By applying his plastic theory to a rectangular beam, the author has determined the position of the neutral axis in the section, the plastic strain, the distribution of stress and the modulus of rupture at the time of breakage and obtained an approximate deflection curve of a beam.
It is an experimentally well-known fact that, with the increase of the bending moment, the neutral axis is shifted towards the compression side, the distribution of stress changes in the form of a curve and the modulus of rupture becomes greater than the tensile strength. These phenomena as well as the effect of Poisson's ratio on them can be theoretically explained by the author's theory. Besides, it seems that the theory will make it possible to calculate the increase of the bending deflection of beams due to plasticity.

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During the Pacific War, air-raids by the Allied Forces started many fires in various places of Japan and not to speak of wooden houses, reinforced concrete structures also were badly destroyed.
It will constitute a very important problem scientifically to judge the safety of such fire-damaged structures and to study methods of their rehabilitation.
In this connection, a decision was made to take up a systematic study for judgement of the safety of war-damaged concrete structures and for their reinforcement.
Preliminary to the study, actual state of war-damaged structures were investigated.
In this paper are stated the results of one of these investigations made in the Narihirabashi Works of the Japanese Tobacco Monopoly Bureau.
The investigation made clear the cause of the fragility of fire-damaged structures especially in case of earthquakes.

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In view of many war-damaged concrete structures being repaired and newly used, we formed a group to study the safety of such structures and carried out investigations for following items:
i) actual state of concrete structures damaged by fire
ii) changes in properties of concrete through heat
iii) the durabilities of damaged structures

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When the lateral wheel pressure acts on the track, it produces lateral bending and torsion in the rail. In the lateral bending, the author clarified that the action of the lateral pressure on the track had the tendency highly concentrating near the acting point, and determined the condition producing the rapid course deflection of the track. In the torsion, he determined the limitting lateral pressure by which the dog-spike yields up from the cross-tie. Discussion was made about the dynamical property of rail torsion. Further calculation was made about the deformation and he compared it with the simpler one.

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In this paper are stated the results of an experiment carried out chiefly of the materials to be used in electrical curing of concrete.

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Through the experiment the bending failure mechanism was made clear of the materials with such low shearing strength as that of wood.
In this paper are stated results of investigations for
i) a law covering the relations between bending failure co-efficient and its affecting factor, that is, load and span height ratio,
ii) limits to span height ratio which determines normal stress distribution and characteristics of shearing failure, in cases of some principal loads, and further stated the author's view of his theory of bending failure with reference to ordinary designing.

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On the assumption that a rectangular slab is devided into a proper number of sections and the rigidity in the same section is approximately uniform, the author worked out a method of approximate calculation of the deflection, bending moment, etc. by using the slope deflection formula which had been introduced by him for a rectangular slab under vertical load.

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Proper plans can hardly be formulated in accordance with paper location unless the location is carried out on a definite principle. Moreover, a systematic paper plan is necessary for increasing the utility of the diagrams.
In this paper, solutions of the problems arising in connection with the determination of the shortest route are given as examples, and methods are described with respect to typical topographic conditions, of graphical determination of the shortest route on a definite gradient and of the shortest route with the length of line being given.

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The dynamical deflection of the rail and the dynamical stresses under the action of the moving wheels may become much larger than those calculated on the basis of the static formula. There are various causes which may produce such an increase in deflection and stress, some of which are discussed in three groups, a, b and c.
(a) Variation in the forces acting on the rail caused by variable spring forces on the wheel; the vertical component of the centrifugal force of the counterweights and the vertical component of the tortes in the connecting rods.
(b) Different kinds of irregularities in the shape of the wheel or rail, such as flat spots on the rim, low spots on the rail and discontinuities at the rail joints.
(c) Inertia force and internal friction of the track materials and the road bed accompanying with their vertical motion under moving loads. In discussing the causes mentioned in (a) it should be noted that their effect on the deflections and stresses in the rails can be calculated without substantial error in a statical way.
In this paper a method is developed for calculating the increase in deflections and stresses produced by the causes mentioned in (c).

