Support method for deep soft rock roadway

Abstract

The invention discloses a support method for a deep soft rock roadway, which includes the following steps: (1) measuring the thickness of the broken rock zone of the surrounding rock of a roadway; (2)determining the relationship between the deformation of the roadway and the creep time; (3) carrying out primary shotcrete support; (4) installing an anchor rod net; (5) carrying out secondary shotcrete support; (6) installing a circular steel bracket; and (7) backfilling the bottom of the roadway. A support method based on concrete-anchor rod net-concrete-shed pipe-steel support is adopted, andthe support structure is rigid-flexible, which can improve the support strength and reduce the number of repairs. The same support structure is also adopted at the bottom of the roadway, and the bottom is backfilled with gravel, which can improve the support strength at the bottom of the roadway and solve the problem of bottom heave. A structure of shed pipe-steel support is adopted, and the shedpipe can withstand a certain amount of deformation, so that the influence of long-term creep deformation of the roadway on the steel support structure can be avoided, and the number of support repairscan be reduced.

Description

technical field [0001] The invention belongs to the technical field of roadway surrounding rock support in mining engineering, and in particular relates to a support method for deep soft rock roadways. Background technique [0002] Soft rock is a loose, loose, soft and weak rock formation with low strength, large porosity, poor cementation degree, significantly affected by structural plane cutting and weathering, or contains a large amount of easily expandable clay minerals. In the deep bottom layer, the surrounding rock is in a high-stress environment, and because the strength of the soft rock is low, the uniaxial saturated compressive strength is also low, and the deformation and damage of the surrounding rock are very strong. Therefore, the deep soft rock roadway has a fast deformation of the surrounding rock. , Large amount of deformation and long duration. Moreover, with the increase of mining depth and the increase of the ground stress of the broken rock mass, the sev...

AI Technical Summary

Problems solved by technology

The buried depth of the soft rock stratum is more than 600m, the traditional support cannot adapt, the metal rigid support is completely destroyed, the U-shaped steel shrinkable support is seriously deformed, and the low-strength bolt support cannot meet the maintenance requirements of the roadway. Therefore, the traditional support method cannot be used. Roadway remains stable

[0003] At present, most of the support methods for deep soft rock use U-shaped steel support or semicircular arch support, such as patent 201710147579.8 "U-shaped steel composite support structure and construction method for deep dynamic pressure soft rock roadway" and patent 201510637612.6 "broken soft rock Entire section of the roadway closed deep-shallow coupling pressure-anchor-grouting support method provides a method to control the surrounding rock of relatively broken and soft rock roadway. U-shaped steel is used for reinforcement and support, and it is difficult to control the deformation in the horizontal direction of the deep soft rock roadway. Practice has proved that the deformation of the side of the deep soft rock roadway is the largest, and the U-shaped bracket cannot solve the problem of side deformation, and the floor heave of the roadway is even more uncontrollable; another example is in the patent 201611040176.5 "a coal mine soft rock roadway support method" provides round The support method of the shaped roadway solves the problem of large stress deformation of the side. The roadway support bracket is divided into 5 parts. It is difficult to repair when the bracket is deformed after installation. It is inconvenient to repair the damaged bottom drum

The above support methods do not consider the time-dependent creep of deformation support, and both support methods have certain defects

Images