Unlike concrete retaining systems, MSE ‘Paramesh’ walls are flexible and durable when facing severe flooding
Maccaferri’s ‘ParaMesh’ – Terramesh and ParaLink – wall system was chosen by the Ministry of Public Works and Housing (client) and the Dar Al Omran Infrastructure (consultant) over the more traditional, but less appropriate, MSE Concrete Panel Retaining Wall system. The project, that is located in Al Zarqa, Jordan, is still under construction.
The proposed Wadi Shomer Bridge is located in Al Zarqa, Jordan, which is part of the ongoing Al Zarqa – Al Sukhnah Road Project. The geographical area in which the project is located, is separated by a deep wadi (Wadi Shomer) that gets flooded with high water flow when it rains. The proposed 240 m long Shomer Bridge will connect the surrounding areas using four highway lanes (2+2) and a 20 m wide carriageway. A critical factor in the design of the bridge is the high velocity flood waters that occur annually in the wadi area.
Flood water would pose a real threat to the foundations of the bridge and as a preventative measure the bridge piers are being constructed on pile foundations. In accordance with the project’s tender documents, the bridge was initially planned as a RCC structure with a piled foundation and two approach roads that were to be constructed on top of the Mechanically Stabilised Earth “MSE” Retaining Walls.
The MSE Retaining wall was intended to be entirely built using MSE concrete panel walls. Maccaferri was invited by the consultant, the Dar Al Omran Infrastructure, to submit an alternative solution to the MSE concrete panel retaining walls.
Maccaferri’s proposed the adoption of a Terramesh and ParaLink “Paramesh” MSE structure instead of the vertical concrete panel faced reinforced soil wall. The client agreed to the proposal based upon the advice that although concrete panel walls can be used successfuly in these situations, there is a risk that they can experience distress due to the wash out of backfill during times of high discharge flooding, and can be unstable when built on silty clay soil layers present at the foundation level. A Paramesh structure, composed of flexible, yet strong soil reinforcement, would resist the high hydraulic loads and accommodate potential differential settlements of the soft foundation without sustaining damage.
A full design of the MSE ‘ParaMesh’ wall was submitted by Maccaferri to the consultant and client. Construction of the wall began on October 10th 2016 and is expected to finish by April this year (2017). As of now the height of the retaining wall on both abutment locations has reached 3 m.
For more information, please download our Case History.