Efficient three-dimensional soil liquefaction potential and reconsolidation settlement assessment from limited CPTs considering spatial variability

作者：Guan, Zheng; Wang, Yu^*; Stuedlein, Armin W.

来源：Soil Dynamics and Earthquake Engineering, 2022, 163: 107518.

DOI：10.1016/j.soildyn.2022.107518

• Liquefaction
• Compressive sampling
• Differential settlement
• Spatial variability
• 3D model
• Cone penetration test

In engineering practice, a two-dimensional (2D) geotechnical cross-section is often used to assess soil liquefaction potential and its consequences on civil structures in a specific site for a given earthquake scenario. However, selection of a representative 2D cross-section for a real site is a challenging task because subsurface soils often exhibit spatial variability (e.g., spatially varying soil stratigraphy and engineering properties) in a three-dimensional (3D) subsurface space. Therefore, liquefaction assessment results interpreted from selected 2D cross-sections for representation of a 3D subsurface space may be unconservative, or even biased, leading to significant risk to civil infrastructure. Furthermore, assessment of 3D subsurface models demands higher computational effort than 2D cross-sections, presenting an additional obstacle. To tackle these issues, this study develops a novel and computationally efficient method for 3D liquefaction assessment with appropriate consideration of soil stratigraphy and property spatial variability within a 3D subsurface space. The proposed method integrates the cone penetration test (CPT)-based simplified liquefaction assessment methods with a novel 3D soil stratigraphy and engineering properties modelling method to characterize the spatially varying soil liquefaction potential and liquefaction-induced settlement for a given earthquake scenario in 3D. The proposed 3D method is illustrated using exploration data from Christchurch, New Zealand. An illustrative example in-dicates that the proposed method can properly assess significantly non-uniform and heterogeneous soils, and evaluate liquefaction potential and liquefaction-induced settlement of soils within the selected methodologies in a 3D subsurface space.

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