条采沉陷计算的空间分层介质力学法

本文把条带开采工程岩体介质简化为具有开挖孔洞的分层各向同性线弹性空间体，不仅考虑了上覆岩体，而且考虑了煤柱和下伏岩体对岩层和地表移动的影响。给出了适合于条带开采的应力边界条件和垂直位移连续而水平位移可不连续的层间几何接触条件，导出了条带开采岩层与地表移动的计算公式。利用本文给出的空间分层介质力学法，不仅可以计算地表和岩层内部的移动变形，包括水平变形和垂直变形，而且可以探讨条带开采亟待解决的其它理论     

条带开采的三维层状介质理论及其应用研究

条带开采是“三下”（建筑物下、水体下、铁路下）压煤开采中,控制地表沉陷的一种比较有效的方法．然而,现有的条带开采尺寸设计一般还是采用威尔逊法,地表沉陷预计沿用全采的该率积分法由于预计参数采用经验公式确定,而对条带开采的主控因素未能明确给出或系统考虑,其预计误差相对较大．此外,对条带开采岩体的内部移动机理知之甚少,如上覆岩体（或下伏岩体）的波浪移动带的定义及其高度的计算,等等．总之,条带开采未能形成系统的理论,从而大大影响了条带开采地表沉陷的预计精度,这就限制了条带开采的合理使用．为此,提出了“条…     

薄基岩条带开采工程地质力学模型试验研究

针对兖州太平矿区内赋存有薄基岩的地层条件，以工程地质力学模型试验为手段，研究了薄基岩条件下条带开采覆岩与地表移动变形及破坏的工程地质机理及其主控因素，揭示了薄基岩条带综放开采引起的上覆岩层的破坏过程、破坏形态、破坏范围及地表的移动变形规律，为工程实践提供了理论依据。     

巨厚松散层下条带开采地表沉陷机理及岩层移动模型的探讨

通过研究认为目前的岩层移动模型不能很好地分析巨厚松散层下条带开采岩土层的移动机理,对地表沉陷的主控因素和机理进行了理论分析和模拟试验,探讨了巨厚松散层下条带开采岩土层移动的复合介质模型.     

巨厚松散层下条带开采地表沉陷机理及岩层移动模型的探讨

通过研究认为目前的岩层移动模型不能很好地分析巨厚松散层下条带开采岩土层的移动机理,对地表沉陷的主控因素和机理进行了理论分析和模拟试验,探讨了巨厚松散层下条带开采岩土层移动的复合介质模型.     

地下开采岩层变形相似材料模拟的数值试验

在金山店铁矿东区浅部开采岩层变形相似材料物理模拟的基础上,结合34#剖面工程地质特征建立了深部开采的FLAC数值分析模型.随后,依据-550 m水平开挖时相似材料物理模拟的地表变形实测值,采用BP神经网络和遗传算法等手段对相似材料力学参数进行了优化,构建了深部开采相似材料模拟数值试验模型.以该数值试验模型对金山店铁矿深部开采岩层变形规律进行了研究,结果表明:进入深度开采后,上盘岩层移动角趋于58°,下盘岩层移动角趋于63°.这种研究方法不仅节省了做相似材料物理模拟试验的费用和时间,而且误差可以控制在5%的允许范围内,其结果对深部开采地表征地和搬迁具有重要的参考价值.     

短壁开采地表移动数值模拟

针对某煤矿短壁开采条件,应用岩石破裂分析系统RFPA,建立了数值模拟模型,并采用五种方案模拟了短壁开采过程,总结了不同煤柱尺寸下地表移动规律。模拟结果表明:煤柱尺寸的大小直接影响地表的水平位移和垂直位移,而且煤柱尺寸的变化倍数对地表的变形控制有非常明显的效果。     

随机介质理论在地下厂房沉降研究中的应用

基于随机介质理论模型,对地下工程开挖引起岩层和地表移动规律进行了分析.认为地下工程开挖引起岩层颗粒运动符合随机介质运动规律,提出了地下工程开挖地表沉陷三维计算模型,并以冶勒水电站地下厂房开挖所引起地表沉陷特征进行了具体分析,并将计算结果与实际观测数据进行对比分析,表明水平移动位移、变形均较小.又因地下厂房开挖较深,水平移动规律不如上层塌陷明显,且地表最大观测沉降值约为200mm,而最大计算值约为370mm;在地下厂房顶部,最大观测沉降值约为400mm,最大计算值约为440mm.最大水平移动计算值为100mm.数值计算的结论较为精确、可靠,显示出分层影响传递规律,并最终影响到地表.     

