For the submarine excavation of the anchorage foundation for the Kurushima Bridge connecting Honshu and Sikoku, a computer aided construction system was set up and used to strictly control all the construction processes, including the submarine topography survey prior to excavation, routine excavation, finish and confirmation of the excavated sea bed. The result was savings in time and manpower, and improvement in quality. High quality control of construction was achieved.
In this paper we will introduce the computer aided construction system that was developed for the above project. At the same time, we will report on research into computer aided construction, which has shown great promise as a new construction method for marine projects.

View full abstract

The Construction for foundation of HAKUCHYO OHASHI BRIDGE was finished in April 1992. inverted construction method applied on this construction had large depth: 76m depth, which we had not experinced before. Threrfore, filling capacity was neccessary to sidewall concrete for high quality construction joint. Also, pumpability was neccessary to bottom concrete in order to evade stoppage under vertical deep conveyning.Accordingly, befor construction we estimated applicaton of concrete using various admixture testing properties. We thus successfully finished it. This paper describes results of testing properties of applied concrete and construction.

View full abstract

Today's pavement design requiers a consideration of aesthetis which brings about attractiveness and comforts through harmonizing with the environment that surrounds pavement. Viewing such social request, this paper aims the development of design suppourting system on which engineers can evolve thier design ideas. The system consists of three subsystems; 1) constuction of pavement materials data base, 2) computer graphics to demonstrate their designs, and 3) a rating system to evaluate designs. Fuzzy Set theory is utilized for a synthetic evaluation of design candidates.

View full abstract

The Hakucho Ohhashi Bridge is a suspension bridge currently being constructed by the Hokkaido Development Bureau. The substructure was constructed using a method for underground liquid natural gas (LNG) tanks. This is the first time in the world that this method was applied in the construction of a bridge substructure. The purpose of this report was to investigate the design requirements and analysis model for the high depth slurry wall used in this project and to identify new design parameters based on its form. Various measuring instruments were installed with in the body of the slurry wall from which readings were taken during construction. These results were used in testing the design method leading to specific recommendation regarding approach to the combination of various seismic intensities.

View full abstract

In tunneling using shields with rectangular cross sections (box shield tunneling method), it is important and necessary to ensure the backfill grouting of the rectangula-shaped tail void to put the method to practical use. In this study, grouting performance was investigated through tests using a full-scale model. The basic characteristics of hardened backfill materials were also examined through a series of tests to propose different mix proportions. Based on the results of the above tests, simultaneous grouting was carried out during experimental tunneling to investigate the state of ground deformation and grouting thickness. The above mesurements proved that the successful backfill grouting of the rectangular-shaped tail void was possible.

View full abstract

Mechanical conditions when a truck crane is overturned are formulated against the two cases where the ground is very stiff and the ground is possible to fail. In the latter case, the bearing properties of the ground can be expressed based on an empilical equation and the degree of danger against ground failure defined by the equation can be almost simultaneously estimated by use of personal computer. The effect of some conditions, including yield stress of ground, boom angle etc, on the overturning conditions of an actual truck crane is finally evaluated.

View full abstract

The effect of side cutting angle β of an equilateral trapezoid grouser on the tractive performance of the flexible rubber tracked vehicle was investigated by means of a rigorous simulation program. As a result, it is clarified that the optimum side cutting angle β is π/6rad when the vehicle is moving up a sloped terrain during driving state and turning on a flat terrain and the optimum angle β is 0rad when the vehicle is moving down on a sloped terrain during braking state.

View full abstract

Here is presented the noise abatement devices, named noise-reducer, which are absorptive devices and mounted at the top of highway noisebarriers. The noise-reducers are developed for the noise mitigation strategy against recent increase in noise pollution problems at residential areas around highways. Scale model and full scale model experiments are carried out in order to specify the form, the size and the structure. Results of field tests at actual highways show that the insertion loss due to the application of the noise-reducer is 2dB to 3dB for road traffic noise.

