According to the previous report, by discussing the frequency range of wave form of the fluctuation amount of flowing water generated inside open channels, the most important information could be extracted, and with this, evaluation of the dynamic character of the open channel system in simplified form became possible. Furthermore, it was found that aside from the flow effect, open channels have the stock effect capable of performing the essential role of the smooth water management. It was also clarified that the general index of both the stock effect and flow effect expressed in mean retention time and relative retention time represents the effect that averages the fluctuations.
In this regard, this report investigates water management considering the stock effect inside open channels in situating the mean retention time and relative retention time for solution of the water management problems by using the method discussed previously.
As a result, the fluctuation absorption has frequency effects and depth effects. Both these factors have effects connected to each other.
As for its application to the problems of water management, open channels that were made as models in the continuous elements were investigated. As a result, the relative retention time is an index to decide the condition of water management (supply-oriented type or demand-oriented type).

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Run-off mechanisms have been changing as a result of great developments in land use. It has become a necessity for reorganize and arrange drainage facilities to switch from policies that encompass only the flow effect to others that have a balance between the flow and stock effects.
In this report, we have evaluated the stock effect of main drainage canals regarding regional drainage.
As a result, in a open channel, the wave of frequency becomes larger, as the changing absorption becomes larger. Mean retention time, which is expressed by the ratio between stock capacity and flow, and relative retention time, which is caused by putting off the input cycle from the mean retention time, are proper for indexi mg to well evaluate absorption.
For total evaluation of the stock effect in the series system that links land and facilities, the average period is used as the indexing. Total averaged period is prescribed by the highest one of the averaged period among the elements which organizes them.
In view of the results so far achieved, the separate evaluation of stock and flow effects, and the averaged period which links the both are the fundamental planning elements for drainage planning.
Reexamination of the stock effect for facilities, thus, is considerable for a basic solution to the drainage ploblems.

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The incidence-matrix-based rigid water column model dealing with slow transients in pipelines is a lumped model described by ordinary differential equations of the first order (ODE). Therefore, the model has great possibility in analyzing hydraulic pipeline systems through application of the control theory in state space. Since the variables employed in the ODE are not the state variables (the minimum ones), it is impossible to carry out state-space analysis. This paper presents a theory for deriving the state variables and state equations in the incidence-matrix-based model. The state variables and state equations can be automatically determined with a computer for not only arborescence pipeline systems but network ones as well.

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Time-marching approach (TMA) for finding steady flows in pipelines, using a water hammer analysis based on the characteristics method, is improved to be practical for the hydraulic design of large pipelines: a basic idea and algorithm for TMA-calculation is clarified when the Hazen-Williams' formula is incorporated into the head loss relation. The existing method for approximating a spectral radius defining the speed of convergence to a steady solution is revised to give more stable computational results, in addition to an algorithm for renewal of time-step sizes. The reformed TMA is examined and discussed through comparisons among numerical results computed with some kinds of time-marching approaches for a typical network system.

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When earth structures, which retain water, are constructed, it is difficult to grasp the permeablity of the earth structures. The method, which identifies the permeable properties in saturated-unsaturated zone, has been developed by the fuzzy theory. Observed data are the heads of water. Identified parameters are coefficients of permeability in the saturated zone and permeable properties in the unsaturated zone.
The reasons why the fuzzy theory must be used are that the observed data are thought to have not only stochastic sources of error but also many fuzzy ones and that the available information (i. e., engineering judgment) can be utilized besides the observed data.
The comparison between calculated heads of water, which are calculated using the identified permeable properties and experimental ones, are in good agreement. The identified permeable properties have a reasonable character of seepage. So, the method developed here is thought to have validity.
Much good information is needed to identify the permeable properties correctly. Usually, a big number of observed data can not be utilized. All identifying methods have this defectiveness. However, the identifying method developed here can use the available information besides the observed data. So, the method developed here is thought to have contributed to identifying the permeable properties.

