Controlling Roof And Strata In Underground In Kazakhstan

Failure of Hard Roof Strata in Underground Mining and Its Hard roof, usually stronger and thicker sandstone, plays a controlling factor in overburden strata (M Controlling Roof And Strata In Underground In Kazakhstan

Controlling Roof And Strata In Underground In Kazakhstan

Failure of Hard Roof Strata in Underground Mining and Its

Hard roof, usually stronger and thicker sandstone, plays a controlling factor in overburden strata (Mondal et al, 2020; Shi et al, 2020) Therefore, it is necessary to have a detailed understanding of the mechanical state of the strata Numerous models were proposed to explore the nature of roof strata behavior induced by the mining operationMONITORING AND CONTROLLING ON SURFACE SETTLEMENT IN SAND AND GRAVEL STRATA CAUSED BY SUBWAY STATION CONSTRUCTION APPLYING PIPEROOF PRECONSTRUCTION METHOD (PPM) Xian Yang1, 2, Yang Liu2, 3 1 School of Resource, Environment and safety Engineering, Hunan University of Science and Technology, Xiangtan, , China,MONITORING AND CONTROLLING ON SURFACEStrata Control Monitoring This is still one area where personnel consciously use their senses (sight and hearing) on a regular basis to monitor conditions, and until quite recently this was the only method of monitoring Increasingly monitoring is being carried out using devices which measure strata movement in various ways to indicate roofStrata Control Monitoring | Introduction | underground

Controlling mine pressure by subjecting highlevel hard

Years of research and practice have led to a set of hardroof control technologies based on underground hydraulic fracturing and blasting (Lu et al 2015; Ge et al 2015; Yu and Duan 2014; Yang et al 2017; Yang and Liu 2017), which are effective for controlling hard roofs at a low level near the coal seam undergroundThe average cover depth of 4# coal seam in 14101 mining face is 6004 m, with average thickness of bedrock 3402 m and unconsolidated layer 2602 mThere are a few aquifers in the roof strata The total thickness of the waterbearing section inOverburden fracture evolution laws and watercontrollingThe movement, fracturing and caving processes of roof strata are the primary concerns of underground longwall mining1 Hard roof, usually stronger and thicker sandstone, plays a controlling factor in overburden strata2,3 The collapse of a hard roof can cause a strong loading to the coal seam as well as its face supportInternational Journal of Rock Mechanics and Mining

Behaviors of overlying strata in extrathick coal seams

near the goaf Besides, this paper proposed a precontrol technology for the hard roof based on fracture holes and underground roof presplitting It could effectively reduce stress concentration and release the accumulated energy of the strata, when mining underground coalSignificance of Strata Monitoring Instruments in Roof Fall Risk Assessment of an Underground Coal Mine Deepak VWalke, Research fellow and Dr RR Yerpude, Assistant Professor Department of Mining Engineering, Visvesvaraya National Institute of Technology, Nagpur (MS), India Abstract: This paper refers to the role of strataSignificance of Strata Monitoring Instruments in Roof FallGround control in undergound mines 1 U Siva Sankar : [email protected] Mining Ground ControlGround Control : A collective term given to the techniques that are usedto regulate and prevent the collapse and failure of mine openingsGround control is the science that studies the behaviour of rockmass intransition from one state of equilibrium to anotherIt provides the basis for the design ofGround control in undergound mines SlideShare

Mechanisms of rock burst in hard and thick upper strata

Rock burst frequently occurs during coal mining at the Huafeng Coal Mine because of the highstrength, thick conglomerate strata above the coal seam Given this situation, theoretical analysis, physical simulation, and field measurement methods were applied to study the mechanism of rock burst of hard and thick upper strata in this paper The results show that rock burst in the mine is causedcondition of the roof strata near the coal seam Three disturbed zones [8] will form in the strata overlying the longwall goaf (from the bottom up): the caved zone, fractured zone and continuousStability Control of Retained GoafSide Gateroad underthe strata identifications as sandstone, limestone and weak strata (coal, shales of all kind and clay stones) This interval contains thinner limestones, sandstones and weaker strata, such as coal beds an shale, and will indicate where the slotted section of gob gas ventholes should be located (Karacan and Goodman, 2009a)Reservoir Engineering Considerations for Coal Seam

Sensitivity Analysis and Numerical Simulation Study on

a major role in controlling the movement of the overlying strata It is called the key stratum in the strata movement When the caving method is used to mine the coal seam, after the coal body is excavated, the roof strata will bend and deform towards the goaf and slide down along the bedding plane under the pin joint action of selfweightThe average cover depth of 4# coal seam in 14101 mining face is 6004 m, with average thickness of bedrock 3402 m and unconsolidated layer 2602 mThere are a few aquifers in the roof strata The total thickness of the waterbearing section inOverburden fracture evolution laws and watercontrollingThe filling mining in the short‐wall caving zone technique was designed and implemented based on the key stratum (KS) hypothesis 28, 29 The thick and hard rock stratum in the overburden that controls the whole and partial strata is defined as the KS The rock strata controlled by the KS will deform and break, keeping pace with the KSA novel short‐wall caving zone backfilling technique for

