Project Description
Highway 2000 is the centerpiece of a multi-year Millennium Projects Program initiated by the Government of Jamaica. Completed in 2006, the project features a 7-kilometer, dual 3-lane toll road with a 250-meter-long bridge and several interchanges. The new stretch of highway doubled the size of the existing road with the goal of easing the traffic and increasing safety in the harbor area.
The design/build project was developed by Bouygues Travaux Publics, the Developer/Concessionaire selected through an internationally supervised and transparent bidding process. Bouygues is one of France’s largest roadwork groups and will operate the toll road for 35 years. With extensive experience as an investor in highway projects, Bouygues is also part of a private/public partnership with the Government of Jamaica in the implementation of the project.
As part of the design/build team, Freyssinet Group companies DGI-Menard and Menard of France worked together to improve land carved out of mangrove forest to allow construction of the highway embankment. To meet the tight project schedule, the two companies simultaneously installed 1.5 million meters of prefabricated vertical drains (wick drains) and 135,000 meters of Controlled Modulus Columns (CMCs).
Ground Conditions
The new highway section is located between the sea and coastal areas and is 1 m to 3 m above existing ground level; the interchange embankment rises up to 10 m above ground level. The motorway crosses very soft soil areas (organic clay and peat), through mangroves ranging in thickness from 12 m to 21 m. And because of the extreme chemical acidity of the soil, it was necessary to use an adapted cement formulation for the CMCs.
Ground Improvement Solution
The ground improvement solution proposed by DGI-Menard and Menard consisted of the extensive use of CMCs for support of the bridge abutments and approaches to the bridge (up to 10 m high) as well as the toll booths, and the installation of prefabricated vertical drains (wick drains) under the embankments for the road.
A total of more than 7,500 CMCs were installed below the embankment of the bridge and below the three bridge abutments. The embankments used a technique called "wrap around," which allowed slopes of up to 1:4 and therefore reduced the quantity of CMC under the embankment.
Wick drains were installed on the remaining area using two drain masts. A combination of 1.5 million meters of prefabricated vertical drains and 90,000 linear meters of horizontal drains were installed with surcharge embankments and horizontal reinforcement under general embankment sections up to 3 m high.
Design and monitoring of settlement was specified for the project. The residual settlement after the road opened to traffic is expected to be 200 mm over 35 years and the static factor of safety against slope failure is expected to be 1.3 in long-term conditions.
Highway 2000 was the first joint venture between Freyssinet Group companies DGI-Menard and Menard. The collaboration and determination of the joint American and French crew allowed the complex ground improvement project to be completed on schedule despite the difficult soil conditions and difficult working conditions, including a 4.5 magnitude earthquake.