Heat transfer and temperature evolution in underground mininginduced overburden fracture and ground fissures: Optimal time window of UAV infrared monitoring

Heat transfer and temperature evolution in overburden fracture and ground fissures are one of the essential topics for the identification of ground fissures via unmanned aerial vehicle(UAV) infrared imager. In this study, discrete element software UDEC was employed to investigate the overburden fracture field under different mining conditions. Multiphysics software COMSOL were employed to investigate heat transfer and temperature evolution of overburden fracture and ground fissures under the influence of mining condition, fissure depth, fissure width, and month alternation. The UAV infrared field measurements also provided a calibration for numerical simulation. The results showed that for ground fissures connected to underground goaf(Fissure Ⅰ), the temperature difference increased with larger mining height and shallow buried depth. In addition, Fissure Ⅰ located in the boundary of the goaf have a greater temperature difference and is easier to be identified than fissures located above the mining goaf. For ground fissures having no connection to underground goaf(Fissure Ⅱ), the heat transfer is affected by the internal resistance of the overlying strata fracture when the depth of Fissure Ⅱ is greater than10 m, the temperature of Fissure Ⅱ gradually equals to the ground temperature as the fissures’ depth increases, and the fissures are difficult to be identified. The identification effect is most obvious for fissures larger than 16 cm under the same depth. In spring and summer, UAV infrared identification of mining fissures should be carried out during nighttime. This study provides the basis for the optimal time and season for the UAV infrared identification of different types of mining ground fissures.

Design of comprehensive test system for detecting overlying strata mining-induced fractures on surface with radon gas

Based on radon gas properties and its existing projects applications, we firstly attempted to apply geo- physical and chemical properties of radon gas in the field of mining engineering, and imported radioac- tive measurement method to detect the development process of the overlying strata mining-induced fractures and their contained water quality in underground coal mining, which not only innovates a more simple-fast-reliable detection method, but also further expands the applications of radon gas detection technology in mining field. A 3D simulation design of comprehensive testing system for detecting strata mining-induced fractures on surface with radon gas (CTSR) was carried out by using a large-scale 3D solid model design software Pro/Engineer (Pro/E), which overcame three main disadvantages of ''static design thought, 2D planar design and heavy workload for remodification design'' on exiting design for mining engineering test systems. Meanwhile, based on the simulation design results of Pro/E software, the sta- bility of the jack-screw pressure bar for the key component in CTSR was checked with a material mechan- ics theory, which provided a reliable basis for materials selection during the latter machining process.

Numerical simulation of gas migration into mining-induced fracture network in the goaf

Gas extraction practice has been proven for the clear majority of coal mines in China to be unfavorable using drill holes in the coal seam. Rather, mining-induced fractures in the goaf should be utilized for gas extraction. To study gas migration in mining-induced fractures, one mining face of 10 th Mine in Pingdingshan Coalmine Group in Henan, China, has been selected as the case study for this work. By establishing the mathematical model of gas migration under the influence of coal seam mining, discrete element software UDEC and Multiphysics software COMSOL are employed to model gas migration in mining-induced fractures above the goaf. The results show that as the working face advances, the goaf overburden gradually forms a mining-induced fracture network in the shape of a trapezoid, the size of which increases with the distance of coal face advance. Compared with gas migration in the overburden matrix, the gas flow in the fracture network due to mining is far greater. The largest mining-induced fracture is located at the upper end of the trapezoidal zone, which results in the largest gas flux in the network. When drilling for gas extraction in a mining-induced fracture field, the gas concentration is reduced in the whole region during the process of gas drainage, and the rate of gas concentration drops faster in the fractured zone. It is shown that with gas drainage, the gas flow velocity in the mininginduced fracture network is faster.

