Failure characteristics of surface vertical wells for relieved coal gas and their influencing factors in Huainan mining area

Based on data from through-hole and logging,we studied the failure characteristics of surface drainage wells for relieved coal gas in Huainan mining area and its influencing factors.The results show that the damaged positions of drainage wells are mainly located at the thick clay layer in the low alluvium and the lithological interface in the upper section of bedrock in west mining area.The failure depth of casing is 244-670 m and concentrates at about 270-460 m deep.These damaged positions are mainly located in the bending zone according to three zones of rock layers in the vertical section above the roof divided. Generally,the casing begins to deform or damage before the face line about 30-150 m.Special formation structure and rock mass properties are the direct causes of the casing failure,high mining height and fast advancing speed are fundamental reasons for rock mass damage.However,the borehole configuration and spacing to the casing failure are not very clear.

Application of DEM overlaying technique in surface subsidence identification─a case study in Ruqigou coal mining area of Ningxia,China

Subsidence occurred in many parts of the world. particularly in densely populated deltaic regions, causing extremely expensive damage. It can be resulted from natural causes. man-made induced causes, or other mixed causes. For identifying surface subsidence, many techniques have been employed, for example, geodetic monitoring, airborne laser subsidence measurement system,differential S.A.R., interferometry DGPS, and satellite radar measurements. However. all these methods require large time span and a large amount of field work. With the development of GIS techniques, identification of surface subsidence is becoming a relative easy problem. Ruqigou coal mining area was selected as a case study to identify the surface subsidence with DEM (digital elevation model) overlaying techniques. The result shows that DEM overlaying technique is a very useful method on surface subsidence identification. The accuracy of the results are largely dependent on the precision of the data-input.

Impact of Coal Mining Subsidence on Sandy Geomorphology and Vegetation Habitat in Sandy Area

[Objectives]To explore the problem of"secondary desertification"caused by coal mining subsidence in sandy area and its control countermeasures.[Methods]The collapse fissure changes,vegetation displacement and tilt,dry sand layer and wind erosion/aeolian deposit rate of the edge,middle and basin of subsidence area were studied in detail.[Results]The width and density of fissures at the edge of subsidence area were the smallest,followed by those in the center,and the width and density of fissures in the basin of the subsidence area were the greatest,while the staggering and surface damage showed the opposite trend.The average displacement length of vegetation in the subsidence area reached 60 cm,the slope was 5.67-28.63,and the maximum wind erosion/aeolian deposit at the trunk roots was-30.52 cm/+25.41 cm,most serious at the edge of subsidence.The changes in displacement length and slope of vegetation were positively linearly correlated with the height and surface damage of collapse fissures.The thickness of dry land layer at the edge of the subsidence area reached 14 cm,4-6 cm greater than that of the control,and the thickness of dry land layer in the middle and basin of the subsidence area was both about 11 cm,1-4 cm greater than that of non-subsidence area.The wind erosion rate at the edge of the subsidence area was up to 83.34%,followed by that(52.06%)in the middle.The aeolian deposit rate in the subsidence basin was 51.84%.[Conclusions]The subsidence edge has the strongest impact on the sandy geomorphology and vegetation habitat,and is a key area for ecological restoration.It is recommended that the coal mining subsidence should be treated in a timely manner to avoid the occurrence of"secondary desertification".

Changes of Precipitation Infiltration Recharge in the Circumstances of Coal Mining Subsidence in the Shen-Dong Coal Field,China

Coal mining subsidence is a universal environmental-geological problem in mining areas. By selecting the Shen-Dong coal mining subsidence area as the research field, this paper studies the changes in precipitation infiltration recharge in the circumstances of coal mining subsidence by means of field geological investigation and laboratory simulation experiments, which is expected to provide a scientific basis for eco-environmental restoration in the mining area. The results indicate that at the unstable stage of subsidence, three types of subsidence in the Shen-Dong mining area have positive effects on the precipitation infiltration recharge, and the type of full-thickness bedrock subsidence has the greatest influence. In the stable stage of subsidence, the precipitation infiltration process after long- term drought and the moisture migration in the aeration zone undergo three different stages： evaporation-infiltration before precipitation, infiltration-upward infiltration-infiltration during precipitation and evaporation-infiltration after precipitation. During a heavy rainfall infiltration process, the wetting front movement in fine sand, coarse sand and dualistic structure of fine-coarse sand consists of two stages： the stage of wetting front movement during precipitation, in which the wetting front movement distance has linear relationship with the depth, and the stage of wetting front movement after precipitation, in which the wetting front movement distance has the power function relationship with the depth. The wetting front movement velocity is influenced by the rainfall amount and the lithology in the aeration zone. However, as the depth increases, the movement velocity will decay exponentially.

