贵州省喀斯特溶蚀地区采煤扰动与地质灾害空间相关分析——以六盘水市为例

为了定量化分析采矿扰动与地质灾害的相关性程度,以六盘水市为例,采用Arcgis 10.2空间分析中的核密度估计与空间相关性分析,对六盘水市矿点核密度与6大地质灾害之间的关系进行定量分析,结果表明:(1)六盘水市采煤活动与地质灾害的发育存在较大的正相关性,其中与地裂缝相关性最大,未考虑地裂缝规模的相关系数为0.674,考虑地裂缝规模的相关系数为0.683;采煤活动对山地灾害的发育促进作用较大,未考虑山地灾害规模的相关系数为0.427,考虑山地灾害规模的相关系数为0.380。(2)贵州省喀斯特溶蚀地区地面塌陷主导诱发因素为地下水过度开采的人为因素,区域内地面塌陷与采煤活动之间相关性很小,以六盘水市为例,平均相关系数仅为0.009 7。(3)基于核密度估算的空间相关分析方法在定量化采矿扰动与地质灾害关系方面具有较好的效果。

永城矿区采煤扰动对土地资源的影响及土地复垦

着重分析了永城矿区采煤扰动对土地资源造成的影响,针对永城矿区实际情况,提出了可采用的不同土地复垦模式,并简要分析了土地复垦效益。

地下采煤扰动影响区数字地貌时空演变特征

以山西太原西山矿区杜儿坪煤矿南三盘区为研究区,以研究区开采前、开采后和当前3期1∶10 000地形图为数据源,以ArcGIS为实验平台,以坡度、坡向和地势起伏度为数字地貌演化分析因子,进行了研究区受地下采煤扰动影响下数字地貌时空演变特征分析。结果表明:坡度与地势起伏度因子能很好地反映地下采煤扰动影响所带来的采煤区数字地貌演变特征,而坡向也有一定的反映。

基于超声波技术的采煤扰动底板破坏深度探测

为获取工作面采煤扰动底板破坏深度实测数据,应用于采煤工作面水害评价工作以防范采煤工作面底板突水,在朝川矿21090工作面正下方的-250 m东翼泄水巷布置了7个间距10 m、垂深30 m的监测钻孔,利用超声波探测技术进行了为期13 d的底板岩层波速监测。结果表明:从3号、5号、6号钻孔监测数据的整理分析,得出了工作面采煤扰动底板破坏深度为23.36~24.46 m,与"三下"压煤开采规程给出的底板破坏深度统计公式计算结果相近,应用于生产时超声波探测结果比统计公式计算数据更为可靠,因而利用超声波技术探查采煤扰动底板破坏深度是可行的。

地下采煤扰动影响土地利用时空演变研究

为了揭示地下采煤扰动影响区地表演变特征,选择太原西山矿区杜儿坪煤矿的南三盘区为研究区,以采煤前后5期遥感影像为数据源,以ERDAS、Arc GIS为数据处理平台,采用最小距离分类法进行研究区土地利用信息提取与演变分析。结果显示:1976-2015年期间,林地、草地是研究区的主要土地利用类型,其中,草地呈逐年减少的趋势,所占比例由56.01%减少至6.66%。而灌木林地所占比例则由0%增至40.85%。建筑用地、裸地、道路、园地、耕地等地类所占比例均较少,但所占比例呈现出逐年增长的趋势,是土地利用类型多元化转变的体现。结果表明:研究区内土地利用类型转移过程和方向与煤炭开采扰动及区域发展过程相吻合,通过时序土地利用图揭示地下采煤扰动影响区地表时空演变特征方法可行,数据可靠。

接种丛枝菌根对矿区扰动土壤微生物群落及酶活性的影响

【目的】研究接种丛枝菌根后不同时间对植物根际土壤微生物数量、酶活性及矿质养分的影响,为采煤塌陷区生态复垦提供理论依据。【方法】采用田间试验,设接种丛枝菌根和不接种对照两个处理,测定接菌后不同时间菌根侵染率、根际土壤微生物数量、酶活性、矿质养分及其相互关系。【结果】与对照相比,接种菌根显著提高菌根侵染率,菌根真菌与植物建立良好的互惠共生关系;相同时间,接菌处理土壤微生物数量大于对照,两处理种群数量上均为细菌数量最多,放线菌次之,真菌最少;同一时间,接菌处理磷酸酶、脲酶、蔗糖酶活性显著(P<0.05)或极显著(P<0.01,下同)高于对照,随着复垦时间的延长,土壤磷酸酶活性不断增加;随着植物的生长根际土壤速效磷、碱解氮、有机质含量均逐渐显著降低,同一时间条件下,接菌区速效磷含量显著高于对照区。【结论】接种丛枝菌根真菌对矿区扰动土壤微生物群落、酶活性、速效磷含量有促进作用。

