Multiscale and probabilistic modelling of progressive slope failure

渐进式边坡破坏的多尺度和概率建模

• 批准号: EP/V028723/1
• 负责人: Tao Zhao
• 金额: $ 33.9万
• 依托单位: Brunel University London
• 依托单位国家: 英国
• 项目类别: Research Grant
• 财政年份: 2021
• 资助国家: 英国
• 起止时间: 2021 至 无数据
• 项目状态: 已结题
• 来源: https://gtr.ukri.org/projects?ref=EP%2FV028723%2F1
• 关键词: Multiscale; probabilistic; modelling; progressive; slope

In the UK and globally, the slope failures of various sizes are crucially affecting the sustainable development of resilient cities, as its occurrence can significantly threaten the populations, infrastructures, public services, and environment. For example, the British Geological Survey has estimated that 10% of slopes in the UK are classified as at moderate to significant landslide risk, with more than 7% of the main transport networks located in these areas. These slopes may fail during prolonged periods of wet weather or more intensive short duration rainfall events. To date, the public awareness of slope failure risk is high, but our understanding of its fundamental failure mechanism and countermeasures are still very limited. This is mainly due to the difficulties in analysing the multiscale responses and characterize the spatial inhomogeneity of material properties of slopes. Laboratory and numerical investigations with well-developed empirical models can explain the general features of some specific slope failure events but cannot be applied universally. Some challenging issues need to be addressed, such as i) How to develop reliable mathematical models with multiscale modelling capability to analyse the progressive failure of slopes? ii) How to address the spatial variabilities and uncertainties of real slopes, e.g. material property, fractures, fluid permeability? iii) How to accurately estimate the spreading of landslide and its impact on infrastructures? The fundamental scientific issue of these challenges is the weakening mechanism of inhomogeneous slopes at different scales as it determines the slope responses under various geological and environmental conditions.The proposed research aims to explore the fundamental mechanism of progressive slope failure and its impacts on infrastructures via a multiscale and probabilistic modelling approach. It enables the large deformation of slopes to be conveniently analysed by FEM as boundary value problem (BVP), while the local fracturing, cracking, or discontinuous behaviours of soil to be evaluated in smaller discrete subdomains through granular mechanics by DEM. The boundary condition of DEM assembly is derived from the global deformation of FEM meshes. In the analysis, the soil/rock properties (e.g. elastic modulus, friction coefficient, strength, and fluid permeability) will be evaluated as random fields with spatial variabilities. The numerical modelling can effectively bridge the gap between the microscopic material properties and the overall macroscopic slope responses. In the numerical modelling, the contributions of material inhomogeneity and discontinuity to slope failure and subsequence landslide spreading can be effectively investigated. The internal fracture would occur naturally when the loading stress exceeds the particle bonding strength at the microscale, which avoids the use of some phenomenological constitutive laws in conventional continuum modelling. As a multidisciplinary research, this project will involve the subjects of geotechnical engineering, computational geotechnics, geology, statistics, soil/rock mechanics and granular mechanics. The proposed numerical model will benefit all researchers and stakeholders in land planning and management by providing efficient and reliable numerical modelling approaches. This will support the landslide risk evaluation, hazard mitigation and long-term land management, from which the environmental, social, and economic benefits can be achieved. As a result, the decision makers would have greater confidence in slope failure risk assessments on which they are basing their infrastructure investment considerations. Consequently, hazard warning systems, protections and land utilization regulations can be implemented, so that the loss of lives and properties can be minimized without investing in long-term, costly projects of ground stabilization.

