Paul A. Korswagen (a) https://orcid.org/0000-0002-2587-7808
Michele Longo (a) https://orcid.org/0009-0007-0266-6112
Alfonso Prosperi (a) https://orcid.org/0000-0003-2278-9236
Jan G. Rots (a)

a Delft University of Technology, Faculty of Civil Engineering and Geosciences, Department of Materials, Mechanics, Management and Design, Delft, The Netherlands

ABSTRACT
Regional subsidence due to mining and gas extraction in the northern Netherlands exposes masonry façades to combinations of greenfield horizontal strain (εGF) and angular distortion (βGF) that differ from classical settlement-only scenarios. Existing approaches, epitomised by the empirical Boscardin–Cording diagram, provide deterministic damage envelopes in the (ε,β) space but do not distinguish between greenfield and façade-level measures, are not probabilistic, and do not explicitly account for Dutch typologies or soil-structure interaction (SSI). This paper presents a numerical, computational-based, façade-specific counterpart and reinterpretation of the Boscardin–Cording diagram: crack-based (damage measure Ψ) fragility surfaces in the (εGF,βGF) space for Dutch masonry façades. A two-tier SSI framework is adopted in which Tier 1 generates target ε,β through boundary-driven non-linear soil blocks with a small-strain hardening law, and Tier 2 couples identical soil blocks to non-linear masonry façades with embedded strip foundations. Three stratigraphic profiles, two typologies (clay brickwork on URM footings, CLBR; calcium-silicate brickwork on RC strips, CSBR), 33 façade geometries and multiple material sets yield over 6 500 simulations and roughly one million (ε,β,Ψ) triplets. The results show that greenfield ε and β are strongly and non-linearly filtered before reaching the façades, with elastic modification factors typically below 0.25 but increasing markedly as cracking and Ψ grow. Fragility surfaces quantify the influence of typology, soil profile and aspect ratio and reveal where Boscardin–Cording bands correspond to median Ψ-based damage and where they are conservative. The proposed framework enables probabilistic, typology-aware use of εGF–βGF from geomechanical models and geodetic monitoring for assessing light, crack-dominated damage in masonry façades.

Keywords: clay masonry, light damage, cracking, angular distortion, greenfield horizontal strain, soil–structure interaction, Boscardin–Cording diagram, fragility surfaces.