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1.
《地质灾害与环境保护》1994,(1)
《非线性工程地质学导引》:秦四清、张悼元、王士天、黄润秋著。西南交通大学出版社1993年12月出版。该书系统研究了节理岩体的非确定性结构与强度特征(包括节理岩体的分维特征与工程地质意义、非确定性岩石力学参数取值及岩体质量分级原理)、室内地应力测试新方法、岩体突变失稳理论(包括顺层斜坡弯曲失稳、层状岩体失稳、斜坡滑动失稳、水库地震、冲击地压)、滑坡灾害非线性动力学预报理论(包括滑坡混沌识别、分叉、灰色—模糊尖点突变模型、非线性动力学模型)。全书共四章,约26万字,书未附有“滑坡灾害预报系统LTFS源程序”。该书系第一作者博士后的研究成果,经专家评审,认为是国内第一部具开拓性、创造性的高水平专著。可供从事分形、混沌、突变等非线性科学研究和从事工程地质和岩体力学等专业的科技人员,以及有关专业的研究生参考之用。每册定价10元。《岩石声发射技术概论》:秦四清、李造鼎、张倬元、邓荣贵著。西南交通大学出版社1993年12月出版。该书系统研究了岩石声发射的微观机理,岩石断裂特性的声发射特征、凯塞效应机理、应用凯塞效 相似文献
2.
不同岩石破裂全过程的声发射序列分形特征试验研究 总被引：3，自引：0，他引：3
通过对不同岩性的岩石进行单轴压缩声发射试验,获取岩石破裂全过程中的载荷-轴向变形曲线及声发射参数,观察试件破裂失稳时的破坏情况,分析破坏过程的载荷变化关系。着重对比了不同岩石的不同力学性质、岩石声发射序列的时域特征和声发射序列的分形特征。研究结果表明,采用声发射率、能率可以很好地描述岩石破裂损伤的整个阶段;计算岩石声发射率、声发射能率的关联维数,可得出岩石破裂过程的声发射序列具有分形特征;岩石破裂过程的声发射分维值D反映了岩石内部微裂隙的统计演化规律;不同岩性的岩石破裂过程的声发射参数序列的分形特征具有一定的共性;归纳总结出岩体声发射序列分维曲线的演化模式,即波动→持续下降演化模式,提出可以将分维值的持续下降作为岩体破裂失稳的前兆。 相似文献
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《岩土力学》2020,(9)
在充填体失稳预警研究中,以声发射前兆特征作为材料失稳预警标志已得到众多学者的一致肯定。然而,声发射前兆特征具有多种形式,这对充填体的失稳预警有一定的影响。基于此,建立了一种形式固定的充填体失稳预警模型。首先,以能量演化特征为切入点,基于尖点突变理论构建了充填体失稳预警模型,随后针对不同灰砂比充填体开展单轴压缩声发射验证试验。试验结果表明,耗散能突变与可释放弹性应变能突变所构成的区间可描述充填体的预警状态,将其定义为预警区间。不同灰砂比充填体预警区间唯一,模型具有较好的灵活性及普适性。以振铃计数率等认可度高的声发射特征参数的前兆特征对得出的预警区间的合理性进行验证,验证结果表明,根据模型求出的预警区间与声发射参数的前兆特征所处时间高度一致,进一步验证了该方法的合理性及普适性,可为充填体的失稳预警研究提供一种新的思路。 相似文献
5.
针对机械施工荷载作用下采空区顶板失稳破坏具有突发性及受力过程复杂的特点,将机械施工荷载简化为移动简谐力,采用力学分析建立了机械施工荷载-采空区顶板力学模型。基于动力学理论,形成了机械施工荷载-采空区顶板的双尖点突变模型,由系统失稳的充分条件和必要条件,获得了机械施工荷载-采空区顶板失稳判据。基于能量原理,推导了机械施工荷载-采空区顶板总能量方程,根据系统临界失稳判据,构建了临界机械施工荷载计算模型。对建立的两种失稳判据分别进行实例验证,结果表明采用突变理论计算得到的理论状态与实测状态一致;采用能量原理计算得到的临界机械施工荷载理论值与实测值较吻合,平均误差为11. 01%。研究可为露天开采下机械施工荷载大小控制、采场结构参数设置、采空区失稳控制与治理等提供参考。 相似文献
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滑坡演化的非线性动力学与突变分析 总被引：19，自引：1，他引：19
基于对任-连续函数, 至少在较小的邻域内可以用多项式任意逼近的数学理论, 运用改进的Backus广义线性反演理论, 以斜坡位移时间序列为基础, 反演建立了斜坡演化的非线性动力学模型。并利用自治梯度系统与突变模型的等价性, 通过变量代换得到标准的尖点突变模型。以黄茨及卧龙寺滑坡为例对滑坡的发展孕育过程进行分析, 结果表明:该非线性动力学模型不仅预测效果十分理想, 而且具有较高的自我调整适应能力; 斜坡临滑前都以突变特征值D的突降至零为前兆特征, 可作为-个具有物理意义的前兆指标。 相似文献
7.
