A review of the geomechanics aspects of a double fatality coal burst at Austar Colliery in NSW,Australia in April 2014

A coal burst occurred on 15 April, 2014 at the Austar Coal Mine, located west of Newcastle, NSW,Australia. The burst resulted in fatal injuries to two men working as part of the mining crew at the development face. At the time, a continuous miner was being used to mine a longwall development gate road through heavily structured coal, at a depth of approximately 550 m. A number of pre-cursor bumps had occurred on previous shifts, emanating from the coal ribs of the roadway, in proximity to the coal face.This paper reviews the geological, geotechnical and mining conditions and circumstances leading up to the coal burst event; and presents and discusses the available evidence and possible interpretations relating to the geomechanical behaviour mechanisms that may have been critical factors in this incident. The paper also discusses some key technical and operational considerations of ground support systems and mining practices and strategies needed for operating in such conditions in the future.     

平顶山矿务局八矿已_(15)煤层回采顺槽稳定性的观测研究

本文通过对特定地质条件下回采巷道围岩的位移、支架的变形及支承压力观测数据的分析研究,提出了两侧均为实体煤时巷道中支承压力的分布规律,对以后这种地质条件下回采顺槽的布置及设计有指导作用。     

软岩巷道底鼓机理分析

近年来,随着煤田深处矿业工程的不断延伸,巷道围压逐渐增大,巷道发生底鼓的现象也愈演愈烈,巷道底鼓是造成巷道变形破坏的常见形式。文章分析了巷道底鼓的主要因素,通过工程实例,简述了巷道的底鼓变化规律以及两帮对于巷道底鼓的联动作用,同时有针对性的提出了锚网索支护对于巷道底鼓变形量的影响。文章为维护巷道及底鼓的治理提供了一定的依据。     

深部围岩开挖损伤区数值模拟研究

针对深部围岩体卸荷的特点,引入拉伸应变来描述损伤,得到了岩石损伤弹塑性耦合本构模型,并将其编译为计算软件FLAC的用户自定义本构模型。在此基础上,对深部围岩开挖损伤区进行了数值模拟,分析了围岩和支护的相互作用以及不同支护形式对开挖损伤区的影响,为选择合理的支护形式和施工设计等环节提供参考。     

电磁辐射法在岩爆监测中的应用

简述了电磁辐射法预测岩爆的原理,实测给出了有岩爆危险时电磁辐射强度和脉冲数的临界值和有岩爆危险时电磁辐射的变化规律。结果表明,采用电磁辐射法预测岩爆是可行的,并且实施需要时间短,准确率高,能够监测到工作面前方的岩体活动情况,是一种很有发展前途的岩爆危险性预测预报方法。     

Decision aid for allocation of transportation funds to guardrails

We address the need for allocation of resources to run-off-road and fixed-object hazards on immense secondary road systems. In Virginia, there are 95,000km of roadway with uncharacterized hazards in need of guardrail upgrade, installation, or related warning signs or other protection. A decision aid is developed to assist the planner in guardrail resource allocation by accounting for the potential crash severities, traffic exposures, costs of treatment, and other factors. A premise is that no single benefit-cost ratio or selection criterion applies across all localities. The decision aid enables the planner to interpret the variety of benefits and costs in their own units, emphasizing the needs and preferences of individual localities. The paper describes: (1) archiving and comparison of protected and unprotected hazards; (2) regional screening of hazardous corridors and (3) multicriteria benefit-cost analyses of guardrail sites. A case study of guardrail selection is presented.     

Stability influence factors analysis and construction of a deep beam anchorage structure in roadway roof

Deep beam anchorage structures based on spatial distribution analysis of the cable prestressed field have been proposed for roadway roof support. Stability and other factors that influence deep beam structures are studied in this paper using mechanical calculations, numerical analysis and field measurements. A mechanical model of deep beam structure subjected to multiple loading is established, including analysis of roof support in the return airway of S1203 working face in the Yuwu coal mine, China. The expression of maximum shear stress in the deep beam structure is deduced according to the stress superposition criterion. It is found that the primary factors affecting deep beam structure stability are deep beam thickness, cable pre-tension and cable spacing. The variation of maximum shear stress distribution and prestressed field diffusion effects according to various factors are analyzed using Matlabòand FLAC3D~(TM) software, and practical support parameters of the S1203 return airway roof are determined.According to the observations of rock pressure, there is no evidence of roof separation, and the maximum values of roof subsidence and convergence of wall rock are 72 and 48 mm, respectively. The results show that the proposed roof support design with a deep beam structure is feasible and achieves effective control of the roadway roof.     

长距离定向钻进技术在巷道掘进超前探查中的应用研究

巷道掘进超前探查一般采用钻探方法的开展工作,常规回转钻进由于受钻进工艺等影响,存在钻孔施工长度短、影响正常掘进、施工精度较差等问题。而采用长距离掩护式定向钻进工艺开展超前探放水工作,可对掘进头600m范围内进行超前探查,钻孔施工长度较常规回转钻进孔长度增大3~4倍,在不影响掘进的前提下,可通过随钻测斜仪器实时对钻孔轨迹进行调整、监控,从而达到高精度、长距离对掘进前方进行超前探查,较常规超前探放水具有较大的优势[1]。     

TSP技术在矿山井巷掘进及采矿生产中的应用探讨

探讨使用TSP技术进行矿山井巷掘进和采矿生产过程中的地质超前预报,为即将掘进的井巷、矿体内部的地质结构及其周围的地质状况提供有用信息。通过配套软件TSP win对岩体力学参数进行评估,获得地层变化的2D和3D图像,岩体中横波和纵波的波速、岩体密度、泊松比、岩体的弹性模量等,得出矿体围岩等级、长度、空间位置,可对不良地质体的空间分布、规模和类别如断层、岩溶及含水量进行预报,为超前支护和衬砌提供依据和参数,为不同地段和不良地质体的施工和采矿生产提供施工方案和解决措施。     

羊场湾煤矿软岩底板炉渣混凝土加固技术

为提高软岩底板强度而供无轨胶轮车等大型车辆行驶,结合羊场湾煤矿16206机巷软岩底板地质条件,研究了炉渣混凝土底板加固技术,确定了合理的配比方案,并对机巷现场进行混凝土地坪铺设应用。研究与应用结果表明：炉渣混凝土底板强度可满足大型车辆连续运输所需,极大地提高了底板承载能力,防止底鼓,为长距离巷道实现连续运输提供了基础保障。