Pre-reinforcement system for overpass planned tunnel line of open cut tunnel foundation pit and construction method

Abstract

According to the open cut tunnel foundation pit overpass planned tunnel line pre-reinforcement system and the construction method, in the construction process, firstly, three-shaft mixing pile blades are used for conducting hard soil layer variable-diameter mixing, and then a profile steel guiding and positioning technology is used for vertically inserting profile steel into the piles to form the three-shaft mixing piles; then, a guide groove is excavated through a hydraulic grab bucket and a hydraulic double-wheel slot milling machine, a glass fiber rib reinforcement cage is put down, main ribs and glass fiber ribs are connected through U-shaped buckles, longitudinal truss ribs and transverse truss ribs are installed for reinforcement, and an underground diaphragm wall is formed; and finally, jet grouting the consolidated body to form a jet grouting pile. The foundation bearing capacity is effectively improved, uneven deformation is reduced, the potential influence of planned tunnel construction on a built tunnel is avoided, the later maintenance cost of tunnel crack repair and the like is reduced, the method has the advantages of being high in construction safety, good in reinforcement quality, capable of saving energy, reducing emission and the like, smooth development of subsequent construction is effectively guaranteed, and the construction period is shortened. The influence of construction on the surrounding environment is reduced, and good indirect economic benefits and social benefits are generated.

Description

technical field [0001] The invention relates to the field of building construction, in particular to a pre-reinforcement system and a construction method for a planned tunnel line on the upper span of an open-cut tunnel foundation pit. Background technique [0002] In recent years, rail transit has gradually shown a trend of network and scale, and usually faces the situation that new lines cross existing lines. Whether the existing line has considered or reserved the crossing conditions of the new line, how to determine the basic method of the new line crossing construction, and what main technical guarantee measures should be adopted, are all practical engineering problems. [0003] The situation of open-cut tunnels spanning the planned tunnels above the foundation pit is relatively complicated. The construction of the planned tunnels will inevitably cause the stress redistribution of the soil and supporting structures around the existing tunnels. The huge risk greatly incr...

AI Technical Summary

Problems solved by technology

[0003]The situation of open-cut tunnel foundation pit spanning the planned tunnel is relatively complicated, and the construction of the planned tunnel will inevitably cause the stress redistribution of the soil and supporting structures around the existing tunnel , the huge risk greatly increases the difficulty of construction

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