Anchoring and shotcreting roadway two-side concrete spray layer shear failure prevention and control method

Abstract

The invention discloses an anchoring and shotcreting roadway two-side concrete spray layer shear failure prevention and control method. Two-side concrete spray layers and an arc section concrete spray layer are arranged in a roadway, a segmentation layer is arranged between the two-side concrete spray layers and the arc section concrete spray layer for separating the two-side concrete spray layers from the arc section concrete spray layer, a flexible yielding layer is arranged in each of the two-side concrete spray layers, the section of the bottom of each of the two-side concrete spray layers is a triangle with a downward closed angle, the bottom of each of the two-side concrete spray layers is provided with a footing anchor rod, and the top of each of the two-side concrete spray layers is provided with an anchor rod and a reinforcing steel band. Shear failure of the concrete spray layers occurring at a part close to the point of the intersection of two-side vertical wall sections and a circular arch when the vertical wall semicircular arch roadway carries out anchor-plate retaining is effectively prevented and controlled, and the long-term stability of the roadway is guaranteed.

Description

technical field [0001] The invention relates to a surrounding rock maintenance technology of a coal mine roadway, in particular to a method for preventing and preventing shear failure of two sides of a shotcrete roadway in a bolted shotcrete roadway. Background technique [0002] The semi-circular arch roadway with straight wall is widely used in coal mine roadway engineering because of its simple construction and the stability of the roadway surrounding rock. The roadway generally adopts anchor shotcrete support to reinforce the two sides of the roadway and the surrounding rock of the roof, and the floor generally has no support. The thickness of the roadway concrete spray layer is generally 50-150mm. [0003] like figure 1 As shown, when encountering a large surrounding rock pressure, the failure mechanism of the two sides of the concrete sprayed layer of the semicircular arch roadway with the straight wall is as follows: [0004] ① For the straight-walled semi-circular...

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Problems solved by technology

[0005] ②Compared with the weak roadway surrounding rock, the concrete sprayed layer has a relatively high rigidity, making it difficult to achieve simultaneous deformation

[0006] ③Because there is no support for the roadway floor or the strength of the support is not enough, the strength of the floor rock mass is seriously weakened, and the rheology of the floor is easy to develop, forming a rheological channel for the surrounding rock mass; The side of the roadway moves toward the center of the roadway along the horizontal direction, and at the same time, the middle of the roadway bottom slab protrudes upwards, and the two bottom corners move inward and uplift, resulting in severe bottom heaving; the bearing capacity of the roadway side and top rock mass and the strength of the support body are also difficult to exert, and the roadway converges. Deformation control is difficult

[0008] However, for the shear failure of the concrete shotcrete in the shoulder area of ​​the roadway, there has not been an in-depth and systematic study on the mechanical mechanism of it, and there is also a lack of effective prevention and control technology

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