Exploratory of Desiccation Crack in Liner Soils Propagation in Clay Liners | Original Article

ABSTRACT:

A laboratory investigation on a scaled model of a landfill liner was conducted to provide data regarding the occurrence fill liner was conducted to provide data regarding the occurrence and extent of desiccation cracking of prototype liners. The crack and extent of desiccation cracking of prototype liners. The crack intensity factor, CIF, was introduced as a descriptor of the extent of intensity factor, CIF, was introduced as a descriptor of the extent of surficial cracking. CIF is defined as the ratio of the surface crack surficial cracking. CIF is defined as the ratio of the surface crack area A, to the total surface area of the clay liner, At. A computer area Ac, to the total surface area of the clay liner, At. A computer aided image analysis program was used to determine CII' values aided image analysis program was used to determine CIF values from scanned photographs of the desiccation process. The variation from scanned photographs of the desiccation process. The variation of the CII' was related to duration of drying and measured soil the CIF was related to duration of drying and measured soil moisture suctions. moisture suctions. The soil of this investigation experienced significant cracking, soil of this investigation experienced significant cracking, with crack widths approaching 10 mm in the first drying cycle and with crack widths approaching 10 rom in the first drying cycle and penetration through the entire 16 cm thickness. Crack propagation penetration through the entire 16 cm thickness. Crack propagation was limited to a very intense period of the desiccation process. was limited to a very intense period of the desiccation process. Nearly 90 percent of the crack development occurred during a 19¬ Nearly 90 percent of the crack development occurred during a 19¬ hour time period, although the total duration of the desiccation hour time period, although the total duration of the desiccation cycle was approximately 170 hours. The soil moisture suction cycle was approximately 170 hours. The soil moisture suction changed by only 2 bars during the period of rapid crack growth, changed by only 2 bars during the period of rapid crack growth, although it changed by more than 40 bars during the period of although it changed by more than 40 bars during the period of reduced growth. reduced growth.