Seepage Induced Landfill Capping Failures and a Conservative Method for Designing Landfill Lateral Drainage Layer

摘要

The long-term stability of landfill final covers becomes a challenge when a combination of significant slopes and geomembranes are present together. The extreme weather generated by 'El Nino' has generated significantly higher precipitation than what USEPA HELP model predicts. The resulting large amount of infiltrating water produces a zone of saturation that generates significant seepage forces in the overlying soil. These seepage forces if not controlled can result in a slope failure during a design surface water event. Such failures have proven to be very costly. This paper focuses on a review of the design of geocomposite drainage layers to satisfy critical design considerations and demonstrates how geocomposite drains can be designed to control these seepage stresses. Actual examples of landfill failures resulting from inadequate drainage are described, and design changes that would have alleviated problems are also discussed.