下垄钨矿樟斗矿区地压区资源回收利用技术及实践

通过对下垄钨矿樟斗矿区地压区地压活动和规律的调查,结合矿山生产实际,提出了在充分保证安全工作的条件下,回收地压区的资源。通过回收利用地压区资源,延长了矿山服务年限,经济效益和社会效益显著。

某黑钨矿采区地压控制技术

矿山开采必然引起采区地压活动,它影响矿区的安全生产和资源的有效回收.通过对某黑钨矿采区地压活动的研究,揭示矿区开采地压显现的基本规律及其破坏特征,并提出控制矿区地压活动的综合性预防措施,通过这些措施的实施,有效抑制采区地压活动,解决矿区回采过程中安全性差和矿石贫化、损失率大等难题,取得良好效果,为矿山安全、高效和稳定的生产提供保障.

软岩高地压特厚煤层区段巷道布置

文章介绍了原区段巷道布置方法存在的问题，改革后采用集中巷布置及分层机巷、分层风巷布置的方式及其优点。

漂塘矿区地压控制

本文介绍了漂塘矿区存在的地压问题,上部采用崩落的方法处理空区;下部设置隔离层;改善采场的应力状态,求得采场的顺利开采。经地压控制方案的初步实施,取得了较好的效果。

深采区大地压回收采区煤柱瓦斯治理技术研究

为解决邢东矿2129工作面在深采区大地压、巷道变形严重、采空区瓦斯向外涌出等各类地质因素影响下,有效回收工作面剩余煤炭资源,采取喷涂化学浆封堵瓦斯释放、合理运用瓦斯抽放系统、调整二水平通风系统增加工作面风量、进回风隅角排沙袋墙封堵采空区瓦斯等一系列综合瓦斯治理技术。结果表明,回风流瓦斯浓度稳定在0.2%,治理效果明显,能够有效的降低工作面瓦斯涌出量。

某黑钨矿采区地压控制技术

近年来,地下开采深度的逐渐增加,在地下开采过程中,地压对于开采安全具有重要的影响。在此基础上,地压控制技术日益受到关注和重视。基于此,本研究以某黑钨矿采区为例,研究了影响地压活动的因素,同时提出了控制某黑钨矿采区地压的建议,以希望能够为矿区生产安全和资源的有效回收提供参考和借鉴。

三维地质统计速度模拟:地压环境中的盐体成像

成功的盐体成像需要精确地描绘出盐体边界和环绕盐体的断层。精确地确定盐体边界对于钻取在盐体边界上倾方向的油气藏是至关重要的;同样,由于环绕盐体的断层对油气圈闭的分隔作用,准确地描绘出环绕盐体的小断层也是至关重要的。但是,成功的盐体成像在很大程度上取决于是否能够建立一个精确的三维速度模型,这是地震成像和准确深度预测所必需的。建立这个模型的一个合理的方法是确保它能够把地质上可用的纵向、横向速度差异和可用的全部井信息结合起来。当处理地压区、礁建造和盐体等复杂地质问题时。

河台金矿中深部采矿方法研究

通过对河台金矿高村、云西矿区浅部采矿方法的实践分析,并结合开展的一些采矿方法综合试验研究,对中深部开采面临的问题,经过深入的探索、研究,提出解决的办法和途径。

Study on Airflow Field of Condensing Zone in Compact Spinning System with Perforated Drum

Negative pressure plays a very important role in compact spinning system.To know airflow field and its distribution is helpful to look into the condensing principle of fiber bundle.Therefore,computational fluid dynamics(CFD)software was used to simulate airflow field in this paper.Airflow velocity distributions both in different fiber layers and under different negative pressures were discussed.The results indicate that airflow velocity in upper layer of the fiber bundle is greater than that in lower layer.Airflow velocities in both X and Y axis directions have a positive correlation with negative pressure.It can provide a theoretical base to make high quality compact yarns in productive practice.

Effect analysis of borehole microseismic monitoring technology on shale gas fracturing in western Hubei

Hydraulic fracturing technology is an important means of shale gas development,and microseismic monitoring is the key technology of fracturing effect evaluation.In this study,hydraulic fracturing and microseismic monitoring were simultaneously conducted in the Eyangye 2HF well(hereinafter referred to as EYY2HF well).The target stratum of this well is the second member of the Doushantuo Formation of the Sinian System,which is the oldest stratum of horizontal shale gas wells in the world.A total of 4341 microseismic fracturing events were identified,and 23 fracturing stages of the well were defined.The fluctuation of the number of events showed a repeating“high-low”pattern,and the average energy of these events showed minimal differences.These findings indicate that the water pressure required for the reconstruction of the EYY2HF well is appropriate.The main body of the fracture network extended from northwest to southeast,consistent with the interpretation of regional geological and seismic data.The stimulated rock volumes showed a linear increase with the increase of the fracturing stage.Some technological measures,such as quick lift displacement,quick lift sand ratio,and pump stop for secondary sand addition,were adopted during fracturing to increase the complexity of the fracture network.Microseismic fracture monitoring of the well achieved expected eff ects and guided real-time fracturing operations and fracturing eff ect evaluation.

