207-871-7771 877-682-9433

2019.13 Exit 45 Embankment Preload

Construction Contract Info
Contractor: Sargent Corporation
Bid Amount: $14,792,753.00
Projected Completion Date: Spring 2021
 
Exit45EmbankmentpreloadOct2019.jpg

Project Scope: 
In 2020 the Exit 45 Interchange in South Portland is scheduled to be reconstructed.  This includes a reconfiguration of the toll plazas and ramps as well as replacing the existing bridge that crosses over the mainline. 
 
The new Exit 45 Interchange will be constructed with additional capacity for future traffic volumes, two new ramp toll plazas and a new, higher and wider bridge.  The new bridge will be raised approximately 6 feet to provide a 16.5 foot clearance over the Maine Turnpike. The area around Exit 45 includes soils that are mostly clay and building in this environment causes an undesirable amount of settlement.
 
Because of this, the new ramp locations and approaches to the new bridge will require preloading with gravel and other materials to minimize settlement after the new interchange opens. Preloading means piling up the material in advance and letting it sit for a period of time so most of the settlement has occurred before pavement and other structures are built on it.
 
In this case, the preload will be installed in one or two stages, depending on the soils. Over the course of 18 months the initial settlement should occur and then construction of the redesigned interchange can begin. A major portion of the preload contract is to install wick drains. Wick drains are a mechanism to remove water from the clay as the preload materials press down on the soils. This increases the rate of soil settlement in order to begin construction sooner.

November 2019 Update

October 2019 Update