Work

Information-theoretic development of a finite-wavelength-corrected ground-motion intensity measure for underground structures

Year: 2026

Type: article

Abstract: The appropriate selection of ground-motion intensity measures (IMs) directly affects the reliability of probabilistic seismic demand models and fragility assessments for underground structures. To address the limitations of existing studies, which have primarily focused on screening scalar IMs, whereas vector-valued IMs have often been constructed without an explicit assessment of information redundancy or a clear physical basis, this study develops four representative soil-structure interaction models of subway stations and employs the wave-input method to impose multidimensional ground motions Using 1000 natural ground-motion records and 51 candidate IMs, and adopting the maximum central-column interstory drift ratio as the engineering demand parameter, a systematic framework is established for identifying optimal and supplemental IMs, constructing and validating a composite IM, and performing seismic fragility analysis. Mutual-information analysis shows that the maximum incremental velocity (MIV) exhibits the strongest and most stable information contribution across all four models. Relative entropy analysis further identifies FR1(=PGV/PGA) as the preferred supplemental IM because it provides effective additional information on the ground-motion timescale. On this basis, by considering the mechanism governing the development of free-field relative displacement over the structural height, a structure- and site-dependent composite IM, denoted as IM λ , is constructed by integrating the effective velocity input intensity, characteristic timescale, and finite-wavelength phase difference. The efficiency and sufficiency tests demonstrate that IM λ reduces the conditional dispersion of seismic demand and weakens the residual dependence of the demand model on earthquake magnitude and rupture distance. Moreover, a preliminary softened-site analysis for RS4 suggests that the relative predictive advantage of IM λ becomes more pronounced as the soil shear-wave velocity decreases. The fragility curves established using IM λ reasonably reflect the evolution of underground-structure damage probabilities with increasing ground-motion intensity. These findings provide a physically interpretable ground-motion intensity measure for probabilistic seismic demand and fragility assessments of underground structures.

Source: Soil Dynamics and Earthquake Engineering

DOI: 10.1016/j.soildyn.2026.110743

Authors: Shiwei Wang, Xin Bao, Boyang Zhu, Zilan Zhong, Kuichen Li, Jintao Huang

Institutions: Dalian University of Technology, State Key Laboratory of Coastal and Offshore Engineering, Beijing University of Technology

Language: English

Topic: Seismic Performance and Analysis

Subfield: Civil and Structural Engineering

Field: Engineering

Domain: Physical Sciences

SDG: Sustainable cities and communities

Open Access status: hybrid

Estimated APC paid: $3,900