The highway is designed to cross a wide terrace by open-cutting with the 1.3km in length, 8m deep, which will incur dewatering of the terrace deposits, aquifer, downstream of the highway. Facility to preserve groundwater-flow is designed as countermeasure against cutting off the flow after making clear the groundwater condition and proving efficiency of the facility by means of simulation and full-scale model test.
The facility consists of discharge well upstream the open-cut, recharge well downstream it, and connecting pipe below it and between both wells. Both the discharge and recharge wells (2m, 12m deep) are furnished with trenches (1.5m wide, 2.5m deep, 20m to 80m long) provided in parallel with the cut-off walls and pits (0.5m, 3m deep) provided at 2m intervals beneath the trenches, so as to complement efficiency of the wells.

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As Extradosed PC Bridge is expected as a new type which covers medium span of bridges between girder bridges and cable stayed bridges, the paper deals with a study of Extradosed PC Bridge.
First of all, features of the new type were given for criteria of bridge type selection at planning stage.
Linear and non linear analysis at both serviceability and ultimate limit states were then carried out to know more detailed characteristics, and necessary data and information for design were stated. From the results of Study, structure of this new type, Extradosed PC Bridge, was confirmed its reliability for safety design from the view point of reality.

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Even when a tunnel is built in hard ground, examination of earthquake resistance in the axial direction must be made if the tunnel has high rigidity, and it is also necessary in the transverse direction if the upper part of the tunnel enters soft ground. The authors identified these necessity analytically. Then, we proposed that the “effective ground displacement” characteristic of hard ground should be taken into consideration, and a method of structural countermesures in hard ground. Finally, we showed an example of application in an actual tunnel.

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This paper describes the problem involved in the excavation work using the diaphragm wall in the soft grounds, which consists mostly of alluvial soft clay layer. In particular, the mechanical behavior of earth and water pressures acting on the outside of the braced walls in the soft clay layers is discussed in detail based on the on-site measurements of some excavation works. As a result, braced wall displacement causes the outside water pressure to decrease. The quantity of decrease and wall displacement show a linear portional relation. The outside earth pressure first drops the active earth pressure level owing to the wall displacement up to 20 to 30mm. After the range is exceeded, outside earth pressure insreases with the wall displacement.

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A questionnaire on urban tunneling methods was conducted to investigate how engineers understand the applicability of the NATM and the shield method to constructing urban tunnels. From 310 answers to the questionnaire, reasons for adopting the NATM or the shield method were revealed. It was found that the occupation and experience of engineers have affect on deciding a tunneling method. Finally, the linear multiple regression model was used to evaluate the answer of the questionnaire quantitatively.

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This paper describes research on a consultation system to cope with landslides and other problems which often occur during the construction of a tunnel portal by grasping the problems involved in the construction of the portal and assisting the study of suitable measures to be taken. This system is designed not only to assist the operations of trained engineers but also to aid even relatively inexperienced engineers to foresee in advance the dangers of a portal site so that the necessary measures can be prepared, and also enables the expeditious preparation of detailed study reports. Also, in consideration of the fact that past experience is of great importance in this type of problem, a dialogue format was adopted so that the process of study at all times clearly draws from this experience.

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Practical application in recent years of shield machines which can be used for continuous excavation of vertical shafts and horizontal adits has given rise to a need to establish the design methods for vertical shafts constructed by this method. The application of conventional vertical shafts design methods will produce a cumbrous structure in which the advantages of the new method are not exploited. In the study reported here, the design conditions used in the construction of caisson type piles were utilised as the design conditions for the segment section of vertical shaft under normal circumstances and during construction, while the seismic analysis method used with conventional shield tunnels was used for the conditions during earthquakes. For the bottom section of the vertical shaft, three-dimensional FEM analysis was iterated to produce an optimum analysis model. These design cases are used to demonstrate that the application of the new construction method will lead to a reduction in the costs of members comprising the vertical shaft structure.

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The purpose of this paper is to study the direction of horizontal earthquake inputs which produce the critical dynamic responses subjected to bearings of the curved girder bridges by the stationary random vibration analysis. This method is based on the assumption that the input excitation is the stationary Gaussian process and the response is stationary . We can calculate the deviation of the displacements and the reaction forces of the bearings by employing the stochastic differential equation. Kanai-Tajimi form and Clough-Penzien form were used to obtain a power spectral density for modeling ground acceleration response during earthquakes. The proposed procedure is demonstrated for an example bridge. Computed results based on the proposed method are shown to be in close agreement with Monte Carlo results obtained through time-history analysis.

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In visco-elasticity analysis using FEM, approximation with nodal load equivalent to creep strain is often utilized. However, the propriety of the use of the aforementioned seems to be left out of consideration.
In this note, the accuracy of this approximation is examined through simulated tunnel construction by firstly obtaining precise solutions and then by comparing them with those obtained through approximation. The comparison proved that the use of approximation results in, in some case, impractical solutions.
A method for correcting this erroneous process is also proposed, which is confirmed to be effective for improving the level of accuracy of the solutions obtained.

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The asphalt mixture for the impermeable membrane of fill-type dam has to possess such properties as impermeability, flexibility, slope stability and durability. Asbestos fibres have been mainly used to obtain slope stability of this mixture. Because asbestos fibres were proved to be the carcinogenic substance, other kinds of slope flow reducing additives which substitute for asbestos fibres are now urgently required. For this reason, we carried out an experimental study on slope stability, flexibility and durability etc. of asphalt concrete containing some kinds of slope stabilizing additives on the market. From this study, we confirmed that rockwool and cellulose fibres were effective for reducing slope flow as substitutes for asbestos fibres.

