SAFETY MONITORING AND STABILITY ANALYSIS OF LARGE-SCALE ROADWAY IN FAULT FRACTURE ZONE
(1. State key Laboratory of Geomechanics and Geotechnical Engineering，Institute of Rock and Soil Mechanics，Chinese Academy of Sciences，Wuhan，Hubei 430071，China；2. College of Civil Engineering and Architecture，Shandong University of Science and Technology，Qingdao，Shandong 266510，China)
Abstract：The lithology in fault fracture zones is complex and the pressure in roadway in these zones is variable. The deformation of surrounding rock and pressure on support structure in fault fracture zone can be grasped through the monitoring measurement of roadway. Based on the measurement，the effects of various supports and the rationality of construction scheme are evaluated. Ventilation roadway in south of Gubei coal mine in Huainan mine area passes through the fault fracture zone. In this area，the geological condition is complex. Because of the influence by tectonic movement，the geostress of surrounding rock is high and the surrounding rock of roadway is large-scale loosened rock. In order to analyze the stability and study the deformation law of surrounding rock in the periods of construction and operation，the surface displacement of surrounding rock，deep displacement，stress of anchors and cables，support pressure and the variation distribution regularity of loosened zone of surrounding rock are studied through the field measurement. The results show that：(1) The horizontal displacement of wall of roadway is larger than that of roof and spandrel；and the stress of anchor is small because of the horizontal shear force and squeeze force from fault F92. And it means that the action of anchoring is not effective. Hence，the strength of anchors and the grouting near fault F92 was reinforced. (2) From the measurement results of surface and deep displacement of surrounding rock，the floor dilates，the two walls converge and the roof sinks. It means that the floor is the weak part in the support of roadway. A revised support scheme is proposed：grouting tube at the corner of floor and rockbolts at wall corner are used to resist the shear displacement at the floor corner with concentrated stress；and the floor is reinforced by anchor and grouting to improve the shear strength of rock mass near floor. The dilation of floor is controlled effectively which means the support effect is good. (3) From the measurement result of pressure of U-shaped steel bracket，the pressure of U-shaped steel bracket from surrounding rock is about 0–0.24 MPa which is far less than the designed bearing capacity of bracket (0.4MPa). This means that the stability of roadway mainly relies on the support of anchor and grouting and the U-shaped steel bracket is used mainly for the safe protection of working face in the construction process of roadway. Based on the analysis of these measurement data，the foundation is provided for the optimization adjustment of design scheme and the information construction of roadway and the reference is provided for design and construction under the similar complicated geologic condition.
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2010, Vol. 29 
