This paper aims to investigate the effects of cyclic shear amplitudes and loading sequences on a soil–structure interface using direct shear tests under a large number of loading cycles. A series of cyclic direct shear tests were performed on a granular soil-rough interface under the constant normal load (CNL) condition. Initially, monotonic interface direct shear tests were carried out as benchmarks to specify test boundaries and proper ranges of assigned cyclic amplitudes. Dry standard Fontainebleau sand in dense and loose conditions and a modified rough surface material were utilized to represent a soil-rough structure interface. A series of CNL cyclic interface direct shear tests was then conducted by varying the applied cyclic shear stress amplitudes and the cyclic loading sequence (small-to-large and large-to-small patterns) with a large number of testing cycles (10⁴). Immediately after the cyclic shear tests were completed, monotonic interface direct shear tests were again performed to examine the post-cyclic behaviour of the soil-rough interface. Test results yielded that the applied cyclic shear stress amplitudes did affect the soil-rough interface by inducing a gradual contraction and an expansion in shear displacement accumulation. The maximum stress ratio could notably influence the volumetric behaviour and shear displacements. The accumulation of mean cyclic displacements was independent of the change in cyclic shear stress amplitudes between two consecutive cyclic loading sequences. The post-cyclic behaviour showed that changing the shear stress cycles between two consecutive packages did not influence the peak stress ratio.

本文旨在通过大量加载循环下的直接剪切试验研究循环剪切振幅和加载序列对土-结构界面的影响。在恒定法向载荷 (CNL) 条件下，对粒状土壤-粗糙界面进行了一系列循环直接剪切试验。最初，单调界面直剪试验作为基准进行，以指定试验边界和指定循环振幅的适当范围。干燥的标准枫丹白露沙在致密和松散的条件下和改良的粗糙表面材料被用来表示土壤-粗糙结构界面。⁴）。循环剪切试验完成后，立即再次进行单调界面直接剪切试验，以检查土壤-粗糙界面的循环后行为。测试结果表明，施加的循环剪切应力幅值确实通过引起剪切位移累积的逐渐收缩和膨胀来影响土壤-粗糙界面。最大应力比可以显着影响体积行为和剪切位移。平均循环位移的累积与两个连续循环加载序列之间循环剪应力幅值的变化无关。循环后行为表明，改变两个连续包装之间的剪切应力循环不会影响峰值应力比。