The difference between the tunnel behavior during excavataion by the mini bench method and the bench cut method is examined using the 3-dimensional finite element technique. In the excavation analysis, the sequence of construction which are excavation, support members and bench length are considered. It is recognized that the tunnel behavior by the mini bench method and the bench cut method are almost same, except leg settlement of upper half section, face squeezing and distribution of shotcrete stress.

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This research was carried out to examine the practical application of an embedded form incorporating three dimensional steel mesh and resin concrete. The result was that, while maintaining durability, the use of the mesh in both the resin concrete and in the placed concrete, an integration of the embedded form was achieved as well as a definite improvement in the resistance to cracking. Furthermore it was found that by applying a colored gel coating to the surface of the panel the finished appearance could be made more environmentally attractive.

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Precast segmental bridges with external tendons and dry joints were employed together with the span by span erection method as the standard structural form for the viaducts in the Bangkok Second Stage Expressway, which contributed in the realization of a megascale rapid construction. This paper, presenting various data, describes the outline of the measures taken in the project such as simplification, standardization etc. and the construction programs and the quality actually achieved.

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In order to decrease the reinforced roadbed thickness in railroad, the FEM analysis in the parameter of train load, roadbed strength, subgrade strength and so on is performed, and the reinforced roadbed thickness in the design was investigated. The analysis method was used the three dimensional FEM in order to represent the actul behavior of the roadbed on tamn load.
The results of FEM analysis offered the economical design than the conventional elastic analysis. And the new reinforced roadbed thickness in design was provided considering the work in field.

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An estimation of maximum velocity responses, which are caused by blasting vibration, gives the important roles on performing and controlling the blasting work. The observation data of blast vibration, which propagate in the soil and rock, have random characteristics. In this study, evaluating the relation between the maximum vibration energy of the wave and the maximum velocity response, it is shown that the maximum velocity can be estimated with a simple relation.

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Geotextiles are often used to from drainage layers within earthfill embankments and at earthfill/foundation interfaces. When designing the drainage layer, it is necessary to predict the probable reduction in permeability that will result from clogging of the drainage material. However, since the reduction of permeability varies according to the type of drainage material, the reduction of permeability should be predicted for the various types of drainage materials to be used for construction. Prediction of the expected reduction in permeability of the drainage layer can be easily accomplished by studying a prediction test method that reflects actual site conditions.

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To counter earthquake damage in the longitudinal direction of shield tunnels, displacement absorption by flexible segments or improved resistivity by ductile segments has generally been adopted. However, the former method is unsuitable when displacement absorption is required over a wide area, and the latter is costly.
By experiment and analysis, the authors have confirmed the effectiveness of creating rigidity-reducing sections using elastic washers, in places where the firmness of the ground or the rigidity of the tunnel lining lacks continuity. Moreover, we have studied and confirmed by experiment the required performance of the washer for the Trans-Tokyo Bay Highway.

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Vibratory consolidation of fresh concrete is known to require adequate vibrators. The author investigated the characteristics of concrete vibration generated by an experimental twin vibrator designed for testing the interference of waves, and applied these characteristics to the development of a new type of twin vibrator, which is expected to increase the effective area of vibratory consolidation. The differences between this twin vibrator and conventional normal vibrator are discussed here with regard to the surface appearance and strength distribution of hardened concrete. This paper also reveals the results of experiments using reinforced concrete specimens whose cross-sectional shapes are prone to cause consolidation-related defects. Conventional vibrator and the newly developed vibrator are compared in these experiments, and advantages of the new type of vibrator are cited.

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Efforts to develop practical expert systems have been mostly concentrated on how to implement experience-based machine learning successfully. Recently several active researches on machine learning have been undertaken from the viewpoints of knowledge base management. The aim of this study is to develop the Concrete Bridge Rating (Diagnosis) Expert System with machine learning employing the combination of neural network and bidirectional associative memories (BAM). Introduction, of machine learning into this system facilitates knowledge base refinement. By applying the system to an actual in-service bridge, it has been verified that employed machine learning method using results of questionnaire surveys on bridge experts is effective for the system.

