THE FAILURE CHARACTERISTICS OF SELECTED BRITISH ROCKS
THE FAILURE CHARACTERISTICS OF SELECTED BRITISH ROCKS
复制标题
选定的英国岩石的破坏特征
DOI：
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发表时间：
1982
期刊：
影响因子：
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通讯作者：
S. Selvakumar
中科院分区：
文献类型：
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作者：
S. Priest;S. Selvakumar
在1000kN伺服试验机上，对直径50.8 mm的邦特砂岩、巴斯石灰岩、波特兰石灰岩、石炭系砂岩、石炭系石灰岩和镁质石灰岩进行了含水率从完全干燥到完全饱和的单轴试验。除浴灰岩外，所有岩石在峰后区域都表现出II类行为。所有岩石的单轴抗压强度、杨氏模量和脆性指数均随含水率的增加而显著降低，符合简单的指数模型。虽然泊松比和膨胀性也受到水分含量的影响，但没有观察到一致的趋势。共进行了37个三轴试验，在浴场，波特兰和镁石灰岩上使用了一个新的140兆帕电池，能够通过平衡活塞加载直径50.8 mm的试件。使用称重传感器、位移传感器和电阻应变计监测单元内的轴向载荷和样品变形。在本部门内设计和建造的用于产生和控制细胞压力的自动电子系统能够将细胞压力维持在程序值的+或-1kpa内，并能够测量细胞油体积变化至+或-4cu mm内。巴斯石灰岩、波特兰石灰岩和镁石灰岩的脆韧转变压力分别约为5、20和30兆帕。大多数试件，特别是那些在高围压下测试的试件，几乎没有宏观失效的迹象。在浴缸石灰石上的试验中，用细胞油体积的变化来测量体积应变，并对泄漏进行了校准。虽然所有的试件都表现出初始的体积压缩，但那些在细胞压力低于约15兆帕的测试中，在高轴向应变下表现出扩张。在15兆帕以上的细胞压力下测试的试件在整个测试过程中都表现出体积压缩。(作者/TRRL)
Uniaxial tests were carried out on 341 50.8mm diameter specimens of Bunter sandstone, Bath limestone, Portland limestone, Carboniferous sandstone, Carboniferous limestone and magnesian limestone, at moisture contents ranging from completely dry to fully saturated, in a 1000 kn servo-controlled testing machine. All rocks, with the exception of bath limestone, exhibited class II behaviour in the post-peak region. The uniaxial compressive strength, Young's modulus and brittleness index of all rocks decreased significantly with increasing moisture content, conforming well to a simple exponential model. Although Poisson's ratio and dilatancy were also affected by moisture content, no consistent trends were observed. A total of 37 triaxial tests were carried out on the bath, portland and magnesian limestones using a new 140 mpa cell capable of loading 50.8mm diameter specimens through a balanced piston. Axial load and sample deformation were monitored within the cell using a load cell, displacement transducers and electrical resistance strain gauges. An automatic electronic system for generating and controlling cell pressure, designed and constructed within the department, was capable of maintaining cell pressure within + or - 1 kpa of the programmed value and measuring cell oil volume changes to within + or - 4 cu mm. The brittle ductile transition pressures for the Bath, Portland and Magnesian limestones were approximately 5, 20 and 30 mpa respectively. Most specimens, particularly those tested at high confining pressures, showed few signs of macroscopic failure. Changes in cell oil volume, calibrated for leakage, were used to measure volumetric strain during the tests on bath limestone. Although all specimens exhibited an initial volumetric compression, those tested at cell pressures below approximately 15 mpa exhibited dilation at high axial strains. Specimens tested at cell pressures above 15 mpa exhibited volumetric compression throughout the test. (Author/TRRL)