Timber pile-supported embankments under traffic loading

Purpose and goal

Timber piling is a method for road and railway foundations with much lower CO2 emissions than e.g. concrete piles and lime-cement columns. Even though timber piles have been used for a long time, the design criteria are conservative due to a lack of knowledge about the load distribution. More timber piles, crushed material and reinforcement are used than necessary. The project aims to give a more realistic picture of the load distribution and contribute to more resource-efficient structures.

Expected effects and result

The result are design criteria for pile spacing, embankment height and reinforcement that take greater variation into account than today´s design criteria and allow a more sustainable product in terms of environmental impact, material cost and production time.

Planned approach and implementation

The project is divided into three parts: 1) follow-up of existing field site along a timber pile-supported highway to quantify the impact of traffic loads, 2) laboratory tests to quantify the effect of soil reinforcement on bank filling and 3) laboratory testing of a scale model of a pile-supported embankment, with complementary numerical modelling. The model tests are performed without soil reinforcement, one geogrid and two geogrids for different pile spacings and embankment heights.