The real-time GPS (Grobal Positioning System) marine surveying system, originally developed by the authors, has been improved for practical use in this research.
This paper outlines the improved system and details the results of the field tests conducted around the Kanmon international channel. The field tests were performed to investigate the ability of the system, i. e., the accuracy of the positioning, the stability of the On-The-Fly calibration, the availability of long baseline surveying, and the influence of obstacles on wave propagation.
The system developed by this research will be available for practical use in marine surveys. It will also improve work efficiency and reduce labor costs.

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In Kawagoe Power Plant, a Liquified Natural Gas (LNG) station has been proposed to construct over a reclaimed land. The land reclamation work was done over a soft alluvial clay deposit in the coastal area. Due to thick soft clay deposit under the reclaimed land, there were some problems, specially, regarding the insufficient lateral resistance for the piles during liquefaction due to the possible earthquakes. It was expected that the residual settlement may further complicate the structure. In order to solve these problems, pumping well installation was proposed at the sand layer above the soft clay deposit, so that the consolidation could be accelerated by lowering the ground water table. Before construction of the LNG station, one in-situ test section was prepared. The pumping rate and the settlement rate were closely monitored using the observational method. It was observed that the design goals were achieved using the observational method. The settlement observed was enough and the lateral resistance was also achieved as required by the design standard.

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This paper is a study on the observational construction of earth-retaining works used on the basis of minimum measured data on the inclination of wall and axial forces of the struts.
The observational construction procedure consists of 3 stages; analysis under present condition to determine wall deformation and bending moment, back analysis for estimating the lateral pressure and the coefficient of horizontal subgrade reaction used the extended Kalman filter, and predictive analysis involves predicting the behavior of the earth-retaining wall. Thus, the method based on field measurement proved to be effective in construction control.

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In order to prevent a tunnel face from landslide and ground surface from subsidence, new technics so-called pre-supporting are usually used with NATM at the shallow covered tunnels in urban area. However it seems that the reasonable design for pre-supporting has not yet established owing to the difficulty in measuring and evaluating the three dimensional pre-supporting effects.
Among those new technics, this paper describes the method of design particulaly for pre-lining which is able to transmit the stress to circular direction The proposed design method is based on the ground characteristic curve method for estimating the earth pressure on pre-lining and the limit state design method for evaluating the structural safety of pre-lining. The appropriateness of the design method was verified by the result of field experiments.

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The seismic isolation structure for urban tunnels, in which an isolation layer is formed between a tunnel lining and surrounding soil, enables us to reduce considerably the sectional forces of a lining in the tunnel axial direction. Such an isolation layer must have a low elastic modulus and a high Poisson's ratio of almost 0.5.
This paper presents a new silicone-based material for a seisimic isolation layer. Laboratory tests were carried out to obtain material properties, and a material injection test was conducted using a large-scale soil chamber and a tunnel model. Then, the appropriatenes of the new developed material as the isolation material was verified.

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Model tests have been carried out using an apparatus with several trap doors, to examine an earth pressure distribution patterns during shield driving execution and the redistribution by the succeeding change of load conditions. The present paper describes the load distribution on lowering trap doors measured by the apparatus, to get vertical load distribution pattern on trap doors and the load distribution by surface loading after lowering a trap door. The typical arching pattern of load and the load concentration on the area adjacent to the lowered trap door have been obtained Further, the anaiytical results by FEM are in relatively good agreement with the test results.

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In this study, the structure of wheel dozen was modeled and kinematic analysis was carried out in order to achieve the autonomous shoveling of fragment rocks by the wheel dozer.
Through this study, oil rate provided to the hydraulic cylinder was derived in order that the backet tip may follow the desired trajectory. Furthermore, a PID control method was proposed by considering the unknown disturbance during the task. Consequently, it was confirmed that the bucket tip can be controlled to follow the desired trajectory, even if the disturbance is added in the control system.

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This paper deals with the wake galloping in tandem cables of cable-stayed bridges under skewed wind direction. Wind tunnel experiments by using conventional smooth surface circular cables and dimpled surface circular cables have been carried out in both uniform and turbulent flows. It was ascertained from test results that the exciting force of wake galloping decreases with the increase of turbulence intensity in the turbulent flow. It can also be seen that lift and drag coefficients are strongly dependent on Reynolds number and that Reynolds number corresponding to the minimum lift coefficient is one of the most significant parameters for wake galloping when wind direction is skewed.

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In this paper, A designing method of surface coatings for jetties deteriorated by chloride attack is proposed. The designing method includes “Evaluation of marine environment by concentration of surface chloride (C₀)”, “Evaluation of durability of structures by apparent diffusion coefficient (D)”, and estimation method of chloride ions in concrete by Fick's law with one dimensional difference equation.
The method is understood to have good accuracy when the estimated deterioration period of structures and that of actual concrete structures are compared. The numbers of “C₀” and “D” are evaluated under the probability study of data sampled from the actual concrete structures.

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In the construction of tall structures, weather have strong influences on their constructability. In this study, therefore the influence of weather on the construction at 14 tall structure sites was studied by investigating job diaries, interviewing supervisors and workers and sending out questionnaires to workers. From this investigation, it was clarified that: (1) the ratio of idle construction of towers with 300m height was as much as 15% because of bad weather, (2) in construction of tall bridge pylons the critical factor was wind, while construction of tall buildings was mainly influenced by rainfall, (3) construction work was usually executed even under unacceptably cold or hot weather, while under wind or rainfall, it was often stopped.