View full abstract

The objective of this study is to propose the algolithm for making the land use conception map by using the land use capability classification model (LF model) developed by ourselves in 1990. In this LF model, we used not only Geographical Information but also the satellite data. The different kinds of training data, which were defined in the LF model as the rural and urban area factor, were set up to evaluate the accuracy of the land use capability classification. As a result, the applicability of the LF model for making the various kinds of the land use capability classification maps was confirmed through the quantification method type-II and III. Furthermore, by combining with these maps, the new land use conception map was made and its effectiveness for supporting the optimization to the mater planning goals was investigated. It was shown that the land use conception map proposed in this study could be supported to discuss the land use master plan and planning from different points of view what is called the development and the preservation.

View full abstract

The author's group has developed a bar code system consisting of the magnetic marker used as a bar code pattern embedded in a road and portable magnetic sensor made up of an exciting coil and a detecting coil. The detecting coil senses small changes in the magnetic field induced by the exciting coil and detects the bar code patterns made of the magnetic markers and spaces. The switching circuit reads a voltage from the exciting coil and transfers it into a serial signal for micro-processor. We have applied this system in a vehicle location system and succeeded in positioning the sensor-attached car which has passed through the bar code pattern on the road.

View full abstract

It is a social problem that the fill space surrounding seashore is getting decrease and the circumstance of land reclamation is getting serious. For the effort to restrain the residual from the slurry shield method, the recycle of the residual material was considered. The restrain rate is assumed to be aproxmately 14% against total excavated volume of tunnel. The technical development was carried out based on the design criteria that the strength of the recycled material must be greater than 60kgf/cm², slump must be over 21cm and high durability against the cyclicloading and chemicals. Forthermore, the execution test in the job site was carried on with real soil for the productivity.
As a result, this new material has no problem of the properties against the existing concrete at the points of the strength, the consistency and the durabirity, but the productivity is less than the design.

View full abstract

Considering actual applicability and effectiveness at the site, two different urethane grout materials currently used forepoling were tested in a laboratory. And following test results were obtained:
(1) Urethan materials are effervesced after grouting, and its cohesiveness and rising time which influence on workability ara affected by temperature.
(2) Concerning reinforcement of ground, quick reinforcing effect is achieved, and not only compressive strength but also tensile strength and adhesive tensile strength of material after grouting are found enough.

View full abstract

This paper deals with a new type of aerodynamic countermeasure developed for suppressing wake galloping in tandem cables of cable-stayed bridges. Wind tunnel experiments have been carried out to obtain the drag coefficients and control wake galloping. It was ascertained that surface patterned cables by dimples have drastic effect of raising the apparent Reynolds number and decreasing the exciting force of wake galloping compared to the other types of cables by introducing roughness on their surface.

View full abstract

The international construction market is based on the stern realities of free competition. Not only design and pure construction technics but construction management shall be essential for maintaining the executive and competitive powers in the market. The cost control, it shall be the main component of the management, creates various vital data for the maintaining the powers regularly & quantitatively.
This study is about the technics for mainly the Japanese contractors for the integration between cost control and the other elements, such as schedule control and contract administration. It can be said that the said technics shall be the most important and effective element for the systematization of Project management. It will be the keystone of the management in the market.

View full abstract

The behavior of an earth-retaining structure is affected to a great degree by the magnitude of the earth pressure behind the wall. In other words, determining the above earth pressure is of particular importance in the design of the earth-retaining structure. Generally, the earth pressure is closely related to the displacement of the wall surfase. In the case of an earth-retaining structure, however, the earth presssure acting on the earth-retaining wall has been difficult to determine because of the characteristics of the above wall, for example, the relatively small wall displacement and its curved shape.
This paper analyzes the earth pressure determined from calculations by using the finite-element method which simulates the excavation work for clayey soil and proposes a new design approach for modeling the earth pressure behind the wall. The accuracy of this method is also verified by comparing the estimated earth pressure and the measured value obtained in the field.

View full abstract

For the failure mechanics of rock anchors, in-situ and laboratory pull-out tests were carried out. From the tests, various forms of failure of rock anchors were deduced. The failure modes of rock anchors involve interfaces present in rock anchor systems rather than the embedment medium as observed in soil anchors with enlarged bottoms. The failure modes of rock anchors are as follows: 1) Tendon failure, 2) Interface failure (tendon-grout interface, sheath-grout interface and grout-rock interface), 3) Combined interface failure. In this paper, the authors show the failure modes of rock anchors and of soil anchors with enlarged bottoms observed in tests and discuss each failure mode by finite element simulations and finally propose a classification for the failure modes.

View full abstract