The Properties and Structure of British Stiff Clays and Mudrocks

土的结构通常被认为是组构(即颗粒排列和缔合)和粒间力(例如粘结、胶结，但不包括纯粹的摩擦性质)的组合。天然沉积粘土的结构在初始沉积时开始发育，并随着地质时间的推移而演变。沉积结构是指土壤的状态沿沉积压缩曲线向下移动时产生的特征，而后沉积结构是指在长期停滞期间埋藏并可能随后卸载后产生的结构，并将包括对土壤的任何构造载荷的影响。该项目系统地研究了英国硬粘土和泥岩中土壤结构的发育，地质时代从三叠纪到白垩纪，包括麦西亚泥岩、利亚斯粘土、牛津粘土、高尔特粘土和克默里奇粘土，以了解土壤结构的发展以及成岩作用、过度固结和老化等沉积后地质过程。将使用各种实验技术，包括先进的微观特征、力学和化学破坏以及岩土力学测试，以明确确定微观结构并将宏观力学特性与颗粒级现象联系起来。硬质粘土和泥岩沉积物在英格兰广泛存在，这项研究的潜在影响将对建筑业的许多重大项目的经济和安全具有重要意义。这项工作还将有助于调查城市可持续性、核废物处理和二氧化碳封存等重大新的战略问题。对这些材料力学机制的系统了解也将有助于未来硬粘土和泥岩本构模型的发展。

Soil structure is generally regarded as the combination of fabric (i.e. particle arrangement and association) and interparticle forces (e.g. bonding, cementation, but excluding those of purely frictional nature). The structure of natural sedimentary clays starts to develop during initial deposition, and evolves over geological time. Sedimentation structure refers to features created as the state of a soil moves down the sedimentation compression curve while post-sedimentation structure refers to that created after burial and perhaps subsequent unloading, during a period of prolonged stasis, and would include any effects of tectonic loading on the soil. The project investigates in a systematic way the development of soil structure in stiff clays and mudrocks from England with geological ages ranging from Triassic to Cretaceous, including any four from Mercia Mudstone, Lias Clay, Oxford Clay, Gault Clay and Kimmeridge Clay, in order to understand the development of soil structure along with the post-depositional geologic processes such as diagenesis, overconsolidation and ageing. A variety of experimental techniques will be used, including advanced microcharacterisation, mechanical and chemical destructuring, and geotechnical mechanical testing, in order to determine explicitly the microstructure and to link the macroscopic mechanical properties to particle-level phenomena.The stiff clay and mudrock sediments are widespread in England and the potential impact of this research will be significant to the construction industry in terms of the economy and safety of many major projects. The work will also contribute to investigations of major new strategic issues of urban sustainability, nuclear waste disposal and carbon dioxide sequestration. A systematic understanding of the mechanics of these materials will also assist the future development of constitutive models for stiff clays and mudrocks.