The “Sutong Changjiang Highway Bridge” is currently the world's longest cable stayed bridge. There is 8 146 m in total length. A double-cable-plane double-pylon steel box girder with main span of 1 088 m is adopted for the main bridge, which ranks No.1 among the same types of bridges all over the world.
This paper reviews first the technical issues and measures in the design, construction and maintenance of the bridge by specially describing the design and construction on the large scale of pile foundations, main towers, main girder, and cables. Moreover, the research, development, as well as verification carried out for the bridge, are also summarized.
Finally, the maintenance considerations of the bridge including structural health monitoring system is also introduced in the paper.

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A two lane road tunnels, which were constructed by a side drift method more than 35 years ago, in a very difficult ground condition had to be extended. Knowing that the initial construction had experienced large deformation and high pressure on concrete lining, a special care was taken for planning, selection of construction method, and the actual extension of the tunnel cross section was completed only with minor deformation with fair confidence in tunnel stability. This paper attempts to reveal a reason behind this fact and tries to associate the success of the operation with an existence of so-called “ground ring” which could have been formed around tunnel lining over time.

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The large-scale rock cavern of underground power station, LPG underground storage, and radioactive waste disposal had been carefully excavated to keep the stability of surrounding rock. On the other hand, the establishment of efficient excavation system is an important subject for reduction of construction cost, in order to realize future construction of more large rock cavern in more deep area. This paper presents the large section bench blasting for efficient excavation on the basis of machine ability improvement and observational construction.

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In the construction of asphalt facing, which is used for dams and reservoirs, the performance of transition layers as a paving foundation much affects their stability.
Transition layers as a paving foundation requires not only strength, flexibility, permeability, but also adhesion to integrate with asphalt facing.
This report proposes the optimum design and construction method of transition layers by testing the function of transition materials through material experiments and construction site pavement experiments, and by proving the function in the construction.

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  There have been only a limited number of attempts to construct a tunnel by the NATM through unconsolidated cohesive soil of the middle Pleistocene and younger geologic ages because of difficult in ensuring the self-standing ability of the ground. As a result, the responses of this type of ground are not yet well known. Because the NATM allows modification of the support structure in accordance with the observed ground state and selection of construction techniques that suit the ground characteristics, extending the applicability of the NATM to wider ground types is desired. Bearing this in mind, this study summarizes the physical and engineering characteristics of unconsolidated cohesive soil, analyzes ground displacement responses during NATM tunneling, and investigates ground deformation properties that are key to numerical analysis.

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  The bare mild steel and the tar epoxy resin coating which is generally used for the unti-corrosion material of the marine steel structure were exposed for 20 years at the Marine Technologies Research Facility (Marine Station Suruga) in Suruga Bay in Shizuoka. This place is one of the international joint exposure sites adopted in the corrosion environmental class C4 of ISO/TC156/WG4. The precious data of the corrosion rate in series at the same enviroment was obtained. On the other hand, the phenomination of the degradiation of tar eoxy coating was different from that of the bare mild steel in marine environment. There was little degradation of coating in splash zone, and big degradation of coating in tidal and submerged zone.

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  The business analysis is done in various organizations because it flexibly correponds to the change in social conditions. The business analysis is to extract the problem from a current business process, and to design the business process model which becomes an improvement. It contributes to the model's efficiency improvement of work and quality securing and recycling promotion by lecturing on the support plan that detects a simple mark difference in a current business analysis when the business process model is edited. Moreover, it contributes to the efficiency improvement of the analytical work by achieving the support plan that discovers a typical problem from the business process model and extracts it.
  In this study, to support efficiency improvement and a quality and recycled securing of the making work of the business process model, the supporting method of the problem discovery that used the business analysis supporting tool and the business process model was developed. And, the supporting method developed by this study was applied to the business analysis intended for the river and the national road office of the MLIT (Ministry of Land, Infrastructure, Trasnport and Tourism) and effectiveness was proven.

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Shield tunnel lining design has conventionally used, as design loads, the loosening pressure and total overburden load. However, it is not sufficient to set up design loads unequivocally without regard to the interactions between the shield tunnel and the ground. Although it may be more rational to set up lining design loads with due consideration for ground characteristics and tunnel sectional shape as well as the shield excavation process, no method has been established to determine these loads. This paper proposes a rational sectional force calculation method for shield tunnel lining ;a segment ring sectional force determination method with due consideration for the excavation process by modeling the lining with beam element and the shield tunnel surrounding ground with plane elements.

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This paper describes the method which quantitatively evaluates the falling of concrete pieces from tunnel linings, comparing the shear stress acting on crack surfaces with the shear capacity. The shear capacity under the various width, inclination angle, and roughness of cracks is investigated based on a double shear test simulating the falling of concrete pieces and on a simulation method, whose applicability is also described in this paper. Core samples including the crack surfaces are obtained at actual tunnels and crack surfaces roughness and its distribution are grasped. The safety in the falling of concrete pieces is estimated based on the proposed method under the situation assumed at the actual tunnels.

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  Composite segment used in shield tunnel has several types. The most complicated composite segment called as the closed composite segment in these type segments was selected in this study, Firstly, the mechanical behavior of the closed composite segment was studied by the flexural tests and the analyses based on FEM and RC theory, and these formulas of yield and ultimate flexural load capacities were proposed. Secondly, the applicability of these proposed formulas for other type segments was verified by these experimental results of Ductile and Reinforced Concrete Segment and Steel Segment with Pre-filled Concrete. As a result, these proposed formulas can be used to estimate yield and ultimate flexural load capacities for these composite segments with good precision.

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  The system obsolescence driven by the change in drivers' needs and technological innovation should be considered in order to investigate the replacement strategies of the large information systems. The obsolescence processes are characterized by a lot of uncertainties. In such circumstances, there exist 1) information options made by postponing the replacement timing, and 2) extension options driven by securing the possibilities to be introduced in future. In this paper, the optimal system replacement model is formulated in order to investigate the optimal replacement timing and the best milieus of subsystems to maximize the expected net benefits. The methodology is presented to measure the values of real options for the systems replacement. The methodology is applied to the optimal replacement problem of the large traffic control systems in the real world.

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The applicability of bamboo as concrete reinforcement was investigated in this study. The tensile strength of bamboo as concrete reinforcement is much lower than steel bar reinforcement. However, one of the merits is the effective use of natural resources. And, there would be no need to consider the problems such as carbonization and salt damage which are fundamental and important on RC structures, since bamboo does not rust. In this study, the tensile strength property of bamboo was experimentally obtained as the basic data. Then the strength properties of bamboo reinforced concrete (BRC) slabs in which the bamboo was used as reinforcement was investigated.

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