Prevention and treatment of mine roadway disrepair
In the main roadway of the mine, there will usually be phenomena such as chipping and roofing. The small one will affect production, and the big one will cause a safety accident. Especially in the old mines in the eastern part of Zaozhuang mining area, the roadway disrepair is a problem that cannot be ignored. It is essential to master the correct roadway repair and treatment methods and preventive measures in production practice, which is an important basis for laying a safe production of mines.
2 Types of roadway repair and its causes
2.1 Types of roadway disrepair
Roadway disrepair is due to the existence of weak faces (fissures, bedding, joints, etc.) in the rock body, which destroys the stability of the surrounding rock and is deformed or destroyed by the ground pressure, resulting in roofing or sheeting. In the production, the common types of roadway disrepair are: topping, piece gang, bottom drum or topping plus piece, piece and bottom drum.
2.2 Causes of roof collapse
Roadway roof fall accident occurs, since the tunnel roof is unstable, and the two groups is more stable rock, stone slate roof roadway under stress, it produces deformation or breakage in the tunnel supporting strength insufficient, resulting in caving.
2.3 Reasons for the chip
Due to the existence of the weak surface in the two gangs of the roadway, when the support strength of the roadway is insufficient, when the stress is applied, the stability of the surrounding rock is destroyed and the gang is produced.
2.4 Causes of roadway deformation
The roadway is arranged in the plastic rock. Due to the dynamic pressure, the stability of the surrounding rock of the roadway is destroyed, and the surrounding rock of the roadway is deformed and displaced. The roadway deformation is mostly manifested as a piece or bottom drum phenomenon.
3 Causes and treatment of roadway roofing and sheeting
3.1 The cause and treatment of the roof and the gang of the naked roadway
As the 16th and 17th roadways are respectively excavated along the ten-ash and eleven-grey roofs, the 16-story roadway is composed of sand shale , and the 17-story roadway is made of clay rock. The mud is cemented and soft, belonging to Class III moderately stable rock formations. It remains stable for more than a month. The ten ash is hard and dense, and the top has a double top; the eleven gray is hard and the top is developed. If the sloping joints develop, it often causes gangs to prevent ventilation and pedestrians. During the treatment, the dangerous rock suspension is usually cleaned from top to bottom and from the outside to the inside. After cleaning, according to the site conditions, unsupported, rod support, anchor spray support, etc. can be used. When the top plate fissures and the diptops are developed, if they are subjected to dynamic pressure, there will be a patch or even a roof. When processing, the fault should be taken in the order of top to bottom, from the outside to the inside, and from the top to the top. Hanging. According to the roof condition, anchor spray, anchor net spray, and shed support can be adopted. In order to avoid exposure of surrounding rock weathering, during design and construction for the roadway nature and length of service, ready to open up the roadway bolt, mesh and shotcrete lining (with steel mesh or iron mesh). Closed shotcreting is used for the mining roadway.
3.2 Causes and treatment of roof failure in bolting and spraying roadway of soft rock layer (including anchoring netway)
The roof collapse and disrepair of the anchoring roadway in the soft rock formation occurred because the support design was unreasonable or the support strength was insufficient, and the balance of the reinforcement arch was damaged due to the stress. The processing method generally adopts:
(1) When the soft rock is located on the roof, if the height of the roof is not more than 3m and the thickness of the soft rock is not large, it can take the form of shed support, anchor spray support, etc. , can be supported by the fake roof top method;
(2) When the two sets of rocks are relatively stable and the soft rock is located on the roof, anchor spray and shed can be selected according to the height of the fall and the lithology of the roof. In order to ensure the various safety clearance requirements, the hanging shed support method can be selected in order to ensure the width of the roadway without changing the width of the roadway;
(3) If the top gang is unstable and the broken roof is broken, the surrounding rock can no longer form a stable reinforced beam section, and the ram can be used to support the shed.
3.3 Causes and treatment methods for roof failure of soft rock and coal roadway support roadway
Soft rock and coal roadway support roadway roof collapse and disrepair, which is mainly caused by stress, creep of surrounding rock, deformation of support or damage of supporting materials. The processing method generally adopts:
(1) When the roof area is not large, the length of the roof can not exceed 5m along the roadway. The two groups are not empty and the roof is at the top. There are safety exits at both ends. It can be taken first and then cleared from the outside to the shed. Help with the way;
(2) When the roof area is large and the ends of the roof area cannot be connected, the order from bottom to top and from the outside to the inside can be adopted, and the wedge method is used for processing;
(3) When the roof is broken after the roof is broken, it can not be treated according to the size of the roadway after the wedge is restrained by the condition. Namely: use the wedge method to help the short leg shed to advance 3~5m, in order to control the purpose of controlling the broken slate, and then replace the shed leg from the outside to the inside.
4 preventive measures
4.1 For the roadway that has been constructed
Adhere to the principle of prevention. Prevent problems before they occur, encrypt the number of roadway inspections, and prioritize the planned repairs. Establish and improve the roadway inspection system, conduct regular inspections of the main roadways, establish inspection patrol accounts, and complete records.
4.2 For unconstructed roadways
According to the law of mine road pressure manifestation, determine the reasonable roadway support parameters; strengthen the quality management of roadway construction, and implement the quality life-time responsibility; carefully collect the geological data in the roadway construction, and take timely targeted support measures to do Good concealed engineering record work; in the design of support, according to the nature of the roadway and service years, it can be considered to increase the support strength coefficient.
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