Domestic metal mine roadway support theory

China has only been in contact with bolt support since the late 1950s. Compared with traditional support methods, such as wood support and U-shaped steel support, bolt support shows great advantages. It is an active support. Protection. The development of the theory is gradually formed along with the development of mineral resources in China, due to the large demand for resources in China and the state's scientific research investment in resource development. So far, China has gradually formed many of its own views on the theory of support, and some of the theories have been confirmed step by step in practice.

The main support theories in China today are as follows:

1. Axial theory and system development theory

The theory holds that the surrounding rock failure of the roadway is caused by the stress exceeding the strength limit of the rock mass. The collapse is the result of changing the axial ratio of the roadway, resulting in stress redistribution, high stress drop and low stress rise, until the self-stabilization balance, the stress is evenly distributed. The axial ratio is the most stable axial ratio of the roadway, and its shape is elliptical. The "excavation system control theory" believes that excavation disturbs the balance of the rock mass. This unbalanced system has self-organizing ability and can be self-stabilized. The theory inherits the idea of ​​the new Austrian law, that is, the surrounding rock has a certain degree of self-stability, and emphasizes that support should be targeted.

2. Joint support theory

On the basis of summarizing the support of the new Austrian law, Feng Yu, Lu Jialiang, Zheng Yutian and others put forward the "joint support technology". The theory holds that it is unreasonable to emphasize the support stiffness for the soft rock roadway support. It is necessary to "first soften, then dig, let the soft, moderate, and stable support", and the theory has developed the anchor spray net support, anchor spray net support technology, anchor belt mesh anchor spray frame Joint support technology such as support. Starting from this theory, there are many joint support methods such as anchor anchor cable support, anchor spray net support, and anchor net support. Therefore, the theory is of great significance.

3. Anchor spray-arc plate support theory

The scholars represented by Professor Zheng Yutian and Professor Zhu Xiaojia proposed the theory of anchor spray and arc plate support. This theory inherits the viewpoint of joint support theory. On this basis, it is considered that it is impossible to emphasize the pressure on soft rock. The pressure is reduced to a certain extent, and it must be firmly restrained, that is, the rigid support form of the first support of the joint support theory is “reinforced concrete arc plate”, and the displacement of the surrounding rock to the hollow should be firmly restrained and restrained.

4. Key part coupling combined support theory

Professor He Manchao's key part coupling combined support theory holds that the roadway support damage is mostly caused by the uncoupling of the support body and the surrounding rock mass in terms of strength, stiffness and structure. To adopt appropriate support transformation technology and make them coupled to each other, the complex roadway support should be divided into two supports, the first is the flexible surface support, and the second is the point support of the key parts. The theory attaches importance to the grasp of the timing of support, that support is a systematic project, and that multiple support is important for the stability of some key parts, and also reflects the idea of ​​both rigid and soft.

5. Surrounding rock loose circle theory

Professor Dong Fangting and others proposed the theory of surrounding rock loose circle. The main point of view is that the surrounding rock loose circle is close to zero in all the nude roadways. At this time, although the elastoplastic deformation of the surrounding rock of the roadway exists, it does not need support. The larger the loose circle, the larger the convergence deformation and the more difficult the support. Therefore, the purpose of the support is to prevent harmful deformation during the development of the surrounding rock loose circle. At present, the application of this theory is extensive, and the testing technology of the loose rock of the surrounding rock is also constantly improving.

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