Simplification is shown of solution of the surging at the surge chamber at the initially full-flowing tail-race tunnel developed in the previous paper by the same author. Approximation is made to the governing equations to make the graphical solution of Schoklitsch applicable. Comparison of the solutions by the graphical method is made with the results obtained from the laboratory investigation described in the previous paper. Good agreement between theory and experiment is affirmed. The simplified method of solution is shown to be sufficiently adequate for practical applications.

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This paper describes a method to estimate the criteria for various bed configurations in alluvial channels. Under the investigations by means of the dimensional analysis, criteria are proposed on a logarithmic diagram plotting the relationship between the bed slope S and the entrainment function ψ. It seems that this method is applicable to the data not only in experimental flumes, but also in natural streams.

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We have studied the characteristics of the soil pressure cells, by compareing with the differences between the observed strain of the cell by the soil pressure and by the air pressure.
A electrical strain gauge was used to measure the strain of the diaphragm or the beam of the cell that is introduced by the pressure.
We have newly introduced the nondimensional parameters D and H, for the absorption of the energy in the soil and for the hysterisis, respectively.
D and H are correlated with the rigidities, the radii of the cells and the elastic constants of the soils, and some of their relations are shown quantitatively for the practical use.

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Assuming that the ground in which a circular tunnel without lining is driven at a deep level under its surface has an anisotropic elasticity, a general equation for the displacement around this tunnel is found theoretically by utilizing the two analytic functions that satisfy the boundary conditions in the general equation for stress components which is calculated by applying the complex functions.
Moreover, from the numerical results which are calculated by these equations, the effects of anisotropie of ground on the radial and tangential displacement around a circular tunnel and the ratio of the horizontal change of tunnel diameter to the vertical one are discussed.

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When the sands and gravells go down one by one in waving water, their plane scattering differ from that in quiescent water. The author knew that their variance was about 10-30% larger than that in quiescent water and the mean dropping points fell from the expected point to the coming side of waves. And in order to reduce their variance, the tying up the stone are effective in waving water, too.
Furthermore, he suggested that the plane scattering of the group falling in quiescent water was expressed the superposition of the Compound Poisson's distribution, and by its aid, he could get the expectation and the variance of the group falling.

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Simplification is shown of solution of the surging at the surge chamber at the initially full-flowing tail-race tunnel developed in the previous paper by the same author. Approximation is made to the governing equations to make the graphical solution of Schoklitsch applicable. Comparison of the solutions by the graphical method is made with the results obtained from the laboratory investigation described in the previous paper. Good agreement between theory and experiment is affirmed. The simplified method of solution is shown to be sufficiently adequate for practical applications.

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A water-hammer action develops in a pipe when the valve is periodically opened and closed at the end of an elastic pipe. Since this phenomenon is similar in appearance to an elastic vibration, there arises a question if a resonant vibration could be introduced at a certain period of alternate opening and closure of the valve to render the resulting water-hammer unstable. Questions have also been aroused as to the spatial and temporal distribution of the water-hammer occurring under such conditions. The present study has treated of these problems both in theory and experiment.

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In this paper, the author describes a compacting method of concrete of centrifugally spun precast reinforced concrete piles. Testing through the hollow-spun specimens made by the special apparatus, the minimum number and time of revolutions necessary to make the hollow form, and next in this speed range, the minimum number and time of revolutions required to obtain the manimum strength of concrete at low, middle, and high speed revolutions are investigated. Consequently at the low speed revolution, a most suitable speed and time for concrete slump are obtained. At high speed revolution, concrete strength is highest when the spun effect (E=kn²t^1/2) is constant. R. p. m. of middle speed revolution is given by n′=n/√2.

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This paper discusses the results of studies on the effect of temperature and humidity during curing on strength of concrete conducted at the Onoda Cement Company Research Laboratory, Japanese National Railway Technical Laboratory and the Civil Engineering Department of University of Tokyo. Results of strength tests of concretes containing various brands of fly ash cured at varying temperatures in the range of 10° to 30° centigrade and at varying humidities are described and it is concluded that (1) curing at high temperatures adversely affects long-term strength of concrete, but judicious use of fly ash is beneficial as it considerably alleviates the ill effects, and (2) the effect of temperature and humidity during curing on strength of concrete containing fly ash was practically the same with the majority of seven brands of fly ash sold on the market except with one brand where peculiar results were recognized.

