The filldams are one of the oldest infrastructures in Japan having 1,400 year history and contributing to supply of irrigation and municipalwater,hydropower generation and flood control. AfterWorldWar II, especially after 1960's, the height and volume of dams increased dramatically with the growth of national economy to pursue the scale merits. In this paper, the development of construction capability is presented with special emphasis on hauling capacity. Compaction equipment and its quality control are also discussed which arevery much related to the strength and deformation properties of earthfill and rockfill. The design considerations are reviewed on the slope stability, seepage control and design flood of spillway. Based on these discussions, the proposals and research topics are given on the design and construction to develop embankment engineering further.

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  This paper describes the outline of “Action on Civil Engineering Structures for Performance Based Design” issued by JSCE in 2008. This guideline is composed of two sections; general remarks and individual actions. In order to apply to wide variety of structures in civil engineering the concept of “action” in design is classified into three categories in this guideline. These are reference actions independent from the structural characteristics of design objects, action model and action effect. Actions of self weight, imposed loads, traffics, wind, seismic, snow, thermal, waves, currents, geotechnical, impacts, explosion, environmental and rains are systemized under this categories and related with recent data bases significantly in terms of reference actions. Social backgrounds of performance based design such as deregulation (structutral adjustment), accountability, globalization and international standardizations are also introduced in this paper to show how the guideline works in recent design work situations.

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  In order to design the segment for shield construction using new type joints without tightening bolts, the joint behaviors of the joint bending test, the joint shear test and the joint pullout test, which are carried out for researching of joint rigidity, were simulated precisely by the three-dimensional nonlinear FEM analysis. The design method which ask for the M-θ relation of segment joints, the shear and tunnel axial rigidity of ring joints, were examined by the numerical test using this analysis. Consequently, as compared with the conventional design method, it was shown that it was the rational designing method, because the physical properties of metal and concrete materials, the influence of axial force and the segment's size variation were able to reflect.

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  It is necessary to optimize underground LNG tank constructions to make underground tanks smoothly and continuously in the severe social and economic situation. The authors investigate the construction categories that are effective for the optimization of underground LNG tank construction from the viewpoint of QCDSE (Quality, Cost, Date, Safety, and Environment). This paper proposes the method for the efficient achievement of underground LNG tank construction from the authors' experience at the sites.

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  On the large rock cavern of underground power station, LPG underground storage, and radioactive waste disposal, the large section bench blasting is a construction method for efficient excavation. However, it is limited to the rock conditions. On the other hand, the loosening blasting increased the efficiency of the excavation on the bench blasting of mine. By studying an actual application of the loosening blasting in the Omarugawa underground power station, this paper presents applicable conditions for the loosening blasting and its effects on blasting efficiency.

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  In order to secure safe railroad network from rainfall-induced natural disaster such as landslides, each railway company in Japan has own regulations concerned with train operations and district patrols for such conditions. Recently more detailed information on rainfall has been required to meet the increasing frequency of train services. For instance, adopting ten-minute rainfall data instead of conventional hourly rainfall data is in urgent need for the revision of the regulations, especially when the case of concentrated heavy rainfalls is targeted; however the data to be treated would become larger and more complicated. Thus, this paper proposes an application of “support vector machine”, which enables quite rapid and precise analyses of huge amount of ten-minute rainfall data, as a sequential renewable method of the train operation regulations.

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  The glued concrete overlay method is one of the promising rehabilitation methods for the elevation and/or the slope correction of the subsidence part in airport concrete pavements. Especially, in the bonded concrete overlay method using epoxy adhesive, these advantages can be expected compared to the method using water jet demolishing, such as to reduce surface treating works, to reduce the debris waste, and then to reduce the total operation cost. In order to attempt the further evolution of this method, the applicability of epoxy spraying machine was examined. And also, the basic evaluation of the epoxy adhesive, the development of the machine system of in-line mixing and spraying of the adhesive, and the test application of this method at HANEDA airport were conducted. In this report, the applicability of this machine epoxy spraying concrete overlay method was discussed based on the indoor examination results and the field application results.

