MPC Research Reports
Report Details

Title:	Evaluation of Secondary Consolidation Settlement Associated with Embankment Construction for Fast-paced Transportation Projects
Authors:	Steven F. Bartlett, Evert C. Lawton, and Zach M. Gibbs
University:	University of Utah
Publication Date:	Oct 2020
Report #:	MPC-20-422
Project #:	MPC-390
TRID #:	01703110
Keywords:	compressible soils, consolidation, construction projects, embankments, fills, ground settlement, highways, soft soils, soil consolidation test

Abstract

This report discusses the design and implementation of surcharging technology and the required laboratory, field, and engineering evaluations. It is hoped that such information will provide a more consistent and technically defensible rationale for deploying this technology on highway projects constructed atop soft soils. Surcharging or preloading of the earthen embankments and underlying compressible soils is the most commonly deployed strategy to reduce the magnitude of secondary compression. Surcharging or overconsolidating of the foundation soils can be used to reduce the post-construction secondary settlement. In this research, 22 consolidation tests and 88 time-rate of consolidation tests were performed on Pleistocene and recent fine-grained, cohesive, lacustrine deposits composed of Lake Bonneville and more recent clays, most likely of Utah Lake origin located along the Wasatch Front in Utah. Plots of the adjusted amount of surcharge (AAOS) were plotted versus the normalized rate of secondary settlement (Cα'/Cα) and compared with prior laboratory data. The data from our research plots agree better with the long-term settlement performance monitoring data obtained from the I-15 Reconstruction Project in Salt Lake County, Utah. Also, this report presents a recommended method for designing surcharge fills, considering post-construction (i.e., secondary compression) settlement effects.

How to Cite

Bartlett, Steven F., Evert C. Lawton, and Zach M. Gibbs. Evaluation of Secondary Consolidation Settlement Associated with Embankment Construction for Fast-paced Transportation Projects, MPC-20-422. North Dakota State University - Upper Great Plains Transportation Institute, Fargo: Mountain-Plains Consortium, 2020.