Finite-element modelling for the assessment of tunnel-induced damage to a masonry building

Abstract

The likely severity and extent of cracking damage in existing masonry buildings caused by shallow tunnelling in urban areas is typically assessed in practice using a phased sequence of calculations of increasing complexity. If initial assessments (e.g. with the building modelled as an elastic beam) suggest that damage could be significant, or for high heritage-value buildings, it may be appropriate to conduct more detailed assessments using 3D numerical analysis. The current paper demonstrates the application of 3D finite element modelling in this context. Models are developed to quantify the effect of shallow tunnelling on an example masonry building founded on strip footings, considering both single and twin tunnel scenarios in a typical London soil profile. The analyses use appropriate constitutive models for the soil and the masonry, and allow for the possibility of slippage and gapping at the soil-foundation interface. The results presented here focus on the interaction between the soil and the building (via its foundations) and on the influence of explicitly modelled window and door openings. It is shown that useful damage predictions can be obtained from 3D analysis of a single facade and foundation, without needing to model a complete building. The study also highlights some of the limitations of current elastic beam assessment methods.

Assessment of Building Response Supported on Shallow Foundation Due to Tunnelling in Cohesionless Soil

“…All other tunnel cover depths and tunnel volume losses in the current analysis showed a similar tendency. A similar tendency of footing settlement has been found for the construction of the tunnels in the previous literature [3,11]. The results show that the total (individual) settlement of footings for buildings with D and 2D eccentricities varies from 61.6 -23.84 mm and 50.71 -43.53 mm, respectively.…”

“…The displacement and deformation of ground and tunnel lining have been estimated and compared with field reports. Yiu et al [3] investigated the likely severity and extent of cracking in the existing masonry building structures caused by the construction of shallow twin tunnels in London clay soil IOP Publishing doi:10.1088/1755-1315/1333/1/012044 2 through 3D numerical analysis. It has been reported that useful damage predictions should be achieved from 3D analysis of a single facade rather than modelling the whole entire building.…”

Cracking and damage analysis of a masonry structure based on joint masonry model caused by a obliquely undercrossing tunnel

“…The effects of the presence of strip foundations have been taken into account in this paper's calculations (Fig. 7 ), considering that the floor and roof will not significantly affect the structural damage 27 , only the building’s exterior, end, and interior walls are considered for simplicity 19 , 26 . Table 2 summarizes the values of material parameters.…”

Tunneling-Induced Deformation of Bare Frame Structures on Sand: Numerical Study of Building Deformations

“…For risk assessments, the first level of investigation typically consists of a two-step uncoupled assessment of the interaction problem (Mair et al, 1996): first, the greenfield response is calculated by adopting one of the available semi-empirical expressions for ground displacements (Mair et al, 1993) and, then, the structural damage is evaluated with reference to specific greenfield deformation or displacement parameters calculated at the foundation level of the building (Burland et al, 1977;Boscardin and Cording, 1989). A more refined evaluation, needed if the category of damage resulting from this preliminary evaluation is not negligible, requires a coupled soil-structure interaction analysis in which the building can be modeled with various levels of detail, ranging from equivalent beams or solids representing the whole structure (Potts and Addenbrooke, 1997;Namazi and Mohamad, 2013;Losacco et al, 2016) to a more or less detailed description of the structural components (Son and Cording, 2005;Comodromos et al, 2014;Fargnoli et al, 2015a;Yiu et al, 2017). In most cases, studies are conducted with the aid of numerical modeling, often in three dimensions so as to accurately describe the structural layout of the building and its relative orientation with respect to the tunnel axis.…”