U-shaped steel bracket capable of actively controlling deformation of surrounding rocks

Abstract

The invention discloses a U-shaped steel bracket capable of actively controlling deformation of surrounding rocks, which comprises an arch crown U-shaped steel, two timber foot part U-shaped steels, two clamping cables, a hydraulic jack and two hydraulic props. The U-shaped steel bracket has the following technical effects that the defects of a conventional U-shaped steel bracket are overcome, a passive supporting stress mode of the conventional U-shaped steel bracket is changed, a setting load can be applied to the surrounding rocks of a roadway and self-supporting capacity of rock mass is played to the greatest extent; the size and the direction of a supporting force can be flexibly regulated according to the surrounding rocks, deformation of the bracket and variation of the pressure of the surrounding rocks and the U-shaped steel bracket can take an effect of actively controlling deformation of the surrounding rocks; the single hydraulic props are reliably hinged with the U-shaped steel bracket, the vertical bearing effect of the hydraulic props is sufficiently played, the adverse bent and folded effects are avoided and reliability for building-in of the bottoms of the hydraulic props is improved; integral and local rigidities of the bracket are improved and stability and reliability of a supporting structure are improved; and the U-shaped steel bracket is suitable for supporting roadways with various sections, the life cycle and safety of the roadway are greatly improved, maintenance cost and frequency of the roadway are reduced and the U-shaped steel bracket has strong practicality.

Description

technical field [0001] The invention relates to a U-shaped steel support structure for controlling deformation of surrounding rock, and belongs to the technical field of coal mine roadway excavation support. Background technique [0002] At present, the shrinkable U-shaped steel support is the main means of coal mine roadway support. However, due to mechanical problems such as high ground stress, strong rheology, and large deformation, the soft rock roadway supported by the shrinkable U-shaped steel support often suffers from support failure. The cross-section becomes smaller, resulting in high roadway maintenance cost, short service life, and low safety performance. It mainly depends on the friction force on the overlapping surface between the U-shaped steels and the positive pressure transmission and bearing capacity of the contact surface provided by the connecting clamp cable through the bolt. Only when the surrounding rock is deformed to a certain extent and sufficient...

AI Technical Summary

Problems solved by technology

[0002] At present, the shrinkable U-shaped steel support is the main means of coal mine roadway support. However, due to mechanical problems such as high ground stress, strong rheology, and large deformation, the soft rock roadway supported by the shrinkable U-shaped steel support often suffers from support failure. The cross-section becomes smaller, resulting in high roadway maintenance cost, short service life, and low safety performance. It mainly depends on the friction force on the overlapping surface between U-shaped steels and the positive pressure transmission and bearing capacity of the contact surface provided by the connecting clamp cable through the bolt.

Only when the surrounding rock is deformed to a certain extent and sufficient friction is generated, this support system can play a bearing role. It cannot exert initial support force on the surrounding rock, and cannot actively control the deformation of the surrounding rock. It is a passive support form; 2. U The post-frame gap between the steel bracket and the surrounding rock makes the bracket unable to play a supporting role in time to control the deformation of the surrounding rock, which intensifies the weathering, fragmentation, and mudification of the surrounding rock, and the bearing capacity of the surrounding rock itself cannot be fully utilized. ; 3. The commonly used U-shaped steel supports can only be "passively" stressed, and cannot reasonably adjust the supporting force according to the pressure and deformation of the surrounding rock, improve the support strength, and effectively control the development of deformation. Large deformation, resulting in the reduction of roadway section, affecting the use function

4. Affected by high ground stress, the shrinkable U-shaped steel bracket often causes damage such as twisting of the bracket and the formation of a spire due to insufficient overall rigidity; the leg section of the shed often bends and deforms due to insufficient local stiffness; the cable connection section often suffers from shrinkage , resulting in damage to the bracket; 5. The commonly used method of improving the support strength of the bracket and providing a certain initial support force by using a single hydraulic prop or a reinforced structure mainly composed of a single hydraulic prop also has defects: the single hydraulic prop can only Provide vertical bearing capacity, the component itself has poor resistance to bending, and is prone to bending deformation and damage; the single hydraulic prop and the roadway floor have a limited "embedded" effect. When the horizontal displacement of the support structure is too large, the support is prone to tipping and loss. Bearing effect, not conducive to structural stability

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