Differential Settlement Assessment of Landfill Liners in Karst Terrain—Cutter-Pinnacle Foundation Conditions

Modern US landfill regulations include provisions for the design of liner systems, including the liner itself, the overlying leachate collection system, and other features. An effective design includes the characterization of the subsurface soil and rock conditions and an understanding of the settlement response of the liner system during all phases of landfill development. Subsurface conditions that include karst geology and topography pose a significant challenge from the perspective of characterizing the subsurface and understanding the settlement response of the liner system to landfill loadings. This paper presents the results of a study performed by the authors to assess the differential settlements of landfill liners constructed over karst terrain when the foundation conditions include alternating intervals of rock pinnacles and soil cutters. Hereinafter, this will be referenced as cutter-pinnacle topography. With regard to this symposium, this paper was prepared to specifically acknowledge the following contributions by Dr. Bonaparte: (1) Dr. Bonaparte has devoted significant efforts to study and report on the performance of landfill liner systems; and (2) Dr. Bonaparte has encouraged his colleagues to “think outside the box” and not to shy away from innovative solutions to problems.