The trapezoidal cross-section roadway, driven along with its medium and fine grain sandstone roof in special thick stratum, was situated in shale strata. Rock-lining wall was employed in roadway, which its roof is in ...The trapezoidal cross-section roadway, driven along with its medium and fine grain sandstone roof in special thick stratum, was situated in shale strata. Rock-lining wall was employed in roadway, which its roof is in the free situation. Under the action of virgin stress, the surrounding rock of roadway was in stability. While under the action of fixed abutment pressure arisen from protection pillar of roadway, which its two sides?seams were extracted, free strong roof of roadway was in the stability. But its two sides?rock-lining walls was fractured, partially broken into pieces, and its floor heave was ob-vious. The velocity of floor heave is 0.4~0.8 mm/d. The size of broken zone of sur-rounding rock of roadway increases doubly. An effective load coefficient of surrounding rock to was quoted illustrate these phenomena. The main reasons of roadway conver-gence are that, rock property of surrounding rock is inferior, protection pillar affects its stability, and supporting pattern employed is improper. At last, effective measures to control roadway convergence should be bolting and grouting lining, which mainly con-solidates surrounding rock of roadway.展开更多
This article studies the influence of the fineness of cement, fly ash(FA), its composite admixture and the amount and way mixed with superplasticizer on the rheological properties of micro fine cement(MC). By means of...This article studies the influence of the fineness of cement, fly ash(FA), its composite admixture and the amount and way mixed with superplasticizer on the rheological properties of micro fine cement(MC). By means of modern instruments and technologies (such as XRD, SEM, laser granulometer and superficial potential apparatus etc.), the article studies the mineral compositions, the appearance character of grains, particle size distribution and superficial potential of FA and its composite materials. And through that, the reducing mechanism of FA is thoroughly analyzed. The study shows that FA and its composite admixture are excellent components which can effectively improve the rheological properties of micro fine cement, and that the superplasticizer has a saturation point and the mixing way of it has a great influence on the rheological properties.展开更多
There are sulfate and chloride ions corrosion and carbonation to concrete in coal mine. Based on taking test of accelerated carbonation, corrosion of 3.5% weight of NaCl solution and 5% weight of Na2SO4 solution of co...There are sulfate and chloride ions corrosion and carbonation to concrete in coal mine. Based on taking test of accelerated carbonation, corrosion of 3.5% weight of NaCl solution and 5% weight of Na2SO4 solution of coal mine concretes, durability of con- cretes which include spray concrete of C20,high performance concretes of C30 and C50 and effect of fly ash on durability have been studied. Results suggest that the coal mineral high performance concretes show good resistance capacities of carbonation, sulfate and chloride corrosion to meet the coal mine construction. And the higher the strength grade is, the better the resistance capacity of corrosion of carbonation is, chloride and sulfate. Moreover, fly ash improves resistance capacity of high performance concrete(HPC) to chloride and sulfate but decreases the resistance capacity of C30’s to carbonation and average dynamic modulus.展开更多
Selected non-burned method and took fly-ash as main material, together with lime and gypsum, to inspire the activity of volcanic ash, took a kind of poly-organics to re-place the clay as binder, and then made small ba...Selected non-burned method and took fly-ash as main material, together with lime and gypsum, to inspire the activity of volcanic ash, took a kind of poly-organics to re-place the clay as binder, and then made small balls with machine, wrapped slurry twice and autoclaved 8 hours at normal atmosphere, made ceramsite in this way can endure higher compression strength. Comparing with common concrete, the ceramsite concrete is about 25% lighter on weight.展开更多
Described the outcomes of a comprehensive numerical modeling on the rock bolting performance for preventing the deformation of stratified, composite roof structure of drift in a coal mine. The investigation was undert...Described the outcomes of a comprehensive numerical modeling on the rock bolting performance for preventing the deformation of stratified, composite roof structure of drift in a coal mine. The investigation was undertaken in the adverse geological condi- tions, with variation of bolt parameters, including length, density, distribution, pretension, as well as the geometry of opening,so as to determine the effect of bolting parameter variation on roof deformation and stability. The outcomes clearly demonstrated that a sig- nificant improvement of roof stability can be achieved associating with bolting parameters optimization, and indicated the importance of flexible geotechnical designation of rock bolting reinforcement in mining practice.展开更多
Bolting of mining roadway for fully mechanized sublevel caving has been practised successfully in Hebi mining area.It provides a new method for roadway support and settles the problem of support difficulty radically f...Bolting of mining roadway for fully mechanized sublevel caving has been practised successfully in Hebi mining area.It provides a new method for roadway support and settles the problem of support difficulty radically for sublevel caving in Hebi mining area.Where anchor reinforcement holds an important station in roadway support.This article brings forward the arrangement project of anchor based on theoretic analysis.Compared with arranged in the middle of the entry, anchor arranged in the vertex of the entry can reduces the length of anchor,shortens the anchor installation time,and heightens the reliability of anchor installation.展开更多
