For the purpose of forecasting the frost heaving of rock masses, the author studied on the relation between the rate of frost heaving and physical properties of rocks such as grain size distribution, specific gravity, water contents, etc. Laboratory tests were carried out to rock specimens which are molded into a cylinder with the height of 3 cm and the diameter of 8 cm, or rock fragments packed in the same scale cylindrical case. These pieces were put in -3°C air for 6 days, and the expansion of height was measured at each pieces. As results, the following facts are pointed out throughout the tests for 123 specimens and 55 cases, namely: . 1) frost heaving is most remarkable in soft and fine-grained sedimentary rocks such as middle -upper Neogene mudstone and tuffaceous rocks. 2) frost heaving is generally found among the rocks which are less than 0.2 in specific gravity or more than 20% in water contents. 3) degree of frost heaving is markedly increased for weathered or sheared masses of above-mentioned sedimentary rocks.
An investigation of the phenomena of sea water intrusion into ground water in the basin of the River Kiki and Miyauchi, Ehime prefecture, arecarried out by examining the contents of chloride ion in ground water. The influence of sea water intrusion is observed remarkably in the region within about 700m from the seashore. The relation between the phenomena of sea water intrusion or drawdown of water level and the pumping amount of ground water is also discussed.
It is important to obtain such physical informations as porosity, size distribution or permeability for the evaluation of aquifers and design of a water well. These physical informations are generally obtained by soil tests or geophysical loggings. In this report, the writer studied the way of evaluation from the data of density loggings (gamma-gamma ray logging) which are most profit for working water wells. Bulk density of the strata is calculated from the value measured by density loggings. But there are some limitations against the use of calculated bulk density. The auther concluded the the value calculated contains the error of about 15% by comparing calculated physical informations with that directly obtained by soil tests from the boring core of water wells at Osaka and Iwakuni. So, from further considerations concerning the causes of error, gamma-gamma ray logging is only applicable for evaluation of an aquifer, which is composed of sand and gravel beds of generally 2.0-2.3 g/cc in the range of bulk density.
Generally speaking, the so-called seismic exploration was usually executed on the earth surface, and the geological structure of deep rocks was to be assumed from the data of geological survey and the result of the seismic explorations on the points of the earth surface. However, in such case of the exploration at the site for the underground power station which is 600 meters deep from the surface, it is necessary to get more accurate results. In this paper, the writer described the fact that the geological condition of such deep rocks and the influence of Isegami Fault, which is the main faults in this region, were concluded from the well to well seismic measurements, utilizing those holes drilled to the depth of 600 meters at the triangular position. The distance between those wells was about 200 meters, and those deep well geophones, whese diameter were 40 mm, could bear the water pressure of 80 kg/cmm2. The cables connecting those wells were especially designed with 14 pieces (6 elements) using steinless wire in order to bear enough the tensile strength of 800gr. Reasonably accurate records were obtained by shooting 100 to 200 gr primer charges in one well bottom.