Argillaceous sediments were sampled in the seven different sites throughout Japan and chemical mineralogical tests were conducted. The influence of the chemical mineralogical composition on compaction and lithification was studied based on the test results. As a result of the evaluation of the relationship between the kinds of authigenic minerals and the buried depth, the sedimentary conditions of argillaceous sediments could be presumed. In addition, it was clarified that the degree of compaction and lithification was greatly influenced by not only cementation of the mineral grains but amorphous mineral content.

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The change of pore water pressure in sedimentary layers is often a major cause of subsidence and re-upheaval of ground surface. In this paper, the compaction and expansion of sedimentary rocks are measured while the pore water pressure fluctuates under constant lithostatic load.
The samples used for the tests were cored from the six depths of a borehole up to the maximum depth of 250 meters at Hamaoka, Shizuoka prefecture. A sample was set within a vessel and weights were place on the sample to produce compression equal to the overburden pressure at the sampled depth. Pore water pressure was then introduced from one side into the sample. The pore pressure was reduced and increased several times. The change in the height of sample was measured. It was observed that as the pore pressure increased, the sample expanded, and as the pore pressure decreased, the sample shrinked. We calculated the coefficient of expansion and compaction due to changes of pore water pressure.
The results of the experiments allow us estimation of amounts of ground subsidence or re-upheaval which would result from changes in the water level 1 meter, the ground level subsides 5 millimeters. When the underground water level rises 1 meter, the ground level uplifts 2 millimeters.
The estimated change of ground level due to the pore water pressure change is only about one tenth of the observed seasonal fluctuation of the ground level of the tip of Omaezaki Peninsula, Shizuoka prefecture, but it is enough to explain the gradual re-upheaval at the Kawasaki City, Kanagawa prefecture. The compaction experiment with the control of pore water pressure provides a valuable tool for estimation of subsidence and re-upheaval due to the change of water level of underground aquifer.

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Diffusion of iodide anion in rock pore water was studied in order to evaluated diffusivity of “non-sorbing” radionuclides in rockmatrix. Effective diffusion coefficients of iodide anion were measured, using a simple diffusion cell, on granite and tuff samples, which were selected as typical homogeneous rocks having different porosities. Effective diffusion coefficients of iodide anion were about 2×10^-12 m²/s for granite samples and about 7×10^-11 m²/s for tuff samples. The porosities, determined by a water saturation method, of the granite and the tuff samples were about 0.8% and 25%, respectively. The effective diffusion coefficient of iodide anion was much larger in the tuff sample than in the granite sample. This fact can be understood by the difference in their porosities.

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Lugeon test is the most universal for investigating permeability of bedrock. But there are many cases which we can not understand reasonably results of the investigation, in spite of the test which is very simple hydrodynamics systems. We concluded the cause of it that there is the large error in the value of the coefficient of pressure loss of water supplying systems. Therefore we have developed the Lugeon tets equipment which is needless to take into consideration of pressure loss of the test systems for calculating permeability from the results. The main points of this development were to measure directly and accurately pressure of the test section in bore hole. For the purpose of measuring it, we have produced the packer combined a pressure transducer and an air packer. Using it, we have repeated many test at the laboratory and the actual bore holes. As a result, it was shown that this equipment is very useful for Lugeon test. Moreover it became clear to be able to use as a equipment of JFT and permeability test at low pressure, low difference water head.

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