Since some years the irregularity index of railway-track has been adopted as a measure by which the track conditions are discriminated and the maintenance of railway-track is put in rational practice by Japanese National Railways authorities. In this paper we shall discuss some properties of this index and present a new measure named relative entropy which has an intimate relationship with the vibration of running car, and explain on the determination of the allowable limit of our irregularity measure related to the velocity of car.

View full abstract

The one-layer, multi-span rigid frame widely applied to civil engineering structures is determined by various theoretical solutions. However, there is not established any definite designing principle. The present report deals with the general trend of bending moment occurring in the rigid frame of one-layer, uniform span, uniform height and uniform stiffness ratio, that is to say the typical rigid frame of one-layer multi-span construction, in order to serve as reference for designing multi-span rigid frame.

View full abstract

The author, at first, theoretically argues about the accuracy of the calculating formulas for the vertical mean velocity, connecting them with the various theories with respect to the vertical velocity distribution in an open channel. Then, applying those formulas to the data obtained in the River Tone, he concludes that it is desirable to adopt the two-point method or the three-point new one, which is introduced by the mean value theorem, in the ordinary condition, and the four-point new method at the place where the flow is exceedingly turbulented. Among the formulas having prevailed up to this time, the three-point method and the four-point one except the two-point one are not valuable at all.

View full abstract

This paper is a fundamental research on the density variation in soil by compaction.
By estimating stresses in the loaded soil by Frölich's formula and developing the stress-strain relation in one-dimensional compression of soil into that in compression of an unconfined soil, the density distribution in the unconfined soil was theoretically obtained.
The theoretical results were checked by experiment, and it has become obvious that the theoretical results are in considerable agreement with the experimental data.

View full abstract

When the theory of orthotropic plate is applied to the analysis of beam bridge, the determination of “equivalent” flexural and twisting stiffness is firstly important. In this paper the theoretical values of equivalent stiffness are compared with experimental values to a large number of cast iron or steel models of beam bridge.
The summarize of results of study is as follows:
(1) Values of ν_y are small in comparison with the values of isotropic plate and values of ν_x are equal generally to isotropic plate.
(2) Eq. (5) is proper to determine the values of D_y when the height of beam is small and the values of A is proper when the height of beam is large.
(3) Generally ν_xD_y is not equal to ν_yD_x.
(4) Eq. (6) is proper to determine the values of 2C.
(5) The values of κ are 1.0-1.3.
These results will be used efficiently to the analysis of RC or PC beam bridge by the theory of orthopropic plate.

View full abstract

In all branches of the soil mechanics, it is important that we know capillary mechanism of soil. But it is a very difficult question to discuss, since capillary systems of soil have many complex elements. In this paper the author discuss quantitative and structural properties of soil capillary based on electro-phenomena and permeability. The results indicated the following:
(1) The quantities of capillary system in single structural soil such as sand have close relations to the gradation, particle size and degree of compaction.
(2) The used method is a convenient and easy procedure to observe the capillary organism and density of soils.
In these studies, it is assumed that capillary condition of soil consists of idealized systems.

View full abstract

The stress-strain relations in matrix notation are denoted by affinor and vector calculations which introduce more simple explanations of elastic constants (E, G, ν) even in the orthogonaly unisotropic stress-strain problems.

View full abstract

In this paper the author deduces general formulas for the deflections of plates, floating on the surface of water and bearing fluctuating loads which move with a variable speed on that plate.

View full abstract