The time forecast system of coal spontaneous combustion was described based on the KJ-90 mine environmental monitoring system in Hulipo Mine, Luzhou, Sichuan Province. In the system, CO and O2 sensor are added, and sp...The time forecast system of coal spontaneous combustion was described based on the KJ-90 mine environmental monitoring system in Hulipo Mine, Luzhou, Sichuan Province. In the system, CO and O2 sensor are added, and special-purpose microcomputer and software are equipped. By means of the system, the fluctuation laws of fire forecast parameters were observed in the process of coal-cutting, blast, exogenous mine fire and working face air quantity variation. This paper puts forward data processing method based on the Raita method.展开更多
基金Supported by Science Technology Research Project of Henan Province (0124150301)
文摘The trapezoidal cross-section roadway, driven along with its medium and fine grain sandstone roof in special thick stratum, was situated in shale strata. Rock-lining wall was employed in roadway, which its roof is in the free situation. Under the action of virgin stress, the surrounding rock of roadway was in stability. While under the action of fixed abutment pressure arisen from protection pillar of roadway, which its two sides?seams were extracted, free strong roof of roadway was in the stability. But its two sides?rock-lining walls was fractured, partially broken into pieces, and its floor heave was ob-vious. The velocity of floor heave is 0.4~0.8 mm/d. The size of broken zone of sur-rounding rock of roadway increases doubly. An effective load coefficient of surrounding rock to was quoted illustrate these phenomena. The main reasons of roadway conver-gence are that, rock property of surrounding rock is inferior, protection pillar affects its stability, and supporting pattern employed is improper. At last, effective measures to control roadway convergence should be bolting and grouting lining, which mainly con-solidates surrounding rock of roadway.
文摘This article studies the influence of the fineness of cement, fly ash(FA), its composite admixture and the amount and way mixed with superplasticizer on the rheological properties of micro fine cement(MC). By means of modern instruments and technologies (such as XRD, SEM, laser granulometer and superficial potential apparatus etc.), the article studies the mineral compositions, the appearance character of grains, particle size distribution and superficial potential of FA and its composite materials. And through that, the reducing mechanism of FA is thoroughly analyzed. The study shows that FA and its composite admixture are excellent components which can effectively improve the rheological properties of micro fine cement, and that the superplasticizer has a saturation point and the mixing way of it has a great influence on the rheological properties.
基金Supported by the National (863) Plan Fund Project China (2003AA33X100)
文摘There are sulfate and chloride ions corrosion and carbonation to concrete in coal mine. Based on taking test of accelerated carbonation, corrosion of 3.5% weight of NaCl solution and 5% weight of Na2SO4 solution of coal mine concretes, durability of con- cretes which include spray concrete of C20,high performance concretes of C30 and C50 and effect of fly ash on durability have been studied. Results suggest that the coal mineral high performance concretes show good resistance capacities of carbonation, sulfate and chloride corrosion to meet the coal mine construction. And the higher the strength grade is, the better the resistance capacity of corrosion of carbonation is, chloride and sulfate. Moreover, fly ash improves resistance capacity of high performance concrete(HPC) to chloride and sulfate but decreases the resistance capacity of C30’s to carbonation and average dynamic modulus.
文摘Selected non-burned method and took fly-ash as main material, together with lime and gypsum, to inspire the activity of volcanic ash, took a kind of poly-organics to re-place the clay as binder, and then made small balls with machine, wrapped slurry twice and autoclaved 8 hours at normal atmosphere, made ceramsite in this way can endure higher compression strength. Comparing with common concrete, the ceramsite concrete is about 25% lighter on weight.
文摘Described the outcomes of a comprehensive numerical modeling on the rock bolting performance for preventing the deformation of stratified, composite roof structure of drift in a coal mine. The investigation was undertaken in the adverse geological condi- tions, with variation of bolt parameters, including length, density, distribution, pretension, as well as the geometry of opening,so as to determine the effect of bolting parameter variation on roof deformation and stability. The outcomes clearly demonstrated that a sig- nificant improvement of roof stability can be achieved associating with bolting parameters optimization, and indicated the importance of flexible geotechnical designation of rock bolting reinforcement in mining practice.
文摘Bolting of mining roadway for fully mechanized sublevel caving has been practised successfully in Hebi mining area.It provides a new method for roadway support and settles the problem of support difficulty radically for sublevel caving in Hebi mining area.Where anchor reinforcement holds an important station in roadway support.This article brings forward the arrangement project of anchor based on theoretic analysis.Compared with arranged in the middle of the entry, anchor arranged in the vertex of the entry can reduces the length of anchor,shortens the anchor installation time,and heightens the reliability of anchor installation.
基金Supported by National Natural Science Foundation of China (50274061) and National High Technology Research and Development Program of China(2003AA131100-02-06)
文摘The time forecast system of coal spontaneous combustion was described based on the KJ-90 mine environmental monitoring system in Hulipo Mine, Luzhou, Sichuan Province. In the system, CO and O2 sensor are added, and special-purpose microcomputer and software are equipped. By means of the system, the fluctuation laws of fire forecast parameters were observed in the process of coal-cutting, blast, exogenous mine fire and working face air quantity variation. This paper puts forward data processing method based on the Raita method.