Safety appraisement on building natural gas pipeline over coal mining subsidence area

The target of the text is to scientifically appraise dynamic development of surface deformation in subsidence area and its influence on groundwork stability of natural pipe and then adopt some technological measures to ensure safe circulation of natural pipeline. Analysed the influence on natural pipeline from coal mining subsidence in the way of pipeline grade variation, vertical curve variation, transverse deformation, horizontal pull and compression deformation and pipe stress variation etc., and described detailed surface subsidence product and its used time among initial phase, active phase and decline phase in the course of surface movement deformation time. In the context of considering surface subsidence that doesn＇t reach basic latter end and residual subsidence quantity, the text confirmed the calculation method of residual deformation in surface subsidence area, and gave the technological measures about building natural gas pipeline in subsidence area finally.

Use of the area of main influence to fix a relevant boundary for mining damages in Germany

In 2010, the fracking discussion in Germany caused a number of changes in German law, which came into force in 2016.Especially the production of gas had to be regulated.With the legislation amendment, the Subsidence-Area Mining Regulation has been revised, too.The changes expand the compensation of mining damages, especially to the extraction with drilling from the surface and underground storage.Although the Subsidence-Area Mining Regulation has been revised, the area of main influence(subsidence of 10 cm)remains to determine a relevant boundary for mining damages.The determination and prediction of this boundary above caverns are presented in this paper.In addition, further elements of ground movements and their relevance to mine damages are analyzed.The usage of the area of main influence to fix a relevant boundary for mining damages does not correspond to the relevant elements of ground movements.A limit for differences in subsidence(tilt) or horizontal changes in length should be preferred to describe the relevance of mining damages on buildings.Furthermore, this paper outlines the meaning of using the area of main influence to fix a relevant boundary for mining damages.

Effects of Coal Mining Subsided Water Area on Temperature Change in Huaibei Coal Mine

[Objective] The study aimed to discuss the effects of coal mining subsided water area on temperature change in Huaibei coal mine. [Method] Based on the data of monthly temperature from 1957 to 2007 recorded by Suixi （coal mining subsided water area） and Fuyang stations （control）, the effects of coal mining subsided water area on temperature change in Huaibei coal mine were discussed using linear trend estimation and comparative analysis methods. [Result] Spring, autumn, winter and annual average temperatures of coal mining subsided water area （Suixi） were increased in the last 51 years, and the increase of winter temperature was mostly significant with a tendency rate of 0.49 ℃/10 a. Meanwhile, annual temperature range of coal mining subsided water area was decreased from 1957 to 2007. Temperatures of Suixi in four seasons were lower than those of Fuyang from the 1960s to 1990s, and temperatures of coal mining subsided water area （Suixi） were higher than those of Fuyang in spring, autumn and winter but lower than those of Fuyang in summer from 2000 to 2007. [ Result] Coal mining subsided water area had certain effects on temperature change of Huaibei coal mine.

An Evaluation Study on Water Ecological Civilization Construction in Coal Mining Subsidence Area

By combining expert consultation and field investigation,an evaluation system,consisting of 29 indices in 5 aspects of water safety,water ecology,water management,water landscape and water culture,was established for water ecological civilization construction in coal mining subsidence areas.The weight of the indices was determined using improved group-decision fuzzy analytic hierarchy process and fuzzy mathematical method,and their score was determined according to their value before the pilot and the value at the end of the pilot.Combined with the weight,the actual score of the indices was obtained.Finally,a comprehensive index of water ecological civilization in coal mining subsidence areas was obtained.Through the weight and score of the indices,the construction status,existing problems and future tasks of coal mining subsidence areas were analyzed,in order to provide a reference for the region to further clarify the direction and key tasks of water ecological civilization construction.

