【作者】 王汉斌；

【导师】 陈鸿章；

【作者基本信息】 太原理工大学 ， 采矿工程， 2009， 博士

【摘要】 煤与瓦斯突出,是煤矿井下极为复杂的瓦斯动力现象,是煤矿严重的灾害之一。我国是世界上发生煤与瓦斯突出最为严重的国家,突出矿井多,分布范围大,突出次数多,突出频率高,始突深度浅,突出类型全,突出强度大,突出瓦斯大。但因煤与瓦斯突出的机理至今尚未完全认清,故没有一个国家能完全杜绝突出事故的发生。因此,寻求一种更好的非接触式预测措施是非常有必要的。本文从煤与瓦斯突出预测的方法和煤与瓦斯突出机理研究的成果出发,通过现场调研和广泛的资料收集,应用系统工程的理论与方法,对导致煤与瓦斯突出所有可能因素进行了全面的分析,归纳出了影响煤与瓦斯突出的四大类因素,即地质因素、煤体结构、瓦斯和矿山压力(地压),并把这四大类因素进一步划分为八小类共35个影响因素,从而建立了影响煤与瓦斯突出因素的指标体系。由于不同矿井影响煤与瓦斯突出的因素不尽相同,有些因素甚至在某些矿井并不存在,如果对每个矿井都用所有的指标进行预测,势必造成系统复杂而庞大,无效计算工作量剧增,事倍功半。因此寻找影响煤与瓦斯突出的主要因素,确定一个既容易获取数据,又能实现突出预测的综合指标,是一种科学的思路和方法。为此,本文利用从汪家寨、大淑村、邯郸、红卫矿、丰城、三汇一、平顶山、淮南、南桐、桑树坪等矿井收集的煤与瓦斯突出资料,进行了不同地域的资料总体层次分析法计算,计算结果表明,瓦斯因素对突出影响所占的比重最大,达56.639%。为了进一步探究和证实这个结论的可靠性,用同一资料进行了主成分分析法的计算,计算结果是,瓦斯放散指数、瓦斯涌出速度、瓦斯含量这三个瓦斯因素指标在第一主成分中就占到了94.78%。可见,瓦斯是引起煤与瓦斯突出的主要因素,这也符合煤与瓦斯突出的相关机理。而瓦斯放散指数、瓦斯涌出速度、瓦斯含量这三个瓦斯因素指标都是测定指标,有的还需要在实验室进行测量和计算,计算一次需要花费很多时间、占用大量采掘空间,显然在获取上无法做到实时、连续、快捷和非接触,对煤与瓦斯突出预测来说,还是很不方便。因此通过分析这三个指标与瓦斯涌出量的关系,用系统的方法确定了煤与瓦斯突出预测的指标为瓦斯涌出量指标。瓦斯涌出量指标本身就是涵盖所有因素的综合指标,该数据的获取由瓦斯监控仪监测系统实现,不仅方便、快捷、连续、实时,而且真正实现了非接触获取数据,非接触预测,且不需要任何额外投资。为建立煤与瓦斯突出的分形预测理论,本文随机抽取瓦斯涌出量数据,分别计算庞加莱映射、赫斯特指数和功率谱指数,判定了瓦斯涌出具有分形特征,为分形理论预测煤与瓦斯突出奠定了理论基础和实践依据。在此基础上,提出了煤与瓦斯突出分形理论预测的方法。该方法以B矿的掘进工作面煤与瓦斯突出事故的瓦斯涌出时间序列数据为基础进行分析计算,以C矿数据作为佐证。通过确定每次计算所用样本时间序列长度td,该时间内所用的数据量d,每次预测计算的数据移动步距tl,以及每计算一次移动的数据个数l,据此绘制瓦斯涌出折线图,并用该图计算瓦斯正常涌出和煤与瓦斯突出时期的分形盒维数,将分形盒维数的计算结果列表、作图,寻找出由无突出到突出分形盒维数的变化规律。提出了煤与瓦斯突出“分形盒维数临界值”的概念。临界值是指物体从一种物理状态转变到另外一种物理状态时,某一物理量所要满足的条件点。对于B矿井而言,无突出时分形盒维数为D=1.4-1.7533,突出时为DO=1.8106,突出临界值Dc=1.7533。实例佐证矿井C矿正常瓦斯涌出量较B矿大得多,然而计算结果为正常无突出时,D=1.4-1.7617,突出时Do=1.8177,临界值Dc=1.7617,与B矿相差甚微。同时,通过两个矿井分行维数变化率的计算,无规律,证实了分形维数是判断突出与不突出的唯一标志。C矿与B矿距离很远,且不在同一煤田,本研究提出的“分形盒维数临界值”得以佐证。提出了煤与瓦斯突出预警时间问题。B、C两个矿井三次瓦斯突出的数据表明,工作面的瓦斯浓度分形盒维数达到临界值的时间到瓦斯突出的时间,有一定的间隔时间,这一段时间可称之为煤与瓦斯突出的预警时间。现有资料表明,由于各工作面的地质条件、工艺过程和技术管理方面存在较大差异,因此煤与瓦斯突出预警时间各不相同,如B矿井的预警时间为19小时,而C矿井的两次突出中,预警时间分别为38和15小时。提出预警时间的概念的意义,一是预警时间就是人们进行“防突”工作的时间,为实施防突措施减少或消除突出事故创造条件。二是它表明突出时间是有办法预先知道的,对于已经有过突出史的矿井,可用第一次达到临界值时距离突出的时间作为预警时间,尚未发生过突出的矿井,可用比较类推法,根据类似自然地质条件已发生突出矿井的分形盒维数资料,结合本矿的分形盒维数,确定临界值和预警时间,估计突出发生的时间。揭示出分形盒维数在预警时间内呈V形曲线特性。研究表明,预警时间内的分形盒维数,经历了由临界值起逐渐降低的过程,而后在接近突出的时刻,突然增高以致达到突出,这个过程呈现V形曲线特性,与人们习惯性地以为突出前的分形盒维数一直递增的完全不同。揭示这个规律可以避免在实际工作中,避免麻痹大意,积极采取防突措施,减少或消除瓦斯突出灾害。在分形理论预测方法的基础上,本文进一步讨论了分形预测理论实施的方法问题。为实现煤与瓦斯突出的实时预测,提出了基于Web Services的预测煤与瓦斯突出信息系统的模型,使数据采集、盒维数计算、盒维数曲线绘制实时完成,为实时预测提供了手段。更多还原

【Abstract】 The coal and gas outburst is one kind of gas power imagination which is extremely complex in coal mines. It is one of serious disasters in coal mine. China is one of the most serious countries in the world where the coal and gas outburst often happens, furthermore, there are some common features related to many outburst wells during these outbursts in China, such as widely distribution, outnumbered outburst, high frequency, shallow penetration outburst depth, completely outburst type, huge outburst strength, amount outburst gas. However, the coal and gas outburst mechanism still hasn’t been fully understood right now. No country can absolutely prevent the occurrence of outburst. So seeking a better contactless prediction measure is quite necessary.In the thesis for the Doctorate, according to the achievement of coal and gas outburst forecast method and gas outburst mechanism research, through deeply field-work, widely collecting information and referencing to the systematic engineering theory and method, this article analyzes potential factors which would cause coal and gas outburst, four kinds of factors which influence coal and gas outburst, geologic agent, coal body structure, gas and underground pressure (geostatic pressure). These four factors can be further divided into