Experimental study of temperature effects on physical and mechanical characteristics of salt rock
Experimental study of temperature effects on physical and mechanical characteristics of salt rock
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DOI：
10.1007/s00603-005-0067-2
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发表时间：
2006-11-01
影响因子：
6.2
通讯作者：
Zhao, Y. S.
中科院分区：
文献类型：
--
作者：
Liang, W. G.;Xu, S. G.;Zhao, Y. S.
由于其优越的物理和力学特性，盐岩被认为是处理核废料的良好寄主岩石。盐岩储存库中的核废料在放置后的几十年内会继续释放出辐射和热能，导致周围盐岩温度显著上升。因此，研究盐岩在不同温度条件下的物理力学特性对于确保盐岩库的完整性和核废料与生物圈的安全隔离是至关重要的。通过对亚硝酸盐盐岩在不同温度(20℃~240℃)下的一系列物理力学测试，发现其力学参数对温度的变化有不同的反应。试验结果表明，试件的声速随温度的升高而减小，单轴抗压强度和轴向应变均随温度的升高而增大，而切线弹性模量E-t则相反。同时，塑性应变逐渐增大，试件的应变软化行为日益明显。在预置角剪切试验中，粘聚力和内摩擦角均随温度的升高而增大。直剪试验结果表明，亚硝酸盐盐岩的峰值剪切强度和极限剪切强度均随温度的升高而增加，说明亚硝酸盐盐岩在高温下的行为仍然有利于盐岩储存库的完整性，保证了核废料与生物圈的安全隔离。
Because of its advantageous physical and mechanical characteristics, salt rock is considered an excellent host rock for nuclear waste disposal. Nuclear wastes in a salt rock repository will continue to emit radiation and thermal energy for decades after placement, resulting in a significant rise of the surrounding salt rock temperature. Consequently, study of the physical and mechanical characteristics of salt rock under different temperature conditions is essential to ensure the integrity of the salt rock repository and the safe isolation of nuclear wastes from the biosphere.Through a series of physical and mechanical tests on thenardite salt rock at different temperatures (ranging from 20 degrees C to 240 degrees C), it is found that the mechanical parameters have different reactions to a changing temperature. Tests show that the ultrasonic velocity of samples decreases with temperature increase and both the uniaxial compressive strength and axial strain increase with temperature, whereas the tangent modulus E-t goes in an opposite direction. Meanwhile, the plastic strain increases gradually and strain-softening behavior of the samples becomes increasingly evident. In the pre-set angle shear tests, both the cohesion and internal friction angle increase with temperature. Results obtained in direct shear illustrate that both the peak shear strength and the ultimate shear strength increase with temperature.We conclude that the behavior of thenardite salt rock at high temperatures is still advantageous to the integrity of salt rock repository, assuring the safe isolation of nuclear wastes from the biosphere.