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This paper discusses the scale effect on the statistics of hydro-geomorphology of a river basin. In which the scale effect is caused by the difference in the length of streams mapped and/or hidden but measurable on contour maps of various scales. Both the Strahler and N₁ systems are applied to set up an ordered stream network. The results are summarized as follows.
(1) Even if we limit the discussion only for stream networks mapped on topographical maps of a river basin with the scales of 1/50, 000, 1/25, 000, 1/10, 000, considerable differences are found in the numbers for a given ordered stream and the maximum order in the stream network systems.
(2) If we apply the Strahler system to a stream network mapped on a topographical map of a smaller river basin, the usefullness of the Horton's law is practically recognized except the stream length law.
(3) We have judged, on the basis of the results of survey in several river basins on a rainy day, that the origin of streams is practically regarded as a point having a ratio of w/l=1, in which w is the width and l the depth in the bend of a contour line in a topographical map. By adopting this definition, we can measure the characteristics of the streamlets hidden on a topographical map.
The statistical characteristics of stream networks including streamlets are examined for several river basins. The relations between stream networks including and excluding streamlets are also clarified.
(4) For stream networks including streamlets, the adaptability of the Horton's law is approximately recognized for both stream networks ordered by the Strahler and N₁ systems although their statistical trends differ slightly from each other.
(5) The variations of non-dimensional statistics such as the river length ratio, catchment area ratio, etc. for a given stream order defined by the N₁ system are smaller than those by the Strahler system. This statistical characteristic is important from the viewpoint of hydro-geomorphology.

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An attempt was made to study the compaction mechanism by employing a static stress-controlled triaxial apparatus and using saturated Toyoura sand.
Specifically, investigations were made into the effects of loading systems (stress-controlled, strain-controlled), initial density of soil sample, stress condition at end of loading-nloading and repeated number of loading-nloading (N) on consolidation and shear behaviors. For these investigations, repeated K₀-consolidation tests were performed. Results from these tests indicated that the shape of principal stress path in repeated K₀-consolidation appears to be governed by the loading systems, but does not be affected by initial density of soil sample and stress condition at end of.loading-unloadng. Also, that N affects the magnitude of internal friction angle (φ').
During the stress-controlled loading system, K₀-unloading principal stress path tends to curve outward and lay above the line of the principal stress path of normal consolidation. This result shows that even axial stress unloads, and radial strain (εr), which exceeds K₀-condition (-0.005%<εr<0.000%), does not occur instantaneously. Meanwhile, even for different initial densities of soil samples and stress conditions at end of loading-unloading, the shape of the principal stress paths in repeated K₀-consolidation are similar.
On the other hand, that densification (decrease in the void ratio) due to repeated K₀-consolidation yields mostly during the normal consolidation step, since much of particle reorientation occurs during normal consolidation. However, for soil samples in the over consolidated state, the effect of cycling the stress on densification is low. However, when the soil samples are reloaded to stress greater than the pre-consolidation stress, the stress-strain curve is essentially the same as if there never had been any unloading.
It was observed that the angle of sliding friction (φf) is essentially constant regardless of the initial density of soil samples and N used in the test. However, when subjected to repeated K₀-cconsolidation, φ' first decreases and afterwards increases with N. For Toyoura sand, owing to its poorly-graded, the above-mentioned result may be understood as the disturbance of the fabric formed at normal consolidation step by first unloading. Then, the fabric is reconstituted into another new one, and becomes denser with N.

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The relationship between the uplift resistance of a circular anchor and strip anchor embedded in dense sand was evaluated by comparing the experimental results with a finite element analysis employing an elasto-plastic model including a shear band. The experiment was performed in a cylindrical container for a circular anchor and in a trap-door testing apparatus for a strip anchor. Each test were measured load-displacement relationships. The experiments showed that the peak load of a circular anchor could not be obtained simply by multiplying the constant value to the load of a strip anchor. The uplift resistance of a strip anchor applied stability analysis was in relatively good agreement with the experimental results, but was not in agreement for a circular anchor. On the other hand, limit loads of both circular and strip anchors by the finite element analysis was able to achieve good agreement with the experimentally observed peak loads.

