CPT-based Analysis on Vertical and Horizontal Capacity of Steel Sheet Piles Installed by the Press-in with Auger-PPT Presentation

PPT Presentation

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The presentation proposes CPT-based methods for estimating the vertical and lateral capacity of steel sheet piles installed by standard press-in (SP) or press-in with auger (PA). PA installation temporarily lifts surrounding soil; its capacity may depend on how the excavated space is backfilled. The study addresses the need for reliable design methods and considers field tests by Ishihara et al. (2024) in soft cohesive and dense non-cohesive soils.<br /><br />For vertical capacity, the study adapts both the LCPC method and Eurocode 7, estimating end-bearing and shaft resistance from CPT cone resistance. To account for the effects of installation and backfilling, it applies reduction factors to PA piles. Compared with standard press-in piles, the factors are lower for simple backfilling and closer to standard values for meticulous backfilling, indicating the importance of backfill quality.<br /><br />For lateral capacity, the study adapts a linear-elastic method using CPT data to estimate the soil’s lateral response. Reduction factors represent the influence of piling method: the reported ranges are 0.2–0.5 for PA piles with simple backfill and 0.6–0.9 for meticulous backfill, compared with 1.0 for standard press-in piles.<br /><br />The proposed approaches aim to make PA sheet-pile design more efficient and better reflect installation effects. The presentation concludes that further validation, assessment of long-term performance, and advanced numerical modelling are needed.

Keywords

CPT

steel sheet piles

vertical capacity

lateral capacity

press-in installation

auger installation

backfill quality

LCPC method

Eurocode 7

soil resistance