Study on Long-term Stability of Rock

岩石是在多种复杂的自然条件下发生破坏的，了解自然环境因素的综合作用对评价岩石的稳定性是必不可少的。然而，与岩体稳定性相关的各因素的影响，至今仍存在一些尚未解决的问题。特别是循环加载和循环加热的实验结果是有限的，尽管他们的重要性。本文研究了考虑低温循环加热影响的岩石耐久性及其估算方法。用弹性波速度估计稳定性.岩石冻融耐久性试验评估.可视化信息技术在岩石裂隙结构分析中的应用第一部分提出用弹性波速度测量作为无损检测手段，评价岩石的长期稳定性。然后，将其应用于由阿马库萨砂岩构成的本都市江户末期建造的只园桥的稳定性诊断。在第二部分中，采用圆柱形试件进行了冻结试验，作为岩石耐久性的评价方法。通过对阿马库萨砂岩低温循环加热风化过程的研究，揭示了该砂岩风化过程的一般趋势。通过对第一部分和第二部分试验结果的比较，阐明了冻融作用试验是评价岩石耐久性的有效方法。第三部分将可视化信息技术应用于岩石裂隙结构分析。

Rocks are damaged under various and complex natural condition, Understanding of the composite action of natural environmental factors is indispensable for estimating the stability of rock. However, there are unsolved problems for the effect of each factor associated with the stability of rock. Especially, experimental results of the cyclic loading and cyclic heating are limited in spite of their importance. We studied on the durability of rock and its estimation method, considering the effect of the cyclic heating under low temperature.This report consists of three parts as follows :I. Estimation of stability by elastic wave velocity.II. Estimation of durability of rock under frost action test.III. Application of visual information technique to analysis on structure of crack in rock.In the part I, measurement of the elastic wave velocity is suggested as the non-destructive test, by which the long-term stability of rock can be estimated. Then, it is applied to the stability diagnosis of Gion bridge, Which was constructed at the end of Edo period in Hondo city, consisting of Amakusa sandstone. In the part II, the frost action test is carried out as the estimation method of durability of rock, using cylindrical specimen. It is shown the general trend of weathering process of Amakusa sandstone by cyclic heating under low temperature. Then it is clarified that the frost action test is available for the estimation of durability of rock, comparing experimental results in the part I and II. Furthermore, in the part III, visual information technology is applied to the analysis on the structure of crack in a rock.