Research on the Influence of Soil Discrete Characteristics on the Bearing Capacity of PHC Pipe Piles in Soft-Soil Areas

DOI: https://doi.org/10.62517/jcte.202606311

Author(s)

Guoping Zhang1,2

Affiliation(s)

1Changjiang River Scientific Research Institute, Wuhan, Hubei, China 2Technology Innovation Center for Mountain Torrent and Geologic Disaster Prevention, Ministry of Water Resources, Wuhan, Hubei, China

Abstract

Alluvial-lacustrine soft soft soils commonly exhibit strong spatial heterogeneity. Large variability in soil mechanical parameters often creates considerable discrepancies between theoretical bearing capacity predictions and field static-load test results for Prestressed High-strength Concrete (PHC) pipe piles. This study investigates a practical engineering case located in an alluvial-lacustrine depression in Wuhan. Geotechnical laboratory tests and static cone penetration measurements were performed to obtain in-situ physicmechanical soil parameters. Combined with data from destructive full-scale single-pile static-load tests, this paper analyzes how soil spatial variability affects single-pile bearing performance. The results demonstrate that silty-mucky clay is the primary stratum responsible for bearing-capacity deviations at this site. When the mechanical parameters of this layer drop to their measured minimum values, the ultimate single-pile bearing capacity decreases by 7.8 %. Direct adoption of standard shaft and tip resistance values yields theoretical predictions 10.1 % higher than measurements from destructive static-load tests. A low-value coupling-attenuation effect emerges when multiple overlying soil layers exhibit simultaneously poor geomechanical indexes, which substantially degrades the overall bearing capacity of the pile. This work can offer practical references for PHC pipe-pile design considering adverse effects induced by soilparameter variability in alluvial-lacustrine soft-soil sites.

Keywords

Alluvial-Lacustrine Soft Soil; Soil Dispersion; PHC Pipe Pile; Single-Pile Static-Load Test

References

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