岩层与地表移动问题的力学模型的选择

岩层与地表移动是一个发展的过程，从开始开采到移动结束，岩的特性发生了很大的改变，使用力学模型 解决岩层与地表移动问题必须使模型简化，但应满足合理的工程精度要求，否则将导致结论的谬误，在反算岩移参数时，可以使用采前的力学模型把开采作为边界条件模拟输入，也可使用采后的力学模型，即岩体已形成了三带，采后的力学模型由于已将来空区考虑为被岩石充填，故计算的应力可能异于顶板尚未冒落的岩体的应力，在承压水上开采     

充分采动区内及主断面上水平移动变形的分布规律

本文根据碎块体理论推出了作为各向异性介质的岩体内部及地表沿移动盆地主断面的水平移动变形的分布规律,对现有水平移动理论作了改进。作者用实测资料及可靠性数学证明了该理论的正确性,指出了在充分采动区内存在着水平移动u残,给出了u残的计算公式,并对峰峰矿区的u残进行了综合分析。在此基础上,说明了水平及倾斜煤层半无限及有限开采时的、沿移动盆地主断面的水平移动变形的分布规律。在本文的基础上,可望提高水平移动变形参数求定及预计的可靠性。     

采场覆岩中复合关键层的形成条件与判别方法

在采场覆岩运动中起主要控制作用的岩层为关键层，而有时关键层是由2层或2层以上岩层形成的复合岩层所组成，我们称其为复合关键层．本文在深入揭示复合岩层形成机理的基础上，给出了形成复合岩层的力学条件与数学表达式，进而建立了采场覆岩中复合关键层的判别方法，并编写了复合关键层的判别程序．实例分析表明，复合关键层在岩层运动中是客观存在的，比同组岩层分开后的单一岩层的控制作用的线性叠加要大得多．本项研究是岩层控制的关键层理论研究的深入和发展，将有力促进岩层控制理论和技术的发展．     

开采沉陷预计参数的确定方法

基于相似理论的基本原理 ,根据我国 1 2 0多个地表移动观测站的监测数据 ,导出了开采沉陷预计参数与岩体综合变形模量E、采深H和采厚M等因素之间的统计公式 ,即地表下沉系数 q、水平移动系数b、主要影响角正切tanβ和拐点偏移距与采深的比值S0 /H与相似准则E/Em 和 ρH2 ( 1 0 0MEm)之间呈线性关系 .研究表明 :岩体的综合变形模量对开采沉陷预计参数的影响显著 ,采深主要影响拐点偏移距 ,对其它预计参数的影响甚微 ,而采厚对所有预计参数的影响都很小 ,可忽略     

Research on Ground Movement Laws for Strip Mining Under Thick Alluvium

With the discrete element method, the simulation and analysis of a series of numerical models were made. This research revealed ground movement laws for strip mining under thick alluvium and gave calculation formulae for the maximum ground subsidence and horizontal movement as a function of basement rock thickness and mining width, thus providing sound evidence for future strip mining under thick alluvium.     

Hydraulic support crushed mechanism for the shallow seam mining face under the roadway pillars of room mining goaf

While the fully-mechanized longwall mining technology was employed in a shallow seam under a room mining goaf and overlained by thin bedrock and thick loose sands, the roadway pillars in the abandoned room mining goaf were in a stress-concentrated state, which may cause abnormal roof weighting, violent ground pressure behaviours, even roof fall and hydraulic support crushed(HSC) accidents. In this case,longwall mining safety and efficiency were seriously challenged. Based on the HSC accidents occurred during the longwall mining of 3-1-2 seam, which locates under the intersection zone of roadway pillars in the room mining goaf of 3-1-1 seam, this paper employed ground rock mechanics to analyse the overlying strata structure movement rules and presented the main influence factors and determination methods for the hydraulic support working resistance. The FLAC3 D software was used to simulate the overlying strata stress and plastic zone distribution characteristics. Field observation was implemented to contrastively analyse the hydraulic support working resistance distribution rules under the roadway pillars in strike direction, normal room mining goaf, roadway pillars in dip direction and intersection zone of roadway pillars. The results indicate that the key strata break along with rotations and reactions of the coal pillars deliver a larger concentrated load to the hydraulic support under intersection zone of roadway pillars than other conditions. The ‘‘overburden strata-key strata-roadway pillars-immediate roof" integrated load has exceeded the yield load that leads to HSC accidents. Findings in HSC mechanism provide a reasonable basis for shallow seam mining, and have important significance for the implementation of safe and efficient mining.     

