Bearing Capacity Evaluation of Deep Foundations in Liquefiable Soils Using Piezocone Test Data

The utilization of cone penetration test (CPT & CPTu) results to assess the bearing capacity of deep foundations stands as a crucial application in geotechnical engineering. This study focuses on leveraging the outputs of the CPT test, considering the distinctive features of piles and the abundance of reliable information, coupled with the rapidity of the test. The CPT test outcomes can be employed both directly and indirectly to ascertain the capacity of the toe and shaft resistance of piles. In seismic conditions, applying earthquake acceleration to sensitive and liquefiable soils induces an increase in pore water pressure Δu, leading to a subsequent reduction in soil strength. Thus, investigating changes in excessive pore water pressure serves as a key dynamic load indicator in seismic scenarios. This research initially determines the bearing capacity of deep foundations through common methods using CPT data. Subsequently, key parameters influencing the development and dissipation of Δu, such as soil sensitivity (St), undrained shear strength (Su), and dimensionless parameters of pore water pressure \(\left( {1 - B_{q} } \right)\) $\left(1-B_q\right)$ and \(\left( {1 - \frac{{u_{2} }}{{q_{t} }}} \right)\) $\left(1-\frac{u_2}{q_t}\right)$ , are meticulously evaluated. This study proceeds to investigate the impact of these parameters on the bearing capacity of deep foundations, drawing insights from a comprehensive database encompassing CPT & CPTu data from 18 diverse sites worldwide. Comparative analysis between the proposed method and conventional approaches reveals a significant reduction in the aforementioned parameters’ influence on the bearing capacity of deep foundations. Consequently, this finding underscores the necessity of incorporating such considerations in geotechnical bearing capacity calculations for projects situated on soils prone to liquefaction.