Research On Rib Spalling Prevention With Technology Of Longhole Grouting In The Front Abutment Pressure Zone In 1307 Large Height Woking Face Of Zhaozhuang Mine

Rib spalling and roof falls of high face mining have been the main factors that limit the capacity of equipment in working face.Coal wall grouting,as the effective treatment,has been widely used.However,most of the grouting methods at the present stage are short-hole grouting in working face,which has many drawbacks such as affecting production and high cost.Besides,it only acts as a means of emergency treatment and the effect of precaution cannot be achieved.The drawbacks of short-hole grouting can be avoided by arranging long grouting drills in two crossheadings.And preventive treatment of rib spalling can be achieved.In this paper,1307 large height woking face in Zhaozhuang mine is appointed as the research background.Firstly,the rib spalling problem existing in large height working face is described.The reason of rib spalling is analyzed.And the measures taked at the present stage to control the rib spalling and its shortcomings are summarized.Secondly,by analyzing the conditions of fracture development in the affected area of advanced abutment pressure,the longhole grouting technology,whose drills are arranged in two crossheadings,is raised.Thirdly,problems such as the arrangment of grouting drills,the reinforced layer,the opportunity of grouting,grouting material and the longhole grouting sealing technology are analyzed to form a scientific and feasible scheme.At last,grouting effect is evaluated after the completion of the construction.The result shows that grouting has a remarkable effect and is benefitial to economics and safety.