わが国では, 航空写真の判読を土木工学の分野に応用した実例はきわめて少ない。
本論文は, 水力開発計画における航空写真の利用についてのべたもので, 特に写真判読による地質構造の研究の例として, 黒部川の大町トンネルの工事にさいしてそう遇した破砕帯付近について行なった研究の結果を示した。
すなわち, 写真判読によって, この地域の特殊な地形に注目し, 各集水区域ごとに水系の頻度と長さをグラフで示して, この水系の方向性が, 破砕帯と密接な関係があることを明らかにした。
なお, 水系の型が地形によってどのような形態を示すかについて説明し, この分類を明確にした。さらに, 一般的に, 土木工学における写真判読の応用の具体的な方法について解説を加えた。

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単純支持の鋼床版箱桁橋の変形および応力を立体的に解析して, その近似解法を提示し, 模型実験によってその信頼性を確かめ, さらに荷重配分に対する床版の協力作用を考察したものである。

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対数正規法により確率降雨強度式を算定する方法を提唱した前報に引続き, 本文では極値極限法によりこれを算定する方法を提示し, さらに本邦短時間強雨特性より誘導した特性係数法によって算定する方法を提唱した。この特性係数法による確率降雨強度式は I_N=β_N・R_Nの形をとるが, ここにI_NはN年確率降雨強度 (mm/hr), β_NはN年確率特性係数, R_NはN年確率時間雨量 (強度, mm/hr) である。本法は前述の2方法と同程度の精度のもとに, わずか2組の降雨資料のみで, 最も簡単に確率降雨強度式を算定できる。さらにこの場合の式中の特性係数の二, 三の誘導法をも提唱論議した。最後に本法の適用例として, Nを10年としたときの本邦におけるR₁₀の確率雨量分布図とβ₁₀の特性係数分布図とを提示した。これらのβ_NとR_Nとは本邦気象庁管下の全気象台, 測候所147地点の降雨資料かち算出決定したものである。

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粘土に一定のひずみを与えた場合の応力の経時特性および応力の終局値に関する理論式を, さきに提案した力学モデルに対して求めるとともに, 新たに製作したレオメーターを用いて一軸圧縮, 三軸圧縮による応力の緩和試験を行ない, さらにその温度依存性などについても調べて新しい特性を見出した。

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斜面の安定解析にわいて, 土の強度をベーン・せん断や一軸圧縮のような非排水せん断試験の結果で表示する従来のψ=0-解析法は, 長期の安定を論ずる場合には真の安全率を与えるものでないことを指摘し, これにかわって有効応力にもとつく, いわゆるc, ψ-解析法の正当性を主張する。この解析法を適用するにあたって, 過圧密土の強度常数はせん断試験のさいの見かけの破壊包絡線から求めるべきではなく, 著者がここに提案する現地せん断強度線を利用するのが合理的であることを示した。

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In case of water power development in Japan, so far, the aerial.photogrammetry has scarecely been applied but to make the topographical maps for planning. We, authors, thought that aerial photography should be utilized not only for the purpose above said but also for many other purposes generally in water power development. Then we introduced a new technique called “Photogeology” and have carried out the investigations and studies, by the techniques, on each area in the basin of the River Kurobe, for the development plan.
It seems that photogeology has never been applied really to civil enginneering in Japan. Therefore, in performing this research we had to resolve the elementary problems at first. And we have carried on the application in a way of “try and test”.
In this paper, we show a research on the Omachi tunnel area above all as an instance.
An unexpected fault fracture zone caused a paralysis of the tunneling work through several months and enormous loss. This paper deals with how that fault fracture zone on aerial photographs appears and how the aerial photography in planning such tuneling works should be utilized in the future.

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As a means of the beam bridge design, hitherto, has been adopted two-dimensional calculation method ; hence, main beams, floor systems and floor slabs were calculated separately. With the recent progress and development of steel highway bridge constructions and the generalization of stress measurings, it is insufficient to treat in customary means the beam bridge design, and the necessity of three-dimensional consideration has been recognized. Inasmuch as main beams of box girder bridges have especially considerable width, it is evidently inadequate to treat them as an assemblage of rods. Accordingly, in this paper, the deformation and stress of a simply supported box girder bridge with steel plate floor were three dimensionally analyzed and its approximate solution was proposed, the reliability of which was confirmed by model experiment. Further the cooperation of the floor slab in the load distribution was considered.

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Succeeding to the author's previous report on the estimation method of the probable rainfall-intensity-formula based on the Logarithmic Normal distributions, another estimation method to which the Extreme Limiting Theory is applied is proposed in the first part of this paper. Moreover, an eatimation method by the “Specific Coefficient” is further proposed, which can be determined by rainfall charactristics of a short duration time in Japan, with considerations of the type of rainfall-intensity curves. For any types of the curves, and various formulas in the past can be reduced to merely one generalized form by this method, which gives the simpler estimation of the curve with higher accuracy than the former methods. It is also an advantage of this method that it can be applicable, even if the rainfall records cannot be obtained for each duration of rainfall over a long period as in the case of local cities.

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This is a report of theoretical and experimental researches on the stress relaxation of clay which play an important role in the phenomena of earth pressure. The assumption of a special model of clay is sufficient to express a stress relaxation which proceeds linearly with the logarithm of time and after a certain duration the stress relaxes to a final value. In the new type rheometer, the constant deformation is given to clay specimen and the relaxation of the internal stress is measured. Further, the thermal effect on stress relaxation of clay is discussed. Main results obtained here are as follows

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Of the different types of analysing the stability of earth slopes the most convenient is known as the Swedish method, in which the circular slide surface can be commonly used. The socalled ψ = 0-analysis, based on the result of undrained shear tests, such as in situ vane tests or unconfined compression tests in the laboratory, is not appropriate for estimating the long-term stability, though it might give a correct result under fortunate conditions, when the stability of slopes just after a construction operation is treated.
This paper concerns with some important problems involved in another analysing method, called as c, ψ-analysis, in which the shear strength of soils is expressed in terms of effective stress. The stability analysis is applied to a slide occurred along a small river in the Norwegian quick clay. Combining the results of borings, samplings, in situ tests and pore pressure measurements in the field, together with those of laboratory tests, it is concluded that the composed slide surface should be used, in stead of simple circular surface. As the cause of the slide it is assumed that considerably large amount of excess pore pressure in the clay layer might contribute to the occurrence of the slide.

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