Analysis On The Original Rock Stess And Geomechanics Causes Of Rock Burst In The Datai Mine

The depth of the-510 horizontal haulage roadway in Datai mine is about 1000m.There is a kind of rock easily burst in roadway advancing, however, the other rock nearby has no significant mining dynamic behaviors. On the basis of the above engineering, this paper takes the geomechanics causes of diabase burst as basic studying point. By laboratory experiments, field tests, system development and theoretical calculation, the paper studies the geomechanics causes of the diabase burst in Datai mine, the layout and the support of the deep roadway preventing burst systematically.The ground stress is measured by using hollow inclusion stress-relief method. The measurement shows that the vertical stress is equal to the gravity of the overlying strata. The maximum principal stress is almost twice of the vertical stress, and the azimuth is 155°. The leading of the in-situ stress field is tectonic stress. The measurement is according with the data of fundamental database of crustal stress environment in continental China.Based on genetic algorithm and FLAC3D, the ground stress back analysis system named GA-FLAC3D is developed by the object-oriented language C#. Using the stress from the ground measurement and the inverted mechanics parameters, the back analysis of the Datai mining ground stress is studied. Using the inverted mechanics parameters, the distribution of the ground stress of the-610 horizon is obtained. The horizontal stress changes little. The further from the siltstone and the sandstone, the higher the normal stress is. The-610 horizontal roadway should be laid closed to the interbed of the siltstone and the sandstone.By rock mechanical experiments, rock burst dangerous level of diabase is evaluated from the impact energy index and rock impact proneness. Using micro-structure and energy spectrum analysis, the causes of diabase rock burst is revealed from rock composition and geological processes. Rock burst regions are predicted from in-situ stress, mining depth and geological structure. From reducing the thickness of single roof, surrounding rock reinforcement and improving stress conditions of surrounding rock, layout and support measures on the prevention of rock burst occurred in-610 horizontal roadway of Datai mine are proposed.