Prestressed fish belly sill with length-adjustable stay bars for retaining and protecting for deep foundation excavation

Abstract

The invention discloses a prestressed fish belly sill with length-adjustable stay bars for retaining and protecting for deep foundation excavation. The prestressed fish belly sill with the length-adjustable stay bars for retaining and protecting for deep foundation excavation comprises a waist beam (1), at least one stay bar (2) and at least one pull cable (3); the upper ends of the stay bars (2)are fixed on the waist beam (1) through high-strength bolts; the lower end of each stay bar (2) is connected with a cable supporting joint (9); each pull cable (3) penetrates through a pull cable channel of the corresponding cable supporting joint (9); and two ends of each pull cable (3) are anchored in pull cable anchoring devices (5). Two ends of the fish belly sill are spliced with adjacent surrounding purlins, and symmetric or angle brace supports are arranged at the ends of the fish belly sill. By application of prestress and the supporting effect of the stay bars to the waist beam, the bending stiffness of the fish belly sill is high, the number of braces can be reduced, and thus, an operation space in the pit is increased. The lengths of the stay bars in the prestressed fish belly can be adjusted telescopically according to monitoring data, and deformation of a foundation pit supporting structure can be controlled well; and by mounting of a standby cable, the rigidity and emergency capacity of the fish belly sill are improved.

Description

technical field [0001] The invention relates to the technical field of civil engineering, in particular to a prestressed fish-belly beam for deep foundation pit support with adjustable length of struts. Background technique [0002] For general foundation pit engineering, it is necessary to carry out reasonable foundation pit support structure design and construction in combination with geological conditions and surrounding environment. As the most commonly used and widely applicable support structure in deep foundation pit engineering, the retaining structure includes anchor-pull type, support type, cantilever type, double-row pile and reverse method, etc. Among them, anchor-pull and double-row piles will occupy more underground space around the foundation pit, and the cost of double-row piles is relatively high, and deep foundation pit projects are generally located in densely built (structure) areas inside cities, so these two Supporting structures are less used. The ca...

AI Technical Summary

Problems solved by technology

The technical problem to be solved is to overcome the shortcomings of the deep foundation pit support structure in the prior art that it is difficult to meet the requirements of strong deformation control ability of the support structure, large construction operation space in the pit, and less underground space around the pit.

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