Bearing Behaviour of Dubai Standstone and Dubai Siltstone Due to High-Rise Structures-Paper

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The study investigates the bearing behaviour of Dubai Sandstone and Dubai Siltstone, which support many of Dubai’s high-rise buildings through bored piles and barrettes. Conventional geotechnical reports had assigned these rock layers relatively low stiffness values, often resulting in conservatively oversized foundations.<br /><br />Researchers examined subsurface conditions using 166 boreholes and analysed 116 static pile load tests from 28 construction projects involving more than 40 high-rise buildings. They compared measured pile load–settlement behaviour with finite-element simulations based on reported soil parameters, then calibrated the models against the test results. In one example, a 40 m long pile carrying about 32 MN settled only 0.7 cm; the original parameters did not reproduce this response.<br /><br />Back-analyses indicate that the rock stiffness is generally at least 1,500–2,700 MN/m²—around 21 to 36 times the values in conventional reports. One test required a calibrated value of 5,500 MN/m², approximately 70 times the reported estimate. A simplified assessment of Burj Khalifa’s settlement also supports stiffness near 1,600 MN/m².<br /><br />The findings suggest that Dubai’s sandstone and siltstone are substantially stiffer than previously assumed. Using better-calibrated parameters could improve foundation design and reduce construction materials, cost, time, and carbon emissions. The authors note that further optimisation may be possible with Combined Pile-Raft Foundations, alongside appropriate safety checks and monitoring.

Keywords

Dubai Sandstone

Dubai Siltstone

bearing behaviour

bored piles

barrettes

pile load tests

finite-element simulation

rock stiffness

foundation design

Burj Khalifa