Continuum solutions for tunnel–building interaction and a modified framework for deformation prediction

Abstract

In this paper, the response of buildings to tunnelling-induced ground movements is studied with elastic and elastoplastic continuum solutions that consider the structure as an equivalent simple beam. A comparison is made between these simple solutions and centrifuge test data to provide insights into flexural and axial building deformations of low-rise bearing wall structures on strip foundations; the influence of wall openings and the foundation scheme on the equivalent beam bending stiffness is also addressed. Subsequently, the effects of structural continuity across greenfield sagging and hogging regions on tunnel-structure interaction are investigated. Finally, the continuum solutions are used to propose a modification factor formulation that accounts for the change in settlement trough shape (compared to the greenfield) due to soil-structure interaction. This formulation, for example, accounts for the change in transverse length of the hogging and sagging regions of a building due to soilstructure interaction, eliminating the need to divide the building at the greenfield inflection points when calculating modification factors. The proposed formulation, which is compared with numerical, experimental and field data from previous research, is shown to better predict flexural building deformations.

A new simplified meta-model to evaluate the transmission of ground movements to structures integrating the elastoplastic soil behavior

“…The ∆ / L ratio, called the deflection rate, is frequently used to assess the behavior of structures subject to differential settlement and to evaluate their damage [6,7]. Since the damage depends upon the rate of movement transmitted to the building, the structure response to the ground movement is usually evaluated through the deflection transmission ratio, defined as ∆/∆0 [8,9]. Different methods (analytical, numerical, experimental, empirical field data results) have been developed to predict the building deflection in response to the ground movements [6][7][8][9][10][11][12][13][14][15].…”

Timoshenko beam models for the coupled analysis of building response to tunnelling

“…Depending on the shape of the building settlement profile, modified relative stiff factors ρ ′ sag and ρ ′ hog in Equation ( 6) were defined by Franza et al (2019b) for Euler-Bernoulli beams with pure bending deformations relatively to the structure lengths B sag,bld and B hog,bld in the sagging and hogging zones (rather than for the greenfield values B sag,g f and B hog,g f ).…”

“…With a negligible shear flexibility, total stiffness is approximated by a pure bending behaviour (EI) EB (Goh and Mair, 2014;Haji et al, 2018b). Therefore, the bending reduction factor α ′ to be applied to EI EB given by Melis and Rodriguez Ortiz (2001) accounts for both the increase in bending and shear flexibility given by openings, whereas Franza et al (2019b) proposed to estimate λ ′ as 1 -O, where O is the ratio of openings. The equivalent Euler-Bernoulli beam characteristics are…”

Ground Deformation Characteristics Induced by Mechanized Shield Twin Tunnelling along Curved Alignments

“…It has been estimated that the length of the tunnels constructed annually since 2013 reaches approximately 5200 km, and that the current tunnelling market represents 6-7% of the global infrastructure construction market. erefore, tunnelling has always been a significant focus of research in the area of civil engineering [4][5][6].…”