Tunnelling-induced Damage Assessment of Vulnerable Historic Structures
Lead Research Organisation:
University of Oxford
Department Name: Engineering Science
Abstract
This project falls within the EPSRC Structural Engineering, Ground Engineering, Infrastructure and Urban Systems research areas.
The presented research summary is related to the damage assessment of vulnerable historic masonry structures, which features interdisciplinary aspects related to structural and geotechnical engineering. The rapid population growth is one of the global challenges of the 21st century. In particular, urban population growth causes various infrastructure problems, including severe traffic congestion on the transportation network. Recent developments in the infrastructure technology enable responding to this demand with the construction of underground transportation systems. However, tunnel construction and deep excavation usually create vertical and horizontal ground movements, which can cause damage in nearby structures. Thus, the building response to tunnelling and excavation-induced ground movements needs to be examined in detail for safe underground constructions.
There are multiple uncertainties to be considered while modelling tunnelling-induced damage in historic masonry structures. For instance, defining the boundary conditions in the soil-structure analyses or the material properties and existing cracks in the masonry building for different structural elements will involve many uncertainties. In the literature, tunnelling-induced building damage is determined by considering the following procedure: 1) the ground movement is investigated in the free-field conditions, 2) the effect of building stiffness is computed for the free-field ground movement conditions, 3) the building damage is estimated by considering the soil-structure interaction and 4) the level of the building damage is evaluated. Additionally, the procedure may combine results from physical model tests and numerical modelling calculations with field observations.
The risk of tunnelling-induced damage in existing masonry buildings is typically assessed in current engineering practice by either modelling the building as an elastic beam or by modelling the tunnel construction, soil and the building in detailed finite element analysis. However, while the elastic beam model is a relatively crude approach to model the tunnel-soil-building interaction, the detailed three-dimensional (3D) numerical analysis requires high computational cost and time. The motivation for the this research is to develop numerically efficient and practical modelling procedures to assess the tunnelling-induced damage to masonry buildings by increasing the accuracy of the model while simulating the critical aspects of the problem and by requiring less computational time and cost compared with detailed 3D finite element models.
The overall objectives of this research are summarized as;
simulating complex building response by developing practical new numerical models,
developing detailed constitutive models for the individual structural elements of the model that can be employed to specific case studies,
modelling the behaviour of special features such as pre-existing cracks and the irregular openings in the masonry buildings,
improving a practical soil-foundation model to represent the effect of soil-structure interactions and the transmission of the tunnelling-induced ground movements to the structure
using innovative structural health monitoring methods such as fibre optic sensors and digital image correlation systems to collect the building response data(by measuring the displacement and strain behaviour of the whole structure) from the field experiments;
In conclusion, this research will contribute to decrease the uncertainties in the modelling process of the soil-structure interaction and the masonry building behaviour due to tunnelling-induced ground movements. The outcomes of the research will be useful to identify optimal modelling strategies, which can make future assessments of tunnelling-induced damage in masonry buildings more reliable.
The presented research summary is related to the damage assessment of vulnerable historic masonry structures, which features interdisciplinary aspects related to structural and geotechnical engineering. The rapid population growth is one of the global challenges of the 21st century. In particular, urban population growth causes various infrastructure problems, including severe traffic congestion on the transportation network. Recent developments in the infrastructure technology enable responding to this demand with the construction of underground transportation systems. However, tunnel construction and deep excavation usually create vertical and horizontal ground movements, which can cause damage in nearby structures. Thus, the building response to tunnelling and excavation-induced ground movements needs to be examined in detail for safe underground constructions.
There are multiple uncertainties to be considered while modelling tunnelling-induced damage in historic masonry structures. For instance, defining the boundary conditions in the soil-structure analyses or the material properties and existing cracks in the masonry building for different structural elements will involve many uncertainties. In the literature, tunnelling-induced building damage is determined by considering the following procedure: 1) the ground movement is investigated in the free-field conditions, 2) the effect of building stiffness is computed for the free-field ground movement conditions, 3) the building damage is estimated by considering the soil-structure interaction and 4) the level of the building damage is evaluated. Additionally, the procedure may combine results from physical model tests and numerical modelling calculations with field observations.
The risk of tunnelling-induced damage in existing masonry buildings is typically assessed in current engineering practice by either modelling the building as an elastic beam or by modelling the tunnel construction, soil and the building in detailed finite element analysis. However, while the elastic beam model is a relatively crude approach to model the tunnel-soil-building interaction, the detailed three-dimensional (3D) numerical analysis requires high computational cost and time. The motivation for the this research is to develop numerically efficient and practical modelling procedures to assess the tunnelling-induced damage to masonry buildings by increasing the accuracy of the model while simulating the critical aspects of the problem and by requiring less computational time and cost compared with detailed 3D finite element models.
The overall objectives of this research are summarized as;
simulating complex building response by developing practical new numerical models,
developing detailed constitutive models for the individual structural elements of the model that can be employed to specific case studies,
modelling the behaviour of special features such as pre-existing cracks and the irregular openings in the masonry buildings,
improving a practical soil-foundation model to represent the effect of soil-structure interactions and the transmission of the tunnelling-induced ground movements to the structure
using innovative structural health monitoring methods such as fibre optic sensors and digital image correlation systems to collect the building response data(by measuring the displacement and strain behaviour of the whole structure) from the field experiments;
In conclusion, this research will contribute to decrease the uncertainties in the modelling process of the soil-structure interaction and the masonry building behaviour due to tunnelling-induced ground movements. The outcomes of the research will be useful to identify optimal modelling strategies, which can make future assessments of tunnelling-induced damage in masonry buildings more reliable.