Study on environmental impact of coal mining subsided water area in Huainan mining area

The subsided water areas with different times of subsidence are chosen to monitor the physicochemical indexes and heavy metal elements. The results indicate that subsided water areas are polluted in different degree. Some physicochemical indexes of subsided water areas are increased with the development of the subsidence and are changed with the changing of the season. The concentration of As, Cd, Cu, Pb, Se, Zn of subsided water areas is less than national fishery, and surface water quality standards of China , except Hg. And the quality of subsided water hasn＇t been polluted by heavy metal seriously. Analyzing and appraising the quality of the subsided water can give a reasonable data as basis in using the subsided water resource.

The Architecture Design Based on the Landscape Conditions: Taking the Architectural Design of Subsidence Area for Example

The relationship between architecture and people, architecture and city, architecture and nature has always been the soul of architectural design. In the architectural design, study on the relationship between architecture and nature needs "site analysis"(mapping), and "natural environment" tends to affect the design results[1]. In many special areas, the design needs analysis of geology, geomorphology, hydrology, vegetation and other landscape elements. Coal mining subsidence area is the product of the conf licts between human activities and natural environment in the process of industrialization. As the research object, coal mining subsidence area can be a good study object to demonstrate architectural design strategies and methods based on landscape, and fi eld defects of the site may be the origin of architectural space organization: architectural concept, structure, morphology, spatial organization are all from the landscape elements.

Investigations on longwall mining subsidence impacts on Pennsylvania highway alignments

Over 600 longwall panels have been mined in Pennsylvania in the last 50 years. Of those 600 panels, 25 panels undermined interstates highways. Despite this quantity of panels, much is still unknown regarded the detailed effects of undermining highways. The Gateway Mine, the Emerald Mine, and the Cumberland Mine undermined I-79 with 17 panels in 1982–1989 and in 2003–2008, respectively;Mine 84 undermined I-70 with 4 panels in 1987–2000. Through the examination of the panels that undermined I-70 and I-79, it is possible to determine which factors have most impacted the highway alignments. In some locations, the highway intersects with panels at angles ranging from 45° to 80°;and at the others, it runs between two panels, which simulates the effect of gateroads on the subsidence. The panel width to overburden ratio varies between 0.64 and 1.7, meaning that the interstates were influenced by both subcritical and supercritical subsidence basins. The face advance rates and overburden depths also vary between the panels. Unfortunately, specific information detailing highway impacts associated with unique characteristics of the subsidence basins are limited. In this paper, using the profile function model and influence function model within the surface deformation prediction system(SDPS), the effects of overburden,panel size, and orientation of the road on the highway can be indirectly assessed.

Offset Tracking在煤矿沉陷区地表大变形监测中的应用研究

针对传统煤矿沉陷监测方法存在监测周期长、提取的矿区地表变形量准确率不高的问题,提出将Offset Tracking技术应用到煤矿沉陷区地表大变形的监测中。以张双楼煤矿作为研究对象,应用Offset Tracking技术对该煤矿沉陷区的SAR影像进行处理,采用互相关系数过采样因子法建立地形起伏与噪声偏移量模型,使用最小二乘模拟轨道偏移分量,获取了矿区方位向和距离向的二维变形图和矿区变形信息。利用实测数据对Offset Tracking技术的监测结果进行评价,结果表明,利用Offset Tracking技术监测到的矿区最大沉降位置和变形方向与实测数据基本一致,误差仅为1cm,说明Offset Tracking技术能够准确、有效地监测煤矿沉陷区地表大变形,为煤矿沉陷区的合理治理提供依据。

