Effect of climate on internal erosion in embankment dams and flood defences

内部侵蚀发生在土壤从岩土工程结构（如堤坝和堤坝）内部被水渗透侵蚀的地方。它是世界范围内和英国水坝和堤坝失败的两个最常见原因之一。潮湿的冬季将导致河流流量峰值急剧增加，夏季干旱的风险增加，随后是对流风暴，这将增加山洪暴发的发生，这意味着水坝和堤坝将受到更大的水力负荷。建造这些设施的土壤也将受到与蒸发和降雨增加有关的更大的湿润和干燥循环的影响。这种循环对土壤抗侵蚀性的影响尚不清楚。这项研究将是第一次研究这种气候过程如何影响内部侵蚀。结果将被放置在一个非饱和土力学框架内，以便深入了解气候变化的影响，以及驱动这些影响的具体机制。这些数据将用于创建一个基于科学的预测模型，预测这些土壤在受到气候周期影响时可能会如何恶化。实验研究的假设是：-气候引起的湿润和干燥循环将导致恶化，导致路堤填料的抗侵蚀性降低。受影响的基础设施将包括英国的堤坝和堤坝。这种周期一直在发生，但由于气候变化，其严重程度可能会增加。该项目的具体目标是：1）建造和调试一个最先进的孔蚀试验装置（HET）。HET是一种用于确定路堤土壤抗侵蚀性的实验技术，是用于此目的的最广泛使用的研究工具。模型土壤的试验结果将与其他小组公布的结果进行基准比较。2)使填充物经受润湿和干燥路径，以模拟真实的填充物中的路径。将对真实的路堤填料和具有与英国大坝敏感材料相似特性的实验室土壤进行测试。该方法应该是可重复的，并产生在密度和含水量方面均匀的样品。3)进行一系列HET试验，以获得描述土壤抗侵蚀性的高质量数据，这些土壤：（i）压实后和（ii）压实后经过湿/干路径。4)创建一个预测模型，预测路堤材料的抗侵蚀性在其使用寿命内可能如何变化。这将把可测量的土壤特性与压实状态下抗侵蚀性的变化联系起来。

Internal erosion occurs where soils are eroded from within geotechnical structures such as embankment dams and levees by water seepage. It is one of the two most common causes of failure in dams and levees, both worldwide and in the UK. Wetter winters will lead to dramatic increases in peak river flows and the increased risk of summer drought followed by convective storms will increase the occurrence of flash floods, meaning that dams and levees will be subject to greater hydraulic loads. The soil from which they are constructed will also be subject to greater wetting and drying cycles related to increased evaporation and rainfall. The effect of this cycling on soil erosion resistance is unknown. This research will be the first to study how such climate processes affect internal erosion. The results will be placed within an unsaturated soil mechanics framework to allow a deep understanding of the effect of climate change, and the specific mechanisms which drive these effects. The data will be used to create a science-based predictive model about how these soils may deteriorate when subjected to climatic cycles. The hypotheses for experimental investigation is:- Climate induced wetting and drying cycles will cause deterioration leading to a reduction in the erosion resistance of embankment fill materials. The affected infrastructure will include UK embankment dams and levees. Such cycles have always occurred but their severity is likely to increase due to climate change. The specific Objectives for the project are:1) Construct and commission a state of the art hole erosion testing device (HET). The HET is an experimental technique to determine the erosion resistance of embankment soils and is the most widely used research tool for this purpose. Results of tests on model soils will be benchmarked against other groups' published results. 2) Subject fills to wetting and drying paths to mimic those in real embankments. Both real embankment fills and laboratory soils with similar characteristics to susceptible materials from UK dams will be tested. The method should be repeatable and create samples which are homogeneous in terms of density and water content. 3) Carry out a series of HET tests to obtain high quality data describing the erosion resistance of soils which are: (i) as compacted and (ii) subjected to wetting / drying paths following compaction. 4) Create a predictive model of how the erosion resistance of embankment materials is likely to change over their lifetime. This will link measurable soil properties to the change in erosion resistance from the as-compacted state.