根据冲击地压发生的力学条件和地质条件, 引入 (Ruina,1983年)单状态变量本构模型(Single state variable model, SSVM)对冲击地压的动力学行为和演化行为进行了描述。研究表明：模型中参数K， 对冲击地压系统动力学行为和状态变量演化行为贡献较大，而系统动力学行为和演化行为对 ，f初值的敏感性相对较低。模型模拟了冲击地压系统的粘滑特性和冲击地压系统的动力失稳过程，较好地解释了冲击地压的发生机理，为冲击地压失稳破坏的预测预报提供了理论依据。 相似文献
8.
根据冲击地压发生的力学条件和地质条件，引入(Ruina,1983年1单状态变量本构模型(Single state variable model，SSVM)对冲击地压的动力学行为和演化行为进行了描述。研究表明：模型中参数K，β对冲击地压系统动力学行为和状态变量演化行为贡献较大，而系统动力学行为和演化行为对φ，f初值的敏感性相对较低。模型模拟了冲击地压系统的粘滑特性和冲击地压系统的动力失稳过程，较好地解释了冲击地压的发生机理，为冲击地压失稳破坏的预测预报提供了理论依据。 相似文献
9.
隧道变形失稳过程的非线性动力学分析与破坏判据研究 总被引：1，自引：1，他引：0
隧道变形失稳过程与破坏判据研究是地下工程的热点与难点之一。运用协同学与混沌动力学,分析了隧道变形失稳过程的非线性动力学演化特征,并将其划分为平衡、非平衡线性、非平衡非线性等3个演化阶段;从系统分析的角度,研究了整个隧道系统的涨落关联机制,建立了隧道变形失稳的动力学演化模型。在此基础上,分别给出了大数据量(≥3000)与小数据量(3000)条件下稳定性演化过程的动力学判别准则。结合隧道变形失稳的阶段性特征,建立了其破坏的混沌动力学判据。将以上研究应用于广州地铁某立体交叉隧道的稳定性分析中,验证了该动力学演化模型与判据的合理可靠性,对隧道稳定性状态的判别具有一定指导意义。 相似文献
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隧道失稳破坏的动力学演化模型及其判据与能量演化模型及其判据是对同一系统分别从动力学过程与能量状态两个角度的描述与判别。从两种模型对围岩分区的描述出发,利用非线性动力学中的热力学熵S、Kolmogorov熵、关联维 的关系,证明了两模型在空间上的一致性,并通过演化时间建立了两模型的联系,证明了其在时间上的一致性。根据两种判据分别描述不同演化阶段的稳定性状态,从其对系统演化阶段的划分出发,研究了隧道系统在一般发展条件与跳跃式发展条件下动力学判据与能量判据的统一性。上述研究相互验证了两种模型及判据,并进一步阐释了隧道失稳破坏的非线性机制,对隧道围岩稳定性的状态判别与控制具有一定指导意义。 相似文献
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为解决超长工作面过大断面空巷极易发生片帮和大面积冒顶等难题，以晋城成庄矿某超长工作面为背景，建立大断面空巷的三维模型，将工作面顶板划分为煤柱顶板、空巷顶板和待采区顶板3部分。通过理论分析，推导了煤柱失稳的判据，并利用FLAC3D数值模拟分析了大断面空巷顶板应力演化过程。结果表明:煤柱宽度W≤40 m时，工作面超前支承应力与空巷超前支承应力在煤柱上叠加，煤柱开始发生塑性变形；W≤10 m时，煤柱顶板应力逐渐达到峰值16.6 MPa，煤柱发生破坏并失去承载能力，工作面超前支承应力向待采区转移，空巷顶板应力达到峰值12.7 MPa。根据空巷顶板应力演化规律，确定高水材料充填支柱支护的合理强度及空巷两帮煤壁注浆加固的时机，辅以空巷锚索梁补强，提出了大断面空巷综合治理措施，现场应用效果良好。 相似文献
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Nonlinear Evolutionary Mechanisms of Instability of Plane-Shear Slope: Catastrophe, Bifurcation, Chaos and Physical Prediction 总被引：1，自引：0，他引：1
Summary. A cusp catastrophe model is presented and the necessary and sufficient conditions leading to landslides are discussed. The
sliding surface is assumed to be planar and is a combination of two media: medium 1 is elastic-brittle or strain-hardening
and medium 2 is strain-softening. The shear stress-strain constitutive model for the strain-softening medium is described
by the Weibull’s distribution law. This paper is a generalization and extension of the paper by Qin et al. (2001b), in which
the shear stress-strain constitutive model for medium 2 was described by a negative exponent distribution; a special case
of the Weibull’s distribution law. It is found that the instability of the slope relies mainly on both the stiffness ratio
of the media and the homogeneity index and that a new role of water is to enlarge the material homogeneity or brittleness
and hence to reduce the stiffness ratio. A nonlinear dynamic model (also called a physical forecasting model), which is derived
by considering the time-dependent behavior of the strain-softening medium, is used to study the time prediction of landslides.