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This paper aims to investigate experimentally the impact resistance of a cutter bit of the shield tunneling excavation machine. As a metal specimen and a falling weight impact blade, different kinds of hard metal of sintered alloy, two kinds of carbon steel and a cored steel were prepared. Thereafter, several impact tests were executed by use of a new falling weight test method. The critical impact values when the metal specimens are broken at fracture probability 99% in Weibull's distribution of impact fracture stress have been measured. As a result, it is clarified that, for hard metal, the critical impact bending resistance is increased with the increment of the flexural strength and with the decrement of the hardness, the critical impact shear resistance is almost constant for all hard metals, and the critical impact bending resistance becomes almost six times of the critical impact shear resistance.

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Applicability of partially anchored cable-stayed bridge to long-span bridge with center span length of about 1000m has been discussed based on the results of both static and dynamic analysis. The results show that the partially anchored system is superior to the self-anchored one as a long-span cable-stayed bridge because of the following: reduction of stress resultant is possible and this fact leads to the economical structure; rigidity of bridge is easy to be ensured. It has been also revealed that no problem may occur from both wind and earthquake resistant viewpoints.

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In order to investigate utility of mixed materials using fly ash and flue gas desulfurization wastes as subbase course material, firstly, unconfined compression tests were performed on specimens compacted at regular intervals after mixing materials and cured with various temperatures. Secondly, test pavements were conducted at two existing roads and both the conditions of road surface and bearing capacity of subbase course under traffic load were measured. As a result, it was found that the material concerned can be satisfied with the quality standard of subbase course, in addition, performance and durability seem to be maintaining satisfactory condition.

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We have studied the Extruded Concrete Lining method using the steel fiber reinforced concrete (SFRC) applied to subway. The target of our study is to develop the economical and durable lining method without the settlement and leakage induced by tunnel construction. The allowable stress design method, which has been conventionally used out design tunnel lining, cannot sufficiently evaluate the characteristics of SFRC on its tensile strength. So we carried out the loading tests using ring specimens and beam ones to establish the rational design method to compute the capacity of member section of the characteristics of SFRC which can transmit the tension through a crack opening with steel fibers bridging it. This paper presents the new limit state design method by defining the tensile strength and stress distribution of SFRC after the initiation of crack.

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Surveying the position of working vessels is a fundamental task for constructing offshore structures, dredging sea bed, observing tide behavior, and managing port facilities. Therefore, a real time positioning system with high accuracy is needed in practical harbor works. The Global Positioning System (GPS) is a surveying system using artificial satellites.
GPS offers several advantages over conventional surveying methods. Three dimensional vectors of long baselines can be determined with high accuracy. Intervisibility between sites is unnecessary. Measurements can be taken during night and day, under varying weather conditions.
In this paper, a real time positioning system using GPS has been developed for surveying the position of working vessels. This system is based on the kinematic method of relative positioning. In order to verify the practical applicabilities of the system, field investigations were conducted. It could be concluded that the system is useful and effective for positioning working vessels.

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The result of GATT Uruguay Round Negotiations has made the matters of opening the Japanese construction market much more realistic.
This report is a study on the problems arising from the new conditions on their countermeasures fitting for the new environment of the construction market.
This study is based on analyzing the reality of the construction management systems in Japan such as tendering systems, standard conditions of contract, standerd specifications, estimation systems, cost control, schedule control and contract administration.
Each item is analyzed from the view of the international practice of construction management for finding out suitable and effective solution to the problems.

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This study discusses the field tests and its analysis on the Extruded Concrete Lining method which was adopted in the Akima Tunnel of Hokuriku Shinkansen Project (Hokuriku Super-Express Line Project) as the first application in Japan, and the ground pressure which are important factors to design the tunnel lining. We propose the method to obtain the strength and the modules of elasticity of concrete at the age of removal of forms from the maturity, and the method to obtain the ratio of release of rock. the newly proposed design method is based on the limit state design method. In this method, it's prescribed that the compressive-section area shall be down to 50% of the entire design section.

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