Improvement of side resistance prediction for pile foundation using construction information

Problems such as the inclination and settlement of buildings after construction completion have been reported in recent years. Quality control during construction and mieruka (“visualizing” the work quality) are increasingly demanded. In light of this, the present study addresses execution with a “rotary penetration steel pipe pile (RPS-pile),” which is a system that is able to collect information in real time during the piling process. When an RPS-pile is placed, high push-in and pull-out bearing capacities are expected because the spiral blade at the pile tip resists at the bottom of the borehole against an external force. Additionally, continuous real-time data on the pile-head torque and the auger penetration depth per revolution are obtained, as these mechanical indicators are necessary for piling. This study aims at developing a method for the real-time confirmation of work quality at construction sites by utilizing construction information (information obtained during piling). Specifically, a method is proposed for the sequential updating of reliability in the estimation of the side friction acting on a drilled pile. In this method, real-time information on the pile-head torque and the auger penetration depth per revolution obtained during piling are used in addition to N-values that are observed in a standard penetration test conducted in advance as part of subsurface exploration.