March 2019 Meeting

Monday, March 11, 2019
6:00 - 7:30 pm

Pellissippi State Technical Community College
10915 Hardin Valley Road, Knoxville
J.L Goins Administration Building
Faculty/Staff Dining Room


Probabilistic Modeling of Settlement Risk at Land Disposal Facilities Download!


Dr. Te-Yang Soong
Principal Engineer at CTI and Associates, Inc.


The long-term reliability of land disposal facility final cover systems - and therefore the overall waste containment - depends on the distortions imposed on these systems by differential settlement/subsidence. The evaluation of differential settlement is challenging because of the heterogeneity of the waste mass at most land disposal facilities (caused by inconsistencies in compaction, void space distribution, debris-soil mix ratio, waste material stiffness, time-dependent primary compression of the fine-grained soil matrix, long-term creep settlement of the soil matrix and the debris, etc.).

Deterministic approaches to long-term final cover settlement prediction are not able to capture the spatial variability in the waste mass and subgrade properties, especially discontinuous inclusions, which control differential settlement.

An alternative is to use a probabilistic model to capture the non-uniform collapse of buried structures and cover soils and the subsequent effect of that collapse on the final cover system. The results show how this analytical technique can be used to connect a metric of final cover performance (inundation area) to the susceptibility of the subgrade to collapse and the effective thickness of the cover soils. The modeling effort informs the design, approval, construction, operation, and maintenance of land disposal facilities.



Dr. Te-Yang Soong is the Principal Engineer at CTI and Associates, Inc. He has more than 28 years of experience in teaching, research, engineering consulting, technical and constructability reviews, and served as expert witness related to multiple geotechnical and geo-environmental projects. His areas of expertise include landfill liner and cover design and durability of barrier materials.

Dr. Soong has published more than 60 papers. Several of Dr. Soong's publications are highly referenced by the geo-environmental design community and used as industry standard. Dr. Soong has conducted technical training seminars on numerous subjects including US EPA's webinar on state-of-the-art landfill design methodology. He has also been invited numerous times by several State regulatory agencies to present advanced design and construction technologies.

Dr. Soong has worked on projects throughout the United States and has also advised landfill projects in China, India and Brazil for private, state and World Bank funded projects. Specific to his recent LLRW landfill experiences, he was the Principal-in-Charge of the closure of the Maxey Flats Disposal Site; the Principal-in-Charge of the Design/Build team for the Mixed-Waste Disposal Unit Cell 25 at the Nevada National Security Site; a consultant to UCOR for their EMDF design at Oak Ridge, TN; and was the Engineering Design Subject Matter Expert supporting the EM's PPR review for the OSWDF at Portsmouth, OH.



Page updated March 23, 2019