在英国和全球范围内，不同规模的边坡破坏对弹性城市的可持续发展有着至关重要的影响，因为它的发生会严重威胁到人口、基础设施、公共服务和环境。例如，英国地质调查局（British Geological Survey）估计，英国10%的斜坡被列为中度至严重滑坡风险，超过7%的主要交通网络位于这些地区。这些斜坡可能在长时间的潮湿天气或更密集的短时间降雨事件中失效。迄今为止，公众对边坡破坏风险的认识程度较高，但对其基本破坏机制和对策的认识仍然非常有限。这主要是由于在分析多尺度响应和表征边坡材料特性的空间非均匀性方面存在困难。采用成熟经验模型的室内和数值研究可以解释某些特定边坡破坏事件的一般特征，但不能普遍适用。一些具有挑战性的问题需要解决，例如i)如何开发具有多尺度建模能力的可靠数学模型来分析边坡的渐进破坏？ii)如何解决实际斜坡的空间变异性和不确定性，例如材料性质、裂缝、流体渗透率？3)如何准确估计滑坡的蔓延及其对基础设施的影响？这些挑战的根本科学问题是不同尺度非均质边坡的弱化机制，因为它决定了边坡在各种地质和环境条件下的响应。本研究旨在通过多尺度和概率建模方法，探讨渐进式边坡破坏的基本机制及其对基础设施的影响。它使边坡的大变形可以方便地用有限元方法作为边值问题（BVP）进行分析，而土壤的局部破裂、开裂或不连续行为可以通过颗粒力学在较小的离散子域上通过DEM进行评估。由有限元网格的整体变形导出DEM装配的边界条件。在分析中，土/岩石属性（如弹性模量、摩擦系数、强度和流体渗透率）将被评估为具有空间变异性的随机场。数值模拟可以有效地弥合材料微观特性与整体宏观边坡响应之间的差距。在数值模拟中，可以有效地研究材料的不均匀性和不连续性对边坡破坏和随后的滑坡蔓延的贡献。在微观尺度上，当加载应力超过颗粒结合强度时，内部断裂自然发生，避免了传统连续介质模型中使用一些现象学本构定律。本项目是一项多学科研究，涉及岩土工程、计算岩土工程、地质学、统计学、岩土力学、颗粒力学等学科。建议的数值模型将提供有效和可靠的数值模拟方法，使土地规划和管理的所有研究人员和利益相关者受益。这将支持滑坡风险评估、减灾和长期土地管理，从而实现环境、社会和经济效益。因此，决策者将对基于基础设施投资考虑的边坡破坏风险评估有更大的信心。因此，可以实施灾害预警系统、保护措施和土地利用法规，从而在不投资于长期、昂贵的地面稳定项目的情况下，将生命和财产损失降至最低。

项目成果

Study on the non-linear deformation and failure characteristics of EPS concrete based on CT-scanned structure modelling and cloud computing

基于CT扫描结构建模和云计算的EPS混凝土非线性变形破坏特性研究

• DOI: 10.1016/j.engfracmech.2021.108214
• 发表时间: 2022
• 期刊: Engineering Fracture Mechanics
• 影响因子: 5.4
• 作者: Feng X

Failure mechanism of boulder-embedded slope under excavation disturbance and rainfall

• DOI: 10.1007/s10064-023-03369-z
• 发表时间: 2023-08
• 期刊: Bulletin of Engineering Geology and the Environment
• 影响因子: 4.2
• 作者: Xiang Yu;Tao Zhao;Bin Gong;Chun’an Tang

Modeling the single particle crushing behavior by random discrete element method

• DOI: 10.1016/j.conbuildmat.2023.134519
• 发表时间: 2024-01
• 期刊: Construction and Building Materials
• 影响因子: 7.4
• 作者: Du-min Kuang;Zhi-lin Long;Tao Zhao;Biao Luo;I. Ogwu;Feng-lan Kuang

Analysis of slope fracturing under transient earthquake loading by random discrete element method

• DOI: 10.1016/j.ijrmms.2022.105171
• 发表时间: 2022-09
• 期刊: International Journal of Rock Mechanics and Mining Sciences
• 影响因子: 7.2
• 作者: Tao Zhao;G. Crosta;Yong Liu

Investigating projectile penetration into immersed granular beds via CFD-DEM coupling

• DOI: 10.1007/s10035-023-01364-5
• 发表时间: 2023-09
• 期刊: Granular Matter
• 影响因子: 2.4
• 作者: Jiayu Lin;Tao Zhao;Mingjing Jiang