Foundation of High-Rise Buildings by Minimal Threshold Settlement Micropiles-PPT Presentation

PPT Presentation

Pdf Summary

The 150-metre Alto tower at La Défense in Paris required its surrounding glass-and-steel exostructure to settle compatibly with the tower. The tower core is supported by diaphragm walls and barrettes, while the exostructure is founded on micropiles. Because the tower’s construction and long-term settlement could otherwise cause differential movement—estimated at 12–16 mm—the micropiles needed both to transfer loads and to control settlement.<br /><br />A solution relying on micropiles alone was considered, but raised concerns about material availability, uncertain friction and the reliability of settlement estimates. The project instead adopted a composite foundation combining micropiles with elastomeric bearing pads, a combination not previously used together in this way. The micropiles support the exostructure, while the pads help accommodate the required movement.<br /><br />To verify the design, micropiles were compression-tested on site and the bearing pads were tested at the factory. One tested pad carried 15,620 kN and settled 7 mm, matching the theoretical prediction. The approach reduced uncertainty and associated risks by checking that the components’ real performance aligned with the design assumptions.

Keywords

Alto tower

La Défense

Paris

micropiles

exostructure

differential settlement

elastomeric bearing pads

composite foundation

compression testing

foundation design