急倾斜煤层开采地表移动变形数值模拟

针对急倾斜煤层开采复杂的地质条件,对朝阳某煤矿分别选取了六种方案进行模拟,岩层依次变软,得出六种方案的水平和竖直方向的地表变形曲线及模型在x、y方向的等值线图.结果显示:方案一和方案二的最大值分别为0.026 85 m、0.049 39 m;方案三和方案四的最大值分别为0.066 75 m、0.089 4 m;方案五和方案六的最大值分别为0.134 1m、0.260 3 m.可以得出随着弹性模量的减小也就是随着上覆岩层的变软,地表水平和竖直方向的位移都逐渐增大,影响范围也逐渐变大;地表变形的最大值并不在采空区的正上方,而在采空区法线方向与地表的交点左右.可以为研究急倾斜煤层的开采及变形移动规律提供理论支持.     

Time-domain characteristics of overlying strata failure under condition of longwall ascending mining

Ascending mining is one of the most effective ways to solve problems of water inrush, gas outburst and rock burst in coal seams mining. In order to reveal the law of motion and spatiotemporal relationship of overlaying strata, field measurement has been done in a mine. Long distance drillings were constructed from 4# coal seam to 6# coal seam at several certain typical positions, and movement and failure law of overlying strata after mining was analyzed by drilling video and observing the fluid leakage. Besides, we also analyzed the spatiotemporal development law of overlying strata failure with different mining heights and time intervals in the lower coal seam. The results show that: ascending mining is significantly affected by time-domain characteristics of overlaying strata failure after the lower coal seam’s mining, height equations of caving zone and fractured zone are given in this paper, and the feasibility of ascending mining was compartmentalized concretely according to the spatiotemporal relationship. Research methods and conclusions of this paper have certain referential significance for the study of ascending mining, mining under water, mining under building, mining under railway and stress-relief mining.     

Subsidence over room and pillar retreat mining in a low coal seam

The objective of this paper is to study the behavior of a low thick and low depth coal seam and the overburden rock mass. The mining method is room and pillar in retreat and partial pillar recovery. The excavation method is conventional drill and blast because of the small production. The partial pillar recovery is about 30% of the previous pillar size, 7 m × 7 m. The roof displacement was monitored during retreat operation; the surface movement was also monitored. The effect of the blasting vibration on the final pillar strength had been considered. Due to blasting, the pillar reduced about 20%. The consequence is more pillar deformation and roof vertical displacement. The pillar retreat and ground movement were simulated in a three-dimensional numerical model. This model was created to predict the surface subsidence and compare to the subsidence measured. This study showed that the remaining pillar and low seam reduce the subsidence that was predicted with conventional methods.     

Subsidence control method by inversely-inclined slicing and upward mining for ultra-thick steep seams

Ultra-thick steep coal seam mining will inevitably lead to the increase of greater and violent ground subsidence and deformation. A subsidence control method by inversely-inclined slicing and upward mining is proposed in this paper. By this method, the sequence of collapse of overlying strata and the direction of propagation of strata movement are changed, the extent of roof-side deformation thereby is lessened, and boundary angle of roof-side subsidence is reduced by 5°–10°. The mechanism of this mining method for control of strata movement has been evidenced by numerical simulation and experiments with similarity materials. A subsidence prediction model based on the variation of mining influence propagation angle can be used to evaluate the surface movement and deformation of the mining method. The application of the method in No.3 Mine in Yaojie mining area has yielded the expected result.     

排上村—75m以上岩层及地表移动与变形分析

通过有限元方法对东乡铜矿排上村 -75 m以上岩层及地表移动与变形分析 ,得出尽管伴随顶板岩层崩落过程 ,地表会产生较大的移动、开裂和其他变形 ,但岩层崩落不会达到地表的结论 ,并通过实践证明给出的结论是正确的 .