Studying Of Some Key Problem About Laying Fabricated Strap With Open-cut And Cover-dig Combination In Subway Station Construction

This article is based on the Qilizhuang station in Beijing subway Line9, we do a systematic studying about the Laying Fabricated Strap Method. In response to this method, we do a studying about parameter influence on laying system. And we also focus on the pipeline suspension and resistance slipping capability monitoring. The main conclusions are as follows:(1)By analysing the characteristics of the various construction methods, compare and get their shortages:For open-cut method, its construction speed is slow, human capital investment is large, and has a significant impact on the environment. For cover-dig method, its cost is high, The complexity of upper loads on structure and support system leads that the land subsidence and the structural deformation are beyond control. Mining method is easy constrained by the geological conditions, and its construction speed is also slow. For these shortages, we put forward a new method-The combination of open-cut and cover-dig method. This method cost low, construction speed is fast, mechanization degree is better, and it can effectively meet the needs of the surrounding environment and traffic.(2)We do a studying about parameter influence on laying system. Research content include laying system position, number of the middle of the pile in vertical, the middle pile vertical spacing, the size of the middle of the pile, concluded:If the road is heavy traffic, then do many laying system in one side of the pit.If the traffic is small flow,then do less laying system in one side of the pit to ensure the smooth flow of traffic. It is appropriate that set two rows of middle piles vertical. This can meeting the construction requirements, but also beneficial to the force of the middle pile.In the setting of the middle pile vertical spacing, we need considering integrated construction factors. In setting the size of the middle of the pile, we can’t choose small size, because small size can’t support. But it is not significantly affect that choosing big size.(3) We described the construction method of pipeline suspension, and use the finite element method to calculate if it is safe. This calculate is useful for other engineering applications.(4)Because there is shortcoming in the method of resistance slipping capability monitoring now, we discover a new method to resistance slipping capability monitoring. This method is measuring the size of angular to calculate the resistance slipping capability. Also proposed the position and project about monitoring of laying system, and analyzed monitoring results.