Definition of passive support It is a type of support that is not immediate action, it is characterized because it does not exert force on the rock mass developing its resistant capacity as the rock is deformed Definition of wooden pictures They are a type of Sustainability structure according to the type of terrain and special conditions of each Mine. They are used in horizontal and inclined work. Its dimension is according to the design of the work. Types of wooden pictures There are 3 types of wooden frames: 1. conical wooden picture 2. square wooden picture 3. Picking wooden picture These tables are used according to the direction of the efforts and the section of the work Conical wooden picture They are used when the greatest pressure comes from the gables (boxes). The difference with the straight frames, only lies in the fact that in the conical frames the length of the hat is reduced, inclining the posts, in such a way as to form angles of 78 ° to 82 ° with respect to the floor, leaving the frame of shape trapezoidal Square wooden picture They are used when the greatest pressure comes from the roof. The difference with the conical squares lies in the angles that form 90 ° with respect to the floor. Picking wooden picture They are used in narrow veins less than 3 m in power. Its use allows to gain work space. They can be vertical or inclined according to the dip of the mineralized structure. Support forms (Cimbras) The forms are built with steel profiles Generally used for the permanent maintenance of advance work, in conditions of rock mass, highly fractured or very weak, which give bad to very poor quality, subjected to high stress conditions. The forms are used due to their excellent mechanical resistance and their deformation properties, which counteracts the closing of the excavation and prevents its premature rupture.The advantage is that this system continues to provide support after major deformations have occurred. Electrowelded mash Electrowelded mesh for support consists of smooth bars, cold rolled, longitudinal and transverse, which are crossed in a rectangular shape, being welded at all intersections, this prevents the release of small rocks Schocrete The shotcrete consists of concrete placed by high speed pneumatic projection from a nozzle. Its components are aggregates, cement and water, and can be supplemented with fine materials, chemical additives and reinforcing fibers. There are two types of schocrete Dry way Wet war Conclusion The type of support in underground mining is very important, applying a good method of support taking into account factors such as RQD, resistance to compression, number of joints, etc. we can avoid deaths by rockfall and reduce costs.
