12
DEC
2013

Test Embankment Program – A Project Innovation

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US 460 Mobility Partners has implemented a test embankment program, an innovative soil testing methodology to determine the performance of the site soils over time under test conditions. This progressive testing methodology is the first of its kind for a roadway project in Virginia. The test embankment structure installed in Wakefield, VA is approximately 300 feet square and 35 feet high, holding 66,000 cubic yards of soil. Trucks hauled soil daily from a local borrow pit to the test embankment site for approximately 25 days to achieve the desired structure. Many thanks to the local community for your patience through the hauling period.

Test embankments are not commonly constructed. Saturated soils, such as around harbors or ports are prime for a test embankment installation as soft, wet soil makes the determination of the rate of settlement and the amount of settlement very challenging. Understanding these key factors are necessary to define the performance of future embankments constructed for the project.

The composition of the soil in the southeastern Virginia coastal plain compels a test embankment installation. This region’s soil is characterized by poorly to well sorted unconsolidated marine and fluvial sediments, varying from soft saturated clays to gravels. Preparing a test embankment provides the necessary investigation and analytics required prior to building the actual embankments for the new roadway.

The large embankment widths needed to support the new roadway, on the order of 300 feet, and the high stresses generated due to weight, will impart large stresses hundreds of feet into the ground. The test embankment will allow engineers to measure soil weight bearing, underground pressures, settlement, drainage, safety and stresses over an approximate six month period. Actual measurements will be made at various intervals to document performance and the deformation magnitude and rate. These measurements will promote the long-term prediction of soil performance.

The Project team looks forward to learning all we can through the testing period to best plan the construction schedule.