When we try to apply the Horizontal stud welding method with large diameter and long length which we have developed to the connected structure between footing concrete and steel sheet pipe pile wall, we have carried the experimental studies.
Main experimental studies are the mechanical test of stud welding and large scale model test of concrete for steel pipe sheet pile. Large scale model test is the comparison between the new deformed bar stud and some former methods. One of former methods is the connection of shear plate and moment plate, and other is the deformed bar fixed into the concrete in the steel sheet pipe pile. Through these tests we have proved that this connection method has the sufficient shear transfer capacity comparison to the former methods.
While we carried the experimental studies, we have developed the semi-automatic stud welding machine and quality assurance device. Last in this paper, we describe these machine and device briefly.

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The suitable slurry pressure in a slurry type shield should satisfy the following conditions: 1) to keep stability in the cutting face. 2) to minimize the deformation of ground around the cutting face. 3) never to generate the hydrofracturing around the cutting face by the slurry pressure. This paper investigates the suitable slurry pressure in sandy as well as cohesive ground using a model slurry type shield machine. As a result, it is clarified that the pressure acting on the cutting face is the sum of the slurry pressure and the pushing pressure on the cutting face by the cutter and that the suitable slurry pressure is given by Eq. (1).
P_ms=σ_h-P_c…(1)
P_ms: the suitable slurry pressure, σ_h: the earth pressure at rest around the cutting face, P_c: the pushing pressure on the cutting face by the cutter

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Testing hypotheses for the accident frequency rates in construction works were applied to discover the significant changes in the accident situation in succeeding intervals of time. The time intervals between occupational accidents were employed as a useful indicator to measure the safety performance in construction sites. In order to save the sample number of accidents as well as the time periods to reach a statistical decision, sequential probability ratio tests were utilized for testing hypotheses of accident frequency rates. By making use of the sequential tests for various types of accidents, some features of accident situation were identified. Diagrams illustrating a sequential testing procedure could also be used as a control chart in safety management.

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The new method of measuring settlement using one bore hole which has enable the increase of measuring points during observation were developed. The principle of this method is based on two unique points, one of which is application of a permanent magnet as an indicator of settlement, and the other is the exploitation of semi-conductor magneto-resistance elements for detecting the magnetic fields. In advance of the observation, the magnets are forced into the earth penetrating the VINYL CHLORIDE casing of bore hole by the oil jack at suitable depths and intervals, and the small sized magneto-resistance element is much use of realization of this idea.
In this paper, the principles of this method, measuring procedure, the special characteristics and potential of this system and the results of field trials are described.

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The purpose of this study is to investigate the effect of ice on the seismic response and dynamic stability against sliding of a large-scale off-shore structure that is surrounded by thick ice. The nonlinear soil-structure-ice interaction system was analyzed by the two-dimensional finite element method. In modeling the system, a modified joint element was employed to simulate sliding phenomena at the interface between the soil and the structural base. Three accelerograms having different predominant frequencies were used as input motions to examine the effect of frequency on the structural response and stability. Three different values of Young's modulus were used for the ice. It was found from the analyses that the ice decreased the seismic response of the structure and increased the stability against sliding.

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The impulsive behavior for steel barriers protecting a falling rock is experimentally investigated. A sand layer or a pile of used tires is usually laid on the steel barriers as a shock-absorbing material against a falling rock.
Investigation has been carried out from the following points of view:
(1) a discrepancy of the shock-absorbing potentialities and the effects of a dispersion of an impulsive force through both materials.
(2) behavior of steel barriers under a static load and a impulsive force.
(3) the effect of flexibility of steel barriers upon the impulsive behavior.
From the test results the impulsive design load and the applying area of it to the barriers are proposed.

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A chimney whose body is made of light-weight and flexible material is proposed. In order to maintain the shape of the chimney, 3 types of supporting methods are proposed. The one is to use a kytoon, the second is to utilize the pressure difference between inside and outside the chimney and the third is to exploit pressure of the air enclosed inside the twofold wall itself. One of the most useful application of the chimney is to liftup and diffuse pollutant gases emitted from automobiles on a road side. Suppose that the chimney of 100m height and 2m in diameter is made, the weights of the body material of each three supporting methods are estimated as 285kg, 400kg and 4545kg, respectively, in case that the wind velocity is 30m/s.

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Total length of highway pavement has been rapidly increasing and past explosive expansion of traffic volume has been causing serious deterioration to our nation's highway system. It is of critical importance for highway agency to maintain pavement condition above desired level within limited available funds. Hence it is essential to establish a rational and efficient procedure to allocate the funds in an optimal manner.
The objective of this paper is to develop “CAMPAS” (Computer Assisted Management for PAvement maintenance System) which will assist a highway engineer to set up an optimal maintenance and rehabilitation schedule on new and/or existing highway pavement. Dynamic Programming is incorporated as an optimization tool.

