Comprehensive Monitoring Method And Simulation Study Of Fault Activity Under Mining Conditions

During the exploitation of coal resources,various geological disasters will be encountered.Under the conditions of mining,some of the mine accidents caused by fault activities have caused huge economic losses and casualties.This has caused widespread attention and high attention in the mine,and is trying to study the law of the development of fault activity in the stope by means of related monitoring techniques and other methods.At present,there is too much single method to study the law of fault activity in the stope,the degree of quantification is not high,and the accuracy of the detection is hard to be guaranteed.Therefore,the related monitoring technology and numerical simulation method are used to effectively detect and analyze the fault activity under the influence of mining.It is found that the change rule and evolution mechanism are of great significance for the safe and efficient production of coal mines.This paper introduces the working principle and acquisition method of CT technology and Brillouin optical fiber strain test.Then according to the theory of knowledge of fault activation,using Flac3 d numerical simulation software to establish the model of dynamic mining direction of fault dip,gap,different,evolutions of relative displacement and shear contact surface position through the study of fault stress,to reveal the effect of response characteristics of induced activation of the fault.Finally,2 kinds of on-site in-situ test system are built respectively.According to the response characteristics of geoelectric field and stress field,the fracture distribution and evolution rule of surrounding rock in fault activation zone are studied.The main conclusions are as follows:(1)Based on the flac3 d numerical simulation method,the relative displacement and shear stress variation laws of normal faults with different dip angles,different drops and different mining directions are analyzed and studied.When the single influence factor changes,the relative displacement and shear stress near the low angle normal fault are larger,the angle normal fault table is bigger,and it is easy to generate activation.The greater the normal fault drop,the greater the relative displacement and the shear stress at the top of the seam roof at the footwall of the fault,the more easily the position of this position is activated.For normal faults,when mining from footwall,the influence of mining on fracture surface is more obvious than that of fault footwall mining,and it is more obvious that relative displacement and shear stress respond to coal mining.(2)2 kinds of on-site in-situ test method system,namely CT method and fiber strain test method,are used to monitor the fault activity development rule of the roof and floor.The apparent resistivity inversion results to determine the Huainan pan two mine 11223 working face floor under the influence of fault fractured cause coal mining depth is in the range of 20 m,lower ash did not affect the stability of the rock mass,and the floor limestone water and not because of the cracks within the scope of the fault zone and conduction up.The monitoring results show the strain of Pan Yi mine 1231(1)working face roof FS2 fault plane near the influence of mining stress concentration,fault prone to slide along the shear plane position,and according to the relationship between the fault stress distribution and coal mining,can put forward to protect the coal pillar width reasonable for more than 60 m.(3)The CT method as a traditional geophysical technology is feasible and practical.The Brillouin optical fiber strain measurement method has high sens itivity and high accuracy.These 2 testing methods from the early test design,si te construction and installation,the data acquisition and processing,or to monit or the final results of the analysis,the whole process is clearly and accurately reveals the use of the 2 kinds of the mature and effective monitoring method to master fault activation deformation the distribution and evolution characteris tics of surrounding rock zone for deep coal seam fully mechanized caving min ing is of great significance.