Design and Construction Monitoring of Surcharged Embankment
http://www.mountain-plains.org/research/projects/downloads/2012_mpc_390.pdf
Record Type: UTC

Preserving the health of pavement and bridges, particularly on the National Highway System (NHS) is critical to the structural integrity, functionality, and cost effectiveness of the Nation’s transportation system (DRAFT DOT Strategic Plan 2010-2015). In areas along the urban Wasatch Front in Utah, soft, clayey deposits can cause excessive differential settlement and premature pavement damage at bridge approaches resulting from secondary consolidation settlement of the foundation soils. Such settlement is long-term in that it accumulates over many years and can produce a significant bump at the bridge approach. In some cases, the approach fills need to be reconstructed, or frequently maintained using asphalt overlays in the damaged area. Surcharging of the embankment is a common strategy used by the Utah Department of Transportation (UDOT) to reduce secondary consolidation settlement of the underlying foundation soils. Surcharging entails the construction of additional embankment above the final design subgrade in order to overconsolidate the foundation soils. Such surcharging must be sufficiently high and left in place for sufficient duration to overconsolidate the foundation soils effectively; hence reducing the amount of secondary settlement. Unfortunately, design and monitoring of surcharged embankment is not well understood by local geotechnical practice and is often misapplied. The research proposes to develop guidance for the design, monitoring and release of surcharged fills. Determining the amount of surcharge and the corresponding time that such surcharge should remain in place is paramount to accelerated bridge construction on soft ground. Often, the surcharge duration time strongly affects or even controls the construction schedule; hence this aspect of the construction monitoring is vital to timely project delivery for accelerated construction. No such guidance for developing and controlling this process exists in the geotechnical literature or within UDOT design guidance. The objectives of this research projects are to: (1) Develop design guidance for determining the amount of surcharge required in terms of settlement performance goals and pavement life-cycle-cost. (2) Recommend the appropriate type of geotechnical laboratory testing to support surcharge design. (3) Recommend in situ geotechnical methods that may be coupled with laboratory testing to develop the design and reduce the cost of the geotechnical evaluations. (4) Develop methods to monitor and release surcharge fills that are consistent with the design data, project performance goals and field monitoring data. (5) Evaluate the consequences of underestimating the amount of primary consolidation settlement when surcharging is used as a method to accelerate primary consolidation without the aid of PV drains. (6) Develop a technical report to assist UDOT and its consultants in applying these methods to future projects.
Start date: 2012/1/1
End date: 2014/12/31
Status: Active
Contract/Grant Number: DTRT12-G-UTC08
Secondary Number: MPC-390
Total Dollars: 80650
Source Organization: Mountain-Plains Consortium (MPC)
Date Added: 05/09/2012
Index Terms: Pavement distress, Bridge approaches, Ground settlement, Foundation soils, Surcharge (Soils), Subgrade (Pavements), Geotechnical engineering, Life cycle costing, Design, Utah,

Research and Innovative Technology Administration
University Transportation Centers Program
Department of Transportation
1200 New Jersey Avenue, SE
Washington, DC 20590
USA

Kline, Robin
Phone: (202) 366-2732
Email: robin.kline@dot.gov

University of Utah, Salt Lake City
College of Engineering, Department of Civil Engineering
Salt Lake City, UT 84112-0561
USA

Mountain-Plains Consortium (MPC)
http://www.mountain-plains.org
North Dakota State University, Fargo
P.O. Box 5074
430 IACC Building
Fargo, ND 58105
USA

Bartlett, Steven
Phone: (801) 587-7726
Fax: (801) 585-5477
Email: bartlett@civil.utah.edu

Lawton, Evert