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In designing structural systems to withstand random excitation such as earthquakes, it is important to take account of the response behavior which is not only nonlinear and hysteretic but stochastic, as the earthquake loads are powerful and random functions of time.
The purpose of this paper is to give a hybrid solution method for a single-degree-of-freedom (SDF) system including the methods based on the Markov vector and equivalent linearization approaches, i. e., the response probability characteristics are derived from Fokker-Planck equation and the hysteretical ones are represented by the equivalent linearized parameters assuming that the structural materials show nonlinearities of the hyperbolic type in nature.
First, the effects of three parameters, or, the input accelerations, the continuance time and nonlinear parameter of the system, which affect the response, were examined.
Second, to verify the validity of this approach, artificial earthquake waves were generated to simulate response both by the equivalent linearization method and hystresis-loop-pursuit one with the Masing rule.
Consequently, it was able to be shown that this method gives good results falling in the middle of both simulation values.

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The kinetics of settling particles in clay suspensions was examined and described by using three kinds of forces which are exerted on solids: gravitation, elastic force and viscous types. Then, it was related to the hydraulic flow phenomenon through fine solids system, this relation enabled us to evaluate the hydraulic conductivity of dilute clay suspensions from their settling characteristics.
The measured hydraulic conductivity for dilute bentonite suspensions, whose initial solid ratio ranged from 2.0 to 4.0%, was far greater than 103 of that predicted by the Kozeny-Carman equation. This difference increased to 10⁶-fold, as the initial solid ratio decreased to 2.0%.
To express the failure of the Kozeny-Carman equation in clay suspensions, a “macro pore model” was proposed. This model is based on the assumption that aggregates may form in suspensions and hydraulic flow mainly depends on macro pores, namely, inter-aggregate pores. We formulated the effect of macro pores into Eq.(16), which proved to be effective in explaining deviations from the Kozeny-Carman equation.

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The conventional design method of upright cylindrically shaped grain storage silos, both made of reinforced concrete (RC) and steel, is based on the approximation that long-term major loadings are horizontal grain pressure and vertical loading which are the sum of the frictional force of grain (including the loading and unloading impact effect), the self weight and the overburden due to the weight of the roof equipment. On the othe hand, main horizontal force is asumed to be induced by the shor-term loads, such as earthquake, and wind loadings. In computing the design sectional forces, the simple estimation method of membrane ring tension neglecting the bending moment due to the longitudinal variation of pressure and bending moment due to horizontal load, which assumes a silo as a beam, avoids the complex mechanical analysis of cylindrical shell.
In this paper, although the loadings are limited to the grain pressure, the cylindrical shell analysisis used to obtain exact sectional forces, and is compared to the conventional methods in both RC and steel silo for typical grain silos. As a result, some engineering findings related to sectional design of both types of silos are discussed.

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The consistent use of the Galerkin finite element method in all space coordinates is made with the basis functions: the two-dimensional linear and Chebyshev polynomial functions in the horizontal and vertical, respectively. For explicit time-marching, the Kawachi and forward-time schemes are employed for the coupled flow and salt transport equations respectively. Incorporation of these schemes in the spatially discrete equations is successfully achieved with the aid of the selective consistency technique. Useful guides for determination of the time increment that allows stable computations are given through a simple theoretical analysis. Computing the wind-induced circulation in a fictitious basin, the capability of the model is tested in terms of the steady-state appearance of velocity and salinity profiles in relation to the key parameters. It has been concluded that the model has high versatility, flexibility and efficiency in solving real flow problems under the shallow water assumption, and thus, it is capable of being an alternative to the established models of the same family.

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