Estimating liquefaction-induced ground settlements from CPT for level ground

TLDR

Key factors influencing liquefaction‑induced settlement estimation are discussed, underscoring the need to account for them in analyses. The study presents an integrated CPT‑based approach for estimating liquefaction‑induced ground settlements on level ground and recommends accounting for key influencing factors, suggesting its use for low‑ to medium‑risk projects and as preliminary estimates for higher‑risk projects. The method combines a CPT‑based liquefaction resistance estimate with laboratory‑derived volumetric strain data for sandy and silty soils, and was applied to the Marina District and Treasure Island sites affected by the 1989 Loma Prieta earthquake. Calculated settlements closely matched measured values, demonstrating the method’s accuracy and suitability for low‑.

Abstract

An integrated approach to estimate liquefaction-induced ground settlements using CPT data for sites with level ground is presented. The approach combines an existing CPT-based method to estimate liquefaction resistance with laboratory test results on clean sand to evaluate the liquefaction-induced volumetric strains for sandy and silty soils. The proposed method was used to estimate the settlements at both the Marina District and Treasure Island sites damaged by liquefaction during the Loma Prieta, California, earthquake on 17 October 1989. Good agreement between the calculated and measured liquefaction-induced ground settlements was found. The major factors that affect the estimation of liquefaction-induced ground settlements are also discussed in detail. The recommendations for taking the effects of these factors into account in estimating liquefaction-induced ground settlements using the proposed CPT-based approach are presented. It is suggested that the proposed method may be used to estimate liquefaction-induced settlements for low- to medium-risk projects and also to provide preliminary estimates for higher risk projects.Key words: liquefaction, settlements, earthquake, sand, in situ testing.