Advanced slot stress control method of underground

An underground excavation method which reduces or eliminates the need for roof supports includes the cutting of one or more slots in a radial direction ahead of the advancing underground excavation The plane of the slot is disposed perpendicular to the tangential stress that is expected around the prospective opening, so that the tangentialblasting, the impact of roof strata collapse on the surrounding rock of the roadwaycan be reduced en, cooperate with the original support method to achieve the purpose of controlling the large deformation of the roadway e key technical parameters of presplitting blasting mainly include the depth, angle, and spacing of presplittingblastingholesPresplitting Blasting the Roof Strata to Control Largeunderground water impoundments are also addressed These include bulkhead anchorage, concrete specifications and placement, the grouting of permeable strata, and the sizing of barrier pillars A case study involving hydrostatic tests conducted on a single bulkhead seal constructed in the Safety Research Coal Mine of the Bureau's PittsburghWater in Underground Mines Records Collections

Gas Control | Introduction | underground COAL

There are 4 ways of capturing/ containing gas to keep it out of airways: Drilling boreholes into the coal seam (possibly also in adjacent seams) prior to mining and connecting these to a pipe range to remove any gas to a place where it can be dealt with, most commonly the surface Usually a vacuum is applied to the pipe range to enhance gasIn underground coal extraction of fully mechanized caving, the overlying hard–thick sandstone main roof could control the failure extent and the movement evolution of the entire overburden strata The instantaneous failure of the hard–thick sandstone main roof possibly causes strata pressure behaviors, rockbursts and abnormal gas emissionsFracture failure analysis of hard–thick sandstone roof andThe average cover depth of 4# coal seam in 14101 mining face is 6004 m, with average thickness of bedrock 3402 m and unconsolidated layer 2602 mThere are a few aquifers in the roof strata The total thickness of the waterbearing section inOverburden fracture evolution laws and watercontrolling

Advanced slot stress control method of underground

An underground excavation method which reduces or eliminates the need for roof supports includes the cutting of one or more slots in a radial direction ahead of the advancing underground excavation The plane of the slot is disposed perpendicular to the tangential stress that is expected around the prospective opening, so that the tangentialThe reason is that several factors controlling the strata behavior are difficult to determine, such as the bulk factor of the caving zone, strength factor of the major roof and load factor of the overlying rock strata In this study, the back analysis method is employed to address this problemAn integrated approach for the prediction of undergroundunderground water impoundments are also addressed These include bulkhead anchorage, concrete specifications and placement, the grouting of permeable strata, and the sizing of barrier pillars A case study involving hydrostatic tests conducted on a single bulkhead seal constructed in the Safety Research Coal Mine of the Bureau's PittsburghWater in Underground Mines Records Collections

"An integrated approach for the prediction of

A reliable prediction of the strata behavior and support capacity of longwall workings has always been a challenge for mining engineers It is still difficult to quantitatively predict some important mining parameters, such as support capability and the interval of periodic caving of the major roof under given mining and strata conditions The reason is that several factors controlling theblasting, the impact of roof strata collapse on the surrounding rock of the roadwaycan be reduced en, cooperate with the original support method to achieve the purpose of controlling the large deformation of the roadway e key technical parameters of presplitting blasting mainly include the depth, angle, and spacing of presplittingblastingholesPresplitting Blasting the Roof Strata to Control LargeGeotechnical Considerations in Underground Mining/Department of Industry and Resources Guideline Document No: ZME723QT 10 INTRODUCTION The potentially hazardous nature of underground mining requires the application of sound geotechnical engineering practice to determine the ground conditions, the ground support and reinforcement requirements, as well as the size, shape andGeotechnical considerations in underground mines

Mechanics of coal mine bumps and the interaction

In this thesis, the existing Geomechanics Classification (Bieniawski, 1979) was modified for use in underground coal mines through the introduction of adjustment modifiers for strata weathering, horizontal stress, and roof support Sixtytwo roof case histories were collected from two mines exploiting the Pittsburgh and Lower Kittanning coal seamsNote that this comment refers to naturally occurring gas coming from the seam or surrounding strata The ventilation system still has to deal with introduced gases such as diesel exhaust, shotfiring fumes and blackdamp (an atmosphere deficient in oxygen) There are two ways of controlling gas levels in the atmosphere within a mine:Gas Control | Introduction | underground COALDownload or read book entitled Control of High Stress and Weak Strata Conditions in Underground Coal Mines written by Energy Technology Support Unit (ETSU), Harwell (GB) Coal R and D Programme and published by Unknown online This book was released on 04 October 1996 with total page 4 pages Available in PDF, EPUB and Kindle Control Of High Stress And Weak Strata Conditions