An in-ground LNG tank with the capacity of 160, 000kl is being constructed in the ground of Tokoname-layer of neogene in Minamihama district of Chita city in Aichi prefecture. During the inner excavation, several me asurements, such as deformation of diaphragm wall, rebound of ground, etc., were carried out.
Additionally, the elastic modulus of ground was formulated on the basis of the results of triaxial compression test by LDT.
Consequently, the deformation of diaphragm wall and ground can be numerically simulated by using the measured data.
Also, the loadings (earth pressure and ground water pressure) on the diaphragm wall and the deformation properties of ground can be obtained.

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Increasing efforts are being made today to develop rectangular-section shield tunneling machines primarily because rectangular cross sections, often used for highway, railway, and power cable tunnels, reduces the amount of unnecessary excavation. In shield tunneling, segments are as important as the shield tunneling machine, and the development of rectangular-section segmental linings satisfactory in both performance and economy is hoped for. Rounded-corner rectangular-section concrete linings usingsegments designed by applying the design method for curved beams hace been developed, and their performance was verified through joint tests and ring load tests on full-scale specimens.

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On-netoh bridge was constructed on National Highway Route 44 using seismic-isolation devices. The Hokkaidoh-toho-oki Earthquake with magnitude of 8.1 occurred on October 4th 1994. The epicenter of this earthquake was about 100kms from the site of this bridge. The intensity of the earthquake motion might have been equal to the design condition that is established as level 1 earthquake in Specifications For Highway Bridges.
In this paper, the frequency transmitting characteristic of the bridge structure and the behavior of the seismic-isolation device were analyzed using the acceleration record. The effectiveness of the seismic-isolation device was assessed considering the result of above analysis.

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Jet-mixing method, as one of the ground improvement methods, has been applied to the vertical direction generally. Considering that one of the subjects to establish the horizontal execution of jet-mixing is to prevent any influence to the surrounding ground caused by varying earth pressure from the initial state. It is inevitable to vary the soil pressure on it's execution since the ground becomes liquefied instataneously. Therefore, aiming that the most proper soil pressure should be maintaine during the execution in order to minimize the infuluence, the authors have determined the most proper soil pressure by using numerical analysis and verified it's effectiveness by field experiment.

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The authors proposed a liquefaction countermeasure method using soil-cement-column earth walls with reinforcing rings to counter the liquefaction of the ground around tank foundations constructed before the latest seismic design code for them. Sets of model tests using a shaking table and numerical analyses showed that this method was effective in mitigating the settlement of tanks. The main concept of this method is to construct soil-cement-column earth wall around a tank foundation in order to increase the lateral restraint of the ground under the tank foundation and suppress the ground deformation.
A method of estimating member forces of the structure is proposed and the values are compared with the results of the model tests and with those of numerical analyses. As the result, it is found that the proposed method is useful as a design method of the structure.

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Knowledge acquisition is one of the most crucial requirement for expert systems, because knowledge is usually based on experiences or subjective judgement of engineers. In this paper, a knowledge refinement method is proposed for crack diagnostic expert system. The inference engine is constructed for a reciprocal network based on min-max composition algorithm. Knowledge refinement function is installed into the engine by using the concept of back propagation algorithm usually used for layer-type neural networks. The inference and refinement method are applied to the rule-base system for crack diagnosis of damaged bridge slabs. It is confirmed that existing knowledgebase can be easily transferred to another system for rule-base shearing by using the algorithm proposed here.

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The authors devised “Wing Segments”, making cost reduction of segmental lining, because of simplification of longitudinal joint structure by transporting bending moment with sharing stiffness of the joint. In this paper, the structural mechanism of transporting bending moment with sharing stiffness of the joint, was expressed by “Soe Bari Model”, and the effect was established by “Soe Bari Model” using experimental value of bending and sharing spring of the joint by fundamental loading tests of prototype segments. At the result, it was confirmed that the sharing stiffness and the overhang length of the longitudinal joint were effective to transport bending moment in “Wing Segment”

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The homogeneous bed rock is generally assumed in the design of penctock of the undergroud hydroelectric power station. The distribution of real values of local elasticity of the rock around the steel lining penstock is not uniform. The local value of the elasticity of the rock can be measured by the jack test, the test of water pressure chamber, and so on. The effects of the nonhomogeneus of the rock and grouting by cement milk are treated in is paper.

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Car accidents often occur at the beginning of snow fall, especially on the bridge, and pipe heating system for roads has been developed as a measure to counter accidents. However, there have been little design data for the system, and the design of the system is based on the designer's experience.
In order to obtain fundamental design data for the pipe heating system, laboratory and field tests have been conducted. The tests were focused on the pipe spacing and other effects of water temperature to snow-melting. The finite element analysis has been also carried out to compare the experimental results.

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The road surfaces on steel deck bridges have more amount of frost and snow cover than any other ones, because the heat capacities of their decks are small. Antifreezing system with phase change material which has the 2-5°C solidifying point was developed and has been into practical use in Fukui city, a snowy and rather mild city. Simulations of the road surface temperatures with and without phase change material are useful for popularizing this system in other regions. Taking into account radiate, sensible, latent and conductive heat fluxes which were estimated using weather data observed the meteorology observatory, we carried out the numerical simulations.
The numerical results for successive 10 days which were frosty and snowy alternately agree with the measured ones.

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The limit state design method was adopted for railway superstructure design in 1991 and substructure design in 1997. They deal with large scale earthquake (M=8, Epicentral Distance=40km) and consider very large ground acceleration. But January in 1995, the huge earthquake attacked the Southern Hyogo prefecture. The scale of this earthquake is far larger than the scale considered in the present design guideline. Therefore it can be said that the establishment of the foundation design method which consider such a large scale earthquake force is an urgent necessity. In this paper the authors describe the proposition of the design method of spread foundation considering large scale earthquake force.

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In a previous paper, we proposed a new method for setting the earth pressure on the back side and equilibrium and passive earth pressures on the excavated side, and the coefficient of subgrade reaction on the excavated side in regard to clayey soil. These are the elements for the ground spring method employed widely in the design of earth-retaining structures.
This paper proposes extending the above-mentioned method to cover the case in which hard ground exists below the excavated bottom. This paper also demonstrates the result of a study on applicability of the earth pressures and the coefficient of subgrade reaction derived in this and previous papers. On the basis of these studies, we propose a rational and practical method to set earth pressures and the coefficient of subgrade reaction for use as input items in the ground spring method for ordinary earth-retaining structures in clayey soil.

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