Cap beams are an essential element in the pile construction of earth retaining structures during the excavation of basements in buildings. Their main function is to evenly distribute loads and provide stability. The capping beam is placed at the top of the pile cap, so that the upper structure rests on it.
The importance of the capping beams lies precisely in their ability to distribute the loads of the columns supported on them to the underlying piles. They also hold these piles together and reduce the risk of unexpected movements.
In cases where there are no columns above the capping beam, its function is then to bind the piles together and support the lateral pressures of the soil. However, where the capping beam supports the columns of an overlying structure, it must be capable of supporting additional point loads. Its design then requires a detailed analysis to ensure a cross-section that avoids deformation or structural failure.
By Jorge Laguna, head of the structures section of Amusement Logic’s Architecture Dept.
