大跨度悬挂式单轨钢箱组合梁总体设计及关键技术研究

Research on the Overall Design and Key Technology of Long-SpanSuspended Monorail Steel Box Composite Beam

悬挂式单轨是一种轻型、中速、低成本的新型轨道交通方式,结构轻盈、美观,但是当跨越河流、沟壑等障碍时,存在明显短板。从结构受力、运行安全角度出发,提出一种在斜拉桥的主梁上架设轨道墩柱和轨道梁的新型组合梁结构方案,突破常规悬挂式单轨跨越能力受限的壁垒。为研究斜拉桥主梁与轨道梁墩柱结合部位复杂的受力情况和传力路径,采用ANSYS软件分别建立钢箱梁区段和混凝土箱梁区段有限元模型。结果表明:钢箱梁区段,墩柱荷载主要传递给与之直接相连的横隔板以及中腹板,其中,横隔板受力比较均匀,中腹板受力主要集中在以墩柱为中心,半径约2 m的范围内,基本可以传递至钢梁底板。墩柱轴力的58%传递给与之直接相连的横隔板;墩柱横桥向弯矩的传递过程中,58.8%的剪力传递给与之直接相连的横隔板;墩柱顺桥向弯矩的传递过程中,53.4%的剪力传递给中腹板;混凝土箱梁区段,墩柱荷载主要传递给与之直接相连的混凝土腹板、横隔板。混凝土受力主要集中在以结合面为中心,半径约2 m的范围内,墩柱荷载在结合面以下约0.5 m的范围内基本完成传递,墩柱轴力的68.8%传递给与之直接相连的横隔板;墩柱横桥向弯矩的传递过程中,86.4%的剪力传递给与之直接相连的横隔板;墩柱顺桥向弯矩的传递过程中,44.6%的剪力传递给中腹板。

The suspended monorail is a new mode of rail transit with light weight,medium speed and low cost.It has a lightweight and aesthetically pleasing structure but has obvious limitations when spanning obstacles such as rivers and valleys.From the perspective of structural force and operational safety,this paper puts forward a new composite beam structure scheme,in which track piers and track beams are erected on the main beam of a cable-stayed bridge,overcoming the limitations of conventional suspended monorail spanning ability.To investigate the complex force situation and the load transfer path at the junction of the main beam of the cable-stayed bridge and the track beam piers,finite element models of steel box girder section and concrete box girder section were established using ANSYS software.The results showed that,in the steel box girder section,the pier load was mainly transferred to the diaphragm and the middle web directly connected to it.Among them,the diaphragm load experienced relatively uniform stress,while the middle webs stress was mainly concentrated within a 2-meter radius centered around the pier,which could be mostly transferred to the steel girder bottom plate.58%of the piers axial force was transferred to the directly connected diaphragm.During the transfer of the pier columns transverse bending moment,58.8%of the shear force was transferred to the directly connected diaphragm.During the transfer of the pier columns longitudinal bending moment,53.4%of the shear force was transferred to the middle web.In the concrete box girder section,the pier load was mainly transferred to the concrete web and diaphragm directly connected to it.The concrete stress was mainly concentrated within a 2-meter radius centered around the joint surface,and the pier load was basically transferred within about 0.5 meters below the joint surface.68.8%of the piers axial force was transferred to the directly connected diaphragm.During the transfer of the pier columns transverse bending moment,86.4%of shear force was transferred to the directly connected diaphragm.During the transfer of pier columns longitudinal bending moment,44.6%of shear force was transferred to the middle web.