Piling plan of the access ramp on the north bank with new piles (green) and old piles (red) were added between the old pile rows to produce a grid with centre to centre pile spacing of 2.5 x 2.5 m (8 x 8 ft). Due to limitations in available space, the piled embankments were designed with vertical slopes, using geogrid-reinforced soil, designed following the 2017 Dutch Design Guideline CUR198 for soil retaining constructions of reinforced soil. Solutions During Construction The bottom 0.80 m (2.6 ft) of the geosynthetic-reinforced piled embankment was filled with crushed demolition waste granulate. This material has a high frictional strength. Above this layer, sand is usually applied in the Netherlands to fill the rest of the embankment. To reduce the amount of primary building material and costs, the contractor proposed using an immobilised fly-ash mixture instead of sand. This mixture will harden to form a material like low-grade concrete. The fly-ash mixture was premixed with sufficient water to allow for the required curing of the immobilising cement. To reduce the amount of primary building material and costs, the contractor proposed using an immobilised fly-ash mixture instead of sand. Temporary support of the vertical slope DEEP FOUNDATIONS * MAR/APR 2024 * 109