The Practical Application of Cone Penetration Test in a Coastal Reclamation Area

The coastal reclamation area of Qinzhou, Guangxi, is widely covered with thick layers of fill and soft soil, where traditional geotechnical investigation methods face challenges of low efficiency and high costs. Therefore, this study introduces the cone penetration test (CPT) for the first time in geotechnical investigations in this region, aiming to improve efficiency and reduce costs. Continuous penetration resistance curves were obtained through CPT, and soil stratification, soil property evaluation, natural foundation bearing capacity estimation, and sand liquefaction assessment were conducted based on standardized formulas and empirical relationships. Meanwhile, the CPT results were compared and validated against traditional methods such as drilling, standard penetration tests (SPT), dynamic penetration tests (DPT), laboratory soil tests, and plate load tests.The results demonstrate that CPT can accurately delineate soil layers and evaluate the density of sandy soils. The recommended bearing capacity estimation formulas yielded results with less than 10% error compared to plate load tests, and the liquefaction assessment results were largely consistent with those from the SPT method. This study confirms that the cone penetration test exhibits high accuracy and reliability in geotechnical investigations for coastal reclamation areas, providing valuable references for similar engineering projects.