试件尺寸对岩石膨胀力测试值影响的研究

Research on the Influence of Specimen Size on Test Value of Rock Swelling Force

岩石膨胀力试验是测定膨胀岩在水环境下产生的膨胀应力,试件尺寸对膨胀力测试值具有重要影响。本文通过对不同尺寸的岩石试样在烘干状态下进行膨胀力试验,经对比分析,研究试件尺寸对岩石膨胀力试验结果的影响规律和程度。结果表明,试件高度对岩石膨胀力测试值的影响显著,岩石膨胀力测试值随着岩石试件高度的增大而增大,并呈较好的线性关系。试件高度对岩石膨胀力试验结果的影响与岩石的结构特征有关,岩石的饱和吸水率越大,岩石的孔隙率越大,密实程度越差,则试件高度对岩石膨胀力试验结果的影响越显著。试件直径对岩石膨胀力试验结果的影响不明显。试件尺寸对岩石膨胀力测试值的影响将导致试验数据无可比性,影响岩石膨胀性的判定,因此,有必要在试验方法标准、规程规范中明确试件的尺寸范围,或通过研究给出试件尺寸的修正公式。

Rock swelling force test is to determine the swelling stress of swelling rock under water environment.The specimen size of rock has an important influence on the test value of swelling force.In this paper,the swelling force test of rock samples with different sizes under drying condition is carried out,and the influence law and degree of specimen size on the experimental results of rock swelling force are studied through comparative analysis.The results show that the height of the specimen has a significant influence on the experimental results of the swelling force of the rock,and the test value of the rock swelling force increases with the increase of the specimen height,and presents a good linear relationship.The influence of specimen height on the experimental results of rock swelling force is related to the structural characteristics of the rock.The higher the saturated water absorption rate of the rock,the greater the porosity of the rock and the worse the degree of compactness,the more significant the influence of specimen height on the experimental results of rock swelling force.The influence of specimen diameter on the test result of rock swelling force is not obvious.The influence of the specimen size on the test value of the rock swelling force will lead to the non-comparability of the test data and affect the determination of the swelling property of the rock.Therefore,it is necessary to specify the size range of the specimen in the test method standards and codes,or to give the correction formula of the specimen size through research.