# Seismic Fragility for a Masonry-Infilled RC (MIRC) Building Subjected to Liquefaction
###### Abstract  
Historical earthquakes have documented that lateral spread and settlements are the most significant damages induced by soil liquefaction. Therefore, assessing its effects on structural performance has become a fundamental issue in seismic engineering. In this regard, the paper proposes to develop analytical fragility curves of a Masonry-Infilled RC (MIRC) structure subjected to liquefaction-induced damages. In order to reproduce the nonlinear cyclic behavior (dilation tendency and the increase in cyclic shear strength) due to liquefaction, nonlinear hysteretic materials and advanced plasticity models were applied. The findings herein obtained in terms of seismic fragility of the MIRC building subjected to liquefaction may be implemented as guidelines or code provisions. analytical fragility curves; Masonry-Infilled RC (MIRC) Building liquefaction; numerical simulations; opense +
Footnote †: journal: Applied Sciences  
**Citation**: [PERSON], [PERSON] Seismic Fragility for a Masonry-Infilled RC (MIRC) Building Subjected to Liquefaction  
during the 2012 Italian earthquake. Moreover, Ref. [20] demonstrated that 3D models are necessary to obtain realistic estimations of liquefaction effects since 2D models may be over-conservative. Anyway, 2D models are interesting because they allow for considering the influence of soil parameters on liquefaction, saving computation time. Moreover, Ref. [21] compared various approaches in order to assess the resulted responses. Recently, several contributions (e.g., [22]) concentrated on liquefaction risk assessments, with particular attention to the evaluation of post-seismic settlements in liquefiable soils [23]. In addition, Ref. [24] considered the interaction between masonry with precast and reinforced concrete confining elements. Bridges were also the object of several contributions, such as [25], that investigated the effects of soil site amplifications and liquefaction on the failure mechanisms of bridges by performing 2D numerical simulations of a 3D bridge-foundation system. More recently, several contributions applied the probabilistic-based approach of fragility curves to study liquefaction-induced effects on structures. For example, Ref. [26] considered RC buildings subjected to liquefaction-induced differential displacements, while in [27], curve modifiers were proposed to include nonlinearity connected with site effects and SSI. The very recent [28] investigated the combination of ground shaking and soil liquefaction together with SSI for RC frame buildings. Following the latter contribution, the present paper aims to apply 3D numerical models to assess the complex 3D structural behaviour of buildings under liquefaction. In particular, fragility curves significantly represent the cumulative distribution of damage and may be used to predict economic losses and provide helpful information on levels of damage. Historically, fragility curves were developed as a tool to assess structural damage [29; 30], with many applications. For example, Ref. [31] proposes fragility curves for investigating the role of inelastic dynamic soil-structure interaction. Fragility methods were extensively used for several structural configurations. For example, they were applied on masonry buildings by [32], a highway over-crossing bridge in [33], vital buildings by [34], a concrete arch dam [35] and pile foundations [36]. This paper moves from this background to propose a probability-based assessment of liquefaction of a Masonry-Infilled RC (MIRC) benchmark building. Several novelties are addressed: (1) the high nonlinear numerical model allows for considering soil and structural nonlinearities, among the previous contribution; (2) the development of analytical fragility curves to estimate the probability of liquefaction for such class of MIRC buildings may be considered another novelty; (3) the outcomes may be useful for driving important applications for professionals and implementations in code prescriptions.