Use of rock classification to estimate roof caving span in oblong workings     

P. R. Sheorey 《Geotechnical and Geological Engineering》1984,2(2):133-140

Summary Indian coal measures have widely varying caving characteristics. The maximum roof span of a longwall or depillaring panel at the time of nether roof collapse is shown to have a direct relation withRQD from a study of 12 case histories. A similar relation between maximum unsupported span of openings and rock mass quality as defined by theQ-system was also demonstrated. A simple nomogram is presented to predict the face advance required to cause roof collapse when theRQD or rock mass quality is known.  相似文献   

Roof bolting in underground mining: a state-of-the-art review   总被引：1，自引：1，他引：1  

Syd S. Peng  D. H. Y. Tang 《Geotechnical and Geological Engineering》1984,2(1):1-42

Conclusions With continuing investigations and developments, roof bolting today can in most cases successfully reinforce the mine roof in underground mining. In order to cope with the increasing use of roof bolts, efforts should be made to maximize the safety and minimize the cost. With regard to mechanical bolting, two important parameters need more advanced improvements and study, namely, optimum design of the shape and type of expansion shell and optimum bolt tension for a specific bolt pattern. For the fully grouted resin bolt, the most critical requirement is to develop a fast-setting, low-cost, intoxic, inflammable grouting material that can be used in the high speed mining cycle. It should be noted that geological conditions such as the strata type, rock properties,in situ stress, and planes of weakness play an important role in the successful application of any roof bolting system. These factors should be specified as accurately and quantitatively as possible in the design of any roof bolting system. Finally, proper and careful installation and continuous monitoring are imperative for the success of any roof bolting system.  相似文献   

The stability and behavior of a frictional system with a two state variable constitutive law     

Michael L. Blanpied  Terry E. Tullis 《Pure and Applied Geophysics》1986,124(3):415-444

  相似文献   

Rock moisture content in the field and the laboratory and its relationship to mechanical weathering studies     

Kevin Hall 《地球表面变化过程与地形》1986,11(2):131-142

Rock moisture content is a major control of mechanical weathering, particularly freeze-thaw, and yet almost no data exist from field situations. This study presents moisture content values for rocks, taken from a variety of positions and conditions, in the maritime Antarctic. Additional information regarding the amount of water the rock could take up, as observed from laboratory experiments, is also presented. The results show that the approaches used in simulation experiments, particularly that of soaking a rock for 24 hours, may produce exaggerated results. It was found that the saturation coefficient (S-value) was a good indicator of frost susceptibility (based on water content) but that the derivation of that value may underestimate the potential of some rocks. The distribution of moisture within rocks is seen as an important, but unkown, factor. The results of these field moisture contents suggest that for simulations of freeze-thaw or hydration to be meaningful then they should have rock water contents based on field observations.  相似文献   

Complex behaviour of a coal sample in a large scalein situ compression test     

Tadeusz Cyrul 《Geotechnical and Geological Engineering》1986,4(4):257-271

Summary A large scalein situ compression test of a laminated coal cube is described. The cube was uniformly loaded by a system of hydraulic jacks supplied simultaneously from one pump. At the same time both load and deformations were controlled. Deformations were measured by 60 longitudinal gauges located at the side surface of the cube in the regular net. Due to the heterogeneity of the rock the readings showed scatter. As a first approximation, the scattered data were fitted to the plane using the least square method. Orientations of the planes were analysed and show permanent relative movement between adjacent lamina indicating complex behaviour of the cube under loading. Detailed analysis of this behaviour indicated that the cube was subjected to both bending and twisting.  相似文献   

三山岛金矿矿柱的稳定分析     

凌荣华  丁恩保 《工程地质学报》1995,3(2):42-46

本文基于三山岛金矿工程地质条件，针对设计所提出的采场和矿柱的尺寸，提出了分析矿柱稳定性的一种新的方法，并应用该方法分析了矿柱的稳定性；同时，提出了提高矿柱承载能力的一种有效途径。另外，还详细讨论了矿柱顶点的深度与长度之间存在的关系。  相似文献   

岩体水力学概述   总被引：8，自引：0，他引：8  

仵彦卿 《地质灾害与环境保护》1995,6(1):57-64

本文通过伙在工程活动与地质环境相互作用分析，揭示了人类工程、岩体与地下水之间的关系；论述了岩体水力学的研究对象，学科地位，研究内容以及研究方法。  相似文献   

节理岩体断裂的分形机理研究          下载免费PDF全文

杨太华 《地震工程学报》1995,17(1):10-14,22

本文在考察了节理化岩体的断裂力学特征的基础上，结合现代分形几何原理，建立起追踪裂纹裂分形模型，对不连续岩体的断裂韧性的分形效应进行了深入研究，并通过压剪试验得到难。  相似文献   

Identification of strength equilibrium rock slopes: Further statistical considerations     

A. D. Abrahams  A. J. Parsons 《地球表面变化过程与地形》1987,12(6):631-635

Strength equilibrium slopes are rock slopes whose gradient θ and rock mass strength (RMS) are in adjustment. The identification of such slopes depends on the accurate specification of the strength equilibrium envelope. Previous attempts to delimit the envelope are reviewed and modifications are proposed that permit its more rigorous statistical definition. Because θ can be measured much more reliably than RMS, the structural relation between these variables is estimated by regressing RMS on θ, and the strength equilibrium envelope is defined by the 95 per cent confidence limits. The analysis is performed on a data set of 268 rock slopes, representing all the data on RMS and θ hitherto employed in published studies of strength equilibrium slopes.  相似文献   

Source mechanisms and microfracturing during uniaxial cycling of rock   总被引：1，自引：0，他引：1  

C. H. Sondergeld  L. H. Estey 《Pure and Applied Geophysics》1982,120(1):151-166

Focal mechanisms for 116 acoustic emission events associated with uniaxial cyclic loading of Westerly granite have been investigated using P-wave first-motions. Polarities were observed at eight transducers positioned on the sample to provide good azimuthal coverage. The P-wave radiation patterns can be fit by a quadrupole source but not by a simple pure tensional source. The predominant orientations of the two nodal planes for the quadrupole fit were subparallel to and perpendicular to the ₁ direction. Events with close hypocenters, i.e., within a radius of 3 mm, display a remarkable similarity in focal mechanisms irrespective of the cycle or time within a cycle at which they occur. The polarity observations of 48 of 116 acoustic emission events could be fit with the simple quadrupole indicating that the microfracturing processes even in uniaxial compression often simplistically portrayed as propagating axial cracks are indeed quite complex.  相似文献