Study On Advanced Geological Prediction Of Roadway In Xulou Iron Mine In Anhui

With the rapid development of social economy in China,the mining scale and quantity of underground metal mines are expanding constantly.In the process of mine roadway construction,carrying out advanced geological prediction is an important means to reduce and prevent geological hazards in underground roadways,and has a very important guiding significance for improving the safety of roadway construction.Xulou Iron Mine is a typical contact metasomatic magnetite deposit formed by magma intrusion into limestone.The reserves of iron ore resources are huge,but construction is often delayed because of the prevention and control of water in the roadway and the prevention of rock fall.In this paper,the advance prediction of two ore-drawing roadways at-205 m and-217 m levels in the second ore belt of Shilou Iron Mine,Xulou,is studied by means of in-situ geological survey,DTH drilling,TRT-6000 and TST detection techniques.The comprehensive interpretation results of the advance prediction are obtained by sorting out and analyzing the prediction results.Based on the prediction results,the numerical simulation of surrounding rock stability of roadway is carried out by Flac3 D software.By analyzing the plastic zone of surrounding rock of roadway vault,the stability of surrounding rock is quantitatively analyzed and evaluated,and the prevention measures are put forward.Finally,the actual sketch of roadway excavation is used to check the advance prediction results,and the prediction accuracy is obtained.This study draws the following conclusions:(1)When using TRT and TST advanced detection technology to judge the weak alteration zone or fractured zone in front of the palm,the three-dimensional tomographic scan of TRT-6000 shows strip-like blue stripes(negative reflection),while the migration image of TST shows red-blue stripes(red stripes indicate positive reflection,blue stripes indicate negative reflection)in groups.On both sides of the shift map,there are many groups of alternating occurrence and stripe coarseness.(2)According to the actual excavation test of roadway,the results of advanced drilling are basically the same.TRT and TST prediction system have good effects in predicting joints and fissures,ore-rock contact alteration zone and weak zone,karst,etc.The accuracy of TRT prediction is over 68.2%,TST prediction accuracy is over 63.8%,and the prediction accuracy of comprehensive analysis results of advanced forecast reaches 85.0%.TRT system has a general performance in predicting aquifer in front of roadway.Combined with TST detection system,it effectively improves the prediction accuracy of aquifer.It can provide reference for advanced geological prediction of other similar metal mine roadways.(3)Flac3D software is used to simulate the excavation of roadway.The simulation results show that the plastic zone of roadway vault surrounding rock within 0.6-2.6 m may fall or local collapse,which is the key research area of roadway surrounding rock stability evaluation and roadway support.