The conventional formula, the so-called logarithmic spiral equation, for uplift capacity of enlarged base anchor foundation for transmission towers is capable of evaluating accurately the uplift capacity in horizontal grounds, and thus is widely used in engineering practice. However, in the evaluation of the uplift capacity in inclined grounds or other complex embedment conditions, control of minimum embedment depth or conical soil volume to insure a sufficient overburden weight, or some empirical approach, is employed. This paper examines the uplift capacity of anchor foundation embedded in a slope crest. For this purpose, the three-dimensional elastoplastic finite element analysis is utilized. The effect of the distance from the edge of slope crest on the uplift capacity is investigated for different slope angles. The analysis result shows that, if the edge distance is less than a certain value, the uplift capacity decreases significantly with a decrease in the edge distance. It is also found that the uplift capacity decreases nonlinearly with an increase in the slope angles, and it shows a larger decrease as the edge distance is smaller.
In Japan, the government reinforces the environmental regulations and people worry about the environmental stability of waste landfill, so the site of landfill is diversified from inland to coast near urban areas. However, as the standards of the environmental stability and the monitoring procedures are not established, the coastal landfills have been constructed and operated without a long-term evaluation of the performance. This paper focuses seepage control works which play an important role in coastal waste landfills. The long-term quantitative evaluation considering the degradation of the seepage control works is performed using 3-dimensional seepage and convection-dispersion analysis on the leakage behavior of waste leachate which may contain toxic substances. As an example of the results, a possibility that the amount of leachate leakage would increase remarkably by taking degradation of the seepage control works into consideration as compared with the ideal state where degradation of seepage control works does not advance was shown.
In this study, in order to investigate the characteristics of shear and volumetric strain and development of excess pore water pressure for compacted tire chips specimen, a series of drained and undrained monotonic and undrained cyclic triaxial tests were performed. From the results of the monotonic tests, linear development of volumetric strains and excess pore water pressure were observed during loading up to 20% axial strain. It was further observed that the volumetric strain and excess pore water pressure induced by shear loading recovered to zero during unloading. In cyclic triaxial tests of tire chips, there was no marked development of pore water pressure, resulting in non-liquefaction. The on-line pseudo-dynamic response tests were performed aimed at clarifying the earthquake response characteristics of tire chips. The experimental results confirmed the quake-absorbing excess pore water pressure control and seismic isolation effects of tire chips as a geomaterial.
To establish a quantitative evaluation method of rock deterioration by repeated freezing and thawing, the authors studied evaluation method of the rock deterioration from initial strength or other mechanical properties of rock. As a result, we found linear negative correlation between the logarithm of reduction ratio of unconfined compression strength of rock and the square root of number (N) of freeze-thaw cycle ( √N approximation). To estimate rock deterioration safely, we constructed an approximation method by applying √N and exponential approximation. We also found that constant obtained by regression analysis with √N and exponential approximation and boundary number of freeze-thaw cycles of the both had high correlations with dynamic modulus of elasticity of rock. These findings can be used for evaluating the deterioration degree of rock strength quantitatively in relation to the specific number of freeze-thaw cycles that rock may undergo.
In order to evaluate the progress of the carbonation of steel making slag quantitatively, the authors examined the methods to determine the carbonate content of steel making slag by using the ignition method that was one of the carbonate tests. As the results, it was found that the carbonate contained in steel making slag was completely disengaged by igniting more than 3 hours at 700°C and the carbonate content in steel making slag by using ignition method increased with decreasing the particles sizes of steel making slag. Furthermore, gas included in the samples of particle size 9.5-37.5mm expanded and ruptured under igniting at 540°C and so it was not possible to perform the ignition methods. Thus, in order to measure the carbonate content of the steel making slag by using the ignition method, it is necessary to ignite a 20g sample of particles smaller than 4.75mm in diameter for 3 hours or more.