In this paper, a bespoke stress and temperature controlled direct shear apparatus to test soil-geosynthetics interfaces is introduced. By adopting the apparatus, a series of ‘rapid loading’ shear tests and creep tests were conducted on the Clay – Geosynthetic Drainage layer (GDL) interfaces to assess the functionality of the apparatus. The experimental results indicate that, the modified apparatus can allow the shear deformation behaviour of soil-geosynthetics interfaces under environmental stress during thermal and drying-wetting cycles to be investigated, with a reliable performance. The resistance of Clay-GDL interfaces to shear deformation under the rapid loading of shear stress decreases after drying-wetting cycle and at elevated temperature. In the creep tests, the interfaces subjected to drying-wetting cycles and thermal cycles fail under a lower shear stress level than that of the interfaces without experiencing drying-wetting cycles and thermal cycles, respectively. The impacts of drying cycles on the horizontal displacement is significantly larger than that of wetting cycles. The first drying cycle has the largest impacts on the horizontal displacement than those of the following drying cycles. The impacts of drying alone on the horizontal displacement of Clay-GDL interfaces during drying cycles are small, and the main influence factor is the elevated temperature.

本文介绍了一种定制的应力和温度控制的直接剪切装置，以测试土工合成材料的界面。通过采用该设备，在粘土-土工合成排水层（GDL）界面上进行了一系列“快速加载”剪切测试和蠕变测试，以评估设备的功能。实验结果表明，改进后的装置可以研究土壤-土工合成材料界面在热和干湿循环过程中在环境应力作用下的剪切变形行为，具有可靠的性能。在干湿循环后和高温下，在剪切应力快速加载下，Clay-GDL界面对剪切变形的抵抗力降低。在蠕变测试中 经受干湿循环和热循环的界面在比界面低的剪切应力水平下失效，而没有经历干湿循环和热循环。干燥循环对水平位移的影响明显大于润湿循环的影响。与随后的干燥循环相比，第一个干燥循环对水平位移的影响最大。在干燥过程中，单独干燥对Clay-GDL界面水平位移的影响很小，主要影响因素是温度升高。干燥循环对水平位移的影响明显大于润湿循环的影响。与随后的干燥循环相比，第一个干燥循环对水平位移的影响最大。在干燥过程中，单独干燥对Clay-GDL界面水平位移的影响很小，主要影响因素是温度升高。干燥循环对水平位移的影响明显大于润湿循环的影响。与随后的干燥循环相比，第一个干燥循环对水平位移的影响最大。在干燥过程中，单独干燥对Clay-GDL界面水平位移的影响很小，主要影响因素是温度升高。