Mt. Fugen in Unzen erupted on November 17th 1990 after 198 years of silence. The volcanic disaster of Mt. Fugen is prolonged and enlarged more than four years. Disaster prevention officials of roads and railway considered emergency and permanent restoration plans after debris flows and pyroclastic flows attacked their facilities. In this paper, emergency counterplan, damage and both temporary and permanent restoration plans of roads and railway systems to volcanic disaster of Mt. Unzen and their social affects are reported and discussed. Problems which now have to be solved as well as some lessons to be learned are also explained.

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The long-term volcanic activity of the Fugendake of Unzen Volcano rendered severe bad effects on the local economy in commerce, industry and agriculture. The Ministry of Construction showed a project to construct a superdam for erosion control. Following up on the making the reconstruction plan, the reconstruction plan in Unzen eruption hazard area is investigated. It is very important to accommodate facilities and equipments for countermeasures against disasters and urban facilities to the long-term volcanic activity in Shimabara district. A survey is undertaken to know need about the countermeasure for improvement of urban infrastructure, considering the prolonged volcanic activity. In this paper, the results are shown and discussed.

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Mt. Fugen in Unzen erupted on November 17th 1990 after 198 years silence. Local governments organized their departments to cope with situations such as mountain collapsing, debris flows and pyroclastic flows. The Meteorological Agency, universities and local governments set up monitoring and warning systems to volcanic activities of Mt. Fugen in Unzen. In this paper, the local government's risk management, monitoring and warning systems, evacuation plans and transmission system for warnings are investigated and discussed in detail.

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More than ten thousand inhabitants were obligated to stay in temporary dwelling for a long time without their ordinary works during the eruption of the Mt. Fugen in Unzen erupted on 17 November 1990. The long-term volcanic activity rendered severe bad effects on the local economy in commerce, industry, agriculture and fishery as well as sufferers from volcanic disaster. Governments made effects to support the sufferers.
In present paper, measures for relief systems are investigated in detail and discussed.

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In this section, I'd like to refer to the case which is made with 3-D Computer Graphics to support the construction for distribution pipes in multi-service tunnels.
We've been developed the mechanism to link Walkthrough and PERT in this system and construct the environment to support the construction for distribution pipes in multi-service tunnels synthetically with sharing the data and operation. It could realize effective planning of schedule data and easily understanding of the structure by using the visible data of a plan. Using this system, we could finish the construction in term. It tells the system like that can use the construction and schedule control very efficiently in the future.

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The blasting is not suitable for building tunnel near residential areas because this method involves tremendous shock waves and noise. For hard rock tunneling by non- blasting, after forming a slot (free face) by drilling continuous holes at the tunnel face, excavation of the tunnel is carried out using a rock-fracturing method that fractures rock toward the slot.
In this paper, we describe using general purpose equipment in the slot method, and a continuous hole drilling method which was superior to conventional methods in terms of efficiency and accuracy of continuity. Furthermore, we describe also currently working on a rock- fracturing method that used a rubber tube type rock-fracturing machine.

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Rubber gasket at joint part of immersed tunnel is required to both bearing capacity of compression force and water-tightness. To cope with large scale earthquake force and large water pressure, three kinds of new type rubber gasket which have large deformation capacity are proposed. Water-tightness test for these rubber gaskets is carried out to know phenomena of water leakage and lateral movement of the rubber gaskets. It is made clear throuh the test that smooth surface of the rubber gaskets gives large lateral movement and stopper is effective to prevent from this lateral movement and water-tightness.

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The strengthening technique of the steel plate gluing method has been widely applied to the repair of deteriorated reinforced concrete bridge slabs, where epoxy resin is always used as injection material. The technique is also used as a counterplot for the increase of the standard design load. However, Portland cementsysteminjection materialsare considered to be more favorable from the view point of construction liability and economy. Various tests madeon thecement were properties of the system injection materials for the application of ribbed steel plates in strengthening actual highway bridge slabs. This paper describes the process of the selection and the test results of the required properties in detail.

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Today, the ecological design in the field of civil engineering, for example, the artificial slope of the bank, reservoirs and river repairs, is urgently required. The exploration of nature's process inherent to site and re-evaluation of ecological aesthetics make an important role in the design process in order to create ecological aesthetics in the place. In this paper, I examine the inherent meaning and power of landscape and show how the creative design process creates the ecological aesthetics.

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Japan Highway Public Corporation has been gathering several data which measured or observed under tunnel construction by NATM, and the data have saved on the Data Base system since 1981. This study attempts to show the tendency of the rock mass behavior during tunnel excavation. Mean volumes of the deformation were shown and discussed for each rock mass condition and employed support. The accuracy of some regression models for the maximum displacement estimation using displacements in early stage after excavation of the working face is verified. Lastly, the possibility to predict occurrences of some accidents using displacements in early stage is discussed. In this study, the order statistic concept is employed in order to avoid influence of outliers in the data set.

