Study on downward borehole bolt and grouting reinforcement technology of mine soft and weak mudstone roadway floor

Acoding to the dificult conrol problem of the foor heave in the mine thick and sot mudstone roadwayin combination with the engineering geological conditions of the west wing ral tasportation roadway in Shunhe Mline, the roof grouting reinforcement priniple and the foor grouting reinforcement principle of the mineroadiway were compared and analyzed and a downward borehole construction tfechnology of thesof and wealk udstone mine roadwa foorwas proided to prevent te borehole collapsed.According to the equivalent excavation concepton.therational foo groutig reinforcement depth and the row d istance paramneters betveen the bolt and grouting boreh ole spaces were delermined.The resutis showed that using a7.5 m long anchor set dow in the borehole for the anchor grouting was a rational rinforcement method of the foor in the thick sot mudstone roadvay.The optimal row spacing and colunmn spacig of the grouting hole wererespectivel 25 m and 1.3 mDue to the shallow rock stratumo of the foor was broken a deep borehole drlld all a once was extreme ly hard and the borehole formning effect was poo.Therefore a haow borehole pre-grouting was frstly conducted and a deep boreholegrouting would be conducted ater a certin time. This construction method coui fectively redu.ethe foora lig dificulty in sof mudstone roadway and inprove the boreholeforming efftct.The bolt grouting reinforcement technology of the soft mutstone foor was successfully applied to Shunhe Mine and the floor heave problem was effectively controlled.