Research On The Grouting Materials And Mechanism Of The Second Air Craft In Pingdingshan’s Sandstone Formation

Water disasters in a coal mine would a negative impact on the project progress andquality,worsen the miners’working environment,increase drainage facilities and drainageexpenses,bring an unsafe factor into the coal mine production or even result in a submergenceaccident which would cause great losses of lives as well as property. In the course of theconstruction of the second air shaft in the north of the third plane of Tian’an’s Sixth Mine,which is located in Pingdingshan’s sandstone formation, a good amount of water burst intothe air craft and the water was blocked by means of cement grouting.Based on therequirement for a grouting project in Pingdingshan’s sandstone formation and thecorresponding grouting materials， this thesis analyses the feasibility of a successful cementgrouting；it highlights seven basic properties of the ordinary Portland cement grout and theMJ-1modified urea resin grout: the gelation time, the viscosity, the fluidity, the syneresisratio, the concretion ratio, the concretion’s compressive streng and flexure strength; it alsoreflects the general characteristics of the grout’s rheological property by analyzing andcomparing the different performances of these two injection materials of various proportions.Based on the engineering geological and hydrogeological characteristics of Pingdingshan’ssandstone formation, a proper proportion of the injection materials was fixed and a scheme toblock the water by grouting was designed; both the cement grout and the MJ-1modified urearesin grout were practically applied in the preliminary grouting project of the working face ofthe vertical shaft of the second air shaft in the north of the third plane of Tian’an’s Sixth Mine,which proved to be a big suucess; meanwhile the thesis further analyzes the groutingmechanism in Pingdingshan’s sandstone formation and thus provides a solid theoreticalfoundation for the selecting of grouting materials for similar grouting projects carried out in asandstone formation which is alike to Pingdingshan’s.