Numerical simulation of spatial distributions of mining-induced stress and fracture fields for three coal mining layouts

In this study, the spatial distributions of stress and fracture fields for three typical underground coal mining layouts, Le, non-pillar mining （NM）, top-coal caving mining （TCM） and protective coal-seam mining （PCM）, are modeled using discrete element software UDEC, The numerical results show that different mining layouts can lead to different mining-induced stress fields, resulting in diverse fracture fields, For the PCM, the mining influenced area in front of the mining faces is the largest, and the stress concentration factor in front of the mining faces is the lowest, The spatial shapes of the mining-induced fracture fields under NM, TCM and PCM differ, and they are characterized by trapezoidal, triangular and tower shapes, respectively, The fractal dimensions of mining-induced fractures of the three mining layouts decrease in the order of PCM, TCM and NM, It is also shown that the PCM can result in a better gas control effect in coal mines with high outburst potential, The numerical results are expected to provide a basis for understanding of mining-induced gas seepage fields and provide a reference for high- efficiency coal mining,

Multistage hydraulic fracturing of a horizontal well for hard roof related coal burst control:Insights from numerical modelling to field application

Multistage hydraulic fracturing of horizontal wells(MFHW)is a promising technology for controlling coal burst caused by thick and hard roofs in China.However,challenges remain regarding the MFHW control mechanism of coal burst and assessment of the associated fracturing effects.In this study,these challenges were investigated through numerical modelling and field applications,based on the actual operating parameters of MFHW for hard roofs in a Chinese coal mine.A damage parameter(D)is proposed to assess the degree of hydraulic fracturing in the roof.The mechanisms and effects of MFHW for controlling coal burst are analyzed using microseismic(MS)data and front-abutment stress distribution.Results show that the degree of fracturing can be categorized into lightly-fractured(D≤0.3),moderately fractured(0.3<D≤0.6),well-fractured(0.6<D≤0.9),and over-fractured(0.9<D≤0.95).A response stage in the fracturing process,characterized by a slowdown in crack development,indicates the transition to a wellfractured condition.After MFHW,the zone range and peak value of the front-abutment stress decrease.Additionally,MS events shift from near the coal seam to the fractured roof layers,with the number of MS events increases while the average MS energy decreases.The MFHW control mechanisms of coal bursts involve mitigating mining-induced stress and reducing seismic activity during longwall retreat,ensuring stresses remain below the ultimate stress level.These findings provide a reference for evaluating MFHW fracturing effects and controlling coal burst disasters in engineering.

Mining-induced movement properties and fissure time-space evolution law in overlying strata

Mining-induced fracture zone will be produced in the overlying strata after the coal was mined.In this article,the mining-induced deformation of overlying strata and the time-space evolution law of fissure were studied by the methods of physical simulation and field measurement.The results show that bed separation fissure and vertical fissure will appear in the overlying strata above mining face,which form the wedge-shaped fissure zone.The open degree of fissure depends on the size of uncoordinated deformation between neighbor layers,and the absolute strata sinking controls both the width of bed separation zone and the open degree of vertical breakage fissure.At last,the calculating formula was deducted based on theoretical analysis.

Fractured zone height of longwall mining and its effects on the overburden aquifers

As mining depth becomes deeper and deeper,the possibility of undermining overburden aquifers is increasing.It is very important for coal miners to undertake studies on the height of fractured zone during longwall mining and the effects of longwall mining on the underground water while mining under surface water bodies and underground aquifers.In order to study this problem,piezometers for monitoring underground water levels were installed above the longwall panels in an American coalmine.Large amounts of pre-mining,during mining and post-mining monitoring data were collected.Based on the data,the heights of fractured zones were obtained and the effects of longwall mining on the underground water were studied.The results demonstrate that when the piezometer monitoring wells had an interburden thickness of less than 72.7 m,the groundwater level decreased immediately to immeasurable levels and the wells went dry after undermining the face of longwall.The height of the fractured zone is 72.7-85.3 m in the geological and mining conditions.The results also show that the calculated values of fractured zones by the empirical formulae used in China are smaller than the actual results.Therefore,it is not always safe to use them for analyses while mining under water bodies.

Study on the movement and fracture of ＂isolated island＂ working face overburden by numerical simulation

For circumstances of medium-embedding depth and medium-hard surroundings in Jining No.2 Colliery, Yanzhou Group, by using software RFPA2D to simulate the process of overburden fracture, studied the overburden separation which was caused by working face exploitation, its fracture characteristics and the isolated island coalface（IIC） formation systematically in comparison method. After the recovery of the IIC, the surrounding separation areas which lied above the working face and bilateral goaved respectively form a connected region, a region that is like a saddle with low middle （35 times） and high sides. The top boundary line of the separation area is an arc. Then the fracture rise rapidly to 28 times of working thickness; while it is smaller （only 8-17 times recovery height） when extracting bilaterally, though the fracture plane both are in shape of an unsymmetrical trapezium. As the recovery of IIC makes side recoveries change from insufficiency to sufficiency, the consequentially rapid change of characteristics of overburden separation and fracture would enhance the representation degree of mining pressure of IIC.

