OF THE BEHAVIOR OF FREE-STANDING
This thesis investigates the behavior of free-standing gabion walls in areas of mild seismicity. To investigate this behavior, three walls of varying internal cable patterns were constructed at a quarter-scale. These walls were tested with a mass shaker, and mode shapes, tone extractions, and damping ratios were calculated. A modal analysis was conducted using design spectra created from a suite of seven earthquakes from countries bordering Kenya. The corresponding lateral forces to these spectral displacements were found, and the restoring eccentricities from the soil restoring force were backed out through a summation of moments. All analysis was experimentally done due to the complexity of properly modeling the wall system for a secondary analytical comparison. This process was done under the assumption of linear behavior. Similarly, the criteria for failure involved the eccentricity of the restoring soil force exceeding the kern distance (assuming elastic behavior)—criteria that all three of the wall specimens met. However, further research into the nonlinear behavior of this wall type is suggested for future conclusions on free-standing gabion wall behavior.
The Principle of Similitude
(1) IN his article under the above heading (NATURE, March 18, 1915, p. 66) Lord Rayleigh deduces, by the method of dimensions, an equation for the rate of heat transfer between a solid body and a stream of fluid in which it is immersed. Commenting on this equation, M. Riabouchinsky (NATURE, July 29, p. 591) remarks that heat, temperature, length, and time are treated in the deduction as independent units; and that if we suppose only three of these units to be “really independent” we obtain a different and less definite result.
DESIGN CONCEPT OF THE SOIL IMPROVEMENT FOR ROAD CONSTRUCION ON SOFT CLAY
This paper presents an innovative use of soil-cement mixing method using jet grouting technique to improve the bearing capacity of subbase foundation for road construction in Thailand. The construction sequences and the basic design example of jet grouting for embankment works on soft clay are also given in this paper. The design concept and method of analysis of jet grouting work using finite element technique, results of finite element analysis, the installation adopted and effectiveness of soil improvement system are given and discussed. It was found that the total settlement is reduced by the jet grouting. A case history at Pak Phanang Diversion Dam project, Nakornsrithamarat, Thailand is presented describing the engineering design and construction aspects of a successful project, which demonstrated the advantage of soil-cement mixing method over conventional pile driving for this site.