High Modulus Walls in Updated EN 12063

High modulus wall, a pile wall consisting of only primary piles, is getting more popular solution as retaining wall in challenging conditions. This is now recognized also in standardization side and the new updated version of EN 12063, the execution standard for pile walls, considers this type of a pile wall more broadly. This has led also to changing of the name of the standard. The previous name Execution of special geotechnical work. Sheet-pile walls has been changed to Execution of special geotechnical work - Sheet pile walls, combined pile walls, high modulus walls. The design and also the execution of high modulus walls differs from sheet pile walls and combined pile walls. In design of sheet pile walls of U piles there are reduction factors due to sliding of the interlocks in bending. With combined pile walls the secondary elements are causing design forces to primary elements which are causing local shell bending and reduction on overall resistance of the primary piles. With high modulus walls the design is done like with primary piles of combined walls, but without reduction due to design forces from secondary elements. The new updated standard also includes an informative annex on installation of piles with percussion drilling with Down-The-Hole hammer. That has been the most used technique to install the piles during the last 15 years. Down-The-Hole hammer ensures efficient installation of high modulus walls in ground conditions where soft soils, hard soils and boulders need to be penetrated and the piles need to be extended all the into the bedrock.