Improving Lincoln’s Flood Defences
The Lincoln Defences Project is a £6 million investment led by the Environment Agency to improve the city’s flood defences for around 4,000 homes and businesses. As part of the scheme, we installed a total of 340 linear metres of steel sheet piles up to 9.5m in length on a stretch of the Sincil Dyke in Lincoln for bankside stabilisation works.
Challenges and Solutions
The close proximity of residential properties meant the Giken silent and vibration-free method of installation was required. In fact, sheet pile installation happened mere metres away from the houses and gardens of neighbouring properties, which were directly in front of and parallel to the watercourse where works took place. For extra efficiency, two Siken Silent Pilers were set up to work in tandem, installing piles synchronously either side of the dyke.
Heavily restricted access at this site required supporting ancillary equipment and power packs to be accommodated directly behind the Silent Pilers on modular steel platforms, sitting atop previously installed sheet piles. As the Gikens ‘walked’ along the pile line to their next positions, so the crane mats and equipment were moved along in a direct line with them.
It was also necessary to access the far end of the site through an existing warehouse building. To overcome low headroom, a tractor and trailer assisted with the movement of plant and equipment through the building, including a 90T crane needed to pitch piles, which also had to be broken down into modular form. The crane was then rebuilt once through the warehouse building, ready to support piling works.
Due to hard ground conditions the two Gikens operated in Supercrush mode, where the ground is pre-augered as piles are simultaneously pressed-in. Because Giken technology is virtually silent and vibration-free, disturbance and disruption to the daily lives of local residents during works was able to be kept to an absolute minimum – a key requirement on this project.