深厚粉细砂地层具有原状力学特性难准确测定、地基力传递途径复杂、开挖易扰动且扰动后地基承载力的降低规律难以明确等特点，给工程建设带来了巨大的挑战。为研究地基承载力衰减问题，验证粉细砂层作为天然地基持力层的可行性，对比分析了开挖前、后静力触探试验数据，研究了静探统计值（P_S）随开挖深度衰减的变化规律，结合数理拟合提出了P_S的修正系数η，并对修正后的理论推算、规范换算与实测静载数据进行了对比分析。研究结果表明：修正后的地基承载力特征值f_ak理论值与多项实测数据高度吻合，证实粉细砂层作为天然地基持力层的创新型方案切实可行；提出的修正方法在准确性、适用性和实用性方面具有显著优势。该研究不仅为复杂地层条件下的地基承载力预测提供了新思路，也为类似地区地基基础的选型及设计提供了技术支撑，有助于完善区域规范，实现工程建设“降本增效”的目标。

Silty fine sand presents significantly challenges in engineering construction due to difficulties in accurately determining its in-situ mechanical properties, the complexity of load transfer paths within foundations, its susceptibility to disturbance during excavation, and unclear patterns of bearing capacity reduction following disturbance. To address bearing capacity degradation and evaluate the feasibility of utilizing the fine sand layer as a natural foundation, a comparative analysis was conducted on static cone penetration test (CPT) data before and after excavation. The attenuation pattern of static penetration statistical values (P_S) with excavation depth was systematically investigated. A correction factor η for P_S values was proposed through fitting. A three-part comparative analysis was performed, involving corrected theoretical calculations, code-based conversions, and measured static load data. The results demonstrated that the corrected theoretical characteristic value of foundation bearing capacity (f_ak) closely aligned with measured data. The feasibility of adopting the fine sandy layer as a natural foundation stratum was confirmed. The proposed correction method was found to have significant advantages in accuracy, applicability, and practicality. A new approach was provided for predicting bearing capacity under complex geological conditions. Technical support was offered for foundation selection and design in similar regions. This methodology provides valuable references for similar projects, fosters regional standardization, and supports engineering goals of cost reduction and efficiency enhancement.