[in Japanese]

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The second phase construction project of Kansai International Airport started in July 1999. Although the amount of soil for reclamation of this project is 1.4 times as large as that of the first project, construction period of second project has to be almost the same as that of the first project. Therefore, this second project has to be done quickly and safely based on suitable implementation plan. In this condition, it is very useful to make up a construction management system that can simulate the various cases for reclamation, workvessel allocation, etc. in a short time. This paper introduces the construction management system that enables to simulate the progress of construction work based on workvessel allocation plan before the construction work started and to develop a scrutinized plan by comparing design data and observed data in the near future.

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This paper states about the possibility of multiplying the underground shopping mall. At present, “an underground shopping mall is limited to 1 story.” And this rule limits a spatial design to the direction of the height. So, thinking that the multiplicity of the underground shopping mall becomes possible, it describes the influence appeared about the space environment side, the business income and costs side, the safety and protection against disaster side. As a result, multiplying the underground shopping mall can be realized by the present construction technique and the protection technique against disasters. Moreover, it provides very comfortable space.

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In Japan, the application of High Tensile steel superior to HT-80 to penstock has been hoped because of the reduction of construction cost. Therefore, the researches on higher tensile steel HT-100, which has the tensile strength more than 950N/mm², have been carried out in the electric power companies, the mills and the fabricators.
This paper describes the required properties, performance and suitability of the HT-100 plate and that weld joint for penstock, produced by the latest technique and based on the past researches and development.

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It is difficult to find the necessary information on slopes expediently, because most of the information on slopes is recorded only on paper documents. In this study, we constructed a GIS database that consists of disaster reports collected in the past 24 years and general survey data on the slopes. We also proposed a slope failure management support system to find slopes with potential failure risk and to recall past recorded disasters, as well as slope failure warning and evacuation system to support decision-making based on GIS database. Furthermore, these systems are defined as “Slope-GIS”.

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The concrete or soil protection layer, placed on geomembrane, laid over slope surface of the landfills, makes electric circuit to connect inside and outside of stock yard. In this condition, it is too difficult to search and locate the leak points of geomembrane liner by the electrical leak detection systems due to electric potential and current anomaly can't occur close by the leakage point.
Authors have developed the new electrical leakage detection method for the landfill which search leakage by current measuring under controlled electric potential field. This paper presents some principles of our electrical leakage detection system audits ability, examined by an experiment.

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In the recent Japanese domestic shield works, the application of tennon segments are surely increased. However, we have very few data to recognize the actual behavior of tennon segments in the pragmatic shield works executions.
Our research hereby shows that we, through field site monitoring in a certain shield works and various kinds of structural analyses, will verify the evaluation for the given design-analysis methods.

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A newly developed dynamic compacting method (DCOM), in which a cylindrical steel pile of 60cm(D) was driven into ground to a depth of 10m and then pulled 2m upward placing gravel into the bored hole, was tested in three patterns of pile driving pitch at a loose fill site of coarse gravel. It was found that the improved area in the trial fill extended to a range of ±3.5D from the center of the pile, and 4D from botom of the pile. An increase of over 30 blows by SP-testing was observed in the 2D and 3D pitch drivings of the pile, and one of 10 blows for the 5D pitch driving. Model tests in a laboratory were also carried out in order to compare ground movement, and found a similare deformation pattern as that observed by tilting meter tests for the horizontal displacement in the ground.

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Corrosion on a steel plate is not totally random, but has spatial pattern. We propose a statistical model of steel corrosion depths considering spatial auto-correlation, with the help of spatial modeling theories developed in regional analysis. Distribution parameters are derived through moment method and maximum-likerihood method. The statistical model is applied to corroded steel plates cut out from a steel pier. The case study shows that the proposed model fits to the corroded plates better than an ordinal Weibul distribution model neglecting spatial auto-correlation. The parameter of spatial decay of the auto-correlation was stable for selveral number of the applied cases.

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Research on forecasting of slope failures has been carried out in various fields. A critical line is the boundary that considers rainfall either as safe or dangerous and it is generally used as a criterion for populace evacuation. However, the conventional forecasting is not accurate because most forecasts are based on linear critical line. In this research, the methodology to determine non-linear critical line by using Radial Basis Function Network (RBF Network) is proposed. Forecasting results using linear and non-linear critical lines are compared. Furthermore, criteria to determine warnings for evacuation are discussed. Finally, the proposed forecasting that used unexamined data is carried out to reaffirm the forecasting by non-linear critical line.

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This paper presents an analytical simulation procedure by a hybrid FEM based on nonassociated flow rule for ground deformation during shield- tunneling. Firstly, trap door test results for sand are analysed in terms of load, displacement and shearing strain through three kinds of FEM and their applicabilities to the analysis of ground behaviors are estimated. Secondly, actual field measurement results of ground deformation are analysed without stress release rate in accordance with the execution sequences by the same analytical methods.
Consequently the hybrid elastic-plastic FEM method, though roughly estimated soil properties are adopted for the calculation, is concluded to effective for analysis and prediction of ground deformation during shield tunneling.

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A new anti-corrosion method, removing remaining water inside the cable by injecting and circulating dry air, was introduced to the Akashi Kaikyo Bridge cables for the first time in the world. The superiority of this system was demonstrated by the experiments using cable specimens with and without this system. The dehumidification mechanism of this system was clarified by measuring the volume of dehumidified water from the dry air injected specimen. It was also found from the corrosion tests that corrosion ratio of galvanized wires is accelerated by higher humidity, temperature and volume of attached salt. The service life of galvanized wires is then predicted to be sufficiently long when they are kept under relative humidity under 60% using this dehumidification system.

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Recent large-scale earth constructions such as Second Tomei and Meishin Expressways have needed rational compaction method with compaction vibrator roller of a large size. Therefore, in-site rolling compaction tests on two sites and a series of laboratory tests were carried out to develop a reasonable procedure that thick finishing layers can be sufficiently compacted by a big vibrator roller. Tests results showed that settlement performance of embankments with compacted to the layer of 60cm thick by the 300kN vibrator roller satisfies the prescribed quality standard. Furthermore, influence of density gradients on defomation characteristics of soil layer has been quantitatively evaluated.

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In this study, the control algorithm was investigated to carry out the automatic loading of soils to the dump truck by cooperative task between the wheel loader and dump truck. A CCD camera was set on the dump truck and the image from the camera was processed to detect the landmarks on the wheel loader. From the coordinates of two landmarks in the image coordinate, the location and orientation of the dump truck was recognized. In the experiment, the path of the dump truck from the initial position to the wheel loader was generated and the dump truck was controlled to follow the generated path. It was confirmed that the algorithm proposed here works well.

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