A construction method for subway single-storey underground digging stations

Abstract

The invention relates to a construction method of a single-layer mined metro station. The method comprises the steps of station pilot tunnel underground excavation, longitudinal beam, middle column and pile crown beam construction, two middle pilot tunnel middle-span initial support supporting arch casting, middle-span secondary lining supporting arch casting, stable middle-span vertical supporting structure forming, side-span initial support supporting arch construction, and side-span bottom plate secondary lining and side pile inner side sidewall construction. According to the construction method of the single-layer mined metro station, the influence of the multi-cavity effect on stratum settlement is reduced; and the mechanized construction level is improved, the risk of manual hole digging is lowered, meanwhile the construction work of traditional manual underground excavation is reduced, and the construction efficiency is improved.

Description

technical field [0001] The invention relates to a construction method for a subway single-layer underground excavation station. Background technique [0002] When a subway station is set up at a crossing, because there are many underground pipelines under the main road perpendicular to the station or the central part of the station is too close to the starting point of the viaduct, it is impossible to use open-cut enclosures and other factors, often using double-layer open-cut at both ends and a single In addition, only two-story stations are implemented in the early stage of transfer stations, and single-story stations need to be excavated under the existing two-story stations to implement transfer nodes in the later stage (in this case, flat excavation stations are used top straight wall structure), so the single-layer underground excavation station is widely used in urban rail transit. [0003] The construction methods of subway underground excavation stations mainly inc...

AI Technical Summary

Problems solved by technology

It can be seen from the above that there are two upper and lower layers of pilot tunnels in the hole pile method and the single buckle arch method, the effect of group tunnels is obvious, and the construction has a great impact on the surrounding environment

However, there are the following problems in the single-story underground excavation station constructed by the traditional pillar hole method: 1. The pillar hole is divided into upper, middle and lower layers. It is necessary to construct the top longitudinal beam in the upper pilot tunnel and the bottom longitudinal beam in the lower pilot tunnel. The construction space is narrow and the construction is difficult; the height of the upper pilot tunnel is small, and it is also difficult to construct steel pipe columns in the pilot tunnel; 2. Due to the limitation of construction methods, steel pipe columns are used for the center pillars of most underground excavation stations, which have relatively low corrosion resistance and fire resistance Poor; 3. Comprehensive grounding needs to be constructed under the bottom slab of the side span, and the setting of each grid will make the comprehensive grounding construction very difficult; 4. Although the settlement caused by the post hole method is smaller than that of the middle hole method and side hole method, The settlement caused by the construction of the side span is relatively large, and the removal of the grid during the construction of the second lining of the side span will also cause a certain settlement

The main problems of this construction method are as follows: 1. This construction method is generally used for single-column double-span stations. For double-column three-span stations, there are many vertical guide tunnels with a large height, and the soil between the pilot tunnels is stable. 2. During the construction of the side wall, the partition in the pilot tunnel needs to be disconnected, the height of the pilot tunnel is large (about 13m), and the initial support of the pilot tunnel is prone to large deformation, which affects the The pouring quality and thickness of the secondary lining; 3. During the construction of the secondary lining of the side wall, temporary cross braces need to be added to the side walls, but the primary support above the temporary cross braces needs to be chiseled out when the side buckles the arch, and the deformation is difficult to control, resulting in relatively large big settlement

Images