Performance control of root piles using a digital odometer

Abstract

Root piles are injected and installed during mortar shaft construction, using pressures of up to 500 kPa. The executive control is typically done through static load testing, an expensive and time-consuming method. Static load tests on eight controlled piles (diameters between 310 mm and 410 mm) were performed, aiming at evaluating pile ultimate load. This study suggests an innovative, non-destructive approach to validate root pile field performance, using a digital speedometer connected to the drilling rig’s rotating head. The proposed method monitors variables related to bearing capacity during pile installation and proposes an empirical equation to estimate the ultimate bearing capacity of root piles. For the assessed piles, the predictions obtained with the proposed equations agreed fairly well with results from static load tests, proving it as a feasible and helpful option for the executive control of root piles, especially when load tests are not available.