| Compared with many mines in china and other countries, Jinchuan nickel mine has such characters as 'deep, large , rich and fragmentized'. Once production began, studies about it were started. Especially there were much work have been done on the roadway's support and a great of achievements have been got. For example, the principle of carrying out the soft way before stiff way, and making some sidestep before support, which have been directed the roadway's support and have made a important role in 2nd construction of Jinchuan mine. It is completely changed the idea of traditional support that the deformation of the roadway being restrained by eyeframe, since the bolt was introduced, studied as well as popularized. As a result, the idea that strengthening the retained strength of surrounding rock mass so as to improve the self-supporting capacity has been formed.With the increasing of mining depth in recent years, the problem of roadway's support in Jinchuan nickel mine become more and more serious. The traditional ways of bolt and U-formed arched falsework have been destroyed badly in the roadways of 1000m level. It is the first time that the roadway deformation's rate is so quick and the deformation is so large.According to the geological environment and the demand, there exist best roadway's support way and most reasonable intensity. It seems that man's idea about support has been restrained by previous principle, that support must be divided into two steps, and the time is crucial to the 2nd support. But none points out how great the degree of the first soft way and lately stiff way is, what the reasonable range of the support intensity is.Combining with the project that study on roadway's support mechanism in Jinchuan deep mine and simulation of the surrounding rock mass's stability, aiming at the serious problems of the roadway's support, studies have been done in the thesis as follows: the geological condition and the former test results about the rock in Jinchuan mine; the characters of the deformation of the rock mass and roadway; the forms of the support invalidation; the capacity of the bolt support in Jinchuan 2nd mine and the mechanism of the support. The blue print of reparation in the 1150m level of Jinchuan 2nd mine have been analyzed with the ANSYS .The followingare main researches:(1) The theories and technology about roadway's support in china and other countries are studied, which include the U-formed arched falsework, bolt, cable anchor, shotcrete lining and others.(2) The geological condition, the law of stress changing and the test results of the rock mass' mechanics characters are investigated and researched. The author argues that the strength of the rock is low and rock mass' is high, and rock mass can creep. Those are the characters of soft rock.(3)The relationship between deformation of the surrounding rock mass and resistance of the support is studied. The reasonable range (0.2~0.3MPa) of the support is given. After analyzing the bearing capacity and the supporting performance of the U-formed arched falsework, the reason that the actual supporting capacity not reaching the theoretical limit value is the stress is eccentric. According to the analysis about the bearing way and calculation of the bearing capacity of the bolt, both the splint and the bolt have not enough capacities and they are not matching. The estimate bearing capacity of the bolt is given. That is the anchoring force is just about 75% of the drawing force of the bolt test. The deformation mechanism of the shotcrete is studied.(4) The expansion on breaking, time effect and the characters of roadway's deformation are analyzed. The law of the deformation of the roadway's surrounding rock mass and several forms of bolt becoming invalid are researched. So the result of the capacity of the splint and the bolt is not enough and they are not matching are verified. A support system of strong in initial and steep increasing resistance and high bearing capacity is put forward. It is the effective way to r... |
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