The cable specimens with various kinds of corrosion protection methods were exposed near the sea side for four years, and the inside were investigated by opening them. The specimens include the conventional systems used on the Innoshima and Onaruto Bridges, those manly used on USA and UK, and newly proposed methods with improved pastes and S-wire wrapping. The difference was not clear on their appearances among the specimens, but corrosion was detected inside the cable. But, the newly proposed methods showed better performance against corrosion compared with the conventional methods and overseas methods.

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The many retaining walls on housing lots were damaged by the Hyogoken-Nambu earthquake. The characteristics of these damage and the cause for it have been investigated, and the relationship between these damage and various factors has been analyzed. Moreover, on the representatives of the housing lots where retaining walls were damaged, Swedish weight sounding tests have been made in comparison with the housing lots in the neighborhood of them where retaining walls were not damaged. As a result, the cause for damage and the degree of stability to retaining walls of an earthquake occurring have been revealed.

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As one of the efforts in decreasing box girder's construction cost, we have developed a box girder with reduced box girder width.
We firmly believe that by narrowing the box girder's width, costs will most effectively be reduced. By strengthening and increasing the slab thickness, not only is box girder width decreased, but stringers are entirely omitted, further improving it's manufacturing productivity. Revisions to Japanese design standards have contributed to making the aforementioned design related change possible.

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Highway crash cushions are expected to decrease the traffic accidental death caused by vehicle crash against roadside barrier, such as a nose of verging end, end post, toll island and the like.
Therefore this paper investigates the safety perfiormanoe of representative crash cushions by the full-scale vehicle crash testing at the first of our country, furthermore, documents the results of follow up investigation of dash cushions set in the national expressway tentatively.

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Recently, the standard data base of cut-off slope has been tidied up by the Japan Highway Public Corporation Branch of Chugoku base on the data form each stage of the investigation, design, and construction. And the rainfall data can be recorded at the observatory of the Meteorological Agency or the Japan Highway Public Corporation.. The collapse of cut-off slopes in heavy rain is caused by slope evaluation factors as well as rainfall factors. Therefore, we expect the system to forecast the collapse of cut-off slope using the standard data base and the rainfall data effectively.
In this research, we have constructed a system using the given data for application to real time forecasting in actual heavy rain. We present the considered points to construct a forecasting system using standard data base of cut-off slope.

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Since the important structures are often located across or near by tunnels under construction in urban areas, the ground surface settlement is quite important and unavoidable. Especially when a shallow tunnel is excavated in unconsolidated ground, the ground displacement shows often the characteristic non-linear movement influenced by the soil mechanics. The authors conducted two kinds of excavation methods in the diluvial sand layer and vertical anchor volts works to support the excavation in the bank. In the paper the authors analyze the mechanics of ground surface settlement by applying the back-analysis method, and conduct the technical evaluation for effectiveness of each preventive method and works.

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A new method for estimating the wear of disc cutters is proposed to improve the management of shield tunneling operation. Machine torque per unit penetration, called the coefficient of excavation K_T, is a useful parameter for relating the machine performance data and the wear of disc cutters. The invsetigation on data sets obtained from four construction sites shows that the wear rate is proportinal to the squre of K_T regardless the condition of tunneling. On the other hand, the coefficient in the formula depends on the conditions except hardeness of the ground. Thus, wear of disc cutters can be evaluated from the cumulative value of K_T². Outline of the equation and the results of the investigation are given in this paper. The way of applying this method to the management is also suggested.

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It was found by the field survey recently conducted on the Innoshima and Onaruto Bridges that suspension bridge main cables were partly corroded. In order to study the cause of this problem, wide and thorough investigation on corrosion environments of model cables and actual cables, corrosion simulation tests of galvanized wires in wet and dry cycle conditions and tests on galvanized wires in the decayed wire protection paste were carried out. It is found by these researches that the water remained inside the cable plays a crucial role, wet galvanized wires are easily corrode, and the decayed paste used on Onaruto Bridge may accelerate the wire corrosion.

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Hybrid steel pipe pile with soil cement is a new type of pile construction method with lesser vibration, noise, or earth removal. The soil cement column with a larger diameter than the steel pipe pile, is formed in-situ by mixing soil and injected cement milk. Static loading tests were conducted for two piles (vertical test after lateral test for one, vertical test only for another vertical) to establish new design method and to reduce cost at Dai-ni Meishin Tobisima viaduct. This paper presents the property of bearing capacity of these piles and some useful information for the establishment of a new design method.

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Civil works and structures have a tendency to more huge or more high-rise, and therefore a new measuring methods for work progress of these civil works is desirable. In this paper, for new application of GPS, measuring of the perpendicularity of high-rise structure-one of work progress measuring of these structures-is described. The applicability of GPS for high-rise structures measurment is confirmed by 4 tests. The results of those tests are shown as follows: 1) this measuring methods is available at 100m-160m from ground level. 2) the measuring error is about 10mm regardless of height of structures.

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Soil improvement technique is developed for backfills of quay with using the fly-ash cement mixture as the recycled materials with light weight and high strength. Through both of the laboratory and the field experiments, content of cement is determined for the necessary soil strength of backfills. Basic properties of fly-ash cement mixture are also shown in this paper. According to these experimental results, the design procedure is compiled for the calculation of the soil pressure acting on the quay structures from the fly-ash cement mixture backfills. This proposed soil improvement techniques was applied for the backfills of the quay on the Sakata port. Fifty two thousand cubic meter of fly-ash was successfully utilized with addition of five percent of cement.

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This paper describes Genetic Algorithm with Relay Search Method, RS-GA, which is developed in this study to search the multiple design variables in the design space. RS-GA which is based on simple-GA, consists of some functions to search many variables from some wide variable space. It repeats simple-GA, that is the convergence process of simple-GA, which makes many time reiteration itself. From the results of the case studies, it was found that RS-GA can search all peak-variables from the 2-D functions including 5 peaks subject to a variable, whereas simple-GA can search only one or two peaks and fails to search more peak. Finally, RS-GA applied for design-strengthening problems in composite plate girder bridges using the external prestressing technique is also verified.

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In order to investigate the effect of reclaimed asphalt mixture content on the mechanical properties of stabilized soils, California bearing ratio (CBR) tests and unconfined compression tests were performed under various compositions. In addition, plate loading tests were carried out to observe the hardening condition of stabilized subgrade soils containing reclaimed asphalt mixture.
As a result, it was found that the unconfined compressive strength and CBR value increased with an increase in reclaimed asphalt mixture content and that the hardening rate of stabilized soil tended to change in accordance with a variation of subgrade temperature. Therefore, selecting the execution season seems to perform an important role in forecasting the effect of improvement.

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Up to now, ISO is investigating the compatibility of ISO14001/ISO9001. In this International Standard, ISO14000 Series shares common management system principles with the ISO9000 series of quality system Standards, and organization may elect to use an existing manegement system consistent with ISO9000 series as a basis for its enviroment manegement system.
Under these trends, we became the trist Japanese general constructor that achieved ISO14001 accteditation by using a fusion of the existing quality management system and the enviroment system.

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