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In the first report (1) of this series, the author dealt with the elastic vibrations of a gravity dam when the reservoir is empty and in the second (2), with the solution of the dynamic water pressure on the assumption that the dam makes rigid vibrations.
By referring to the results of the above mentioned studies, the author made an attempt to solve the problem of elastic vibrations of a dam when the reservoir is full, of which the details are given in the present paper.
It seems that the periods when resonance occurs at the time of rigid vibrations are stable under elastic vibration and that the resonance occurs at other periods.
At the periods points far apart from there and so far as the period of seismic vibrations is small, the effect of the dynamic water pressure has been found much smaller than that formerly conceived on the assumption that the dam makes rigid vibrations.

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With a view to measuring pressure distribution in comparatively thin sand-layer, the power required and the sand-layer displacement occurring when pulling up a plate buried in sand-layer were simulteneously recorded.
The results of the experiment show an example of determining pressure distribution in sand-layer and the critical angle of normal pressure on it.

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Few proper formulas have so far been introduced for the calculation of the amount of water leakage from earth dams or embankments which have been penetrated by water.
Basic experiments were made by the author for obtaining a formula for the calculation which will be both rational and practical.
The study is now being carried on. Although no definite conclusion has yet been reached it has been ascertained that Q, the amount of water penetration is the function of h, the depth of water on the upstream side and of h₂I, the product of the depth of water on the downstream side (h₂) and the gradient of the moving water (I).

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This paper may be regarded as the sequel of the one entitled “A General Solution for a Given Distribution of Stress on the Boundary” which was published. before.
The author has clarified that, when displacement of the boundary is given, the matter is as well a solution of Fredholm's integral equation through a procedure similar to the one described in the former report. In the conclusion on the solution for the case in which the stress disttribution is given, Fredholm's integral equation of the first kind was reported to be obtainable. As, however, it can be reduced to the second kind through a simple procedure, a revision has been made and is given at the beginning of this paper.

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This paper discribes about the stability condition of surge tank.
To survey theoretically how inertia and resistance of penstock and inertia of rotation parts of turbin and generator and inertia of other generator that is parallel operated exert influence on stability of surge tank.
From these elements, general stability conditions are described, and from the result of this study, in case of the generator that is connected at surge tank is parallel operated, necessary surge tank section area is most smaller than the section which is comperted from the methods of Thoma condition.

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A study was made of the influence on the stability of a pressure adjusting reservoir as exerted by the deflection of the efficiency curve of the water-wheel which is an important characteristic not dealt with in the first report.
In the light of the result of the study, Thoma's condition F>l/2kH₀Ag was revised and a formula, F>ξl/2k H₀Ag was theoretically introduced. On the other hand, the meaning of the correction coefficient ξ in this formula was examined from various view-points.

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Synopsis; In the study previously reported (Report No. 1), Model I was worked out for the investigation on moving to the outside the elements existing in a given area with the least resistance, on the assumption that the resistance is dependent solely upon the concentration of the elements and that the condition of various points on the ground surface is uniform.
As a matter of fact, however, there are ups and downs on the ground surface and geological aspects are different in different places, which means that, as in the case of rivers, the form of ramified structure is varied and that an ideal one cannot be expected. Moreover, among tributaries there are very large ones such as the Kinu in relation to the Tone, of which the idea of trunk and branch lines in Model I will be of no use for explanation.
This fact indicates that the idea of what are commonly called main and tributary courses of rivers does not always coincide with the idea of the trunk and branch lines in Model I. From the view-point of Model I, the relation between the Tone and the Kinu is not the one between the trunk and branch lines but running against each other of two rivers of nearly equal importance.
Two streams runnig side by side and emptying into the same sea sometimes run far apart from, and sometimes draw close to, each other according to the ups and downs of the ground surface; they even run against each other. The collision results in a conflux, where ordinarily the, larger one is called the main course and the smaller the tributary course. Such phenomenas are very often experinced.
For analysing these phenomenas, Model II was worked out on a principle which was quite different from that of Model I, and investigations were started chiefly by means of this new model.

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Influence of vibration load upon beams and slabs has been studied for various purposes.
There are many methods, i. e. Stokes method. This paper describes about the most general case.

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