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  Slope failures were observed in the Japan Mid-Niigata earthquake of 2004 and the Noto Hanto earthquake of 2007, and it is an urgent task to evaluate the seismic stability of existing slopes along expressways. However, the earthquake motions to check the seismic performance of expressway embankments should be different site by site along the expressway. In this study, we measured microtremors at the sites along the actual expressway. Based on the measurement results, the variations of the input earthquake motions considering the seismic site effects are introduced. Thus, the proposed method enables a rational earthquake motion determination of expressways.

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  In this study, we construct a rule which can explain many debris flow disasters from gathered data about the debris flow disaster in Hiroshima on June 29, 1999. The analytical technique is to combine Support Vector Machine, excellent in evaluation of the danger, with rough set that can clarify disaster factors for rules. First, we perform evaluation of the danger using Support Vector Machine. From the result, especially safe data and dangerous data are extracted from the database. In the next process, we make typical rules by using rough set with area for expanded rules. By using this method, we could explain debris flow torrents with a few rules from which expanded rules could be extracted.

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  The cast-in-place lining method has been applied in these years to the case where both of the mountain tunnel method and the shield tunnel method might be adopted. In this method, the concrete is directly cast into the tail void and therefore the surrounding ground is influenced by the concrete casting pressure. The present paper considers the relationship among the casting pressure, the casting volume and the ground displacement and proposes a simple model of the method by introducing the elastic and plastic ranges of deformation. Furthermore the comparison of the calculated values of the ground deformation by the model with the observed data is made and finally the construction control scheme of the casting pressure is discussed.

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  This paper proposes an inverse analysis algorithm of different trigger factors for slope failure hazard zonation, based on Structural Equation Modeling (SEM). In this model, causal factors (i.e., geographical information and satellite remotely sensed data) are used as “observed variables,” while trigger factors caused slope failures are regarded as “unobserved latent variables.” Through measurement equation in SEM, the Inverse Estimation (IE) maps of trigger factor are produced with respect to two kinds of trigger factors that are “rainfall (Case-1)” and “earthquake (Case-2),” separately. As a final outcome, the differences between these IE maps are delineated on a “Trigger Factor Influence (TFI) map.” The TFI map and its interpretation would be useful for assessing differences of trigger factors with respect to slope failures, simultaneously.

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  Biosparging method is an effective technology that remedies benzene-contaminated soils. This method enable to do physical removal of benzene by vaporization with supplying air into aquifer, also encourages biodegradation. However, since the efficient supply method of trofic salts has not exist yet, it has been difficult to do biodegradation continuously. The biosparging method which used soil flushing together that supplies trofic salts effectively under the ground has been developed. This original method was demonstrated its effectiveness through in-situ test, and discussed from the perspective of remediation rate and ability to supply air and trofic salts. As a result, proposed flushing and biosparging method was confirmed superiority compared with the conventional method. In addition, based on a result of the test, a designing method on well layout, sparging air rate and remediation term has also proposed.

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  Experimental study was conducted to clarify the ratio of the section flatness between the tangent and the bent pipe subject to bending in a piping system with a bent pipe and tangent pipes on both ends. A finite element analysis code was also being used extensively for the calculation of stresses and section flatness in the piping.
  As a result, magnitude of the section flatness of the tangent pipe distant 0.5D from the boundary between the bent and the tangent pipe was half compared to that of the bent pipe. A method was proposed to predict the maximum stress produced in bent pipe smaller in bent angle than 90 degree based on the section flatness of tangent pipe subject to in-plane and/or out-of-plane bending.

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   Recently, the maintenance of the road structures such as bridges has been important both in the developed countries and in the developing countries. For the maintenance of road structures, it is important to investigate on the service conditions including the weights of vehicles and the number of vehicles. For that purpose, Weigh-in-Motion is one of the promising methods, but in the developing countries, it is difficult to prepare adequate equipments to perform the existing highly accurate Weigh-in-Motion method. In this paper, attempts to develop portable Weigh-in-Motion with a simple portable measurement system and simplified data interpretation for field measurements were described.

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