Fracture distribution in overburden strata induced by underground mining

Coal-mining activities give rise to a series of ecological environmental problems,such as ground settlement and groundwater pollution.In fact,they are mainly caused by mining-induced fractures.Hence,it is necessary to study the mining-induced fracture distribution to identify the behavior of rock mass movement.However,the fractures in overburden strata cannot be directly measured owing to the special condition.Therefore,the majority of previous studies are based on experiments or experience.For this reason,this study first used a discrete element method to simulate the shape of mining-induced fractures in overburden strata.Then,a geophysical tool of transient electromagnetic method(TEM)was used to investigate the mining-induced fracture distribution.Based on the low-resistivity anomaly area,the water-rich area in overburden strata was analyzed to be mainly caused by fracture seepage.Through the mutual authentication between numerical simulation and TEM results,the mining-induced fractures in overburden strata were explored.This study can enhance the understanding of mining-induced fracture distribution on the one hand and guarantee the coal mining safety on the other,thus guiding the coordinated development between coal mining and environmental protection.

厚煤层大采高综放工作面覆岩断裂演化规律研究

大采高综放开采易形成强烈的矿压显现,上覆岩层的断裂演化规律对工作面安全生产至关重要。以羊场湾煤矿160206工作面为工程背景,运用相似模拟试验、数值模拟和理论分析的综合研究方法,对大采高综放工作面覆岩的断裂过程与覆岩运移规律进行系统研究。研究表明:导水裂隙带内岩层随工作面推进表现为“台阶下沉”,同层岩层下沉趋势沿走向表现为“急剧下降—稳定(最大值)—快速上升—稳定(最小值)”。工作面覆岩运动场由两区分布(加速下沉区、缓慢下沉区)演化为三区分布(加速下沉区、缓慢下沉区、稳定区)。对离层演化与地表下沉规律进行了定量描述,运用理论计算表达式深入地剖析了地表的动态下沉机理及其相关因素。结合相似模拟与数值模拟的试验结果,提出了覆岩断裂演化的形态变化特征:覆岩断裂形态由“单等腰梯形”演化为“双等腰梯形”,表土层影响区由“矩形”演化为“倒梯形”。分析了覆岩中垮落区、离层区、压实区、裂隙富集区的动态演化过程:垮落区逐渐增大至一定程度,高度小幅度降低并趋于稳定,离层区由下至上逐渐发育并随工作面向前移动,离层区逐渐闭合形成压实区,且压实区逐渐增大并最终保持稳定,裂隙富集区位于采空区前后端部并随工作面向前移动。

巨厚覆岩矿震孕育破裂特征与应力触发机制

【目的】深部开采巨厚覆岩破断导致引起地表震感的矿震频发,已成为制约矿区高效生产的最严峻难题,亟待改变矿区巨厚覆岩矿震频度高、防控难现状。【方法】以内蒙古自治区鄂尔多斯呼吉尔特矿区某邻空综采工作面频发巨厚覆岩矿震为研究对象,应用厚板理论分析巨厚覆岩结构破断演化规律,提取矿震波形主成分并采用矩张量反演方法定量研究矿震震源破裂机制,基于张拉、压缩及混合破裂震源主应力作用方式修正应力反演模型,改进应力反演算法,分析矿震震源孕育破裂特征及应力场演化规律,定量解析矿震应力触发机制。【结果和结论】结果表明,巨厚覆岩破断运移为矿震孕育触发的动力、能量源;主成分分析方法可快速提取因采矿环境干扰波形的主成分,为矩张量求解提供优质反演数据;修正后应力反演算法能够满足采动诱发非剪切破裂震源应力反演需求,实现对典型张拉、压缩等非剪切破裂矿震震源应力场反演;工作面邻空回采期间,顶板逐层向上与侧向采空区联动破断,采空区影响使得孕震期间顶板活动性增强,巨厚覆岩断裂特征整体呈显著张拉状态;矿震孕育过程中主应力作用方位基本一致,应力形因子分别为0.66、0.71和0.30,覆岩应力分布由单轴挤压转变为挤压张拉状态,最大主应力单轴挤压作用导致巨厚覆岩瞬时断裂释放大量弹性能是诱发“2·6”和“10·30”矿震的主要原因,工作面邻更大范围采空区开采,最大、最小主应力挤压张拉协同作用将可能诱发更大能级矿震。研究结论可为矿区及周边因矿震问题限制高效生产的矿井从源头调控降载减震提供理论支撑。

