基于SPMT快速建造工法的钢槽组合梁设计  

Design of Steel Tub Girders and Concrete Slabs Composite Structure Erected by SPMT Rapid Construction Method

作　　者：陈金州 冯鹏程[1] 余顺新[1] CHEN Jin-zhou;FENG Peng-cheng;YU Shun-xin(CCCC Second Highway Consultants Co.,Ltd.,Wuhan 430056,China)

机构地区：[1]中交第二公路勘察设计研究院有限公司,湖北武汉430056

出　　处：《桥梁建设》2022年第2期112-118,共7页Bridge Construction

基　　金：湖北省交通运输厅科技项目(2020-2-1-3);国家重点研发计划项目(2017YFC0806008);湖北省技术创新专项重大项目(2018AAA031)。

摘　　要：为降低对既有运营线交通流的影响,开阳高速公路改扩建工程的跨线桥改造项目采用SPMT快速建造工法。基于该工法,新建跨线桥主梁在常规钢槽组合梁的基础上采用“箱形开口截面钢槽梁+钢筋混凝土桥面板”的结构型式,梁高2.00 m,2片槽型钢梁中心间距5.65 m,桥面板厚0.25~0.38 m。根据SPMT驮运支架支撑点的设计位置,采用11道箱内横向联结系和5道箱间横向联结系,提高钢槽组合梁的局部稳定性、整体稳定性及抵抗多支点不均匀受力的能力。提出钢槽梁与桥面板“后结合”的设计方案,使混凝土桥面板处于无应力状态参与钢槽组合梁的受力,并针对驮运支架体系进行了优化设计。采用有限元法对钢槽组合梁建造全过程进行计算,结果表明基于采用SPMT快速建造工法设计的钢槽组合梁结构安全,并提出驮运支架支撑点的相对高差安全阈值为2.5 cm。经施工监控和成桥荷载试验,设计的钢槽组合梁实测试验数据均在安全控制范围之内,满足设计与规范要求。The SPMT(self-propelled modular transporter)rapid construction method that can alleviate the disruption of new overpass construction to the service of underneath existing roadways is proposed.The method is illustrated by the case study of an overpass of the Kaiyang Expressway Reconstruction and Expansion Project.The superstructure of the overpass consists of the steel tub girders and reinforced concrete slabs,which is evolved from the classic steel tub-concrete composite structure.The superstructure measures 2 m deep,center-to-center distance of the two tubs is 5.65 m and the thicknesses of the concrete slabs are 0.25 m to 0.38 m.To improve the local and global stability as well as the resistance to multi-point eccentric loads of the steel tubs and concrete slabs composite structure,11 inner lateral bracings and 5 in-between lateral bracings are installed corresponding to the supporting points of the SPMT.The concrete slabs are erected after the installation of the steel tubs,and then the two are connected,which can allow the concrete slabs to be in the stress-relieved condition when participating in the load bearing performance of the structure.The supporting frame is optimized accordingly.The whole construction process of the steel tubs and concrete slabs composite structure is computed by finite element method.The results demonstrate that the steel tubs and concrete slabs composite structure which is designed to be erected by the SPMT method is safe.It is suggested that the safety threshold value of the relative elevation difference of the supporting points be set at 2.5 cm.According to the construction monitoring and load tests after completion,the data of the proposed steel tubs and concrete slabs composite structure are all within the controllable range,and meet the design and code requirements.

关 键 词：高速公路改扩建 跨线桥 钢槽组合梁 SPMT 驮运支架体系 结构设计 

分 类 号：U448.17[建筑科学—桥梁与隧道工程] U448.216[交通运输工程—道路与铁道工程]