On behalf of the main client Newark Marina Ltd, Aarsleff Ground Engineering was awarded the contract to install steel sheet piled walls that would create the new area of water for boats to enter and moor in the marina.

The specialist works also included wailings and tie bars for some sections of the wall, along with installation of steel H-section columns.

In late May 2019, Aarsleff deployed its Movax vibrator hammer mounted on its 34T excavator unit to supply, offload and install 174No. steel sheet piles which formed a retaining wall approximately 104 lin/m in length. In addition to this, 355No. "free issue" steel sheet piles were also installed extending the retaining wall to 220 lin/m.

Once all the sheet piles were installed, the main contractor excavated the ground to the required level and pumped water into the new area of the marina. Some of the phases of work were put on hold due to adverse weather, with heavy rainfall in autumn 2019 and winter 2020, causing a lot of the site to be flooded.

The next phase of the ground engineering works involved installing 28No. 254mm steel H-section columns of up to 17.5m lengths. These piles were used on the highest section of the retaining wall and were required to ensure the wall could withstand the bearing pressure of a new care home facility to be built adjacent to the marina. These were initially installed with a Movax vibratory hammer to an average of 8m, with the remainder length driven in by a piling rig with a hydraulic hammer.

On the section of wall closest to the river Trent, the sheet piles were restrained using 203/46-203/71 wailing beams and 20mm-25mm and 32mm tie bars, which were anchored off an existing sheet piled wall installed on the rivers bank. These provided the necessary stability and performance required for the weight of water within the new section of the marina.

"Our piling operations at the Newark Marina have showcased our experience and flexibility on marine projects," said Aarsleff's construction manager Jim Wilson. "Despite having issues with the weather, we were able to work closely with our client to ensure we could operate safely and efficiently on site. Our one-stop package provided savings for the client, along with a single point of contact throughout the duration of the project."

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