Research On Floor Heave Mechanism Of High Horizontal Stress And Double Shell Treatment Experiment

At present, floor heave is one of most frequent underground pressure behavior indeep mining. Many experts and scholars have done lots of research on causes andcontrol methods of floor heave. But aiming at the mechanism and supporting methodsof floor heave in high horizontal stress are less. In condition of high horizontal stress,the force condition of floor is far more complicated than in general stress conditions.The deformation in floor is more serious, and the destroying extent and depth are larger.The traditional supporting methods cannot prove effective. Therefor, this article aimingat the high horizontal stress in many mines. Through reading lots of papers andinvestigating engineering geology of some high horizontal stress mines. Combiningwith national natural science foundation of 《The Research of Double Schell GroutingStrengthening Mechanism in Deep Mining Condition》, the continuous double schellcontrolling the floor heave in high horizontal stress mines is ttudied by similar materialexperiment. Analyzing the stress and strain status and distortion and failure character inhigh horizontal stress mines, and the force and deformation under continuous doubleschell supporting. The main results are as follows:(1) Building the mechanical model of high horizontal stress. Obtaining thedeformation distribution law and force condition in floor in high horizontal stress minesby calculating. Analyzing the main factors which effecting the floor heave areexcavation process, abutment pressure, rock dilatation and creping.(2) Constructing three supporting numerical models. Using FLAC3D simulate thethree supporting methods. We draw a conclusion that the double schell control the highhorizontal stress mines efficiently.(3) Analyzing residual stress in roadway surrounding rock which effected bygrounting by using grouted body. We draw a conclusion that with the grouting particlesize getting the strength of grouted body is getting weaker. The strength showednegative correlation with water cement ratio. The strength showed positive correlationwith time.(4) The shallow part of double shell can sealing fractured surrounding rock. Itwould stop the surrounding rock breaking further. The deep shell can stop ground stresstransfer from deep to shollow. Especially in high horizontal stress condition. (5) In deep mine, the main forms of floor heave in high horizontal stress roadwaysis extrusion fluidity. The failure depth got large with horizontal stress increasing.(6) Under the double shell supporting, it can stop the groud stress transfor fromdeep part to shallow part. When the double shell-supporting roadways within very highhorizontal stress. The shallow shell is damaged at first. And the failure mode showedlayered and every layer show vertical cracks.