Research On Three-dimensional Resistivity Detection Of Multi-borehole And Multi-roadway Based On Parallel Electrical Method

In recent years,water disasters in the floor of coal mine face have occurred frequently,and the threat has become increasingly serious.It is an important link of coal mine water disaster prevention to detect the water abundance of floor strata in fine mining face and monitor the effect of floor reconstruction.In this thesis,the threedimensional resistivity detection technology of multi-borehole and multi-roadway is put forward,and the resistivity response characteristics of various abnormal bodies in the floor under the condition of multi-borehole and multi-roadway three-dimensional detection are explored.Through the numerical simulation research on the response law of abnormal floor resistivity,the research on the response law of abnormal floor resistivity based on the physical model of water tank,and the detection of the water abundance of the working face floor and the monitoring of floor reconstruction by the multi-lane resistivity method,the main research results are as follows:(1)The numerical model of electrical detection of working face floor is established,and the resistivity response characteristics of abnormal body under various combined observation modes of roadway and borehole are comparatively studied,and the best arrangement scheme of observation system is obtained.Compared with the conventional two-lane stereo detection system,the advantages of detection depth and accuracy are highlighted.Furthermore,the characteristic law of resistivity response of porous multi-lane system to various attributes such as abnormal body shape,buried depth,development position,development size,number,etc.under the conditions of roadway level and roadway inclination is studied,and the feasibility of high-precision exploration of resistivity of floor strata in working face by this system is verified numerically.(2)A flume model is built based on the proportional reduction of the measured working face site conditions,and the response characteristics of porous multi-lane system to high and low resistivity anomalies are revealed.Through the contrast experiments of many groups of abnormal bodies,the resistivity response law of porous multi-lane system to high and low resistivity abnormal bodies is revealed,and the detection effectiveness of porous multi-lane resistivity stereo system to high and low resistivity abnormal bodies on the floor is clarified in many aspects,such as fine positioning,measurement of development size,development morphology,etc.The resistivity response characteristics of each abnormal body are obtained,and the fitting accuracy of inversion results with the actual abnormal body volume and position is calculated.The reliability of porous multi-lane resistivity stereo detection technology is verified from the perspective of physical experiments.(3)Using multi-borehole and multi-roadway resistivity three-dimensional detection technology to carry out field measurement of floor water abundance in 3103 working face of a mine,and clarify the difference law of floor resistivity distribution before and after treatment.Before the grouting,there was an obvious low-resistance abnormal area connected from top to bottom,and the resistivity of the low-resistance area was lower than 10ω m.The low resistance is located on the east side of the lower bottom pumping roadway,and its development depth is 80-150 m under the conduction floor.After treatment,the overall resistivity of the bottom plate increased obviously,and the resistivity value rose to more than 40Ω·m and tended to be stable.The low resistivity anomaly basically disappeared,and the bottom plate became weak waterrich.At the same time,the variation law of resistivity characteristics in the continuous period of water release and grouting in the rich water area is further obtained: the low resistance range of floor water accumulation gradually increases before water release,and decreases after water release,and the low resistance increases again during slurry injection,until the solidification resistivity of slurry increases steadily and finally tends to be stable.Finally,the grouting effect was checked by checking the borehole water injection,and it was confirmed that the 0-120 m section under the floor formed an effective water-resisting layer,which verified the effectiveness of multi-hole multi-lane resistivity stereo detection technology in the water-rich detection of floor strata and the monitoring of floor reconstruction.There are 74 figures,1 table and 91 references in this thesis.