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In the initial stage of mixing for ultra high-strength concrete, the fine particles of silica and cement contact with water to generate cement balls which deteriorate the concrete quality. Crushing was difficult with conventional mixers, but the manufacturing system with a static mixer which developed, impresses an enormous shearing force on the cement paste to crush the cement balls into uniform particles. So compared with the conventional batch system, the consistency of the concrete is improved, the compressive strength of the concrete is increased by over 10% and the strength disparity decreased to about one-fifth to enable the manufacture of quality ultra high-strength concrete reliably.

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This paper deals with reasonable structures of stiffening truss girder for the wind-resistance degign of an ultra-long span suspension bridge. At first, we studied about the effect of lateral bracing system on torsional rigidity and found that the lattice type lateral bracing is the most effective system to increase torsional rigidity. Next, we proposed a hybrid girder composed of truss and steel deck, and then tentative design was performed for the 3000m center span models. As the result, it was clarified that the hybrid truss girder system is an economical and reasonable solution for the ultra-long suspension bridge.

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In urban and suburban area, rock blasting is often used in tunnelling and formation of housing site, however engineers are often faced with vibration complaints. In this paper, we show the new criterion using vibration level for blasting vibration control, depending on the record of vibration complaints and the measurements of blasting vibration level at a resident area. According to the above criterion, we propose the method of blasting vibration control based on probabilistic approach.

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The author carried out laboratory experiment to discuss various factors influencing the relation of magnetic sensor and bar code pattern made of magnetic substance and space. The following conclusions were obtained. 1) The voltage from the magnetic sensor showed little change within 5 to 8% asphalt contents in the magnetic marker. 2) The voltage from the magnetic sensor became larger as distance between sensor and marker became shorter and as marker was thicker and longer. 3) The voltage from a set of markers was similar to the one from a marker which has the same length to the set-markers. 4) Considering the laboratory data on the voltage-marker's density relation, maximum voltage should be little change for the density variation in the surface mixture after service.

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This paper investigates the methods of calculating the mixing torque for the deep mixing improvement of sensitive soft clay. It is noticed that for higher sensitivity ratio, the degree of mixing is better. Normally, the improved strength ratio of clay from the field and laboratory investigations ranges from 1/2 to 1/5. The present study suggests that this is due mainly to the difference of the applied mixing energy. The strength ratio can be illustrated from a viewpoint of mixing energy ratio. An economical and reasonable work execution is established based on the relationship of the chemical agent content, mixing energy, and improved strength.

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In this paper, the author discussed the relation of magnetic sensor attached to the vehicle and various bar code patterns made of the ferrite mixtures and spaces by means of vehicle running test. This experiment yielded the following results: 1) The serial signal transferred from output of sensor by switching circuit represented the length of bar code set on the road. 2) The number of loop counted in the micro-processor was nearly proportional to the length of bar code independently of vehicle speed and of scale-down-pattern. 3) This bar code system functioned properly, even though with snow, ice and dust between sensor and the bar code and also functioned below the freezing point.

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In recent years, wind-induced cable vibrations of cable-stayed bridge have been observed, and phenomena of these have become a major problem in wind engineering. This paper deals with the vibration control of stay cable by installation of two types of dampers. The authors have derived a practical estimation method for the modal damping in stay cable with dampers. Several examples demonstrating the application of the proposed method are also presented for the cable model with the length of 100m and 250m. From these results, some useful informations for the vibration control of stay cable by installation of two types of dampers are obtained.

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This paper proposes an analytical solution for the bridges with steel decks connected to chord members. In order to analyze this type of bridge, the constant shear flow panel with the edge members which transfer the linear axial forces are presented for the modeling of the steel decks.
Although this analytical method has been already reported, this paper describes how to consider the eccentric connections between steel decks and chord members.
As the examples of this method, a tow-web girder bridge and a Nielsen system arch bridge were analyzed. And the validity of the proposed method was shown in comparison with FEM.

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The purpose of this study is to consider the fundamental properties for shape of rubbles and surface configuration of rubble mounds by the use of the analytical methods based on statistical geometry called “Fractal”. (1) The new three types of shape factor for rubbles were suggested through the different of measuring methods. (2) The statistical characteristics of the surface relief of rubble mounds were studied by power spectrum analysis. (3) The fractal dimension were obtained from the results of the above (1) and (2), so that it was shown that the statistical characteristics of both rubbles and rubble mounds would have some noticeable similarities.

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The objective of this study is to propose a practical method applying fractal for the multi-temporal analysis on the land cover change in case of applying satellite multispectral data. The changed area to the residential over twenty years were extracted through the plural land cover classification maps made by using Muximum Likelihood method. For these areas, the box counting procedure were applied to calculate the fractal dimension. The results of this study are as follows: 1) The distribution of changed areas to the residential showed the fractal properties over a range of spatial scales. 2) Furthermore, it was confirmed that four typical types of the residential form and growth, such as the mono-focal, the ring/radical, the multi-focal and the twin type, could be descriminated by means of fractal dimension. These results suggest that it may be possible to presume and analyze the residential sprawling in the future through the fractal dimension.

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