Irreversible effects of drying-wetting cycles on shrinkage and water retention of compacted London clay
Irreversible effects of drying-wetting cycles on shrinkage and water retention of compacted London clay
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DOI：
10.1051/e3sconf/202338206003
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发表时间：
2023
影响因子：
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通讯作者：
Ana Sofia Dias;P. Hughes;D. Toll
中科院分区：
文献类型：
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作者：
Ana Sofia Dias;P. Hughes;D. Toll
由土方工程支撑的长线性资产，如公路和铁路，容易受到天气周期造成的恶化的影响，这会转化为土壤水力机械特性的变化。由于气候变化，干旱和极端降雨事件变得更加频繁，预计这些土方工程的故障将变得更加常见。本文研究了水分循环吸力范围对活性伦敦粘土的土-水特征曲线和土的收缩-膨胀特征曲线的影响。在普罗克特最佳条件下压实的土样在可变吸力间隔内进行干湿循环。当水含量降低到接近收缩极限的阈值以下时，观察到SSC的变化。随着SWRC变得不那么陡峭，观察到土壤保持吸力的能力降低，因为初级干燥线比后续干燥阶段（扫描干燥线）更陡峭。一旦扫描干燥线与主干燥线相交，就确定了屈服点，土壤失去了进一步保持吸力的能力。观察到不可逆的变形与干湿循环的SWRC变化相关。
Long-linear assets, such as roads and railways, supported by earthworks are susceptible to deterioration caused by weather cycles, that translate into changes in soil hydro-mechanical properties. Failures in these earthworks are expected to become more common due to climate change as periods of drought and extreme rainfall events become more frequent. In the present study, the effect of the suction range of the moisture cycle on the soil-water retention curve (SWRC) and soil shrink-swell curve (SSC) of active London clay is investigated. Soil samples compacted at Proctor optimum conditions were subjected to drying-wetting cycles within a variable suction interval. A change in the SSC was observed when the water content reduced below a threshold that approximates to the shrinkage limit. A reduction in the ability of the soil to hold suction was observed with SWRCs becoming less steep, as the Primary Drying Line was steeper than subsequent drying phases (Scanning Drying Lines). Once the Scanning Drying Line intersects the Primary Drying Line, a yielding point is identified, and the soil loses further ability to hold suction. Irreversible deformations were observed associated with changes in the SWRC from drying-wetting cycles.