| The Zhongqu ore mine locates in Luqu county of Gannan which is in Gansu province. The breakthrough of prospecting for ore has been made since 1991 when the Dashui ore mine was found in this area. Geologists have found Geertuo ore bed, Gongbei ore bed and Zhongqu ore bed, which make up of the ore field which is the largest scale and has the most industrial value at present in metallogenic belt of Xiqinling. Joint and crack develop heavily in laneway because the ore produce in fractured zone. The laneway has been formed and deteriorated by the tectonic stress. The roof collapse exists in local areas. The laneway shows apparently the character of jointed soft rock, which bring about much difficulty to excavate and dig. In addition, the top and bottom of laneway are filled with calcite and formed breccia due to the later tectonic process in ort laneway, which not only result in dilution of ore, but also bring about much threat to the stability of laneway. Therefore, if the laneway is not disposed properly, the large roof collapse will be aroused and it will lead to the difficulty of ore reclaim. What is more, it will bring much threat to miner and facility. This article is based on the harnessing of laneway and the field investigation, and attaches much importance to the research of joint and crack. At the same time, the rock is classified different mass grade according to Rock Mass Rating (RMR) and put forward a set of abridged table of rock mass grade which is applicable to the field construction. This article defines the influential factor of bolting and shotcreting through the research of the principle of bolting and shotcreting and advances the supporting solution. In the last chapter, the laneway is simulated by FLAC3D program, which can supply many evidence to the subsequent dig. The supporting solution brings about much benefit to corporation and guarantee to the personal safety. |
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