King Abdullah University Science Technology
This mega project is a vast university complex which will accommodate 30,000 students. More a city than a university, it includes state of the art architectural buildings, luxurious accommodations, leisure resort, all technical services and facilities spreading over a 2km by 3km area. Having only 3 years to complete the construction, Saudi Aramco has chosen to initiate the Soil Improvement works before any design drawing was issued.
The area is initially very poorly identified, as the geotechnical report includes only 50 boreholes for 6,000,000 m². The subsoil is highly variable, from loose sands to soft clayey silts commonly called "sabkha" over a depth of 6 to 8m. It was evident that the ground conditions would not meet any of the design expectations. The soil investigation indicated that the soil was highly heterogeneous with 8 to 10m of loose soil. Soft cohesive soils of 2 to 5m thick were inter-bedded with loose layers of sand or silty sand. Meanwhile, a solution based on classical foundation such as piles was difficult to be implemented as the layout was not yet fixed when the Works were to be executed. Thus such a solution would have had a dramatic impact on the overall planning, which was not acceptable.
Menard has been awarded as a soil improvement specialist of all the secondary areas around the University, from houses to residential and commercial buildings, for a total area of initially 1,500,000 m², later increased to about 2,700,000m², while keeping the same ending date. Menard has proposed to treat the area by Dynamic Compaction and Dynamic Replacement, mobilizing for the project 13 DC/DR rigs working day and night during 8 months. After 1,500,000 blows applied, soil improvement works have been successfully completed and the DC/DR rigs have left place for the tower cranes and concrete pumps.