Full-scale tests and three-dimensional finite element analysis on micropile groups.
In order to study in detail the effect of micropile group behaviour in terms of group efficiency (ULS) and settlement (SLS), a real-scale test campaign on micropiles has been set up on the Limelette test field of the Belgian Building Research Institute (BBRI). This paper reports the results of axial static load tests of two single micropiles and two micropile groups existing out of 5 and 9 micropiles respectively. All the tested micropiles have a diameter of 150 mm and are installed at a depth of 6 m in a silty layer. To capture the load transfer curves, all the micropiles were instrumented over their entire length with Fibre Bragg Grating (FBG) optical sensors. A 3D finite element model (FEM) was then build and fitted to the measurements for the single micropiles. Good matching was then obtained for the settlement of micropile groups.