Distribution pattern of front abutment pressure of fully-mechanized working face of soft coal isolated island

The front abutment pressure of a fully-mechanized workface of 11061 soft coal isolated island of Liangbei Coal Mine was measured and studied using a self-developed mining-induced stress monitoring system associated with electromagnetic radiation technology, and the effects of abutment pressure distribution on strata behavior we discussed. The results indicate that the miningdnduced influencing distance advanced at the fully-mechanized working face of soft coal isolated island is larger than that at the gen- eral working face at the isolated island, besides the fracture zone in front of working face was widened to some extent, and the influencing range caused by relaxations on both roadways became bigger with the advancing working face. Moreover, it can be indicated that mining has significant effect on strata behav- ior of fully-mechanized working face of soft coal isolated island, which is mostly distributed in the area of stress concentration. The research results have an important reference value for revealing the distribution pattern of the front abutment pressure of a fully-mechanized working face of soft coal isolated island, and controlling the coal-rock dynamic disaster occurrence under similar mining conditions.

Technology of back stoping from level floors in gateway and pillar mining areas of extra-thick seams

According to the special requirements of secondary mining of resources in gateway-and-pillar goal in extra-thick seams of Shanxi, this paper presents a technical proposal of back stoping from level floors. Numerical simulation and theoretical analysis are ccsed to investigate the compaction characteristics of cavities under stress as well as an appropriate mining height of the primary-mining layer based on dif- ferent mining widths and pillar widths. For Yangjian coal mine, the mining thickness of the first seam during back stoping from level floor is determined to be 3 m, which meets the relevant requirements. Gateway-and-pillar goaf of a single layer has a range of influence of 9 m vertically. If gateway-and-pillar goaf occurs both in 9-1 and 9-5 layers, the range is extended to within 11.2 m. When the mining width of a gateway is less than 2 m or larger than 5 m, the gateway-and-pillar goal in the upper layer of the primary-mining seam can be filled in and compacted after stoping. When the working face is 2 m away from the gateway and pillar before entering into it and after passing through it, the coal body under the gateway and pillar is subjected to relatively high stress. During mining of the upper layer, moreover, the working face should interlock the goaf in primary-mining layer for 20 m.

Soft–strong supporting mechanism of gob-side entry retaining in deep coal seams threatened by rockburst

When gob-side entry retaining is implemented in deep coal seams threatened by rockburst, the cementbased supporting body beside roadway will bear greater roof pressure and strong impact load. Then the supporting body may easily deform and fail because of its low strength in the early stage. This paper established the roadside support mechanical model of gob-side entry retaining. Based on this model,we proposed and used the soft–strong supporting body as roadside support in the gob-side entry retaining. In the early stage of roof movement, the soft–strong supporting body has a better compressibility, which can not only relieve roof pressure and strong impact load, but also reduce the supporting resistance and prevent the supporting body from being crushed. In the later stage, with the increase of the strength of the supporting body, it can better support the overlying roof. The numerical simulation results and industrial test show that the soft–strong supporting body as roadside support can be better applied into the gob-side entry retaining in deep coal seams threatened by rockburst.

Analysis of Variation Characteristics of Sunshine in Recent 56 Years in Huanren Area

On the basis of 56 years of measured data concerning sunshine duration in Huanren County, the decadal, annual, seasonal, and monthly variation characteristics of sunshine duration in recent 56 years and its relationship with relative sunshine, total cloudiness, lower cloudiness and water vapour pressure in Huanren area are interpreted in this paper. It demonstrates that the annual, seasonal and monthly sunshine duration show a decreasing trend, decreasing with rapidest speed in spring and slowest speed in winter. The sunshine hours in each month in Huanren area tend to decline, among which the decreasing trend is more obvious in May and less in February. The annual variation of sunshine duration is consistent with sunshine percentage. Sudden change of sunshine duration occurred around 1992. Annual low cloudiness and vapour pressure are slightly increasing. The significantly negative correlation exists between sunshine hours and low cloudiness, and total cloud cover and water vapour pressure are the major factors responsible for decline in sunshine hours in Huanren area.

