桥梁大型沉井基础建造技术发展与展望  

Developments and Prospects of Large Bridge Open Caisson Foundation Construction Technology

作　　者：张永涛[1] 杨钊[1] 李德杰 曾旭涛[1] 朱俊涛 ZHANG Yong-tao;YANG Zhao;LI De-jie;ZENG Xu-tao;ZHU Jun-tao(CCCC Second Harbour Engineering Co.,Ltd.,Wuhan 430040,China;Geotechnical Research Institute of Hohai University,Nanjing 210098,China)

机构地区：[1]中交第二航务工程局有限公司,湖北武汉430040 [2]河海大学岩土工程科学研究所,江苏南京210098

出　　处：《桥梁建设》2023年第2期17-26,共10页Bridge Construction

基　　金：中国交通建设股份有限公司科技研究开放计划项目(2020-ZJKJ-QNCX14)。

摘　　要：沉井基础在大型桥梁主墩、锚碇基础中得到广泛应用,并在沉井工程勘察、工程设计与施工技术方面取得了一定的进展。在工程勘察技术发展方面,地质参数获取方法在现有理论分析法、室内试验法、现场试验法的基础上进一步发展了现场载荷板试验法,研制了侧摩阻力监测装置,对地基承载力、侧摩阻力等地质参数认识不断加深。在工程设计技术发展方面,通过对平面形式与尺寸、结构安全、软弱地基砂桩加固等方面不断进行优化设计,形成了适用于大型沉井的结构与地基处理的设计方法。在沉井施工技术发展方面,针对沉井浮运定位与着床,提出了井孔封闭助浮、多阶段多方式长距离浮运技术,以及液压千斤顶多向快速定位着床技术,研发了锚系定位系统;针对锅底开挖下沉的不足,提出了全节点支撑、中心块状支撑等新型开挖下沉工艺;针对高压射水结合泥浆泵设备取土的不足,研制了四绞刀快速破取土设备、可自移动式快速取土设备、机械臂水下定点取土机器人等新型设备;针对人工监测的不足,采用信息化监测系统进行沉井施工监测,形成了自动监测-风险预警-辅助决策控制-设备自动化执行的智能化监测控制技术;在沉井工业化建造技术方面进行了有益探索,将取土平台与供气管、供水管、排泥管、施工电缆桥架等进行了集成化设计,推动了大型沉井的应用与发展。但在大型沉井理论、智能化装备、智能化建造方面还存在不足,随着工程建设的不断发展,地质参数高精度获取、理论分析方法、大型沉井设计与施工规范、特殊地层建造技术、工业化与智能化施工是大型沉井建造技术发展的方向。Open Caissons have been widely applied as foundations for main piers and anchorages of long-span bridges.Great advances have been achieved in geological survey,design and construction technologies of caisson foundations.In geological survey,a field plate load test method has been developed on the basis of the conventional theoretical analysis method,in-house test method and field test method,which is a better way to obtain geological parameters;apparatuses to monitor caisson surface resistance have been developed to measure the load bearing behavior and surface resistance of foundation,and the significance of these geological parameters has been increasingly highlighted.From a perspective of design technology,consistent upgrading of design methods for plan types and dimensions,structural safety and strengthening soft ground with sand piles,the methods to design large-scale caissons and foundation treatment have been established.The caisson floating,positioning and landing techniques have been improved,caisson cells can be sealed to assist floating,a multi-stage,multi-way and long-distance floating technique has already been practiced in real bridges,an anchor positioning system that uses hydraulic jacks for multi-dimension and rapid positioning and landing has been in application.To overcome the insufficient sinking depth by the pan-bottom excavation(excavating from the center symmetrically towards the edge and finally to form a pan-bottom-type base supports for sinking),novel techniques,such as full-node supporting and central block supporting,are developed.To address the disadvantages of the soil excavation by the conventional high-pressure jet water and slurry pumping equipment,new equipment,including the four-cutter excavation rig,self-moving rapid soil excavation rig and underwater fixed point soil excavation robot,have been researched and manufactured.To supplement the manual monitoring,a computer-based monitoring system has been developed for caisson construction monitoring,creating a systematic intelligen

关 键 词：桥梁基础 大型沉井 地质勘察 工程设计 施工技术 智能化施工 发展与展望 

分 类 号：U443.131[建筑科学—桥梁与隧道工程]