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Liquefaction susceptibility and brittleness of coal ash - a state parameter approach
Description
Limited data exists on the liquefaction susceptibility of combined fly ash and bottom ash deposits. Their low plasticity and settling density pose a risk of liquefaction under certain triggers. The liquefaction potential is linked to the in-situ state, defining its shearing behaviour as dilative or contractive based on relative density and effective confining stress. This can be assessed using the state parameter (Ψ) concept from critical state soil mechanics theory. This paper presents findings from a follow-up to our 2021 study, which used cone penetration test (CPT) based methods to estimate the in-situ state parameter and perform liquefaction susceptibility screening. The 2024 update program included geotechnical sampling and advanced laboratory testing to determine the critical state line (CSL) of representative coal ash samples. The CPT data was reinterpreted using the derived critical state parameters to assess the susceptibility to liquefaction. The state parameter estimates included new methods in addition to those considered in 2021. Brittleness of the ash was assessed using the results of triaxial shear tests against the latest guidance note developed by the ICOLD.
Liquefaction susceptibility and brittleness of coal ash - a state parameter approach
Lexington, Kentucky
Limited data exists on the liquefaction susceptibility of combined fly ash and bottom ash deposits. Their low plasticity and settling density pose a risk of liquefaction under certain triggers. The liquefaction potential is linked to the in-situ state, defining its shearing behaviour as dilative or contractive based on relative density and effective confining stress. This can be assessed using the state parameter (Ψ) concept from critical state soil mechanics theory. This paper presents findings from a follow-up to our 2021 study, which used cone penetration test (CPT) based methods to estimate the in-situ state parameter and perform liquefaction susceptibility screening. The 2024 update program included geotechnical sampling and advanced laboratory testing to determine the critical state line (CSL) of representative coal ash samples. The CPT data was reinterpreted using the derived critical state parameters to assess the susceptibility to liquefaction. The state parameter estimates included new methods in addition to those considered in 2021. Brittleness of the ash was assessed using the results of triaxial shear tests against the latest guidance note developed by the ICOLD.
