Tunneling-induced horizontal strains for buildings with discontinuous foundations are notable and may pose significant risks to the integrity of nearby structures. This paper presents results from a series of numerical models investigating the response of framed buildings on separated footings to tunnel construction in sand. The study examines a two-story, elastic frame with varying building transverse width, eccentricity, and first story height, subjected to tunneling-induced displacements; footing embedment depth and tunnel cover depth are also varied. Results show that tunneling-induced horizontal displacements for separated footings are significant, with greater footing horizontal displacements occurring at deeper footing embedment depths. Building width and eccentricity also influence soil-footing interaction, particularly in determining the values of footing displacements and the distribution of horizontal strains. An increase in footing embedment depth slightly increases shear distortion but significantly increases horizontal strains. The presented modification factors for angular distortion and horizontal strains align well with empirical envelopes, with the horizontal strain modification factor being sensitive to the relative soil-footing stiffness. This research highlights the importance of considering horizontal strains and realistic foundation embedment depth in the damage assessment for buildings with discontinuous foundations due to tunnel construction.

The displacements and deformations of buildings with separated footings caused by tunneling may be significant and could damage the structures. This paper numerically investigates the influences of building stiffness, geometry, and foundation pressure on the deformation of a two-story elastic framed building due to tunneling in sand. An advanced soil constitutive model known as hypoplastic model was calibrated and adopted to simulate the sand behavior. Results show that the roles of building stiffness and foundation pressure on the footing displacements due to tunneling are significant, particularly for a larger tunnel volume loss. An increase in building stiffness reduces both the vertical and horizontal displacements of footings, while a greater foundation pressure primarily increases footing settlements. The influences of building stiffness and foundation pressure on building shear distortion are considerable, while their impacts on panel horizontal strains are minor for the investigated parameter ranges. The results also suggest the potential use of greenfield results as a conservative estimation of the distortion of buildings with separated, embedded footings when subjected to tunneling-induced displacements. Modification factors for shear distortion and horizontal strains are presented and show good agreement with the empirical centrifuge-derived envelopes for buildings resting on the soil surface.