厚硬岩层结构调控低损开采方法及机理研究

为探究厚硬岩层采动结构对上覆岩层下沉破坏影响及新的低损开采方法,采用相似模拟、离散元数值模拟方法分析了厚硬基本顶采动破坏结构演化和堆积特征对覆岩下沉破坏的影响。相似模拟及数值模拟结果均表明,随采随垮的直接顶岩层和周期性破断的厚硬基本顶分别呈现小块度破坏杂乱堆积和大块度破断整齐堆积;受采动结构特征影响,直接顶岩层采动破坏产生的体积膨胀显著大于厚硬基本顶。根据模拟得到的采动岩层破坏堆积特征构建了厚硬基本顶条件下采动覆岩下沉计算模型。根据采动作用下随采随垮直接顶岩层采动破坏膨胀量显著大于周期性破断厚硬基本顶的规律,提出对厚硬基本顶进行采前大规模水力压裂并借助采动超前支承压力进一步破坏厚硬基本顶,降低厚硬基本顶采动破坏块度,使其随采随垮、杂乱堆积并充分充填采空区以控制上覆岩层下沉破坏,实现低损开采。采用数值模拟验证了压裂弱化厚硬岩层调控其采动结构,增大采动破坏岩层体积膨胀量,降低上覆岩层下沉的有效性。提出的厚硬岩层结构调控低损开采方法可为煤矿绿色高效开采提供一定的参考。

厚松散层薄基岩综放开采覆岩破坏与地裂缝发育规律

开采引起的覆岩移动、破坏及地表变形裂缝的研究对于煤矿安全生产和采动损害保护具有重要意义。以郑煤集团某矿12203工作面为工程背景,采用理论分析、现场实测与数值模拟等方法分析了覆岩受采动影响演化机制,给出了回采距离与覆岩发育高度之间的函数关系以及覆岩充分破坏埋深与回采距离之间关系,分析了该地质情况下的地裂缝分布特征。结果表明:①厚松散层薄基岩覆岩破坏演化可分为开始、快速增加阶段、缓慢增加及稳定4个阶段;覆岩破坏高度与回采距离存在Logistic函数关系、与煤层厚度存在线性函数关系,该地质条件下覆岩充分破坏时,回采距离等于埋深;②覆岩裂隙演化中,基岩部分比松散层部分破坏程度剧烈;③地裂缝形态主要为拉伸裂缝与台阶裂缝,二者交互存在,工作面边缘裂缝整体随工作面回采呈现椭圆形—圆形—椭圆形动态变化;地裂缝发育超前工作面一段距离出现,动态超前裂缝距为84.07 m,动态超前裂缝角为73.15°。

深埋煤层开采对河流安全性的影响评价

以文家坡煤矿4105工作面深埋覆水煤层开采为例,采用相似材料模拟和数值模拟方法,研究覆岩破坏和裂隙带发育规律,探究深埋煤层开采对红岩河安全的影响。研究表明:当工作面不断推进,采空区面积随之增加,覆岩在重力作用下发生弯曲变形,形成离层;当重力超过岩石变形极限时,覆岩会破坏变形,部分离层垮落消失,在垮落体上部发育新离层,两侧形成裂隙;4105工作面垮落带高度稳定在164 m;随着工作面的不断推进,导水裂隙带高度逐步上升,最终稳定在244 m;地裂缝自地表向下延伸32 m;导水裂隙带上方存在414 m的岩层做保护层,未导通地表,未与地裂缝沟通,因此红岩河不会发生渗漏,煤层的开采不会对红岩河产生影响。

