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岩石在一定恒定压力荷载作用下可以承受长期的变形,也就是蠕变。虽然关于岩石蠕变研究的现有文献数量比混凝土蠕变研究的文献少得多,但是很多学者已经对这种现象进行了研究和模拟。本文的研究目的是通过改进众所周知的混凝土蠕变模型来研究软岩,以估算岩石的长期蠕变。上述研究中最常见的问题是实验室测试时间短和对已有结果的外推。为了进行岩石物理和力学特性的测试(包括超声、孔隙率、密度以及恒定应力荷载下的强度和蠕变),我们选取了10个直径54mm、高100mm的圆柱形岩样,用蠕变试验来研究软岩的长期蠕变行为。根据CEB-FIP规则得到初期蠕变特性的混凝土样品与被试岩样相比呈现出类似的蠕变特性。文中提出了基于流变学的Kelvin元件和CEB-FIP规则的特定模型用来研究软岩,模型与研究期被测岩样的真蠕变性非常近似。我们注意到蠕变曲线与被测岩样曲线接近的混凝土在荷载作用下产生的单轴压缩强度与干岩石在测试中得到的强度事实上是相等的。这也暗示我们可以通过改变CEB-FIP模型来重现测试期岩石的蠕变性。
Rock under certain constant pressure load can withstand long-term deformation, that is, creep. Although there is far less literature available on the creep study of rock than on the creep study of concrete, many scholars have studied and simulated this phenomenon. The purpose of this paper is to study soft rock by improving the well-known concrete creep model to estimate the long-term creep of rocks. The most common problems in the above studies are the short laboratory test time and the extrapolation of existing results. For the purpose of testing the physical and mechanical properties of rock (including ultrasonic, porosity, density, and strength and creep under constant stress loading), we selected 10 cylindrical specimens of 54 mm in diameter and 100 mm in height using a creep test Study of long-term creep behavior of soft rock. Concrete samples with initial creep characteristics according to the CEB-FIP rule show similar creep characteristics compared with the test samples. In this paper, a specific model of Kelvin element and CEB-FIP rule based on rheology is proposed to study soft rock. The true creep of the rock sample under the model and study period is very similar. We note that the uniaxial compressive strength of concrete with creep curves close to the curve of the measured rock specimen under load is in fact equal to that obtained by the dry rock in the test. This also implies that we can reproduce the creep of the rock during the test by changing the CEB-FIP model.