绥芬河青云市场套(扩)建工程结构设计与施工措施研究

结合绥芬河青云市场套(扩)建改造工程实践,提出了在施工阶段只在原房屋结构顶侧实现新增套(扩)建框架与原房屋框架的类链杆连接,待新增套(扩)建结构沉降充分后,再实现新旧结构在各层的链杆连接的设计思路。通过在原结构顶与外套框架柱间设置混凝土垫块,并在二外套框架柱间布置并张拉预应力筋,来实现施工阶段外套框架柱与原结构顶的类链杆连接。在新增结构施工完成后,将原结构顶上皮标高处二外套框架柱中预埋钢筋焊接连通,并浇筑一定厚度混凝土,来实现在原结构顶标高处新旧结构间的永久性可靠连接。将原框架节点的后植钢筋与外套框架柱的预埋钢筋焊接连接,来实现新旧结构在各层的链杆连接。为确保施工过程中原房屋的正常使用,提出了用挂模钢桁架来承托内置钢桁架-混凝土组合框架梁施工阶段荷载,用挂模钢箱来承托内置钢箱-混凝土组合次梁施工阶段荷载,用垂直于次梁内置钢箱焊接的型钢主楞来承托楼板荷载的施工阶段自承重混凝土楼盖设计与施工方法。

Design methods and construction techniques for the outer-jacketing structure reconstruction (extension) project of the Suifenhe Qingyun Market

In connection with the reconstruction(extension)project of the Suifenhe Qingyun Market,a design approach is proposed,in which similar links are employed to connect the newly-added frame and the original structure only at the roof of the original building,and the new structure and the original structure are connected by links at each floor after settlement of the new structure is complete.Similar connections between the original structure and the outer-jacketing frame columns are formed during construction by using concrete blocks placed between the roof of the original building and the outer-jacketing frame columns and by prestressing the reinforcing tendons between the two outer columns.After the new structure is constructed,steel bars embedded in the two outer columns at the height of the roof of the original building are welded together,and concrete of a certain depth is cast.In this way,the permanent firm connection between the roof of the original structure and the new structure is formed.The post-installed steel bars in the original frame joints are welded with embedded steel bars in the outer columns to work as the connection at each floor.In order to ensure that the original building works as usual during the construction,the design and construction methods of self-supporting concrete floor during construction are presented,the main idea of which is that the steel truss suspended by formwork can bear the construction load of encased steel-truss-concrete composite beam,that the steel box suspended by formwork can support the construction load of encased steel-box-concrete composite beam,and that the channel welded perpendicular to the encased steel box can carry the floor load.