高潜水位采煤沉陷区资源化、能源化、功能化利用构想与实践

高潜水位矿区井工开采往往造成地表大面积沉陷积水,矿区生态环境发生变化,沉陷区国土资源由以土地资源为主转变为水资源为主、水土资源共存的局面。目前,采煤沉陷区水资源开发利用不充分,可再生能源开发、多能互补利用和废弃矿井抽水蓄能等方面具有得天独厚的条件和巨大发展潜力,采煤沉陷区国土空间功能也需结合现有条件重新定位与建构。在此背景下,提出高潜水位采煤沉陷区资源化、能源化和功能化利用构想。系统阐述了“三化”面临的科学问题,如采煤沉陷水域水资源量和水生态环境演变规律、地表残余变形规律;“三化”涉及的关键技术与模式,包括监测与评价技术,如“天-空-地-水-井”一体化协同监测技术体系、采煤沉陷区水生态环境调查评价方法、采煤沉陷区建设场地地基稳定性评价方法,以及治理利用技术及模式,如采煤沉陷区水生态环境修复技术模式、采煤沉陷区水资源保持与高效利用技术模式、水资源区域协调开发与高效利用技术模式、风光互补模式、制氢-合成氨-掺氨燃烧发电模式、废弃矿井抽水蓄能模式、农业用地功能构建(复垦地土壤重构)技术、建设用地功能构建(采空区注浆地基加固)技术、生态用地功能构建(地表水系重构与生态湿地建设)技术;并从产业融合、资金筹集、科技创新、区域统筹等方面提出了具体的政策建议。

煤矿区土壤细菌群落结构及其对不同复垦模式的响应

科学揭示不同复垦模式土壤细菌群落稳定性及其潜在互作关系对于复垦土地差异化管理及可持续利用至关重要。本文以挖深垫浅、煤矸石充填和粉煤灰充填3种模式复垦土壤为研究对象,基于高通量Illumina Miseq 16S rRNA测序技术,采用方差分析、Spearman相关性等分析方法,研究不同复垦模式下的土壤细菌群落结构和多样性。通过构建分子生态网络模型,揭示不同复垦模式下土壤细菌群落的稳定性及菌群间潜在互作关系,明晰对细菌群落结构稳定性起关键作用的微生物种群。结果表明:①不同复垦模式土壤细菌群落的多样性与丰富度水平有显著差异(P<0.05),均表现为挖深垫浅>煤矸石充填>粉煤灰充填;不同复垦模式土壤细菌群落组成相似,变形菌门、酸杆菌门、放线菌门和拟杆菌门是所有模式土壤中的优势菌门,在各复垦模式土壤细菌群落中的占比之和均达70%以上。②不同复垦模式下土壤细菌群落的显著影响因子不同,部分优势细菌门与影响因子间的变化趋势不同,有机质含量是影响挖深垫浅复垦土壤细菌群落组成的主要影响因素,pH是影响煤矸石与粉煤灰充填复垦土壤细菌群落组成的主要影响因素。③挖深垫浅复垦土壤细菌网络复杂,群落联系紧密,能更好地传递物质、能量和信息;煤矸石充填复垦土壤细菌网络内部节点间的连通度低,但菌群信息交换速度慢,拥有4个关键节点,网络相对稳定;粉煤灰充填复垦的土壤细菌网络规模最小,节点连通度不高,在外界环境发生变化时反应快,网络稳定性最差。3种复垦模式土壤细菌群落间关系均以协同合作为主导,煤矸石充填复垦土壤细菌群落间的协同合作关系占比最高。本文揭示了3种不同复垦模式下土壤细菌群落结构与分子生态网络差异,研究结果可为高潜水位采煤塌陷区土地复垦模式的优选以及人为干预方式的选择提供支撑。

长春市羊草沟矿区地面塌陷现状及防治对策

随着煤炭资源的开发,曾经隐于地下的宝藏和财富得以显现,然而开采过程会伴随着严重的地面塌陷问题,对土地资源及地区经济发展带来了深远的负面影响。本文聚焦长春市羊草沟矿区,对其地面塌陷问题进行了细致研究。通过分析该矿区塌陷的分布特点、发育特征以及所引发的一系列问题,系统剖析了导致地面塌陷的多种因素,并基于此提出了坚持政策先行、加强监测预警、开展工程治理、土地利用调整等针对性的预防与治理对策,作为羊草沟及类似矿区矿山地质环境治理工作的参考依据。

高潜水位采煤沉陷区微塑料赋存特征及风险评估

为探明高潜水位采煤沉陷区微塑料污染赋存特征及其环境风险,选取安徽省淮南市春申湖、舜耕湿地公园两个典型采煤沉陷区为研究区域,采集了表层水体,底泥及周边农田土壤样品,采用体视显微镜、扫描电镜、红外光谱对微塑料尺寸、形状、颜色及丰度等赋存特征进行表征.结果表明:采集的样本中多为纤维微塑料和薄膜微塑料,类型主要以聚乙烯,聚丙烯为主,颜色以黄色和透明为主,粒径大多小于500μm.采煤沉陷区的地表水丰度范围为0.77~7.1pcs/L,沉积物微塑料的丰度范围为540~2800pcs/kg,周边农田土壤微塑料的丰度范围为380~2380pcs/kg.采用污染负荷指数(PLI)模型进行评估,地表水和农田土壤的风险评估都为于Ⅰ级,属于轻微污染,而沉积物中的微塑料风险评估为Ⅱ级,属于中度污染.