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This paper explains the process and details of development work carried out in order to introduce the centrifugal compaction applied for manufacturing hume pipes as a new manufacturing method of RC segments that were manufactured using the vibrating compaction in the past. Through this study, the authors were able to establish manufacturing conditions (mold structure, concrete depositing method, concrete mixing condition, conditions for application of centrifugal force) to obtain high strength concrete of stable quality with excellent joint surface finish. Studies were also conducted on production processes and factory equipment, thus enabling realization of this manufacturing method as an actual production line and increasing efficiency in manufacturing RC segments.

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The ground spring method used for calculation the stress and deformation of the earth-retaining wall for braced excavation must express the load and resistance on the ground of the excavated side while simulating them in accordance with the actual ground condition, in addition to expressing the earth pressure on the back side. To express the load and resistance of the excavated side it is necessary to enter the earth pressure at equilibrium, the horizontal subgrade reaction coefficient, and the passive earth pressure. The earth pressure at equilibrium and horizontal subgrade reaction coefficient are used to express the load and resistance when the ground of the excavated side is in elastic state while the passive earth pressure is used when the above described soil is in plastic state.
This paper studies the earth pressure at equilibrium and horizontal subgrade reaction coefficient while using the elastic finite element method. The calculation equation, which includes factors with substantial influence, are proposed on the basis of the above study. Then, through comparison of the proposed equation with existing studies and with mesured value it was confirmed that the proposed equation are practically applicable.

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The objective of this study is to improve the accuracy of extracting areas in danger of the landslide by using the SSE model (Slope Stability Evaluation model) developed by ourselves in 1990. In this SSE model, we use not only Geographical Information (GI) but also satellite data. As a new spatial information for the satellite data, a “Fractal feature” calculated with Box Counting Method was defined. To evaluate the accuracy of SSE Model, three examination cases were executed as follows: CASE-1) Using GI. NVI (Nomalized Vegetation Index) and Fractal Features, CASE-2) Using GI and Fractal features, CASE-3) Using GI and NVI. As a result, in case of using Fractal features (CASE-1 and CASE-2), it was shown that the best accuracy for discriminating dangerous areas on the landslide could be achieved through analyses with the Quantification method TYPE II and III. Furthermore, a subtracted image extracted different pixels between CASE-1 and CASE-3 was proposed. This subtracted image is very useful for supporting the judgement whether the dangerous or not in the field investigation and the countermeasure against landslide.

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In the case of using blasting method to construct tunnels and house-formations in the urban or suburban area, to protect the environmental from pollution, reasonable control and accurate prediction of blast vibrations would be very important and necessary. However, it is difficult to control the blasting vibration because of many factors which could affect the distributions of the blasting waves tremendously. These factors were found and the effect related to rock fragmentation by blasting were reported in this paper. By using the data of the actual blasting wave obtained in field, both the amplitudes and the type of the wave were studied and investigated in detail. Moreover, the influence between factors which are depending on the time delay deviation of detonators, and the effect of rock fragmentation have been assessed by means of the simulation of the blasting waves. The different features between tunnelling blasting and ground surface blasting were presented according to the results of the simulation. In conclusion, a new estimation method for blasting vibrations based on the number of overlapping holes were proposed and proved to be useful for practical purposes.

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Several travelling and compaction tests were executed by use of a two-axle, two-wheel road roller during driving and braking action on an air-dried weak decomposed granite soil. The experimental data were compared with the simulation analytical results. It is clarified that the amounts of sinkage, the driving and braking forces, and the effective driving and braking forces of the front and rear roller increase with the increment of the absolute value of the slip ratio or skid, and the optimum traffic condition of the road roller to obtain the maximum compaction density of the terrain is that both the front and rear roller are operating at -5% skid during braking action.

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The configuration properties of the surface of rubble mounds were studied by the analytical methods based on statistical geometry called “Fractal”. The followings became clear after the investigation by the surface relief data in actual fields. (1) It's possible to classify into some noticeable patterns according to rubbles leveling methods with different work conditions. (2) It become easier to make parameterization of incomplete random properties such as leveling surface by introducing a theoretical factor called “fractal dimension”. (3) It is possible to create several approximate patterns by Brown motin model simulation with non-integral number.

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The objective of this study is to improve the accuracy of the land-use-capability-classification model which is called the “LF (Latency Factor) model” developed by ourselves. In this LF model, we use not only geographical information but also satellite multispectral data. As for the two kernel functions in the LF model, “LFn model” and “LFq model” applying the Quantification method type II and the Neural Network respectively have been newly defined. As the similar area for the characteristic of the training data was discriminated, the land use capability classification map made by using LFn model and LFq model respectively must be ideally corresponded. Based on this basic concept, the purification procedure for the training data was proposed, which is extracted the corresponded pixels of discriminated results with both LFn model and LFq model. Through this procedure, the improvement of 15% or so on the land use capability classification accuracy could be achieved. Furthermore, it was confirmed that the differences of the land use capability classification maps with both of LFn model and LFq model was remarkably decreased.

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