【摘 要】
：
The breaking features and stress distribution of overlying strata in a steeply dipping coal seam (SDCS) differ significantly from those in a near-horizontal one.In this study,the laws governing the evolution of vertical stress release and shear stress con
【机 构】
：
State Key Laboratory of Mining Response and Disaster Prevention and Control in Deep Coal Mines,Anhui
论文部分内容阅读
The breaking features and stress distribution of overlying strata in a steeply dipping coal seam (SDCS) differ significantly from those in a near-horizontal one.In this study,the laws governing the evolution of vertical stress release and shear stress concentration in the overlying strata of coal seams with different dip angles are derived via numerical simulation,rock mechanics tests,acoustic emissions,and field measurements.Thus,the stress-driven dynamic evolution of the overlying strata structure,in which a shear stress arch forms,is determined.Upon breaking the lower part of the overlying strata,the shear stress transfers rapidly to the upper part of the working face.The damaged zone of the overlying strata migrates upward along the dip direction of the working face.The gangue in the lower part of the working face is compacted,leading to an increase in vertical stress.As the dip angle of the coal seam increases,the overlying strata fail suddenly under the action of shear stresses.Finally,the behavioral response of the overlying strata driven by shear stresses in the longwall working face of an SDCS is identified and analyzed in detail.The present research findings reveal the laws governing the behavior of mine pressure in the working face of an SDCS,which in turn can be used to establish the respective on-site guidance.
其他文献
近年来由于铝合金材料强度高、质量轻、耐腐蚀等优点,铝合金单层网壳被广泛应用在工程中。对近20年来铝合金单层网壳典型工程的结构形式、荷载以及受力特点等进行分类介绍,并论述了该类结构在设计和施工中所取得的成果,总结了铝合金单层网壳的各类科研成果,探讨了该领域今后需要进一步研究的问题,并提出了若干建议。
介绍了国内外大型地震模拟振动台及其基础设计的发展现状,对大型振动台基础设计的计算分析方法、控制标准进行了对比研究,给出了大型振动台基础工程的选型及设计建议,提出了控制振动台基础重量与最大出力比的新概念,并对大型地震模拟振动台基础工程设计的研究方向作出展望。
为了揭示充填体材料在单轴荷载下的损伤机理,首先对充填体材料在单轴荷载下的应力—应变曲线进行分析,再以损伤变量作为影响充填体材料力学特性的内变量,基于统计损伤理论、最大拉应力准则和应变等效假说,推导了充填体材料在单轴荷载下的经典损伤本构模型。由于充填体试件在初始阶段存在压密过程,提出了压密系数并将其引入到经典损伤本构模型,弥补了经典损伤本构模型无法合理解释充填体压密过程的缺陷。采用修正损伤本构模型对几种不同试验数据进行拟合,并与经典损伤本构模型进行对比,结果表明:拟合曲线不仅能够较好地模拟充填体试件在初始加
中国已成为300m以上高的超高层建筑发展的中心之一,截止到2021年,全球高度前15栋已建和在建超高层建筑中9栋位于中国,建筑高度已突破600m。在超高层建筑高度不断突破的同时,地基基础面临高基底压力、复杂的风和地震作用、严格的沉降控制等问题。结合国内超高层建筑的建造需求与工程实例,总结了超高层建筑桩基础设计原则、主要深基础形式。阐述了钢管桩、嵌岩桩、大直径超长灌注桩等几种主要基础形式的特点与设计要点,并对应地介绍了上海环球金融中心、南京绿地紫峰大厦、天津117大厦等典型超高层建筑基础工程实践,分别涉及含
Coal is heterogeneous in nature,and thus the characterization of coal is essential before its use for a specific purpose.Thus,the current study aims to develop a machine vision system for automated coal characterizations.The model was calibrated using 80
Potentially explosive atmosphere can occur not only in the production systems of the food,energy,chemical and petrochemical industries but also in the production processes of the mining industry.Gases,vapours,mists and dusts arise can escape in an uncontr
The discharge of acid mine drainage from abandoned high sulfur (S) coal mines has caused serious pollution in the Shandi River,Yangquan,Shanxi Province.To determine the impact of long-term acid mine drainage on the microorganisms in the river,we collected
整体钢平台模架装备是超高建筑物和构筑物建造的关键。基于传统整体钢平台模架、智能控制整体钢平台模架的发展历程,重点论述了内筒外架支撑式整体钢平台模架装备、临时钢柱支撑式整体钢平台模架装备、劲性钢柱支撑式整体钢平台模架装备、钢梁与筒架交替支撑式整体钢平台模架装备、钢柱与筒架交替支撑式整体钢平台模架装备的技术发展。同时对整体钢平台模架装备的一体化技术进行了介绍。整体钢平台模架装备的理论基础与技术体系可为今后该技术的应用提供参考和借鉴。
我国的城市开发建设正处在由以增量建设为主转向存量提质改造和增量结构并重的阶段,随着实体经济的衰退,城市大量的商业建筑逐步改造为办公建筑,这些建筑均面临着重新进行抗震鉴定与加固改造。加固改造的特点也从“结构安全为主的加固+局部建筑功能的改造”向“大拆大改为主+被动性结构加固”模式转变,同时我国的工程建设标准也进行了多次修订,对工程建设的设计要求逐步提高,由此带来了加固改造工程中执行什么样的标准、如何确定合理的设防标准、抗震加固的地震作用取值、加固设计的后续使用年限等一系列的问题。针对城市大型公共建筑
A study of the deformation of the surrounding rock and coal pillars near a fault under the influence of mining is conducted on a physical model for the design of coal pillars to support and maintain the roofs of adjacent fault roadways.This research is ba