Piezocone penetration test-based site characterisation of Chong–Qi Bridge project, China

The piezocone penetration test (CPTU) provides an advanced way of characterising soil deposits in routine site investigation. This paper presents a synthesised application of CPTU in the site characterisation of Chongming–Qidong Bridge project in China, including soil classification, soil property evaluation and pile capacity estimation. Sixteen CPTU soundings and 31 borehole drillings were performed at the testing site, and their results were compared. Four CPTU-based soil classification charts were used to determine the soil types at the testing site, and their accuracy is discussed. Formulas for predicting the overconsolidation ratio and undrained shear strength of soft soils at the testing site were analysed. Six existing CPTU-based methods for assessing the ultimate capacity values of axially loaded piles were evaluated based on a database containing 14 pile load tests collected at the testing site. Practical recommendations for and implications of the use of the CPTU technique in deep-foundation projects are finally summarised.