The hydraulic support is the core equipment of the fully mechanized mining face. During the coal mining process, it can effectively support the weight of the roof rock to prevent the roof from collapsing and endangering the safety of personnel and damaging the equipment. It can also move flexibly as the coal mining progresses to adapt to different mining progress. At the same time, it has a certain blocking effect on the gangue in the goaf and maintains the stability of the working space.
In the coal mine fully mechanized mining face, there are mainly the following types of support:
1.End support
The end support is relative to the middle support and is mainly used at the connection between the two ends of the working face and the tunnel. Because the roof maintenance in this area is relatively complicated, it must bear the pressure of the working face roof and the tunnel roof at the same time.
The structure of the end support is relatively complex, generally with a large support area and high stability. It can provide good support and protective space for equipment such as the head and tail of the conveyor scraper and the transfer machine to ensure the normal operation of this equipment.
Compared to the end support, the transition support is used in the transition area of the working face to adapt to different geological conditions; the middle support is in all positions other than the end support and is the main support equipment for the fully mechanized mining face.
2.Advance support
Advance support is generally arranged in the tunnel in front of the working face. Its main function is to support the tunnel roof in advance to prevent the roof from collapsing prematurely under the influence of mining on the working face. Advance support is usually used in groups, consisting of multiple support units, which are interconnected to form a stable support system. Its structure can be in various forms such as stepping or frame type.
In some coal mine tunnels with complex geological conditions and poor roof stability, the advance support can control the roof deformation in advance and create a safe passage for subsequent coal mining and equipment transportation. Moreover, the support range of advanced support can be adjusted according to actual needs. Some can support the top and sides of the tunnel to provide all-round protection for the tunnel.
3. Support type support
（1）Stack type support:
Its structural features are top beam, column and base. The column is generally arranged vertically and has a large supporting force. This type of support has a relatively direct supporting effect on the roof and is mainly used for working surfaces with relatively hard and complete roofs. For example, in some coal mines where the roof of the coal seam is a relatively hard rock layer such as sandstone, the stack type support can effectively support the roof and prevent the roof from sinking.
（2）Sectional support:
It is composed of more than two mechanically connected sections; each section has independent columns and top beams. This type of support has good flexibility and can be adjusted appropriately according to the shape of the working surface and the distribution of roof pressure. Its support force is also relatively stable and can adapt to a certain degree of roof changes.
4. Shielding support
（1）Single hinge shielding support:
It has a hinge point connecting the top beam and the shielding beam, and the lifting and lowering of the top beam is controlled by the extension and contraction of the column. This support has good shielding performance and can effectively prevent the gangue from the goaf from pouring into the working face. Moreover, its structure is relatively simple, easy to operate and maintain. It is widely used in working faces with broken roofs and high pressure. For example, when the roof of the coal seam is a soft and easily broken rock layer such as shale, the single hinge shielding support can use the shielding beam to block the gangue and ensure the safety of the working face.
（2）Double hinge shield support:
It has two hinge points, making the force distribution of the support more reasonable. When bearing the pressure of the roof, the double hinge design allows the support to better adapt to the deformation of the roof and provide more stable support. It has stronger adaptability to the roof and can maintain good support even when the roof fluctuates greatly, or the pressure is uneven.
5. Support and shield type support
This type of support combines the advantages of support and shield type supports. It has both a large support capacity and good shielding performance. The top beam can effectively support the roof and prevent the roof from sinking excessively. At the same time, the shield beam can prevent the goaf from entering the working face. It is suitable for various roof conditions, especially in complex conditions where the roof pressure is large and relatively broken, the support and shield type support can play a good role. For example, in the deep mining coal working face, due to the large ground pressure and complex roof conditions, the support and shield type support can comprehensively deal with various pressures and roof broken problems.