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The essential point in rational design of pavement thickness is to forecast the bearing value of subgrade which reached equilibrium state after paving.
This investigation dealt with the change that occurred in subgrade condition before the subgrade reached on equilibrium state, but the subgrade condition was treated with each element that had a certain inflence to subgrade bearing value, i. e. these elements are soil suction, process on variation of water content after compaction, dry density, compaction method, thixotropic effect.
Also, this paper shows a proposition with improving the present CBR method, the new CBR method introduced a specimen preparing procedure which gives on equiliblium subgrade condition that estimated from the results of above investigation.

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The effects of curing conditions on the strength of concrete containing fly ash were studied. As a result, it has been found out that the curing conditions, such as the variation of curing temperature and relative humidity, have some influence upon the strength of concrete containing or not containing fly ash in the same way. If the proportion of concrete is designed reasonably, the use of fly-ash is often advantageous for the strength of concrete.

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This paper describes the results of studies on the effects of temperature and humidity during curing on the compressive strength of concrete containing fly ash. Results of the strength tests of the air entrained and non air entrained concretes containing various brands of fly ash cured in water for various periods at certain constant temperatures i. e. 5°C, 21°C and constant or varying humidity are described. Consequently, (1) in case of water curing, it is recognized that the effects of containing fly ash on the strength of concrete cured at 5°C is same as that on the strength when it is cured at 21°C, or, the increase of strength of concrete cured at 5°C is larger than another preferably. And, (2) in case of dry curing, it is recognized that the increase of strength of concrete is smaller than that when it is cured under another condition.

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A broad investigation undertaken by the Subcommittee on the quality of Fly Ash produced by the major firms in Japan, and the tests common to the products were conducted. In the 2nd. and 3rd. Tests, we made certain particular studies such as air entrained concrete with fly ashes and Vinsol resin. As a result, we have found some relations between the weight contents of Vinsol resin and the qualities of fly ash about the absorbabilities of the methylene blue.
This relation seems to be a good indication for the control of the air contents in making the air entrained concrete with the fly ash.

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This article is a report on the results of several tests concerning Prepakt Concrete which is mixed with fly ash produced in eight steam power plants of five firms in Japan. The influence of quality of fly ash on the properties of Intrusion Mortor and also on the compressive strength of Prepakt Concrete has been examined.

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The author studied the drying shrinkage of specimens at constant relative humidity of 44% about several kinds of cement. As a result comparing the drying shrinkage of fly ash mixed portland cement (mixing proportion by weight P.C.: F.A.=80:20) with those of normal portland cement, high early strength portland cement, moderate heat portland cement, natural pozzolana cement, slag cement, the volume change of the fly ash cement has been found always the smallest.
The author also tested the differences of cracking tendency by so-called ring test, comparing with the portland cement types I, II, III and those cements in which 20% or 30% fly ash was mixed in each of I, II, III type portland cements. It was observed that type II cement mixed with 30% fly ash showed the smallest tendency of crack corresponding to the least values of shrinkage and modulus of elasticity.

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This is an experiment to examine if the fly-ash admixed in mortar affects the growth or progress of the corrosion of reinforcing steel.
The properties of the mortar of specimens are as follows; proportion—1:3-1:5, water cement fly-ash ratio (W/C+F)—58-103%, replacement of cement with fly-ash—0-60%. These specimens had been stored for 32 months in a railway tunnel. From the test results, it may be suggested that the corrosion on embeded reinforcing steel is not induced easely unless the replacement with fly-ash exceeds 30-40% and W/C+F is so large.

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This paper discusses the results of studies on use of fly ash pre-mixed with water to form a paste which is stored in large quantities, continuously agitated, and dispensed in small amounts instead of being used in conventional powder form. Basic studies conducted at the Department of Civil Engineering, University of Tokyo as well as studies at the fly ash paste plant installed at the jobsite of the Okutadami Hydroelectric Project, Electric Power Development Company are described and it is concluded that (1) when used in paste form the uniformity of fly ash is considerably improved and control in the case of air-entrained concrete is facilitated while handling problems usually encountered with fly ash are easily solved, (2) when fly ash is used in paste form workability and other properties of concrete are improved and mixing time can be shortened, and (3) a fly ash paste plant is less costly than a plant where fly ash is used in powder form and is less subject to breakdowns.

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