New Tete Bridge over the Zambezi in Mozambique : engineering the environment

Quality control of foundation plays an important role in achieving a reliable deep foundation element. Currently, the most commonly used methods of foundation integrity verification are indirect tests involving acoustic wave propagation, such as the Pulse Echo Method (Pile Integrity Testing or PIT) and Cross-hole Sonic Logging (CSL). More recently, Thermal Integrity Profiling (TIP) has been garnering significant attention from foundation engineering professionals. This article describes the use of CSL during the construction of the new Tete Bridge over the Zambezi River in Mozambique (Figure 1). CSL identified anomalies in two of the piles tested, PP1A and PP1D. These anomalies were evaluated to determine their depth, size and extent relative to the cross-section of the piles. Core samples were later obtained to confirm the existence of defects, and corrective action was taken.