The Properties and Structure of British Stiff Clays and Mudrocks

土壤结构通常被认为是织物（即颗粒排列和结合体）和颗粒间力（如粘接、胶结）的结合，但不包括纯摩擦性质的力。天然沉积粘土的结构在初始沉积阶段就开始发育，并随着地质时间的推移而不断演化。沉积构造指的是土壤沿着沉积压缩曲线向下移动时形成的特征，而后沉积构造指的是在埋藏之后，可能是随后的卸载，在长时间的停滞期间形成的特征，包括构造荷载对土壤的任何影响。该项目系统地研究了英国三叠纪至白垩纪的硬粘土和泥岩中土壤结构的发展，包括麦西亚泥岩、利亚斯粘土、牛津粘土、高尔特粘土和金默里奇粘土的任何四个地质年代，以了解土壤结构的发展以及沉积后的地质过程，如成岩作用、过固结和老化。将使用各种实验技术，包括先进的微表征，机械和化学破坏，岩土力学测试，以明确确定微观结构，并将宏观力学性能与颗粒级现象联系起来。坚硬的粘土和泥岩沉积物在英国广泛分布，本研究的潜在影响将对建筑行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、核废料处理和二氧化碳封存等重大的新战略问题。对这些材料力学的系统理解也将有助于未来发展坚硬粘土和泥岩的本构模型。

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.