This paper investigates the role of masonry elastoplastic constitutive models on tunnelling-induced damage in buildings. A two-stage analysis method (TSAM) is adopted, incorporating input greenfield displacements, 3D masonry walls, and an elastic model for the soil. The paper focuses on four masonry constitutive models that can be readily adopted for routine analysis in industry. Comparison of in-plane yield surfaces with experimental data indicates that, among the considered masonry models, the Concrete Damaged Plasticity model under biaxial calibration gives the best overall performance. The TSAM is then used to study selected tunnel-masonry wall scenarios, confirming a significant effect of the constitutive model and its parameters on masonry wall response to tunnelling, particularly after volume losses where moderate damage is triggered. Also, as masonry stress paths are shown to concentrate in the tensile-compressive areas, with damage prediction being sensitive to the yield surface within this quadrant, numerical damage predictions must rely on the accurate calibration of the constitutive model in the tensile-compressive quadrants. This appraisal indicates that, in the context of routine structure modelling for tunnelling assessments, the selection of elastoplastic masonry models and their biaxial calibration have a non-negligible impact on the damage category estimate.

In this paper, a dynamic model is established to investigate the dynamic behavior of train-tracksubgrade-soil (TTSS) interaction. The effects of interfacial damage of the track slab induced by soil settlement on the dynamic interaction system are considered. The model framework is established by the finite element method. The soil settlement-induced track deformation is calculated by a practical iteration algorithm, where the nonlinear interfacial damage is simulated by the cohesive zone model. The simulation model is verified by comparison with other models. In regards to the excitations of the dynamic TTSS interaction system, two types of track irregularities are considered, namely the conventional track irregularities generated by known spectrums, and the additional irregularities caused by soil settlement. In the numerical study, the dynamic performances of the TTSS interaction subjected to interfacial damage, and soil settlement are compared. Next, the short wavelength irregularity is discussed as well. From the results, the vibration enhancement can be observed in the time and frequency domain. The interfacial damage of the track enhances the vibration both in low- and high-frequency domains, while the impacts of settlement are only observed in the frequency band of 0 similar to 3 Hz. The frequency band of vibrations triggered by short wavelength irregularities is correlated with its wavelength range. Moreover, the settlement with different wavelengths and amplitudes is studied. It is shown that the increase of settlement amplitude and decrease of settlement wavelength lead to higher damage degree in amplitude and wider spatial distribution. In regards to the dynamic responses, the vehicle accelerations, wheel-rail contact forces, track displacement, and soil displacement are more sensitive to the settlement amplitudes varying from 10 to 80 mm, while the sensitive settlement wavelength is concentrated in 20 to 40 m.

The undrained shear strength of contractive fine-grained soils changes with time, reducing due to pore pressure generation and increasing during consolidation. There is an increasing appetite to recognise these temporal soil strength changes in offshore geotechnical design, as it provides a basis for potentially less conservative designs. Contributions to this endeavour are reported across two companion papers. This first paper extends an existing effective stress framework that relates the generation of pore pressure to accumulated plastic shear strain, allowing undrained shear strength to be calculated within the context of critical-state soil mechanics. The main development is the extension of the computational domain to two dimensions, allowing calculations to be made for boundary value problems that cannot be satisfactorily simplified to onedimensional conditions. The magnitude and distribution of accumulated shear strain surrounding objects buried in soil are quantified through a series of large deformation finite element analyses. These spatial distributions are described using a strain influence function in the new 2D framework to calculate the extent and magnitude of excess pore pressure, and in turn the mobilised soil strength around the buried object. The performance of the 2D framework is examined in the companion paper through retrospective simulations of experimental and numerical data.

In-service masonry arch road bridges, mainly realised before the first half of the last century, represent a wide portion of the entire worldwide infrastructural asset. Given their age, during their service life these structures could have experienced damage due to anthropic (i.e. traffic) and natural (i.e. earthquakes, soil settlements, degradation, etc.) actions which may have inevitably affected their load-bearing capacity. The present study addresses the problem of the residual capacity estimation of damaged bridges by investigating the impact of previous loading on the actual strength of the structure. In particular, reference to a past experimental activity retrieved from the literature on reduced-scale bridges subjected to concentrated vertical loads has been made to calibrate a reliable detailed finite element model in Abaqus software. Then, damage of different extent has been introduced by simulating the transit of vehicles of various weights on the structure and the residual capacities of the bridge have been assessed and compared against the undamaged configuration. The results confirm that preexisting damage due to traffic loading may significantly influence the capacity of such structures, with peak load reductions up to 60% estimated through the proposed methodology.