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Abstract With the mine resources development，an alternation of fracturing area and intact area phenomenon so-called zonal disintegration appears in surrounding rock mass of deep mine roadways. This is a newly- discovered special engineering geological phenomenon and it attracts scholars¢ attentions in rock mechanics fields，but related research is not clear. In order to observe zonal disintegration phenomenon，four sections in roadways with different dimensions under about 1 000 m deep mine are considered；three or five bores being arranged in each section. The fracturing through bores of surrounding rock mass is observed by mine bore TV imager；zonal disintegration phenomenon is observed in surrounding rock mass and zonal disintegration distributions in four sections are obtained. Analyses of roadway location，geological data and fracturing shape in bore show that fracturing is caused by excavation. Observation results also show that the radius and thickness of three large sections¢ fracturing areas are almost the same. Small sections¢ fracturing areas are similar with those of large sections，but radius and thickness of fracturing areas reduce correspondingly. Analyses display that the relation between each fracturing area radius and roadway radius r is nearly expressed by (i = 1，2，3，4). There are four fracturing areas in surrounding rock of four observation sections. The thickness of first fracturing area is similar to roadway radius，and the first fracturing area is the most seriously fractured；and the other fracturing areas thickness and fracturing extension reduce consequently. The research results are important for surrounding rock fracturing mode of deep mine roadway and the corresponding stability reinforcement.
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Received: 17 March 2008
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