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We have carried out design of rigid conduit by various analytical methods which are composed of applied earth pressure estimation and structural stability calculation for it. Among them, however, the method which can simulate behavior of a rigid conduit in various site conditions is not yet found. In this paper, a new formula of applied earth pressure and a new method of structural stability calculation are proposed. Bearing capacity and behavior of a rigid conduit with concrete cradle under buried condition are discussed. The validity of two proposals is clarified by field observation.

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This paper explains the behavior of ground water during the excavation in mud rock for a depth of about 40m, by comparing the analysis to the in situ measurement.
The following results are obtained.
(1) Two types of flow phenomena of ground water in mud rock are observed, namely the flow in a homogeneous porous medium (Darcy's flow), and the flow in a jointed material (pipe flow).
(2) Main factors which effect the rate of seepage flow and distribution of the water pressure are the permeability of ground, and the exsistence of high permeability layer such as Sandy-stone, fracture zone, or the low permeability layer like as clay, on the other hand, increase in permeability in local zones by relaxation during excavation affect little for those.
(3) For planning of drainage system of underground structure, it is very difficult to estimate the volume of seepage flow from boring data, and it is strongly recommended that the measurement of the ground water level and distribution of water pressure will be executed and it is important to reflect many measured data during excavation.

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The outline of pre-cooling system using frozen sand with liquid nitrogen (LN₂) and the results of the tests adopted in the development of the system are described first in this paper. As a result of tests, the following items are confirmed; (1) There were no changes in the physical properties of frozen sand. (2) The properties of the pre-cooled concrete using frozen sand were rather improved. (3) Higher cooling efficiency was attained compared to other pre-cooling methods using LN₂. And next the study on thermal crack control measures utilizing this system and the results obtained from the actural construction of the bottom slab of an LPG in-ground storage tank are mentioned. Consequently, thermal crack in the slab was well controlled and this system was confirmed to be practical.

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A new airport is under construction off the coast of the present Tokyo International airport to cope with the increase in passengers and to reduce the noise problem. The construction site is located on the place which has recently reclaimed by soft clay with high water content.
The paper describes the settlement of the ground treated by band drain, the design method for structures under ground settling by consolidation and the behaviour of braced excavations.

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In this paper, the outline of the BIP system, suitable investigation method for rock mass around pre-existing tunnels and its application in design are discussed.
The BIP system is effective in evaluating 1) the scale of voids. 2) loosening zones behind tunnels and 3) direction of dominating cracks and altered zones.
This method will prove efficient in design and construction especially when 2) and 3) are specified. This will enable the suggestion of the area to be pre-bolted and the length and direction of bolts necessary to avoid further spread of loosening zones during the investigation stage.

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Many ground databases have been born for the last few years, and have been made practical application of the ground survey. But many legal problems still remain for inputting, filling, linking, copying and printing of the database. Especially copyright, privacy and the right of citizen are problems. Mainly they are caused from the relation between private ownership of the land and public profit. The wealthy of information is also concerned with those problems.

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In 1984, the Cabinet decided “Government Policy on Environmental Impact Assessment” in order to conduct standardized assessments for various public works under the government's control. Trans-Tokyo-Bay Highway was the first toll road project to which the policy was applied. However, the local governments in which the highway was located had already provided ordinances or policies on environmental impact assessment, and coordination between the government policy and these local ordinances had not been completed.
This paper presents various measures which were adopted in the assessment of the project to coordinate procedures and methods and aitems of evaluation which disagreed each other in the government policy and local ordinances, and discusses some issues to be settled for more efficient and comprehensive assessment.

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In shield tunnels the lining is generally constructed by bolting reinforced concrete or steel segments to each other.
In the newly developed lining method, lining elements in which concrete are placed in I-shaped steel frames are used. After lining elements are installed with the horizontal joints staggered to the mid-length of the adjacent lining elements, they are jointed into a body by pouring mortar into the space between adjacent steel frames.
In the paper, several loading tests of the lining in the laboratory and its application to an actual shield tunnel are presented.

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P 15 foundation in the Sakitama Bridge for a loop road around Tokyo, consists of a highway foundation and twin local road foundation. The Closed Wall Foundation by means of diaphragm wall was adopted for the highway foundation because it was provided between the caisson foundation of local road previously constructed. This method, the construction of closed wall foundation, enable to construct deep foundation safely without disturbing the surrounding soils, but it has less applications. Therefore, for further effective application, the design and construction method have been investigated during this work. This report is described about the result of design, construction and investigation for this work.

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This paper describes the infrared sensing analysis of asphaltic mixture and asphaltic pavement and presents the various application of infrared sensing analysis for civil engineering. In this study, it is concluded that surface temperature of asphaltic pavement depend upon the load of vehicle, materials of pavement components, climate of region and structure of pavement.

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