eight sub-factors, which in total of 35 influencing factors can be summarized, therefore establish an indicator system of influential factors of coal and gas outburst. Due to different mines have different factors influencing coal and gas outburst, some factors may not apply, analyzing every factors to each mine will increase the degree of complexity, thus intensifying the computation work and waste effort. It is a scientific approach to seek for the primary factor influencing coal and gas outburst, which is easy to gain the data and reflect the overall outburst forecast. By using gas outburst data collected from Wangjia Zhai, Dashu village, Handan, Hongwei mine, Fengcheng, Sanhui Yi, Pingding Shan, Huainan, Nantong and Shangshu Ping with overall level analytic method and calculation, the result indicated that gas factor occupies proportion is the biggest in outburst influence, it is about 56.639%. In order to further inquire and confirm this conclusion’s reliability, this article carried on the principal components analytic method computation with the identical material, the calculation result is that the gas diffuses index, the gas discharge speed and the gas concentration contribute to 94.78% in the first principal component. Obviously, the gas concentration is the primary factor of causing coal and gas outburst which conforms to the coal and gas outburst related mechanism. The gas diffuses index, the gas discharge speed and the gas concentration is determination target, some needs to be measured and calculated in laboratory, one time calculation takes too long in time and takes massive excavation space, obviously, it is unable to achieve in real-time, continuously, quickly and the non-contact, and inconvenient for coal and gas outburst forecast. Therefore by analyzing the relationship between these three targets and the gas discharge quantity, using systematic method to determine that the coal and gas outburst forecast target is the gas discharge quantity target. The gas discharge quantity target concludes all factors’overall target, this data’s gain is fulfilled by the gas monitoring meter observation system, not only convenient, quick, continual, real-time, but also it has realize the non-contact gain data truly, non-contact predict and needn’t any extra investment.In order to establish coal and gas outburst fractal prediction theory, this article has pick up gas outburst data randomly, and calculated Poincare mapping, Hurst index and power spectrum index; determined gas discharge’s fractal characteristic and established rationale and practice basis for the fractal theory forecast coal and gas outburst. Based on this, it proposed the coal and gas outburst fractal theory forecast method.The coal and gas outburst fractal theory forecast method which is based on the gas discharge time series of coal and gas outburst accident in B mine coal lane tunneling working surface to analyze and calculate, and took the evidence by the C mine data, as well as entire process gas discharge time series data of outburst conclusion until restores the normal, drawing gas discharge line chart uses each time computation sample time series length td, using data quantity in this time d, data migration step pitch tl of each time forecast computation, and every time calculated once moves data integer l, using this chart calculates fractal box dimension of gas gushes out normally and the coal and gas outburst time, and then makes tables and figures and seeks for change rule from not outburst to outburst fractal box dimension.It also has proposed in this essay a concept that