Collapse and sink intrusion limit construction method for treating wind accumulated sand loess tunnel through stride shed pipe

Abstract

The invention relates to a loess tunnel construction method, in particular to a collapse and sink intrusion limit construction method for treating a wind accumulated sand loess tunnel through a stride shed pipe. The problems of relatively larger construction space, high cost, long period, poor safety and the like of the current stride shed are solved by the method. The method comprises the following steps of: 1) treating ground surface cracks; 2) filling holes; 3) determining an arch replacing range; and 4) performing an excavating method by using a three-step method, setting a radial anchoring rod before the arch is replaced, and detaching a steel arc frame one roof truss by one roof truss after grouting and reinforcing. The excavating method comprises the following steps of: a, detaching a sink intrusion limit section primary support one roof truss by one roof truss by using an excavating machine vibrating hammer and a manual pneumatic pick, and after detachment, timely performing primary spraying to seal a surrounding rock; b, performing forepoling by using a dual-layer stride anchoring rod to form a stride shed pipe structure; c, spanning the steel arc frame, and tamping the stride foot-locking anchoring rod by using upper, middle and lower arc guide feet; and d, after detachment one roof truss by one roof truss according to the steps, timely supporting. The method has the advantages of high construction speed, small required space, simple and convenient operation, low mechanical investment, guarantee in construction quality and safety and wide application range.

Description

technical field [0001] The invention relates to a construction method of an aeolian sandy loess tunnel, in particular to a construction method for treating the subsidence and encroachment of an aeolian sandy loess tunnel with a step-type pipe shed. Background technique [0002] Aeolian sandy loess is mainly sandy soil. For loess, it is sandy loess, which is prone to collapse during construction. Due to the verticality of the structure, its characteristics determine that the mechanical properties of the loess are anisotropic, which is directly related to the stability of the face after construction. If the stress of the surrounding rock after construction is greater than the strength of the loess in the vertical direction, it will be Cause the instability of the excavation working face. In case of collapsibility, the water content exceeds a certain value or after encountering water, there will be a large "subsidence" deformation and loss of bearing capacity. Engineering prac...

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Problems solved by technology

[0004] In order to solve the problem of subsidence and subsidence of existing aeolian sandy loess tunnels, the present invention adopts traditional large pipe sheds for construction, which requires relatively large construction space, high construction costs, long periods, and reinforced

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