction and field monitoring data.[Result]The artificial island wall rip-rap dumping causes the differential settlement of bridge cap and the displacement of pile foundation deviating from the side of island wall.The maximum differential settlement of adjacent pier is 1.9 mm,the maximum horizontal displacement of pier top surface is 0.76 mm,and the maximum horizontal displacement of pile foundation top surface is 2.5 mm,which all meet the control requirements.The field monitoring result indicates that the maximum horizontal displacement of pier is less than 3.0 mm after island wall dumping.It is less than the control standard of 5 mm horizontal displacement,which meets the normal operation requirement for expressway bridges.[Conclusion]The comprehensive construction scheme for building an island under bridge is that first applying isolation steel pipe piles,then jet grouting to reinforce soft soil layer,and finally symmetrically rip-rap dumping the island wall.It can effectively reduce the lateral displacement and settlement of soil,reduce the lateral pressure on adjacent pile foundation,and ensure the normal operation of existing bridge during island wall underpass construction.The successful impl

关 键 词：桥梁工程 桥梁保护 数值分析 下穿既有桥梁 人工岛 加固措施 

分 类 号：U443[建筑科学—桥梁与隧道工程]