Detection And Treatment Of Shallow Empty Area In Engineering Site

The land use of mine(area)is affected by underground goaf,underground karst cavity and so on,and there are various security risks.The goaf may cause environmental safety problems,cause serious geological disasters,and may also lead to casualties and economic losses.Therefore,the detection and treatment of shallow goaf in the engineering site plays an important role in the comprehensive utilization of mine land.This paper introduces the surface and underground goaf of a goaf treatment site in Guye,Tangshan,and the hydrogeological conditions.Geophysical exploration tests such as transient electromagnetic method and high density electrical method are carried out in the field area,and the geophysical anomaly area is verified by drilling method.The stability zoning of goaf development degree is carried out.Through comparison and selection,all filling grouting methods are selected.Grouting treatment design was carried out in the study area.Test the effect of treatment.The ground investigation area is the original bauxite mining affected area,and there are roadway mining,open mining and other mining areas underground.After bauxite mining,some mined out areas in the site are filled by collapsed gravel rock mass,and some roadways have not collapsed yet.The resistance anomaly measured by TEM is analyzed to be caused by goaf collapse or roadway mining area,or electrical anomaly after treatment of Goaf Collapse.Drilling directly verified the existence of tunnel cavity and rock fracture zone.The stability of the site area is divided into different areas to determine whether it needs to be treated.Through the grouting ratio test,the water cement ratio of 1:1 is selected,which has good groutability and high stone strength.During the electrical detection,no low resistance anomaly was found.The analysis shows that the goaf treatment effect is good.According to the water injection test,the drawdown speed of borehole water level decreased from 49.5～56.0m/h to 0.14～0.44m/h,basically reaching the complete bedrock.Figure 52;Table 10;Reference67...