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This paper presents both experimental and analytical approaches for the investigation of dynamic behavior of concrete check dam wing model with longitudinal reinforcement under high speed loading like debris flow. First, static and high speed loading tests were performed for six types of specimen in which the area of longitudinal reinforcement has been changed in the double and single concrete check dam wing models. It was found from the tests that the shear failure modes were seen in the specimens with strong longitudinal reinforcement, but the flexural failure mode was resulted in the specimen with weak longitudinal reinforcement. Second, the distinct element method has been developed by using the material constants and the effective sectional area. It was confirmed that the proposed method could simulate well the failure process in the test results taken by high speed video.

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A packing simulation model for large scale triaxial compression test used rubbles is designed in consideration of the effect of particle breakage and shape of rubbles based on the statistical geometry called “Fractal”. A new parameter for packing condition, Cluster Coefficient, is suggested through “Mathematical Theory of Communication”. The main conclusion can be summarized as follows: (1) This Cluster Coefficient is chiefly dependent on void ratio and confining pressure. (2) The effect of confining pressure to strength characteristics as rubble can be appreciated by Cluster Coefficient. (3) The non-linear relationship clarified from (1) and (2) gives reasonable result for the testing data of some parent rock.

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The purpose of this study is to pursue technical feasibility of a long-span cable-stayed bridge having a 1000m class span length. In the first place, through such conventional procedures as trial design, structural analysis, experiments and so on, comparison was made between cable-stayed bridges and the suspension bridges from the view points of both structural characteristics and economy. Secondly, investigation was carried out for how the basic structural system of a longspan cable-stayed bridge was to be selected. Thirdly, load-bearing capacity of the whole bridge, wind-proofness, aseismic capability etc. were examined, and finally the feasibility of a 1000m class span cable-stayed bridge was confirmed.

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The aim of this paper is to propose improved trial wedge method which can evaluate active earth pressure on cantilever retaining wall by taking into account the heel length of the wall as well as the shape of backfill.
In order to make sure of the applicability of this method, model test and calculation are carried out: the results predicted by this method are in good agreement with the model test; and, therefore, this method is proved to give rational solution to the stability evaluation on cantilever retaining wall.

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The objectives of this study are to extend analysis functions of the multi-Temporal Analysis model with the Fractal theory (termed TAF model) and to improve the accuracy in analysis of land cover change applying the synthetic aperture radar (SAR) data. Through the box counting procedure, the fractal dimensions of the changed areas for the residential and the road-network were calculated, respectively. The high correlation between these two fractal dimensions was confirmed in twelve test areas. Especially, in case of using SAR data, the separability of the four typical types of the residential form and growth; the mono-focal, the ring/radial, the multi-focal and the twin type, was improved. These results suggest that SAR data could be substituted for the optical sensor data in the multi-temporal analysis with the fractal dimension.

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To supplement the results of the model tests, the stability of the embankment with anchor plates on soft ground is analyzed not only by the conventional method of circular arc analysis, but also byusing non-linear finite element analysis.
The results of the finite element calculations, i.e., the calculated axial force on the anchor, the stability of the embankment, and the deformation of the embankment and adjacent ground, agree very well with the results of the model tests. Particularly, the calculated factors of safety for sequence anchors (stable completed embankment) and for discontinuity anchors (collapse occurred midway) are simulated very well. In case of sequence anchor, the results of the stability analysis using the conventional circular are method which takes into account the tensile force in the anchor also show good correlation with the observation.

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The setting method of the training data in the Slope Stability Evaluation model (SSE model) was newly proposed for the stability evaluation of the natural steep slope accompanying the “erosive collapse”. The following two types of the training area were considered: 1) The Present situation type (P-type): Setting the training area just in the middle of the slope where the collapse has been already occurred. 2) The Normative type (N-type): Setting the training area around the upper segment of the slope regarded as the dangerous area based on the knowledge base. The difference map between two maps made by using P-type and N-type training data was derived. This difference map and its interpretation are useful as supporting information in the slope stability evaluation accompanying the erosive collapse as well as in the hazard prevention plans.

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At present, the treatment of construction waste soil is becoming a large scale environmental issue. The soil improvement method which utilizes the construction waste soil instead of sand for sand compaction pile is expected to be one of the solutions for the above issue.
This paper reveals that the dissipation of pore water pressure, consolidation settlement, and the increase of shear strength on the clay surrounding sand compaction piles take place after above the piles are driven into the ground, without the load due to embankment.
The strength of piles made of construction waste soil as well as the installation method of the piles into the ground are also investigated.

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The concrete pavement reinforced with continuos cables instead of deformed bars in existing continuously reinforced concrete pavement has been developed. This new type concrete pavement has some merits such as follows; shrinkage joint is unnecessary, number of rap joints in deformed bar can be decresed and so on.
The paper discribes bond charactristics, the maximum space between cracks in concrete and the stress distribution due to shrinkage in case prestressing strands are used as continuous cables.

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