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981.
软岩巷道弹塑性变形的理论分析 总被引:16,自引:0,他引:16
本文采用莫尔-库仑屈服准则和非关联塑性流动法则分析了轴对称软岩巷道的变形规律。从轴对称平面应变问题的基本方程出发,导出了软岩巷道弹塑性变形的位移理论解答,并给出了现有应力与位移理论解的适用条件。通过实例计算结果表明,本文得出的位移理论解与有限元数值解相当吻合。 相似文献
982.
983.
本文结合厦门海沧经济开发区路网规划工作,着重探讨了区域公路网规划的分区、原则、交通量预测、路网布局、实施方案等问题。 相似文献
984.
中国东部富碱侵入岩铅同位素组成特征模式及其地质意义 总被引:1,自引:0,他引:1
对中国东部11个铅同位素省内45个中生代富碱侵入岩体测定了65个长石和全岩的铅同位素组成,并结合前人资料分析认为。各铅同位素省富碱侵入岩铅同位素组成特征模式与所在铅同位素省中生代中酸性花岗岩类岩石的长石铅同位组成特征模式完全相同,呈等值变化,这就充分暗示富碱侵入岩不太可能属于来自地幔岩浆直接分异产物,而与地壳基底岩石分层深熔或部分熔融作用有关。 相似文献
985.
Michael Hood 《Geotechnical and Geological Engineering》1985,3(2):91-111
Summary A review of the benefits of assisting mechanical tools, notably drag bits, with moderate pressure waterjets suitably directed with respect to the bit is given. These benefits include reduced bit forces, especially the bit normal force, reduced bit wear, reduced dust make, and reduced incidence of frictional sparking. The research work that has been conducted to date to investigate this phenomenon has been empirical in nature. Experiments are described that extend the data bank of this empirical knowledge. In addition, experiments aimed at gaining a better understanding of the fundamentals of the rock fragmentation process with this hybrid cutting method are outlined.Results from the first of these experimental series are used to make recommendations as to the position of the jet with respect to the bit, the stand-off distance between the nozzle exit and the bit/rock interface, and the jet energy. In addition, preliminary findings are reported regarding the increase necessary in the jet energy when the bit velocity is increased. Results from the second test series are discussed in the context of rock fracture behaviour induced by mechanical bits acting alone. The likely influence of waterjets on these fracture processes is analysed. It is concluded that, in terms of the bit force reductions, a dominant influence of the jets when used in conjunction with sharp drag bits, is continuous removal of the rock debris that forms ahead of the advancing bit. The observed reductions in bit wear and incidence of frictional sparking are attributed to reduced heat loading of the bit during the cutting operation. Reductions in the dust make are attributed to effective wetting of the fine rock particles before they become entrained in the airstream. 相似文献
986.
R. W. Greenelsh 《Geotechnical and Geological Engineering》1985,3(3):183-194
Summary Factors affecting the stability of a trial open stope at a depth of 1000 m in fissile foot wall and hanging wall shales are discussed. A combination of systematic support using cable dowels, and reduced disturbance from blasting using low density explosives and single ring firing, allowed successful completion of the stope. 相似文献
987.
在我国东部沿海修建地下水封石洞油库若干问题的探讨 总被引:2,自引:0,他引:2
随着我国大陆架油、气田不断被发掘、开采,石油储运问题已指日可待。我国海岸线的基岩岸约占全长的2/3以上,其中,块状结晶岩体又占基岩岸的一半以上,这就给水封油库的布置提供了良好的基础。在油库的选择和兴建中,应加强对建库岩体和主要结构面、地应力及其分布的充分研究,以期能对洞库稳定问题、地下水位及水量的合理确定问题有所裨盖、 相似文献
988.
J. P. McGreevy 《地球表面变化过程与地形》1985,10(2):125-136
Four rock types (basalt, sandstone, granite, and chalk) are examined with respect to the maximum surface temperatures which they experience when subjected to similar conditions of exposure. Rock temperature measurements are reported for an urban environment and for two experimental situations in which an infrared lamp is used to simulate heating under cold and hot conditions. Differences in rock temperatures are discussed with reference to thermal rock properties (albedo, specific heat capacity, and thermal conductivity). Some natural situations are suggested in which thermal rock properties could conceivably play a role in determining the extent to which rocks would be affected by particular weathering processes. 相似文献
989.
990.
The Stone Canyon well penetrates 600 m of highly fractured and severely altered quartz diorite intimately associated with the creeping segment of the San Andreas fault of central California. Geophysical logs reveal a complex hydrology dominated by major fractures. Fluid pressure in some fractures is sufficient to prevent invasion of the formation by heavy drilling mud, implying pore pressures at least 10% higher than hydrostatic ones. At least three chemically distinct waters are encountered, including a chloride brine clearly segregated from the shallow, potable groundwater. Chemical alteration of the quartz diorite persists throughout the well, far below the depth where the water-rock reactions responsible for the ubiquitous chlorite and mixed-layer clays can be considered weathering. Whole-rock 18O analyses indicate significant interaction of the rocks with a low 18O fluid within some of the fractured and altered zones, whereas a deeper sample shows18O enrichment. High pore pressures encountered in Stone Canyon may be due to tectonic compression. Measurements of temporal variations in the pore pressure at the well may provide a means of predicting earthquakes along this segment of the San Andreas fault. 相似文献