We shared best practices from our Netherland client Sterk last year, showing how they install combi wall projects. This week we’d like to share some images that show their working method for driving AZ sheet piles. The photos were taken at the ring road project in the city of Groningen. Part of the ring road is sunken and lined with sheet piles. A total of 65.000 square meters of sheet pile, ranging in length from 25-31 meters, will be installed. To minimize disruption to traffic the client used 5 piling teams to work on the project simultaneously, the five teams managed to install half the piles within 6 weeks, with the remainder to be completed with fewer teams. Just like in China, residents were concerned about sound and vibrations, so these were monitored to stay within limits.

Let’s analyze the photos taken on site.

The crane chosen for this job has 4 winches, this brings a lot of efficiency to the working process. The hammer is lifted, the hoses are handled, piles can be lifted, and the main winch controls the boom. No auxiliary lifting equipment is needed to perform the job.  So while the team will spend a little more on their crane rental, they can work totally independent of others.

The client used a 32RF resonance free piling hammer for the job. This high frequency, variable moment, hammer avoids resonance and allows the contractor to work close to existing structures. The operators can vary frequency and moment to achieve faster driving times (for details see our previous article: https://www.icevibro.com/article/434/8.html).

When looking closely we see that a hole is cut close to the top of each pile to lift it from the stack and upend it to driving position. We also see that the hoses are lifted by the auxiliary hook of the crane, this avoids a lot of wear and tear on the hoses. It also reduces the manpower needed to handle the hoses.

A guide rail is installed to stabilize the position of the AZ piles during driving, limiting twisting and turning of the sheet piles on the way down. The guide frame consists of 2 H-beams welded to two 5m sections of sheet pile that are vibrated in the right position.

Workers add water to reduce the friction heat in the interlocks, protecting the sheet pile interlocks from damage that could impact the driving speed and verticality of the piles.

We hope you enjoyed these photos and will be inspired by them. These working methods are easy to achieve and at minimal extra expense, while increasing your productivity significantly. If you would like the ICE team to give you advice on your upcoming project, we are happy to receive your call. We look forward to optimizing your workflow so you can achieve similar efficiencies!