Tunnelling-induced Damage Assessment of Vulnerable Historic Structures

隧道开挖造成的易损历史建筑损坏评估

• 批准号: 2261547
• 金额: --
• 依托单位: University of Oxford
• 依托单位国家: 英国
• 项目类别: Studentship
• 财政年份: 2018
• 资助国家: 英国
• 起止时间: 2018 至 无数据
• 项目状态: 已结题
• 来源: https://gtr.ukri.org/projects?ref=studentship-2261547
• 关键词: Tunnelling; induced; Damage; Assessment; Vulnerable

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 structureusing 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.

该项目属于EPSRC结构工程、地面工程、基础设施和城市系统研究领域。目前的研究摘要涉及易损性历史砖石结构的损害评估，其特点是与结构和岩土工程相关的跨学科方面。人口的快速增长是21世纪的全球性挑战之一。特别是，城市人口的增长导致了各种基础设施问题，包括交通网络的严重拥堵。基础设施技术的最新发展使建造地下交通系统能够满足这一需求。然而，隧道施工和深挖通常会产生垂直和水平的地表移动，这可能会对附近的建筑物造成破坏。因此，为了安全地进行地下施工，需要详细检查建筑物对隧道开挖和开挖引起的地面移动的响应。在对具有历史意义的砖石结构进行隧道开挖损伤建模时，需要考虑多种不确定性因素。例如，在土-结构分析中定义边界条件，或者为不同的结构元素定义材料特性和砖砌建筑中的现有裂缝，将涉及许多不确定性。在文献中，隧道施工引起的建筑物损伤是通过考虑以下步骤来确定的：1)在自由场条件下研究地面移动，2)在自由场移动条件下计算建筑物刚度的影响，3)考虑土-结构相互作用来估计建筑物的损伤，4)评估建筑物的损伤程度。此外，该程序可以将物理模型试验和数值模拟计算的结果与现场观测相结合。在现有的工程实践中，通常通过将建筑物建模为弹性梁或通过在详细的有限元分析中对隧道结构、土体和建筑物进行建模来评估隧道施工引起的建筑物损坏的风险。然而，虽然弹性梁模型是模拟隧道-土-建筑物相互作用的一种相对粗糙的方法，但详细的三维(3D)数值分析需要较高的计算成本和时间。这项研究的动机是开发数值高效和实用的模拟程序，通过提高模型的精度，同时模拟问题的关键方面，并通过与详细的三维有限元模型相比，需要更少的计算时间和成本，来评估隧道施工对砖石建筑的破坏。通过开发实用的新数值模型来模拟复杂的建筑响应，为模型中的各个结构元素开发可用于具体案例研究的详细本构模型，对砖石建筑中预先存在的裂缝和不规则洞口等特殊特征的行为进行模拟，改进实用的土壤-基础模型，以反映土-结构相互作用的影响和隧道施工引起的地面移动对结构的传递，使用创新的结构健康监测方法，如光纤传感器和数字图像相关系统，从现场实验中收集建筑响应数据(通过测量整个结构的位移和应变行为)；综上所述，这项研究将有助于减少土-结构相互作用和由于隧道开挖引起的地面移动引起的砌体建筑行为建模过程中的不确定性。研究的结果将有助于确定最优的建模策略，从而使未来对隧道施工引起的砖石建筑损伤的评估更加可靠。