Water vapor transport over China and its relationship with drought and flood in Yangtze River Basin

The characteristics of water vapor transport(WVT) over China and its relationship with precipitation anomalies in the Yangtze River Basin(YRB) are analyzed by using the upper-air station data in China and ECMWF reanalysis data in summer from 1981 to 2002.The results indicate that the first mode of the vertically integrated WVT is significant whose spatial distribution presents water vapor convergence or divergence in the YRB.When the Western Pacific Subtropical High(WPSH) is strong and shifts southward and westward, the Indian Monsoon Low Pressure(IMLP) is weak, and the northern part of China stands behind the middle and high latitude trough, a large amount of water vapor from the Bay of Bengal(BOB), the South China Sea(SCS) and the western Pacific forms a strong and steady southwest WVT band and meets the strong cold water vapor from northern China in the YRB, thus it is likely to cause flood in the YRB.When WPSH is weak and shifts northward and eastward, IMLP is strong, and there is nearly straight west wind over the middle and high latitude, it is unfavorable for oceanic vapor extending to China and no steady and strong southwest WVT exists in the region south of the YRB.Meanwhile, the cold air from northern China is weak and can hardly be transported to the YRB.This brings on no obvious water vapor convergence, and then less precipitation in the YRB.

Equilibrating Pressure with Auto-Control Valve in Water Distribution Networks

This paper probes into the feasibility of equilibrating pressure of water distribution network through (using auto-control valves) in theory and in the economy. An optimal valve control model is designed to minimize the sum of squares of residual pressure in the network. Such an analog simulation has been performed on the year 2003 programming network of a certain littoral district in North China, through which this paper confirms that it is feasible to equilibrate pressure with auto-control valves in theory. The research work has brought about a discovery of applicable conditions of valves in economic feasibility, which avoids a great economic loss due to the wild use of auto-control valve. In addition, simulated annealing algorithm is applied to optimize valve settings and shown to identify global optimum or near-optimum.

Research of prediction for mine earthquake basing on underground rock's movement and deformation mechanism

Movement and deformation of underground rock include vertical dislocation and horizontal deformation,and the energy released by mine earthquake can be calculated basing on deformation energy.So put forwards the prediction for degree and spread of mine earthquake according to the underground rock's movement and deformation.The actual number of times and spread of mine earthquake on site were greatly identical to the prediction.The practice proves the possibility of prediction for mine earthquake basing on the analysis of underground rock's movement and deformation,and sets up new approach of mine earthquake prediction.

The Environmental Factors and Strategic Priorities in Northwest Power Development

Based on the energy distribution and economy status In the Northwest Region in China, this paper analyzes the probability of power sources complementation between Northwest Power Grid and the adjacent regional power grids, and points out that the strategic emphases for Northwest power development are to speed up 750 kV transmis-sion system construction, expand the Regional power market, rolling-develop hydrdpower stations on the Upper Yellow River, speed up thermal power bases construction and boost the interconnection between Northwest and North China, etc.

Inversion of the Volumetric Strain of Aquifer According to the Tidal Effect of Groundwater in North China

The change of the confined aquifer level reflects the pore pressure change,and the pore pressure change of the aquifer is closely related to the aquifer pressure. This paper uses the tidal response of the well water level data in the North China region to calculate the tidal factor of each well and extract the effective water trend information. Then,the volumetric strain of an existing confined aquifer well in the North China region is inverted,and the contour maps are plotted on a half-year scale from 2009 to 2012. Results show that it can reflect the state of stress and strain in deep crust to a certain extent in the North China region.

Effects of freeze-thaw cycle on engineering properties of loess used as road fills in seasonally frozen ground regions,North China

Compacted loess is widely used as fills of road embankments in loess regions of northern China.Generally, densely-compacted loess can satisfy the requirements of embankment strength and postconstruction deformation. However, uneven subsidence, pavement cracks and other related damages can affect the integrity of loess subgrade after several years of operation,and even cause some hazards, especially in North China, where the strong freeze-thaw erosion occurs. In this study, cyclic freeze-thaw tests for both densely and loosely compacted loess samples were performed to determine the variation in engineering properties such as volume, void ratio, collapsible settlement,microstructure, and the related mechanisms were addressed. The experimental results showed that an obvious water migration and redistribution occurred within the samples during freeze-thaw cycles. Ice lenses and fissures could be identified in the upper frozen layers of the samples. After freeze-thaw cycles,the dry densities of the upper layers of samples changed significantly due to strong freeze-thaw erosion. The dry densities decreased for the dense sample and increased for the loose sample. It can be found that dense samples become loose, while loose samples became dense with the increasing number of freeze-thaw cycles. Their related void ratios changed reversely. Both void ratios tended to fall into a certain range, which verified the concept of a residual void ratio proposed by Viklander. The loosening process of densely compacted samples involves the formation of large pores, volume increase and density reduction as well as the related changes in mechanical properties because freeze-thaw cycles may be important contribution to problems of loess road embankments.Adverse effects of freeze-thaw cycles, therefore,should be taken into account in selecting loess parameters for the stability evaluation of road embankment in seasonally frozen ground regions.