倾斜煤层群覆岩“三场”非对称特征及靶向抽采机制

倾斜煤层群“三场”(应力场、位移场和裂隙场)演化规律较为复杂,对卸压瓦斯运移和储集具有重要意义。为了探究倾斜煤层群“三场”演化规律,研究以新疆1930煤矿为对象,开展了倾斜煤层群多重采动相似模拟实验。分析了上覆岩层垮落形态,获得了覆岩应力演化特征,分析了覆岩位移分布和移动方向特征,阐明了采动裂隙分布特征。进而探究了三场演化规律对瓦斯运移的影响,并开展了定向钻孔瓦斯抽采现场试验进行验证。研究结果表明:倾斜煤层群多重采动下,采动裂隙矩形梯台呈现明显的非对称特征。低位侧覆岩应力变化较大,随开采次数增加,卸压效应更为明显,而高位侧覆岩应力变化较小;结合重力−倾角效应,高位侧覆岩更易破坏,垮落次序优先,呈非对称特征。覆岩位移分布呈非对称特征,高位侧位移显著且移动方向变化较大。高位侧裂隙区网格内采动裂隙频数明显高于低位侧;高位侧裂隙区破断裂隙分布更多,且开度较大;采动裂隙呈“高位扩展−低位压缩”的非对称特征。多重采动使得“三场”非对称特征更为显著。此外,覆岩贯通度存在“慢速减小−快速减小”的现象。基于“三场”演化特征和瓦斯运移的关系,揭示了瓦斯抽采靶向优选机制。结合试验结果,构建了基于“三场”演化规律的裂隙带瓦斯抽采靶点区判定流程。现场瓦斯抽采效果良好,保证了工作面安全高效回采。研究结果为倾斜煤层群卸压瓦斯精准抽采提供了理论参考,旨在提高倾斜煤层群瓦斯抽采量,防止上隅角瓦斯超限,实现倾斜煤层群安全高效开采。

高强度采动覆岩——地表偏态下沉规律研究

科学认识和掌握覆岩破断特征和地表下沉规律是煤炭绿色开采的重要基础,有利于减小煤炭开采扰动对地表构筑物和生态环境的损伤程度。基于离散元模拟软件建立数值模型,探究了不同推进距离下覆岩破断运移特征,得到了地表偏态下沉规律,采用理论分析和物理模拟手段验证了研究结果的可靠性。结果表明:开切眼侧岩层破断角大于工作面侧岩层破断角,覆岩的偏态垮落传导至地表,造成地表的偏态下沉。该研究成果为研发煤炭减损开采技术提供创新性理论支撑。

深部复杂覆岩结构煤层开采冲击地压致灾层位判识研究

以孟村煤矿401102工作面为研究对象,系统开展深部复杂覆岩结构煤层开采冲击地压致灾层位判识数值模拟研究,建立覆岩冲击地压致灾影响系数Wrb,揭示工作面不同覆岩条件下各岩层致灾影响程度特征与致灾关键岩层分布规律。研究表明:(1)401102工作面煤层上方100 m范围亚关键层均为致灾影响程度较大岩层,同时非关键层运动破断的冲击致灾作用也不可忽视;(2)401102工作面基本顶为最主要冲击致灾岩层;(3)当对401102工作面内Wrb较高岩层采取地面水平井压裂后,冲击地压治理效果较好。研究成果可为深部煤层开采顶板灾源准确识别与冲击地压精准防控提供借鉴与指导。

裂隙发育过程对采动裂隙椭抛带压实区的影响研究

采空区瓦斯抽采的关键是了解工作面上覆岩层裂隙的演化过程。为了研究综采工作面覆岩采动压实区演化规律,高效进行煤矿采空区瓦斯抽采工作,以神东某矿区2207工作面为原型,通过物理相似模拟实验,利用自主研发的覆岩裂隙监测系统将图像进行直方图均衡化增强和中值滤波去噪处理,获得二值化裂隙图像后利用分形理论定量描述裂隙率,对典型周期来压覆岩垮落裂隙率进行统计分析,建立了裂隙发育程度受工作面推进时间的时空函数和采动裂隙椭抛带压实区演变修正模型。结果表明:覆岩平均裂隙率变化符合DoseResp函数关系,裂隙的发育过程包括产生、扩展蔓延、压实闭合3个阶段,裂隙在产生、闭合这2个阶段发育速率较平缓,而在扩展阶段发育速率陡增。采空区上覆岩层裂隙场形成旧裂隙区、压实区和新裂隙区3个区域,裂隙发育周期的不同导致旧裂隙区与新裂隙区在发育状态、压实程度和空间形态上有着明显差异,这些差异导致了采空区覆岩非对称性下沉现象的发生。通过分析覆岩应力恢复与覆岩内部裂隙演变关系,进一步验证了采用DoseResp时间函数曲线可以很好的表现采空区上覆岩层裂隙异速演变特征。最后建立了考虑覆岩裂隙异速演变效应的采动裂隙椭抛带压实区修正模型,并结合现场工程实践,有效提高瓦斯抽取高位钻孔布置的准确性,为工作面的安全开采提供理论指导。