An algorithm of inversion on the nonlinear dynamic model is suggested for seeking the precursory abnormality and abstracting
mechanical parameters from the observed series of a landslide. A case study of the Jimingsi landslide is analysed and its
nonlinear dynamic model is established from the observation series of this landslide using the suggested model and the algorithm
of inversion. It is found that the catastrophic characteristic index |D| shows a quick rise till reaching an extremely high peak value after the slope evolves into the tertiary creep, and subsequently
approaches a zero value prior to instability, which can be regarded as an important precursory abnormality index. By taking
into account the evolutionary characteristic of the slope being in the secondary creep, a simplified nonlinear dynamic model
is proposed for studying the properties of bifurcation and chaos. It is shown that the emergence of chaos depends on the mechanical
parameters of the sliding-surface media. 相似文献
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De-zhong Kong Wei Jiang Yi Chen Zheng-yang Song Zhenqian Ma 《Arabian Journal of Geosciences》2017,10(8):185
Low recovery of longwall top coal caving (LTCC) remains one of the most difficult engineering problems in this mining method and impedes its application. The top coal left in the gob at face end accounts for a large portion of the total coal loss, and the instability of the leftover triangle coal at face end has long been a threat to the safety of miners and the mining equipment. In this paper, based on the engineering background of Ruilong mine, we explore the stability of the roof at the end of the face by using theoretical analysis, numerical simulation, and field measurement. Results reveal that in the inclined longwall top coal caving face, the immediate roof forms an “arch” structure, and the basic roof forms a “masonry beam” structure after the roof collapses; working resistance of the support calculated by the method of ultimate bearing capacity was adequate to meet the requirement of roof load; roof load of coal pillar was related to the length of key block and fracture position; and increasing the size of coal pillar could ensure the stability of both coal pillar and roof. 相似文献
14.
煤矿突水溃砂灾害的发生与煤层上履含水层性质、岩性特征及破坏程度等诸多因素有关。通过研究己15煤层顶板基岩与第四系底部的含、隔水性能及顶板覆岩岩性组合特征,计算出一次全部开采3．6m煤层时,其导水裂缝带最小发育高度为38．46m,最大为47．95m,确定了采煤活动导致的上覆顶板含水层发生水力联系的范围,认为己15—13030工作面煤层开采时发生顶板突水的可能性不大;计算一次全部开采3．6m煤层时,防砂安全垂高最大为23．5m．防塌安全煤岩柱最大垂高为12．5m,结合煤层顶板基岩及第四系底部岩层的水文地质特征,认为工作面回采时顶板溃砂的可能性也不大。强调在生产过程中,要加强顶板涌水的观测,同时增加现有排水系统的排水能力,从而为工作面安全回采提供支持。 相似文献
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Summary Based on field instrumentation in eight different coal mines representing varying depths and strata conditions, a relation for obtaining the critical convergence value has been established. In development heading for bord and pillar workings this relation can be used successfully to control the premature collapse of the roof. An empirical relation for rock load has been established. This can be utilized for optimum design of support system. The roofs have been categorized as stable, short-term stable and unstable. Proper attention should be provided for an unstable roof and the support design is to be changed before the convergence reaches the critical value. 相似文献
