Undrained Cyclic Strength of a Hydraulic Coal Ash

This study presents the physical properties and the triaxial undrained cyclic strengths of the hydraulic coal ash at Taichung thermal power plant In-situ penetration and seismic test results are also given. The tested samples include undisturbed block samples, thin-wall tube samples and remolded samples. It is found that the in-situ coal ash is a high void ratio, high water content, high fines content, low unit weight, low specific gravity, non-plastic, cohesionless, spherical, granular soil. Although the in-situ coal ash is soft and non-plastic, its cyclic resistance is significantly higher than those of the hydraulic sandy soils in the neighboring area. This higher resistance may be attributed to the high fines content and fine-grained size of the coal ash. The influence of several factors on the cyclic resistance of the coal ash is also summarized.