Tectonic Movement Regularity Of Stress-type Mine Goaf Roof Strata

Metal mine is usually associated with the characteristics of the tectonic stress field. Whenthe tectonic stress is greater than gravity stress,cavity roof strata movement and ground surfacedeformation is mainly controlled by tectonic stress,and with deep resource recovery,itstectonic stress effect is more obvious. However, the strata movement under the action oftectonic stress is still in exploring stage,which has become safe, efficient and sustainablebottleneck. Therefore, researching roof strata movement deformation law due to undergroundmining under the action of the tectonic stress is imminent.Against the status quo, with thetypical tectonic stress type mine-Long Qiao iron mine as the engineering background, usingfield monitoring, numerical calculation and theoretical analysis, the high tectonic stress undercomplicated environment condition of goaf roof strata movement rule was studied.In thispaper, the main research contents and results are as follows:1、In the research field of geological setting, rock physical and mechanical characteristics,stress condition etc,using FLAC3D numerical simulation platform, getting comparativeanalysis of the gravity stress and tectonic stress under the background of two cavity roof stratastress and displacement evolution law,and reveale the tectonic stress under the action of cavityroof strata movement characteristics. Study found that compared with gravity stress type mine,the tectonic stress caused by gob roof there is an obvious stress concentration phenomenon incertain areas, and with the increase of span mined-out area and the extension of mining depth,the stress is moving along the surface of bearing, serious damage goes with the integrity ofcavity roof.2、Numerical calculation results show that compared to the whole mine roof stratasubsidence deformation characteristics of gravity stress type.Goaf roof strata deformation areais a clear different phenomenon with rising and sinking deformation; At the beginning of theore body mining, roof strata subsidence deformation zone near the empty area in the verticalorientation distribution is small, and the quantity is less than the corresponding value undergravity stress field, and the mined-out area corresponding to the surface and under a certainrange of the rising of the deformation of surrounding rock distribution area is large; with theincrease of cavity span and roof strata subsidence deformation area across the surface ofbearing, sinking deformation is greater than the corresponding value under gravity stress field,at the same time deformation range of rise of the roof strata reduces gradually, but its risingdeformation increases.3、Based on many deficiencies of traditional detection technology in detection of complexcavity, this paper adopts the advanced3d laser detection system of zone C-ALS nondestructive detection,and mining software Surpac to establish the three-dimensional entity model of emptyarea, carrys on the comparison and analysis between the actual height empty cavity height andmining design and the theory, reveals the empty area roof caving conditions. At the same time,with macroscopic observation area roof caving of the empty drilling apparatus, gets the emptyarea appeared macro strata caving characteristics,and probes into the cavity and roof cavingmining, the relationship between the activity time.4、With application of the theory of structural mechanics,the top rock physical andmechanical analysis model was established, under the condition of considering the horizontaltectonic stress, the deformation mechanics of roof strata were studied, based on this, analyzedthe Long Qiao destroy iron ore goaf roof caving the critical span.