权益分类	功能权益	普通用户	{{item.name}}会员
{{category.name}}	{{benefitItem.name}}

Microscale investigations of the hydro-mechanical behaviour of unsaturated granular soils with computed tomography

利用计算机断层扫描对非饱和粒状土的水力学行为进行微观研究

基本信息

批准号：
401096010
负责人：
Professor Dr.-Ing. Marius Milatz
金额：
--
依托单位：
Institut für Geomechanik und Geotechnik
依托单位国家：
德国
项目类别：
Research Grants
财政年份：
2019
资助国家：
德国
起止时间：
2018-12-31 至 2022-12-31
项目状态：
已结题

来源：
https://gepris.dfg.de/gepris/projekt/401096010?language=en
关键词：
Microscale investigations hydro mechanical behaviour

项目摘要

The planned research project deals with the experimental investigation of unsaturated granular porous media such as glass beads and sand by application of the imaging technique of computed tomography (CT). In the framework of substantial experimental research, the macroscopic hydraulic and hydro-mechanical soil-behaviour will be investigated based on conventional laboratory tests and compared to the results of CT-Scans of unsaturated soil specimens on the microscopic grain-to-grain-scale.The investigations focus on the water retention behaviour as well as on the mechanical effects of capillarity, e. g. in the form of capillary cohesion. For this purpose, different experimental set-ups have been devised, allowing for hydraulic and hydro-mechanical tests on unsaturated specimens and their visualisation by CT-images.In a first biennial funding period, the hydraulic and hydro-mechanical experiments will be conducted in the soil mechanics laboratory of the Institute of Geotechnical Engineeringand Construction Management as well as at the Institute of Biomechanics at TUHH, where a desktop micro CT-scanner is situated. The extensive image material will be evaluated with an already existing software and will be thoroughly analysed and interpreted. In an intended biennial continuation period, further CT-investigations under application of synchrotron-based X-ray radiation at the German Electron Synchrotron (DESY) in Hamburg are planned. This allows for even higher spatial resolutions and for the imaging of fast transient effects in unsaturated soil due to short durations of exposure. Furthermore, the experimental investigations are supposed to be supplemented by numerical studies using a Bonded-Particle-Model (BPM) in the framework of the Discrete-Element-Method (DEM), allowing to model capillary bridges in DEM-models derived from the obtained CT-data. Amongst other goals, these studies seek to improve the available capillary bridge models.

计划中的研究项目涉及通过应用计算机断层扫描（CT）成像技术对玻璃珠和沙子等不饱和粒状多孔介质进行实验研究。在大量的实验研究的框架内，将根据常规的室内试验研究宏观的水力和水力力学土壤特性，并将其与微观颗粒尺度上的非饱和土试样的CT扫描结果进行比较。G.以毛细管凝聚力的形式。为此，设计了不同的实验装置，允许对非饱和试样进行水力和水力力学测试，并通过CT图像进行可视化。在第一个两年期资助期间，水力和水力力学实验将在岩土工程和建筑管理研究所的土壤力学实验室以及TUHH的生物力学研究所进行，台式微型CT扫描仪所在的位置。将使用现有软件对大量图像材料进行评估，并进行彻底分析和解释。在预定的两年期内，计划在汉堡的德国电子同步加速器（DESY）应用基于同步加速器的X射线辐射进行进一步的CT研究。这使得更高的空间分辨率和成像的快速瞬态效应在非饱和土壤中，由于曝光时间短。此外，实验研究应该是补充的数值研究，使用键合粒子模型（BPM）的离散元法（DEM）的框架，允许模拟毛细管桥的DEM模型来自所获得的CT数据。除其他目标外，这些研究旨在改善现有的毛细血管桥模型。