Study on Roof-fall Mechanism and Supporting Countermeasure of Rich Water Soft Rock Roadway

To the problems that water spary and large area roof-fall during excavation process of rich water soft rock roadway,it taking roadway of 110203 working face of Beixinyao coal mine as example,and then the following means that theoretical analysis,laboratory testing,field testing and numerical simulation were used to analyzed roof-fall mechanism,and also specific countermeasures were put forward.The results showed that as roadway span increased,roof cohesion decreased,and roof separation possibility appeared,as roof structure was weaken by water,and surrounding rock cohesion was decreased more,and progressive failure appeared,rich water state of roof was determined by transient electromagnetic method,and provided basis for 'controlling dewatering',the shallow structure of roof was controlled by high-pretension short cables,provided technological means for'reasonable water conservation',after practical testing,rich water soft rock roadway could be controlled effectively.