采煤沉陷区框架结构抗变形研究现状与展望

针对我国矿山城市采煤沉陷区土地资源工程建设利用难的问题,在统计采煤沉陷区发展现状、综合治理及其工程建设利用率的基础上,分析了利用采煤沉陷区场地进行工程建设的必要性。从框架结构抗变形原理、共同作用机理、混凝土框架结构及钢框架结构抗变形技术等4个方面,总结分析了框架结构建筑物变形损害与保护技术的研究发展历程与不足之处;并展望了框架结构建筑物抗变形技术的发展方向:地表移动变形下大跨及多高层框架结构附加效应的动态演化规律,地表移动变形下地基-基础-结构共同作用的力学行为及变形协同机制,框架结构建筑物新型抗变形技术,框架结构建筑物抗震抗变形调控技术,以便形成地表移动变形下框架结构建筑物的综合理论与技术体系,为实现采煤沉陷区进行大型框架结构建筑物工程建设利用提供理论和技术支撑。

基于多数据源的采煤沉陷区早期识别及地面形变特征监测——以神木市大柳塔镇为例

煤矿区生态环境问题受到社会的广泛关注,如何实现采煤沉陷区精准、高效、经济的早期识别和动态监测显得尤为迫切。本文在资料收集与整理分析的基础上,利用2000—2022年5期DEM数据进行差分解算,同时利用2015年6月15日至2023年7月15日共计164期长时间序列Sentinel-1数据,对煤矿区地面沉降进行动态监测,查明了神木市大柳塔镇采煤沉陷区现状分布与地面沉降特征,形成了一套基于多数据源的采煤沉陷区早期识别方法。研究结果表明:①大柳塔镇采煤沉陷区分布面积为252.70 km 2,包括地面塌陷、采空区悬顶两种类型,神华公司石圪台、哈拉沟、大柳塔、活鸡兔4大矿区煤矿塌陷问题严重;②将分辨率为2 m的DEM数据重采样为5 m后进行差值运算,误差为0.01 m,精度较高且计算高效;③DEM差分解算、SBAS-InSAR技术均能对地面塌陷范围进行精准识别,匹配度高,且各方法间互为补充,相互印证。

采煤塌陷区湿地生态修复与景观再生设计研究——以徐州市潘安湖为例

采煤塌陷区由于历史遗留和开发建设问题,致使其区域生态环境较为脆弱。以徐州市潘安湖湿地为例,在分析塌陷区基本情况和特征的基础上,借助可持续发展理论和灰色模糊理论,对该地进行了生态修改和景观再生设计,重构了该地生态功能模式。结果表明,潘安湖湿地的生态系统较为脆弱,环境绩效指标权重达到0.673,且其在植物景观布设上的多样性、丰富性和层次性还有待提高(权重>0.05)。从土地平整、水系贯通、功能分区优化、植物生态景观布设等方面,详细分析了治理措施。设计内容和修复措施的生态应用效果显著,为地区生态环境治理和经济发展注入了新的动力。

海孜煤矿深部勘查区中组煤层气储层物性特征分析

【目的】煤层气储层的物性特征是进行煤层气开发研究的关键因子。【方法】重点对海孜煤矿深部勘探区域中组煤储层的物性参数进行调查,以对井田内中组煤储层物性特征进行研究。【结果】研究表明,煤层的物性特征适宜开采,其中有机显微组分占优,无机显微组分次之。该煤层含气量多,虽然煤层渗透率相对较小,但符合煤层气开采条件。煤层开采时的吸附作用一般,但有利于煤层气储集和缩短煤层气的开发周期。【结论】研究结果可为该研究区煤层气抽采提供可靠的技术参考。