昌平泵站调蓄池工程大型深基坑临时栈桥的设计与施工

Design and construction of a temporary trestle bridge spanning a deep foundation pit in Changping pump station storage pool project

在大型深基坑开挖过程中,常需要利用基坑的支护结构,建造用于方便现场车辆交通及基坑施工的栈桥。栈桥可以有多种结构形式,较为常见的一种是以基坑的混凝土支撑为主梁,以现浇混凝土板为桥面板的栈桥。这种栈桥的上部结构需要经过仔细计算和设计。以一个实际工程为例,应用ANSYS软件,建立栈桥的结构模型,详述了各相关部分的设计与验算方法,指出栈桥施工应注意的一些问题。分析表明,栈桥不会对支撑结构的受力性质产生过大的影响,可因地制宜地进行设计应用,优化基坑的施工过程。

During the excavation of a large and deep foundation pit, a trestle bridge is usually needed to build to facilitate the on-the-spot transportation and the foundation pit construction by virtue of the support structure of the pit. The bridge can be of many different structures, a common one of which is using the concrete support of the pit as its girder and cast-in-situ reinforcement concrete plates as its decks. The superstructure of this kind of bridge needs careful calculation and design. This article takes an actual project as an example, builds the structural model of a trestle bridge using FEM software ANSYS, and recounts the design and checking approach of each correlative part. In the end, some problems about the trestle bridge construction that should be paid attention to are also pointed out. Analysis shows that trestle bridge will not affect the mechanical property of the support structure so much, Therefore appropriate trestle bridges should and could be designed and applied according local conditions to optimize the construction process of foundation pits.