顶进涵后背选型与设计

在顶进涵设计中，作为临时设施的后背设计是整个设计工作的重要环节之一。后背造价占整个工程投资的比重较大，后背设计是否合理，直接关系到整个工程的经济效益和施工工期。结合某顶进涵工程实例，介绍了后背结构形式的选择，根据现场情况重点阐述了重力式后背的结构形式、尺寸拟定及检算。实践证明，所选顶进涵后背结构经济合理，确保了施工和行车安全。

The Type-Selection for and the Design of the Back of the Jacked Culvert

In the design of a j acked culvert,the design of the back as a temporary facility is one of the important links among the whole design work.The cost of the back takes up a comparatively large proportion of the total investment of the proj ect,owing to which whether the design of the back is rational will be directly related to the economic benefit and the construction duration of the whole proj ect.With a certain j acked culvert as a practical example,the structural type-choice for the back of a jacked culvert is introduced in the paper,with stress placed,according to practical site conditions,on introducing the structural forms of the gravity-type back,the determination of its size and the checking calculation.Practice shows that the chosen structure of the back of the jacked culvert is found to be economically rational and to have ensured the safe construction and safe operation of the railway.