Coal ashes generated in a coal-fired power station are classified into two categories, clinker ash and fly ash. Among these two types of ashes, the number of utilized cases of clinker ash has been increased as a geomaterial such as embankment material, base course material, frost heaving restraint material and drainage material of ground due to its properties of light weight, high shear strength and high permeability. And also the application of clinker ash to vertical drain material, compaction pile material and tree planting matrix material on rock bed are studied at present. However, a study to identify material characteristics of clinker ash such as physical properties and mechanical properties is very little. From now on, increase of generation of coal ash and decrease of its dumping sites are surely so inevitable that utilization of coal ash to many fields have become a problem to be solved. On this account, in this paper, we report physical properties and mechanical properties of clinker ash and also the result that examined applicability as geomaterials.

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The Yoshinogari Fun-kyu Tomb, located in Saga Prefecture, Japan, was constructed by one construction method similar to 'Han-chiku' method, and this construction method is supposed to be transferred from ancient China. In this research, the authors investigated more than ten earth-filled remains located in the Yellow River Valley, where 'Han-chiku' method were very prosperous two thousands years ago. The characteristics of earth-filled remains and the period of occurrence of earth-remains constructed by the well-developed method of 'Han-chiku' were investigated. The Chengziya remains located in Shandong Province was treated as one typical case of earth-remains constructed by the well-developed method of 'Han-chiku', and geotechnical investigation were carried out on it. The results of investigation showed that the 'Han-chiku' method could lead to the Yellow Loess obtain very high dry density, and restrain some defects of the Yellow loess when it is used as construction materials. Finally, the authors supposed that the necessity that 'Han-chiku' method used for construction of geotechnical projects by soils occurred in the Yellow River Valley is closely related to the inferior properties of the Yellow Loess distributing in the area.

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Land subsidence due to the seasonal fluctuation of ground water level in Saga Plain has been caused by pumping up in summer for agricultural purposes. The database of observation data obtained by ground subsidence observation well, leveling, pumpage investigation, meteorological observation and ground water quality investigation in several organizations was made in order to centralize the information on the ground subsidence in Saga Plain. A useful systematization of the database was established, as it could search the observation point information and express the distribution or the correlation of observation data.

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Air-foam treated lightweight soil is used in expectation of lightweight properties, early age shear strength and effective utilization of dredged soils. The most of previous researches have focused attention on either the density adjustment or the shear strength development. Thus, the long-term material characteristics associated with the deterioration have not been studied yet. This paper clarifies the deterioration characteristics through the long-term settlement under either air or water infiltration conditions. In addition, the countermeasures for the long-term deterioration settlement are discussed.

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SPT N-value is affected not only by energy transfer ratio (e) in relation to the hammer's free falling energy, but also by the size of apparatus such as the rod and the hammer. Although modification for N-value by driving efficiency (e) has already been standardized internationally by ISMGE, but modifications for the size of apparatuses are not clear. In this paper, laboratory model tests of SPT N-value for Toyoura-sand are described, and another modification method of energy transfer ratio (√e method) is proposed. Based on one dimensional wave transfer equation, theoretical maximum driving stress in the rod is formulated, and the formula is verified by laboratory model tests. Finally modification method for the size of apparatus is proposed.

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The laboratory tests of capillary barrier, whose drainage layer was each composed of Hachinohe Shirasu or Toyoura sand, were carried out to study the applicability of Hachinohe Shirasu as a material of capillary barrier. The intensity of rainfall were varied from 5 to 40 mm/h. Under that steady state conditions of high rainfall intensity, Hachinohe Shirasu had good performance, comparing with Toyoura sand. Then by using hydraulic property which acquired from laboratory tests, the finite element analysis of saturated-unsaturated seepage were performed and predicted the behavior of infiltration due to rainfall. Comparing the calculated behavior with measured one, it can be concluded that the calculated behavior agreed with observed one.

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This paper deals with the uncertainty evaluation of different results of laboratory soil tests. The main objective of this study is to find out the cause of uncertainty in the result and its degree of effect, reliability of the results with specific uncertainty evaluations. In order to measure the uncertainty factor, seven types of physical properties tests and an unconfined compression test were carried out. It was measured that the range of test results of natural soil sample were large. Considering large differences in the range of test results, relatively expanded uncertainty method was applied. According to the test results, the unconfined compression strength showed the highest uncertainty of 37.2% whereas silt content of particle size distribution of physical property test showed 33.3%. The uncertainty of the remaining tests was ranged from 2.2 to 6.3%. It is understood that the prime factor to take place large difference in the uncertainty ratio of physical properties tests was due to lack of consistency of inconsistency of experimenter and types of soil. In case of unconfined compression strength, the large difference in the uncertainty ratio was comprehended due to lack of inconsistency of experimenter and apparatus.

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