煤矿覆岩主控致灾层位危险识别及现场应用

针对煤矿地面水力压裂技术施工中工作面覆岩主控致灾层位难以准确辨识的难题,以孟村煤矿401102工作面地面水力压裂工业试验为背景,采用理论分析、微震监测、现场调研等方法,揭示了煤矿厚硬覆岩运动诱发矿震和冲击地压的动力灾害机理,分析了基于载荷三带理论的厚硬覆岩分区运动特征与诱发动力灾害之间的关系,建立了基于关键层运动状态的矿震能量预测模型与采场等效附加应力估算模型,提出了基于K-means聚类算法和肘部法则的煤矿覆岩主控致灾层位识别技术方法,确定了现场压裂施工层位并进行工业试验,根据现场微震监测数据及理论分析结果进行了效果验证,得到结论如下:孟村煤矿401102工作面致冲关键层及矿震关键层均为距离煤层66 m的安定组关键层R9,其初次破断运动采场等效附加扰动应力理论值为7.23 MPa,初次破断运动释放矿震能量理论值为6.08×105 J,致灾危险性较强;震−冲关键层压裂后,矿震能量理论值降幅94%,采场等效附加扰动应力理论值降幅76%,工作面上方5×10^(3)J大能量微震事件出现明显上移趋势,上移量约为15 m;10^(3)J及以上能级微震事件频次占比显著下降,由60.39%降至17.89%,最大微震事件能量由6.65×10^(5)J降至9.75×10^(3)J;10^(2)J及以下能级微震事件频次占比显著上升,由39.61%增至82.11%。

多工作面连续开采地表沉陷与强矿震联动响应规律

深部矿井多工作面大空间开采导致大能量强矿震事件频发,同时地表伴随剧烈的下沉变形,掌握具体地层条件下地表移动与强矿震时空分布响应规律对于深部矿井动力灾害防控意义重大。以兖州矿区东滩煤矿63_(上)04,63_(上)05,63_(上)06工作面为工程背景,基于关键层理论与复合破断原理,对东滩煤矿复杂地层进行了科学划分,现场实测了深井厚硬岩层下多工作面开采地表沉降规律及强矿震时空分布特征,分析了多工作面连续开采下关键层组运移演化规律,揭示了关键层组破断演化、地表沉陷规律与大能量强矿震分布的联动效应。研究结果表明:(1)东滩煤矿六采区地层可以划分出4个关键层组,每个关键层组包含一层关键层和若干坚硬岩层,相比单一关键层,关键层组发生复合破断时的矿震能量更高、破断步距更大,对上覆岩层的运移及地表下沉影响也更为突出。(2)地表沉陷观测结果显示,63_(上)04,63_(上)05工作面开采结束,地表下沉系数分别为0.189,0.458;63上06工作面当前已开采808.29 m,地表下沉系数为0.492,受多关键层组地质赋存特征影响,东滩煤矿六采区地表下沉系数远小于兖州矿区其他矿井平均地表下沉系数(0.75~0.85),地表未达到充分采动,下沉趋势为:无明显下沉–下沉空间显著–下沉空间逐渐增大。(3)矿震监测结果显示,63上04工作面开采时,大能量强矿震事件主要集中在低位关键层组Ⅰ,Ⅱ层位,随着多工作面连续开采,大能量强矿震逐渐向高位转移,逐渐集中至关键层组Ⅱ,Ⅲ层位。(4)由地表沉陷及大能量强矿震实测数据可知,东滩煤矿六采区多工作面连续开采下关键层组复合破断覆岩结构呈“断悬”结构–“铰接”结构交替上升,逐层演化过程验证了覆岩运动、地表沉陷及大能量强矿震3者之间存在一定的联动效应。研究成果可对类似工程地质条件下多关键层组复合破断研究及大能量强矿震预控提供一定参考。