This paper describes a new procedure of the dynamic load testing to estimate ‘static’ load-displacement curve. Rational soil models which have been proposed by other researchers are used in the signal matching analysis of pile driving. The soil model parameters except the shaft resistance and the end-bearing resistance are estimated from the soil test results. Only the shaft resistance and the end-bearing resistance are identified through the signal matching analysis. Applicability of the proposed procedure was examined against an open-ended steel pipe pile. The proposed procedure was further applied to a total of 102 steel pipe piles driven in diatomaceous mudstone for foundations of Noetsu bridge No. 3. The results of the dynamic load tests showed that bearing capacity of all the piles increased rapidly after the end of pile driving and exceeded the design ultimate bearing capacity one day after the end of pile driving.

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Both scanning electron microscope and mercury intrusion porosimetry are used in parallel to identify the pores of the cemented diatom earth. Triaxial compression tests are carried out to investigate the mechanical behaviors of the cemented diatom earth.
The structural characteristics of cemented diatom earth are illustrated clearly. The microstructure of the cemented diatom earth is also schematically proposed. The mechanical behaviors of the cemented diatom earth are explained based on the microstructure. Failures of the diatom earth are caused by particle crushing and stractural breakdown.

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This paper describes the results of the measurements of energy budget during a pilot test of storing energy by compressing air into an unlined natural rock cavern and proposes a thermos-fluid model for evaluating the energy storage efficiency. It also shows that relatively simple measurements enable evaluation of the energy stored, leaked and transmitted into surrounding rock and that the energy loss to the rock can be significant. The entire storage process can be described by a relatively simple control-volume analysis based on the conservation laws. The method can be applied to evaluate efficiency of storing other fluids in underground cavern.

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Estimation accuracy of pile tip levels relies heavily on the number and location of the boreholes which act as the main survey of pile tip levels. The number of boreholes for a given site is primarily limited by the cost to drill each borehole. However, there is greater flexibility in assigning the location of the boreholes, unless the site is constrained by obstructions such as structures. The following discussion describes the optimality criteria for borehole location design based on the reliability of estimates. Numerical analysis was used to various correlation coefficients between pile tip levels and ground surface levels. Genetic algorithms (GA) are used to optimize the location of the boreholes.

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The authors have proposed temporary storage of heated water in openings excavated in rock mountain. In this case, countermeasures for the reduction of thermal stress around openings and preventing leakage of heated water from openings become important. In this study, the authors proposed the reduction of thermal stress by using adiabatical material, resin lining system and combination lining system of resin and adiabatical material as a countermeasure for preventing leakage and reduction of thermal stress. The results of the test of physical properties of adiabatical material and resin at high temperature are described. And using these values, temperature distribution and stability of openings were analyzed and discussed.

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Bridge foundations, when affected by inertial forces and soil pressures, experience loads in the horizontal and vertical directions which act at the same time. Thus, it is necessary to consider the effect of inclined loads in evaluating the bearing capacity of foundation. However, in the present, horizontal and vertical loads are considered separately in evaluating stability of pier foundations.
In this study, equations for estimating horizontal plastic subgrade reaction are formulated according to geometrical admissive velocity field method based on the upper bound method. These are based on model test results of pile under inclined loads and bearing capacity characteristic of piles determined by finite element analysis. Moreover, the validity of the proposed equations is confirmed by its good agreement with test results.

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A simplified procedure for estimating the maximum shear stress in the ground during earthquakes was proposed. In the procedure, the same parameters as conventional method and supplemental parameter SI were used and no precise parameters such as stiffness of the ground or depth of the base ground was necessary. In order to clarify the validity of the procedure, maximum shear stress ratios and liquefaction potentials were estimated for actual ground profiles of Port Island in Kobe-city, Akune-city and Sendai-city in Kagoshima-prefecture by using accelerograms recorded at the surface of each locations, and the results were compared with that of the conventional method.

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In order to investigate the consistency limits of acidified soil by air drying, liquid limit and plastic limit tests were performed on soils sampled from the excavation slope. As a result, the hydrogen-ion concentration exponent (pH) values decreased with preserving time and the decreasing degree was influenced by preserving temperature. In addition, it was found that the consistency limits decreased with a decrease of pH, the classified group for engineering purpose transmited from C'H-group to ML-group. Therefore, pH is the most important factor in considering geotechnical environments.

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Water tightness of rock mass has been evaluated by the exceeding probability of Lugeon values. While constructing a darn, a curtain wall is often constructed to ensure the water tightness and the tightness is measured by the Lugeon values. This paper proposes a modeling of new Lugeon values distribution and evaluates the effectiveness of curtain wall from the exceeding probability of Lugeon values distribution proposed herein. The evaluation method described above is utilized to two target sites and successful results are obtained.

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This paper describes the topographical and geological observations, degree of weathering and laboratory tests on the weathered granites in the two sites of Japan, one in Hiroshima, and other in Abukuma. The weathered granites in both sites were clearly classified into DL, DM and DH according to the rock classification of Honshu-Shikoku Bridge Authority and the stress-strain behavior of the weathered granites were controlled by the soil structure influenced in the particle crushing. The paper also discusses the comparisons of the mechanical characteristics to simulate the stress-strain behavior of the weathered granites with elasto-plastic soil model, t_ij-sand model. The simulations show the good agreement until the peak strength for the both case. The results make it clear that the influence of the local conditions such as rockforming minerals and weathering environment are important to the mechanical characteristics on the weathered granites.

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In order to model the process of clogging in porous media, a laboratory column experiment by infiltrating the pumped groundwater and a numerical simulation have been carried out. Hydrated oxide of iron was identified as a major substance of the clogging. The parameters in the prediction model are calibrated by the least square estimate. A design of an artificial groundwater recharge using the numerical simulation model and an ultra filter membrane reducing the clogging substances is proposed.

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This paper was presented that various soil tests, such as the consolidation test, the triaxial compression test and the uniaxial compression test on samples compacted in mold and undisturbed core samples taken from the embankment constructed by cohesive soil treated with the cement stabilizer were performed to estimate the effect of soil stabilization to prevent the consolidation settlement of cohesive soil embankment.
It also was described that the application of the field quality control by means of a modified cone-penetrometer test to confirm the improved effect of cohesive soil by cement stabilizer in the field.

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