综合物探技术在矿井工作面底板含水构造探测中的应用

为了查明汾源煤业文明矿5-101首采工作面底板岩层赋水情况和煤层地质异常体情况,并对其进行突水危险性区域划分及评价,采用瞬变电磁法、直流电法和无线电波透视法三种物探方法综合勘探,综合分析三种物探方法探查结果,并结合揭露情况和钻孔验证。结果表明:位于切眼往外(0~250)m范围内,工作面底板相对破碎、裂隙岩溶发育或富水性强,导高大,且煤层内部较不均匀,存在多条5m以上落差含水断裂破碎带,此区域突水危险性最大;切眼往外(300~380)m范围内存在局部富水区域,导高较小,但不存在构造破碎带,突水可能性较小;工作面其他区域都较安全。综合物探比单一物探更具有准确性和可靠性,更符合工程实际情况,为采取针对性的治理措施从而实现安全回采提供了参考依据。     

Integrated-signal-based leak location method for liquid pipelines

Leaks in pipelines can cause major incidents resulting in both human injuries and financial losses. Among the considerable leak detection and location methods, the Negative Pressure Wave (NPW) based method has been widely used in locating leaks in liquid pipelines. The NPW based method only monitors the pressure changes at two ends of a pipeline. But the pressure is apt to be fixed by the end equipment and the change of it induced by a small or slow leakage is too small to be detected, which limit the application of the NPW based method in these situations. This paper presents a novel leak location method based on integrated signal, which is a combination of the pressure and flow rate signals. The representation of the integrated signal is derived from the transient analysis of the leakage. For the change of the integrated signal induced by a leakage is larger than the pressure change and it is also unaffected by the end equipment, the proposed method can be used to detect and locate small or slow leakage in a pipeline and can also be used in pipelines which end pressures are fixed by some kinds of equipment. The validation of the proposed method also confirms its advantages.     

A new shock tube configuration for studying dust-lifting during the initiation of a coal dust explosion

The traditional defence against propagating coal dust explosions is the application of dry stone dust. This proven and effective safety measure is strictly regulated based on extensive international experience. While new products, such as foamed stone dust, offer significant practical benefits, no benchmark tests currently exist to certify their dust lifting performance in comparison to dry stone dust. This paper reviews the coal dust explosion mechanism, and argues that benchmark testing should focus on dust lifting during the initial development of the explosion, prior to arrival of the flame. In a practical context, this requires the generation of shock waves with Mach numbers ranging from 1.05 to 1.4, and test times of the order of 10's to 100's of milliseconds. These proposed test times are significantly longer than previous laboratory studies, however, for certification purposes, it is argued that the dust lifting behaviour should be examined over the full timescales of an actual explosion scenario. These conditions can be accurately targeted using a shock tube at length scales of approximately 50 m. It is further proposed that useful test time can be maximised if an appropriately sized orifice plate is fitted to the tube exit, an arrangement which also offers practical advantages for testing. The paper demonstrates this operating capability with proof-of-concept experiments using The University of Queensland's X3 impulse facility.     

基于皮电、心率和β波的指挥人员应急能力度量

指挥人员的应急能力是决定应急工作效率的重要因素,按照生理、心理性指标度量的指挥人员的应急能力,是选择指挥人员的重要依据之一。首先,分析指挥人员应急能力与情绪、生理性应激的关系。然后,利用E-prime软件,通过情绪Stroop效应范式诱发情绪,用生物反馈仪测量生理性应激状态下生理指标变化,研究高应急能力指挥人员应具备的能力条件。试验结果表明,高应急能力组人员应激前后皮电、心率、β波以及反应时间等指标变化率显著低于低应急能力组人员。试验结果与人的应急能力分类指标相符,能力较强的指挥人员的生理指标变化率较低,适合从事应急指挥方面的工作。     

Simulation analysis on structure safety of coal mine mobile refuge chamber under explosion load

In order to check structural strength of coal mine mobiles refuge chamber, and do security evaluation of the mobile refuge chamber, a refuge chamber model was established, then a finite element method was instituted for it to ensure the refuge chamber would not be severely damaged when gas or coal dust explosion suddenly happened. A triangle shock wave with 1.2 MPa over-pressure, 300 ms lasting time was settled. Explicit nonlinear dynamic analysis program was used to simulate response of the refuge chamber. The maximum stress was 244 MPa, located in central part of sides and tail end of the last capsule. The maximum displacement was 29.32 mm, located in central part of sides and tail end of the last capsule. The calculation indicated that the refuge chamber was not obviously damaged. It could reliable work to meet safety requirements. Compared with the reported experimental results, the simulation method was verified. Based on analysis, suggestions were put forward for further improving.     

瓦斯爆炸传播过程中障碍物激励效应的数值模拟

笔者对瓦斯爆炸传播过程中的障碍物的激励效应的物理机制进行了分析 ,并构建了相应的物理模型 ,设计了 3种情况下 ,对冲击波经过障碍物附近时的变化特征进行了数值模拟。结论表明 ,非燃烧区的障碍物同样存在激励效应 ,激励效应取决于瓦斯爆炸冲击波的初始强度 ,即爆轰状态激励效应最为强烈。     

INLET CONCENTRATION TIME NOMOGRAM FOR URBAN BASINS1

ABSTRACT: A physically-based nomogram to determine inlet concentration times for composite developed basins is presented. This nomogram is constructed from previously derived kinematic wave formulations of both catchment and gutter flow components of surface runoff. With specified physical properties of a basin and rainfall intensity-duration relationships, the inlet time can be obtained from the nomogram directly.     

EFFECT OF RAINFALL-EXCESS DETERMINATION ON RUNOFF COMPUTATION1

ABSTRACT: Four methods of determining rainfall-excess are considered. They include Ø-index and equations of Horton, Kostyakov and Philip. These methods are utilized in a nonlinear kinematic wave model to predict surface runoff from two natural agricultural watersheds. The effect of determining rainfall-excess on surface runoff response is then examined. It is observed that errors in rainfall-excess constitute a major source of error in runoff prediction. The choice of a method of determining rainfall-excess is thus crucial to runoff computation.     

KINEMATIC FLOW ON LONG IMPERMEABLE PLANES1

An analysis of more than 200 overland flow hydrographs generated by simulated rainfall on long impermeable planes showed that kinematic waves prevailed over dynamic waves. Although laminar flow appears to occur at low flows, most flows appear to be either in the transition from the laminar to the turbulent state or in a fully developed turbulent state. Location of the laminar-turbulent transition could not be explained in terms of Reynolds number alone. The transition was significantly affected by rainfall intensity-a factor which rendered quantification of the transition indeterminate. However, the error involved in treating all flows as turbulent would be small with the resulting analysis made considerably less complex.     

高大建[构]筑物的共振震害

分析了国内外典型地震的共振震害个例。论述了致灾的长周期和大振幅地震波形成规律：①地震波周期随震级和震中距而增大;②长周期波出现与地基类型有关,软弱地基能传递长周期地震波,地基越软弱,越厚所能传递的波周期越长;③松软地基对地震波起放大作用,特别是表层松软、下层坚硬的地基,放大作用更显著,对高大建筑物危害更大。提出了减轻共振震害的对策。随着经济发展,高大建筑和结构物越来越多,潜在震害日益加重,研究共振震害对防震减灾具有现实意义。