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Abstract By analyzing the project example of Jijiapo tunnel?s lining fracturing，studies were done on the karst developing characteristics of the tunnel district，and a kind of water bearing structures，steeply inclined and filling type of karst fissure，was probed. Its configuration，filling?s characteristics and disaster-causing mechanisms were studied. Measurements，as fissure-blocking，perinous grouting，discharge of water and release of pressure，substitution of structures，as well as information grouting assessment methods，were taken to govern water inrush-lining fracturing in tunnels. Steeply inclined and filling type of karst fissure-water bearing structure occurred in a steeply inclined angle of fissure，easily accumulate water and form a high water pressure in its fissure space. In addition，sediments easily accumulate at the bottom for its slow migration in a fissure. Because of dead weight stress and high water pressure compaction，the filling medium changes to poorly permeable，hard or semi-hard sedimentation and cementation. It is often neglected when excavated and revealed for there is no or a litter of water inflow. However，after a period of time?s excavation，the filling medium of the fissure is washed out gradually by water and will finally lead to piping，soil flow or entirely extrusion out；and then import underground，cavern or surface water into the tunnel，causing disasters of lining fracturing，water inrush and so on. Research results are not only used for the controlling of water inrush in Jijiapo Tunnel，but also have strong reference value for avoiding and controlling similar disasters.
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Received: 22 February 2011
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2011, Vol. 30 