华北隐伏型煤矿主要充水含水层水化学组分来源及演化机制分析

为了确定华北型煤矿区主要充水含水层水化学组分的主要来源及演化机制,以平顶山矿区为研究对象。基于平顶山矿区内285个水样常规离子(K^(+)+Na^(+)、Ca^(2+)、Mg^(2+)、Cl^(-)、SO_(4)^(2-)、HCO_(3)^(-)、CO_(3)^(2-))、pH及TDS等数据,利用Gibbs图分析其主要控制因素、Piper图分析其主要水化学类型、离子组合比及主成分分析揭示其水化学组分的主要来源及演化机制。结果表明:寒灰水主要水化学类型为HCO_(3)^(-)Ca·Mg及HCO_(3)·SO_(4)-Ca·Na·Mg型,其中HCO_(3)^(-)、Ca^(2+)、Mg^(2+)、SO_(4)^(2-)主要来自碳酸盐岩(白云石)、硫酸盐岩(石膏)的溶解,Na^(+)主要来自岩石中,这是Ca^(2+)-Na^(+)、Mg^(2+)-Na^(+)的负交替吸附作用;七灰水主要水化学类型为HCO_(3)^(-)Ca及HCO_(3)·SO_(4)-Na·Ca·Mg型,其中HCO_(3)^(-)、Ca^(2+)、Mg^(2+)主要来自碳酸盐岩(方解石)的溶解,SO_(4)^(2-)来自黄铁矿的氧化作用;砂岩水的主要水化学类型为HCO_(3)^(-)Na型,其中HCO_(3)^(-)、Na^(+)主要来自硅酸盐岩的溶解;二灰水主要水化学类型为HCO_(3)^(-)Ca及HCO_(3)·SO_(4)-Na·Ca·Mg型,也有部分HCO_(3)^(-)Na型,其中HCO_(3)^(-)、Ca^(2+)、Mg^(2+)和SO_(4)^(2-)的来源与七灰水的来源相同,Na^(+)含量高是由于砂岩水的混和作用。此外采煤扰动作用导致研究区地下水径流条件发生改变,影响了水化学组分的来源及演化机制,这对以后矿井防治水有深远影响。

Top coal flows in an excavation disturbed zone of high section top coal caving of an extremely steep and thick seam

Compared with gentle dip long-wall caving,the length of a working face in fully-mechanized top-coal caving for extremely steep and thick seams is short,while its horizontal section is high with increasing production.But the caving ratio is low,which might result in some disasters,such as roof falls,induced by local and large area collapse of the top coal in a working face and dangers induced by gas accumulation. After the development of cracks and weakening of the coal body,the tall,broken section of the top coal（a granular medium）of an extremely steep seam（over 60°）shows clear characteristics of nonlinear movement.We have thoroughly analyzed the geological environment and mining conditions of an excavation disturbed zone.Based on the results from a physical experiment of large-scale 3D modeling and coupling simulation of top coal-water-gas,we conclude that the weakened top coal can be regarded as a non-continuous medium.We used a particle flow code program to compare and analyze migration processes and the movements of a 30 m high section top coal over time before and after weakening of an extremely steep seam in the Weihuliang coal mine.The results of our simulation, experiment and monitoring show that pre-injection of water and pre-splitting blasting improve caving ability and symmetrical caving,relieve space for large area dynamic collapse of top coal,prolong migration time of noxious gases and release them from the mined out area and so achieve safety in mining.

Characteristics and applications of gas desorption with excavation disturbances in coal mining

According to the deficiency of experiment system for gas adsorption and desorption in coal mass, a large scale experiment system is developed independently by researchers. This experiment system is composed of primary and auxiliary boxes, power transmission system, mining system, loading system, gas charging system, data monitoring and intelligent acquisition system. The maximum experiment coal consumption is 1200 kg, the mining system is developed to conduct experiment for gas desorption under excavating disturbance, and the plane-charging cribriform ventilation device is developed to realize uniform ventilation for experiment coal sample, which is accord with the actual gas source situation of coal bed. The desorption characteristics of gas in coal are experimentally studied under the conditions of nature and mining using the experiment system. The results show that, compare with nature condition, the permeability of coal and the velocity of gas desorption could significantly increase under the influence of coal pressure relief and destruction caused by mining, and the degree of gas desorption could somewhat increase too. Finally, pressure relief gas extraction of current seam and adjacent seams after mining in a certain coal mine of Yangquan mining area are introduced, and the gas desorption experiment results is verified by analyzing the effect of gas extraction.