CONTROLLED MODULUS COLUMNS SET A WORLD DEPTH RECORD IN LOUISIANA 

In the United States, very soft clay deposits are frequently found along the Gulf coast. This raises the cost of foundations for oil storage projects in the region, which is ideally located between Texas and the oil-rich Gulf of Mexico. Menard USA was asked to propose a ground reinforcement solution able to support four 43-metre diameter tanks with a height of more than 12 metres. Preliminary ground investigations showed a clay deposit of nearly 60-metre thickness, with the clay becoming harder at a depth of 40 metres. The use of 40-metre Controlled Modulus Columns (CMC) was therefore recommended. Because none of the drilling rigs in the company’s fleet could reach this depth, the US subsidiary of Menard called on Bermingham, a subsidiary of Soletanche Bachy in Canada specialising in the production of drilling and pile driving equipment. In less than eight weeks, two drilling rigs able to reach 50 metre depths were designed and built. On the strength of this engagement and the technical appeal of the solution, Menard was awarded the contract to improve the foundation soil. The technological feat paves the way for Menard to win further CMC contracts in the United States.