[in Japanese]

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When planning and designing of continuous viaducts especially in urban surroundings, it is important to study the landscape under aesthetical concept of a civic design. In this process, once viaducts are selected based on a specific design principal, which includes a design concept as well as a method, developed under the aforementioned civic design concept. In this study, a questionnaire survey was conducted to analyze the level of satisfaction of the conceptual achievement, using few real cases of viaducts as the study area. The results show clearly the importance of the landscape in the viaduct design. Further, based on this analysis, it will make discussions on the design principle with respect to how viaduct design should be linked with the surrounding landscape and aesthetics.

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In this paper, an attempt is made to develop a new comprehensive database system for planning, design and construction of road systems. The proposed system is accomplished based on the framework of multi-agent system to integrate the various existing civil structures databases used for individual purposes. Considering each existing database as an agent, It is possible to provide necessary information services. Moreover, a total integration system is proposed to utilize the information regarding the civil structures in a long term period. The system consists of the construction directory service, the knowledge providing service, and the portal service. Then, the necessary information can be obtained without changing the architecture and function of existing database. A practical application experiment is conducted between the main office and a branch of Hanshin Expressway Public Corporation to demonstrate the validity, applicability and efficiency of the proposed system.

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This paper presents the development process of construction technique in New Pre-Lining Support (New PLS) method. The purpose of this study is to present the fundamental data obtaining from the construction by New PLS method, and to present an idea of technical development in civil engineering. The development process consists of actual construction data from 3 tunnels, i.e. “basic step” “plactical step” and “expansion step”. Rearrangement of results and ploblems in actual construction are important, working out countermeasures of problems in onsite data can contribute more rational construction technique.

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Many viaducts of highway in urban area are covered by bridge enclosure for beautiful view. In order to evaluate the possibility of omitting the repainting of steel girders inside the bridge enclosure, the corrosivity inside and outside the bridge-enclosure of viaducts of Osaka-Kobe highway was investigated with ACM (Atmosphere Corrosion Monitor) sensors, thermo-hygrometers, steel coupons and measurement of pollution. The results showed that rainwater and pollution could enter through the gaps between the panels of the bridge enclosure and stay at the surface of steel girders, which induced the rusting of steel girders. It is proposed in present study that the tightness of bridge enclosure should be increased for improving the rusty resistibility and thus omitting the repainting of steel girders inside the bridge enclosure.

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The paper presents a survey to apply the basic concept of infrastructure asset management to new road construction projects practically intending to apply for New National Highway No. 3 (NH-3) to be constructed under Road Network Development Project in Northern Hanoi. Firstly, results of Interviews to Vietnamese engineers comprehensive management considering the performance deterioration of pavement and embankment slope are proposed. Furthermore, this paper focuses on the importance of higher education and training concerning comprehensive road asset management.

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It has been reported that aged bridge steel decks tend to be severely damaged by traffic loading fatigue. However, economically effective retrofit process for these damaged steel decks has not been suggested in literature. To solve this problem, the authors investigated a new retrofit method, in which a pseudo stain hardening fiber reinforced cement composite, ECC, is effectively utilized as strengthening covering layer on steel decks. This paper describes the outline of the proposed retrofit system and the requirement for the constitutive components in the system. Analytical and experimental investigation conducted in this study revealed this system's feasibility to achieve excellent anti-fatigue performance in steel bridge deck.

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High strength bolted connections have been designed for four types of steel bridge using F10T class bolts with 22, 30 or 36mm in diameter (M22, M30 or Ml6), the number of bolts (the number of holes) and the weight of splice plates have been calculated, and then the material cost (bolts and splice plates) have been estimated. Working time for opening the holes and tightening the bolts have been also estimated for the designed connections. On the basis of these results, the influences of bolt diameter used on the material cost and working time have been indicated for each type of bridge.

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In this study, the problem of land subsidence due to groundwater extraction in urban areas was stressed. The Bangkok Metropolis and its vicinity were focused as the study area, and the problems caused by land subsidence were discussed. The relationship between groundwater withdrawal, piezo-metric drawdown and compression of aquifer system was described as the main cause of land subsidence. Stochastic methods using 3-D Finite Different model to model the uncertainties associated with groundwater flow and land subsidence analysis were introduced, particularly the uncertainty in future groundwater pumpage. The variation in groundwater drawdown and land subsidence was assessed and risk against flooding due to land subsidence was also discussed.

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Model experiment and numerical calculation were carried out to develop a evaluation method for deformed tunnels caused by earth pressure. The model experiment enabled us to know a relationship between displacement and load according to the load condition or defects of tunnel lining and influence of 3-dimension effect on the behavior of tunnel. Then, the simulation for the model experiment was carried out by using a 3-dimensional calculation method in consideration of crack progress and verified that calculation results are in agreement with experimental results including the shape of progressing cracks. The influence of loading position is investigated by using this calculation methods.

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Using data gathered during construction of the expressway tunnels in Shikoku, this paper serves to distinguish between typical rock mass in Shikoku and other geological regions by analyzing rock mass characteristics in each region. The typical rock masses in Shikoku are the Ryouke Group, the Izumi Group, the Sanbagawa Group, the Chichibu Group and so on. The results of comparing two rock mass characterizations, ultimate displacement and the convergence process, are as follows: During tunneling, there was little difference in rock classification in both Shikoku and the other regions. However, despite being of the same classification, rock mass behavior varied, due to different causes, from region to region. Convergence of the displacement curve can be expressed in terms of exponential functions, Rock mass characteristics, as well, can be expressed in terms of exponential functions. It is shown that the results of the analyses are mostly in accordance with that recognized by engineers and technicians.

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The need that Consensus-building on infrastructure development as for the process to adjust a wide diversity of opinions and interests among stakeholders is pointed out. However, the system in order to support the processes reaching consensus has not been established yet. This paper proposed the analysis model using drama theory to get over the limitation of game theoretic model, which has characteristics of imperfect rationality, possibility of change a game by pre-play communications, and property of phased and systematic feature. It was shown that aptitude as a tool for analyzing a mechanism of problems was verified by case study, and that possibility of the approach to manage some incentives by using our model.

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The vertical pre-reinforced method has widely been applied to prevention of the surface settlement in the shallow depth tunnel and landslide prevention at the portal area. However, the design of vertical pre-reinforced method based on the experience in respect of the equivalence force between ground. Movement and rock bolt. It is not a method for sufficiently evaluating the stiffening effect to protect a ground settlement a land slide. The authors carried out the detailed field measurement at the tunneling site applied the vertical pre-reinforced method during construction to estimate the support mechanism by the vertical pre-reinforced method. As the result, the vertical pre-reinforced bolt behaved an axis reinforcement model to assist the ground arch of the ground by tunnel excavation. As the result, the load of tunnel excavation is effectively distribute in the front and side of the tunnel face by its reinforcement. This ground reinforcement. Model by using vertical pre-reinforced bolt has established by evaluating the result of field measurements.

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Many highway bridges built in the high economic growth period become ageing, and it is important to extend the life of these bridges as precious social capital. The typical conventional strengthening methods for the steel bridges are splice reinforcement and/or external cable reinforcement methods, however the cost performance of those methods is not so remarkable. A new strengthening process by using the thermal prestressing method was developed herein. By this thermal prestressing method, the load carrying capacity of bridges can be upgraded to B-class live load. In addition, the durability and the life cycle cost of bridges can be improved effectively In this paper, also predicated is an example of strengthening through analytical calculation of continuous girder by using the thermal prestressing method.

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