库区深水浅覆盖层大跨度钢栈桥施工技术  

Construction Technology of Large Span Steel Trestle in Deep Water and Shallow Overburden Layer of Reservoir Area

作　　者：王鑫 WANG Xin(The Third Engineering Co.,Ltd.of China Railway Construction Bridge Engineering Bureau Group,Shenyang 110043,China)

机构地区：[1]中铁建大桥工程局集团第三工程有限公司,沈阳110043

出　　处：《国防交通工程与技术》2024年第5期41-45,60,共6页Traffic Engineering and Technology for National Defence

摘　　要：钢管桩锚固是钢栈桥施工关键,在山区河流河床为浅覆盖层甚至裸岩的状态下,利用振动锤直接插打的施工方式无法将钢管桩下沉到位。针对困难工况,新建乙赛黄河特大桥钢栈桥采用“浮箱法”工艺施工。栈桥采用组合式桁梁,具有更强的承载能力和更大的跨越能力,减少在水中设置钢支墩的数量;使用六七式标准舟节浮箱拼装成浮箱平台、配合150 t履带吊插打钢管桩,锚桩采用清水成孔、水下灌注混凝土成桩。介绍了浮箱平台的拼装、下水、锚定,履带吊上浮箱和钢管桩的接长和施打。施工实践证明在水文地质条件不良条件下“浮箱法”钢栈桥施工工艺安全可靠,操作方便,保证了大桥施工的顺利进行。In complex and dynamic mountainous river environments,especially when the riverbed is covered with shallow overburden layers or bare rocks,traditional vibratory hammer direct driving of steel pipe piles proves ineffective in achieving the designated depth.To overcome this challenge,the Yisai Yellow River Extra-large Bridge project has introduced the"floating box method"construction technique.The steel trestle design incorporates a composite truss structure,significantly enhancing the bridge's load-bearing capacity and greatly improving its ability to span complex terrain.This design effectively reduces the number of steel piers directly installed in the river.The core of the"floating box method"involves meticulously assembling Type 67 standard boat joints into a stable floating box platform.This platform serves as a temporary work surface block capable of supporting efficient operations with crawler cranes of up to 150 tons.In addition,the anchor pile construction employed the clean water drilling technique,followed by underwater grout injection to ensure the solidity and reliability of the anchor piles.Detailed descriptions were provided for key construction steps including the assembly,launching,anchoring of the floating box platform,floating the pontoon with crawler cranes,and the extension and installation of steel pipe piles.Construction practice has demonstrated that under challenging hydrogeological conditions,the"floating box method"for steel wharf construction is safe,reliable,and operationally efficient,ensuring the smooth progress of bridge construction.

关 键 词：浅覆盖层 钢栈桥 钢管桩锚固 浮箱平台 组合式桁梁 

分 类 号：U448.18[建筑科学—桥梁与隧道工程] U443.159[交通运输工程—道路与铁道工程]