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涉水砂性河滩悬浇梁直线段支架体系施工设计优化
张天宝, 徐 德, 刘 强
(中建三局基础设施建设投资有限公司,430073,武汉)
摘 要: 针对某跨河悬浇梁直线段架体施工,存在涉水砂性河滩透水性强、地基坡陡场地不足、净空高
的问题,对原少支点支架体系以及侧模板二次利用进行优化调整,最后利用 Midas Civil 软件对支架体系进
行数值模拟分析。研究表明,充分利用挂篮施工的侧模板进行直线段施工,不仅节省了材料费用,而且外观
效果良好。优化后支架体系能满足受力要求,避免了交叉施工,保障了施工工期;利用枯水期法以及吨袋围
堰能较好地保证地基承载力。
关键词: 跨河悬浇梁;砂性河滩;设计优化;支架体系;数值模拟
中图分类号:TU 753 文献标志码:B 文章编号:1000–4726(2022)05–0569–05
DESIGN OPTIMIZATION FOR STRAIGHT SUPPORT SYSTEM CONSTRUCTION OF
CANTILEVER BEAM ON WADING SANDY BEACH
ZHANG Tian-bao, XU De, LIU Qiang
(CCTEB Infrastructure Construction Investment Co., Ltd., 430073, Wuhan, China )
Abstract: In view of the construction of a straight section of a cross-river suspended beam
frame body with water-related sandy river bank with strong permeability, steep foundation slope with
insufficient site and high headroom, the original bracket system with few pivot points and the secondary
use of side formwork were optimized and adjusted, and finally the bracket system was numerically
simulated and analyzed using Midas Civil software. The study shows that making full use of the side
formwork of hanging basket construction for straight section construction not only saves material cost,
but also has good appearance effect. The optimized bracket system can meet the force requirements,
avoid cross-construction and guarantee the construction period; the use of dry water method and tonnage
bag cofferdam can better ensure the foundation bearing capacity.
Keywords: river-crossing cantilever beam; sandy beach; design optimization; support system;
numerical simulation
1 工程背景
某跨河悬浇梁(图 1)上部构造为55m+100m+55m
预应力混凝土变截面连续箱梁,左右幅独立两座桥设
计。箱梁顶板横向宽 16 m,箱底宽10 m,顶板悬臂
长3 m,箱梁高度和底板厚度按 1.8次抛物线变化。
箱梁 0号节段长 10 m,每个悬浇“ T”纵向对称划分
为11个节段,边跨现浇直线段长 3.88 m,合龙段长
度为2 m。该河一般过水断面最宽处约 200 m,最高
水位27.31 m,常水位为 26.96 m,大桥东侧跨越青凤
村河堤。沿线桥址河堤标高 30.6~31 m,沿河景观平
台地面标高26~27 m,主河床标高约 17.8~20.5 m。
11 号、14 号墩高度分别为 15.4 m、10.59 m,两侧直
线段施工均采用少支点支架体系。
钢箱梁
直线段
中风化片岩 中风化片岩
(a)
(b) 中风化片岩
水
件
线
10 11 12 13 14
图
1 某跨河悬浇梁横断面及平面示意
(a)横断面示意;(b)平面示意
2 悬浇梁直线段支架体系原设计
原支架体系设计:上分配梁采用 10 cm×10 cm方
木,间隔30 cm布置,下分配梁采用 I 25 b(翼缘板处)
和I 18(底板处),间隔 75 cm布置(腹板处加密间
隔30 cm),主分配梁采用 H 700,横桥向布置,采用
630×8 钢管作为钢立柱。在钢管顶面及底面各焊接
收稿日期: 2022–02–10
作
涉水砂性河滩悬浇梁直线段支架体系施工设计优化(论文).pdf