| Nowadays, Along with gradually growth of mine depth tendency, many gateways have to encounter with the problem of floor stability. In special, some gateways generate floor heave which close to one side, under influence of adjacent advancement. Meanwhile, the shallow broken rock of floor produce extruding flowing heave because the gateway advancement, and the deep complete rock of floor produce flexible folded floor heave by adjacent gateways excavation. Therefore, it is very important to similar floor heave’s governance which correct explain mechanism of extruding-flexible heave in deep gateway under the condition of both sides asymmetric.Based on research background of+211level belt carrying gateway in Yang quan coal group’s5mine. The paper study deformation characteristics, influence factors and control measures of deep gateways floor under the condition of both sides asymmetric. Which adopt methods of rock pressure observation, theoretical analysis,element numerical simulation, similar material simulation and industrial test spot. The special research jobs and some beneficial understanding are as follows:(1)The spot observation manifest that deep not alone gateways have some characters which own thin layer floor:①high crustal stress;②the rock stratum of floor are layered, soft rock, and low intension;③neighboring gateways exist different sequence of excavation;④the peak point location of floor heave is close to one side;⑤the form of floor heave is extruding-flexible composition.(2)Though mechanics experiment about sample rocks, the paper analyzed parameters variation of rock’s compressive strength and elasticity modulus in deep gateways. Combined with Mohr-Columb criterion and Griffith criterion, we put forward a new comprehensive index of rock stability, which determined5level and6level are majority and provided effective technology help before decision-making engineering.(3)Based on the analysis of two-side’s abutment pressure distribution law and the width of limit equilibrium zone, this paper researched the damage mechanism of extruding-flexible floor heave under influence of both sides asymmetric abutment pressure, determined model’s boundary and established the model of extruding-flexible floor heave combined with rock occurrence condition. For superficial part’s extruding flowing floor heave, it assumed that the location of the displacement was zero and did the derivation united variation principle, when did analysis of flexible folded floor heave in deep used the thin plate bending theory. Finally it got analytical method for calculating about peak point location and the amount of floor heave(4)By similar material simulation experiment, this paper analyzed floor horizontal stress and vertical stress and deformation rule of the form after deep gateway was excavated, which would provide reliable gist to extruding-flexible floor heave’s deformation general rule in deep gateway under asymmetric.(5)The asymmetric condition’s deep gateway was numerically simulated, analyzed floor heave rules under the influence of adjacent and reasons of toward one side.(6)Combined analysis of analytic equation with numerical simulation. we thought that floor rock structure,the abutment pressure distribution, sectional shape and excavation sequence is extruding-flexible floor heave toward one side of important influence factors.(7)Utilized numerical simulation got general floor heave influence factors. which refer to the change of roof and side lithology, the similar lithology’s rock structure in small area, geologic fault and fold in large area.(8)The paper used derived mechanics and numerical simulation to study the merit and demerit of high stress gateway’s floor heave control, which was basement of manipulative extruding-flexible floor heave under condition of asymmetry.(9)For belt carrying gateway in Yang quan coal group’s5mine, applied theoretical equation to account supporting scheme, came up with "asymmetric design thinking" and "whole section bolting-grouting+replace concrete block in peak point location of floor heave " control technology, we made spot observation to manifested rationality. Then offered example to control the special floor heave. |