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倾斜煤层沿空半煤岩巷由于围岩结构的非对称性和非均质性,受采掘扰动影响,巷道围岩呈现更严重的变形破坏。为揭示不同基本顶断裂形式对倾斜煤层沿空半煤岩巷围岩稳定性的影响规律,采用数值模拟方法针对该类巷道4种基本顶断裂形式下巷道围岩变形特征进行了研究。结果表明:基本顶断裂线位置对该类巷道围岩稳定性的影响程度由小到大依次为:采空区侧、煤柱上方、实体煤侧、巷道上方;基本顶断裂线位于采空区侧时,煤柱轴向、横向应力增速均小于其他情况,垂直位移也最小,煤柱变形在允许范围内,可保持后期对顶板的支承能力,对巷道维护最有利。在此基础上,以贵州某矿1511工作面回风巷为工程背景进行了工业试验,通过理论计算和现场钻孔探测综合分析得出,为避免基本顶断裂线位于煤柱上方靠巷道侧,下一步掘进时煤柱宽度应由3 m改为5 m。掘采期间断面检测结果显示,断面最大收缩率为23.3％,最大非对称变形率为5.2％,巷道整体均匀协调变形,进一步验证了研究成果的可靠性。 相似文献
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研究由顶板-煤体-底板所构成的煤岩组合体变形破裂声发射和微震的规律,对于研究冲击机制具有重要意义。利用SANS材料试验系统、Disp-24声发射监测系统和TDS-6微震信号采集系统,对单轴受压的不同煤岩组合试样进行声发射和微震试验,得到不同组合试样在受载破坏过程中的声发射和微震信号。试验研究表明：组合试样发生冲击破坏时的声发射和微震信号的强度随试样的单轴抗压强度、冲击倾向性以及其顶板与煤层的高度比值的增加而增强;微震信号的振幅可以反映组合煤岩体的冲击倾向性强弱;微震频谱幅度的分布随着抗压强度和冲击能指数的上升而向高频移动。上述结论对指导现场冲击矿压的监测预警以及评价有着重要意义。 相似文献
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淮南矿区煤层为石炭二叠纪煤层,13-1煤属下石盒子组,煤层全区稳定,平均厚度为3．5m。由于该区视电阻率曲线在砂岩及煤层反映为高电阻率,而泥岩电阻率相对平缓,针对这个特点,利用约束稀疏脉冲反演方法,结合地震数据,重构富含顶底板砂泥岩信息的波阻抗曲线,得到了联井波阻抗剖面及煤层顶板属性切片图,该成果图可清晰反映13—1煤层及顶板以上10m范围内的砂、泥分布。通过该实例的应用,对如何建立地质模型、重构波阻抗的方法、子波估算方法及稀疏脉冲反演中的A值的选择等几个重要环节进行了剖析。 相似文献
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Arka Jyoti Das Prabhat Kumar Mandal Satya Prakash Sahu Angad Kushwaha Rana Bhattacharjee Subhashish Tewari 《Journal of the Geological Society of India》2018,92(6):732-742
The rock mass around an excavation is generally traversed by different geological discontinuities such as faults, folds, slips, joints, etc. Fault is one of the major geological discontinuities which creates lot of difficulties during underground winning of coal. Entire stress regime and ground conditions in the formation are altered in and around the faults. Faults also impose detrimental effects by introducing impurities, including clay and various forms of mineral matter into the coal seams; opening of pathways for the influx of water and gas into the underground workings; displacing the coal seams upward/downwards making the coal seams difficult or sometimes impractical to mine. Appropriate evaluation of the effect of the fault on the stability of the underground workings is a requisite for safe design of the underground mining structures. In this paper, a study has been carried out to assess the effect of the fault on the stability of underground coal mines by numerical simulation with distinct element method (DEM). On the calibrated DEM model, parametric study has been performed by varying the selected parameters, the dip and the friction angles of the fault. The analysis of variance (ANOVA) shows that both the factors have statistically significant effect on the strength of the coal pillar. Similarly, the displacement of the immediate roof and the height of the disturbed strata are evaluated by the DEM modelling and statistical analysis when the fault passes through the middle of the gallery. The results of ANOVA for both cases indicate that the both factors have significant effect on the displacement of the immediate roof and the height of the disturbed strata. It is obtained from the study that the low angle fault causes high instability in the immediate roof. The paper has been supplemented with the field observations where instability in underground roadways of a coal mine in India is caused by the fault. It was observed in VK-7 incline mine of Singareni Collieries Company Limited, India that there was sudden failure of immediate roof of a roadway where a low angle fault crosses the middle of the roadway. The findings of the paper help to understand the behaviour of the coal pillar and the surrounding rock mass in the presence of the fault. The study would also help to take appropriate decisions about the unstable regions of the working safeguarding safety in underground coal mines. 相似文献