区分 |
甲 |
氏
名 |
Imam Achmad
SADISUN |
| 論文題名 |
COMPREHENSIVE STUDY ON SLAKING OF
ARGILLACEOUS ROCKS BY MEANS OF STATIC SLAKING TESTS AND ITS ROLES IN
ENGINEERING DESIGN |
| (
静的スレーキング試験による粘土質岩のスレーキング特性ならびにその工学的 設計に関する研究 ) |
| Slaking of argillaceous rocks has
been received an extensive attention in consequence of numerous
slaking-induced engineering problems. This study was carried out to deal
with the detailed characterization of argillaceous rock slaking by means
of static slaking tests, and in turn, with an attempt to accounting
slaking into the frameworks of engineering design. As a case study, some
argillaceous rock samples were collected, in which three samples were
coal-measure rocks, obtained from Ikeshima Coalmine, Nagasaki Prefecture,
Japan and from Bukit Asam Coalmine, consisting of Ombilin and Tanjung Enim
collieries, Sumatra Province, Indonesia, and another sample was obtained
from a developing area of the northern part of West Java Province,
Indonesia. This dissertation is presented systematically into seven
chapters summarized as follows. |
| Chapter 1, Introduction, is
intended to provide a general description of the study carried out
including background of study, problem statement, scope and objectives as
well as outline of the dissertation. Chapter 2, Review on slaking of argillaceous rocks, is to give a brief review of past studies related with the argillaceous rock slaking, involving the suggested mechanisms, modes, and its induced engineering problems, such as in coal mine activities, hydroelectric projects, and areal developments. An overview of the testing techniques developed is also described in this chapter. Chapter 3, Fundamental characteristics of studied argillaceous rocks, presents fundamental characteristics of the argillaceous rocks. The first part of this chapter offers brief information of general geological conditions of the areas in which the samples were collected. Then, the second part describes the detailed fundamental characteristics of the argillaceous rocks, consisting of petrographical and basic engineering properties. Geologically, the argillaceous rock samples used in this study could be classified into Ikeshima mud-shale, Ombilin siltstone, Tanjung Enim mudstone and claystone, and Subang claystone. They offered visibly marked differences in petrographical analysis, involving mineralogy and texture/fabric, revealed when they were subjected to X-ray diffraction (XRD) and scanning electron microscopy (SEM) analyses. Moreover, these differences in petrographical characteristics were highly corresponding to the basic physical properties which further presented fundamental basis for evaluating slaking characteristics. Chapter 4, Laboratory testing for argillaceous rocks slaking, is devoted to a description of various slaking tests performed in this study. In order to develop better testing procedure for measuring slake-susceptibility of the argillaceous rock samples, several modifications on slaking index test was proposed and investigated with regard to the sample type, time duration, and the nature of slaking liquid. Furthermore, a classification scheme on the basis of single cycle slaking index test was suggested. Moreover, a new index called slake-susceptibility index (SSI) resulting from a combination numerical class values of slaking index (SI) and observation index (OI) was introduced and proposed for a comprehensive classification. Evaluation results indicated that modified slaking index test could be suitably put to practical use as a routine means for characterizing of argillaceous rock slaking, providing valuable complementary data when the standard slake-durability test was unavailable or impermissible. Chapter 5, Slaking characterization of studied argillaceous rocks, describes the detailed slaking characteristics of the argillaceous rocks, including differences in mechanism, mode, and rate/intensity of slaking as well as the main factors affecting the slaking processes. In general, exposure slaking characteristics indicated that under free air condition, most studied argillaceous rocks were characterized by an appearance of initial cracks or already existing open microcracks, which were specific on each rock type in term of time needed to initially cracking and the shape of developed crack. Meanwhile, in the wetting phase, slake-deterioration processes of the studied rocks were shown to occur rapidly, mostly less than one day. In this case, slaking by fast wetting was mainly caused by entrapped air pressure, which existed on dependent of initial rock water content, wetting or water uptake rates, and air thrust. Whereas, slaking by slow wetting mostly depends on clay mineralogy and type of liquid in which the rocks were exposed. The results of modified slaking index test have confirmed well a significant variability of slakeability for the argillaceous rocks. Due to the lack of mechanical agitation, this modified slaking index test was shown to be very effective to visually characterize slaking mechanism, mode, and rate/intensity. Meanwhile, the evaluation on slaking characteristic of the argillaceous rocks, on the basis of petrographical characteristics, obviously showed that expandable minerals of smectite and pyrite, soluble minerals of calcite and siderite, and released-strain energy as well as diagenetic maturity seemed to be major factors affecting the slake-deterioration processes. Chapter 6, Role of slaking in engineering design, presents practical applications of modified slaking index test to the evaluation of slaking-induced erosion, slope instability and their suggested measures using a covering technique. Evaluation results of a suggested lining material of cemented fly ash and rock fragments or aggregate based on laboratory experiment and numerical analysis are also presented. In this case, four distinctive potential erosion problems have been identified in studied argillaceous rocks. These distinctions tended to suggest the possibility to use slaking characteristics as a suitable indicator for analyzing erosion potential problems of argillaceous rocks. The slope performance analysis made during field observations suggested that the cutting slopes of argillaceous rocks, particularly claystones, generally tended to be rapid and intense in slake-deterioration, inducing some slope instability problems. In this study, a physical-based model of cutting slope design was derived for Subang claystone, which is considered to be reliable enough to be extended for the design of cutting slopes in other similar geo-environmental conditions in somewhere else. Meanwhile, a lining material consisting of flyash, cement, water, and aggregate has been suggested as an engineered control structure to prevent argillaceous rocks for slake-deterioration. Chapter 7, Conclusions, offers the general conclusions of this study. |