coal and gas outburst“the fractal box dimension marginal value”. The marginal value refers to a certain condition spot that a physical quality needs to satisfy when an object transforms from one physical state to another. As to mine well B, when there is no outburst, its fractal box dimension is D=1.4-1.753, otherwise, its fractal box dimension is DO=1.8106, outburst Marginal value is Dc=1.7533. Here is a proved example that as to the normal gas discharge quantity, it is larger in mine pit C rather than B, however, the calculated result in mine pit C in normal condition with no outburst, D=1.4-1.7617, and when outburst Do=1.8177, Marginal value Dc=1.7617,it is almost the same with what happens in mine B. At the same time, through calculating the branch dimension rate of mine B and C, in disorder, this article confirmed that the fractal dimension is the only symbol in order to judge whether there is outburst or not. As a corroboration of“the fractal box dimension marginal value”proposed in this research, C mine is far away from B, and they are in different coal fields.In this essay, it also has started an issue regarding the coal and gas outburst warning in early time. Reference to data of gas outburst happened three times both in mine pit B and C, it indicated that between the time that gas density fractal box dimension achieves the marginal value of the working surface and the time of gas outburst, there is an interval time, called the coal and gas outburst early warning time. Because of various working surfaces’ geological condition and the difference of the technological process and the technical management aspects, the coal and gas outburst early warning times are various. For example, the early warning time of the mine B is 19 hours, and it is respectively 38 and 15 hours in the outbursts of mine C two times. Thus the significance of proposing the early warning time concept is, firstly, the early warning time is used for people to work and prevent outburst, and to create condition to reduce or eliminate outburst accidents; secondly, the outburst time means to predict outburst accident. And as to a mine pit where accidents happened once, the time when outburst reaches the marginal value can be used as the early warning time. As to a mine pit where outburst accident has not happened, we can comparatively analyze in order to determine the marginal value and the early warning time both according to fractal box dimension of the similar geological-condition mine pit where outburst once happened and the fractal box dimension of this mine.It announced that the fractal box dimension assumed V curve in early warning time. Related research indicated that the fractal box dimension in the early warning time has experienced a process during which from the marginal value, the fractal box dimension reduced gradually, then suddenly advanced and reached to outburst when it is closed to outburst. And it is quite different that as people habitually believe the fractal box dimension progressively ascends f before outburst. By applying this rule, it reduces or even eliminates the gas outburst disaster in practical.Based on the fractal theory and predictive technique, it is in this paper further discussed how to perform the fractal prediction theory. In order to realize the coal and gas outburst real-time forecast, this paper also stated a web service based information system model for predictive coal and the gas outburst, which helped real-time data acquisition, box dimension computation and box dimension curve plan, and it provided a way for the real-time forecast更多还原