For the reason that geology condition is complicated, generally speaking, it is very difficult to understand streaming distribution and the condition of groundwater in landslide area. Construction of road in the landslide area has possibility to cause landslide disaster. It is very important for landslide investigation to understand the groundwater condition to prevent the area from landslide disaster.
An example of the most suitable planning for the countermeasure of landslide by the detailed groundwater survey is reported in this paper.

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Recently, Pneumatic Flow Mixing Method, is developed for sea reclamation and land development, in which dredged clay is mixed with relatively small amount of cement in a transporting pipe. The soil mixture forms several separated mud plugs in the pipe, and is thoroughly mixed by means of turbulent flow during the transporting. This method is applied to construct a man-made island for Central Japan International Airport at Nagoya area. The construction project started in 2000 and will be completed in 2005, where about 10 million cubic meters of dredged soil was stabilized by the method. In this article, the execution technique of the method and its application to the Airport construction project are described in detail.

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When a large-scale linear under ground structure is constructed, groundwater flow is blocked and it causes many bad influences to existing structures. To prevent that, many measures have been taken. In this study, many present systems have been studied to develop rational design procedure of the system. Based on the studies on present countermeasures and the measurement data, the countermeasures have been categorized by basic principles and the consideration matters on application are studied. In this study, a design method of countermeasure for preservation of groundwater flow using water collecting and recharging well method applied to open excavation has been proposed.

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This paper presents an application of the genetic algorithm for real transmission tower design work. The proposed method utilizes the conventional transmission design program tool, which is certified to satisfy the regulations by the relative authorities. Instead of human efforts, the genetic algorithm searches the geometric optimization of transmission truss structures. The search skill of the genetic algorithm is tuned by using diversity elite and clone elimination strategies. The design solutions obtained by proposed method are cost effective averagely 4% with satisfying fully the real design regulations.

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The excavation mechanism of TBM with rectangular face consists out of hydraulic jacks connected to an extendable cutter spoke, which is operated through a computer-controlled system.
In the present study, the performance of excavating system at the cutter face is evaluated by observing the excavation torque, quality of excavation of corners, and the stability of the cutter face. The performance of cutter bit was tested in the laboratory, and a fluid flow of soil in the cutter face was simulated by numerical analysis. These results were compared with the actual data obtained from a tunnel with a cross section of 40m².

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Most civil engineering work consists of public works for national or regional public organizations. Public confidence and economy are critical factors in planning such public works, and achieving these requires a good grasp of bid and contract procedures. A new bidding and contract system was introduced in 1994. This article analyzes the new bidding system to determine whether it was implemented in line with its stated goals, and examines the current status of the former designated competitive bidding system. The results confirm that the new system is realizing the effects of economy and competitiveness, and that implementation of this system should be promoted.

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This paper discusses the applicability of the satellite Thermal-Infrared data (TI data) for the inverse estimation of trigger factors with respect to the shirasu slope failures, based on the analysis of covariance structures model. In this model, a “Trigger Factor Influence map (TFI map)” could be produced through the measurement-equation defined by the trigger- and the causal-factor, such as the geographical information (GI) as well as the satellite data. In producing the TFI maps, the following examination cases were executed: Case-1) Only using GI, Case-2) Using the TI data and GI. In the Case 2 of applying the TI data, the better goodness fit of the model is confirmed through the hypothesis testing. Furthermore, as a practical utilization of the TI data, the “Risky- and Safe-side assessment” sub-area is delineated on the difference map between the TFI maps in each case.

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The purpose of this study is to grasp running characteristics of wheel system vehicle running on soft terrain. The influence of tire inflation pressure on running characteristics of tire is investigated based on a laboratory experiment and a proposed simulation. The object of the test is 1000-R20 off- the- road tire with initial inflation pressure of 550kPa. It was observed that the sinkage is accompanied by the set of the inflation pressure of the tire. The result shows that running performance of vehicle could be controlled by setting of inflation pressure. Furthermore, it is revealed that tractive force increases with decrement of inflation pressure.

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This paper proposes a method of assessment that focuses on the vibration characteristics of the boulder or the unsteady stone, and enables the evaluation of the potential danger for rockfalls in a, quantifiable and objective manner. This method places vibrometers on both the boulder or the unsteady stone to be investigated and the supporting ground, and seeks to evaluate the potential danger by the difference in their vibration characteristics. First, the correlation between the results of field tests to the experiments using models was confirmed, and a diagram for evaluating the potential danger for rockfalls was produced. Moreover, comparisons were made between the results of field investigations of cracks and the results of evaluations of potential danger, and the reliability of the proposed method was validated.

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The corrosivity inside box girders of steel bridges was investigated. The humidity controlling and rust prevention using a special desiccant were studied. The desiccant used in this study is capable of absorbing and releasing the moisture at high and low humidity respectively. The effects of humidity controlling and rust prevention of the desiccant were confirmed by the field test inside the box girders. On the basis of above investigations, a rust preventing system was proposed, in which the desiccant was used instead of painting inside the box girders. The life-cycle cost for the rust prevention of steel box girders can be remarkably reduced by this rust preventing system.

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Combination of foundation improvement is determined, based on the data obtained from unconfined compression strength of laboratory test, so as to secure the safety during construction. However, the intensity of the improvement soil after actual construction may differ from it considerably. Writes focused on volume change of the improvement soil, the strength property and investigated volume change of grain size distribution of the soil and the improvement soil. Consequently useful knowledge was obtained when examining design mix from now on.

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