Granitic saprolites are abundant in many regions around the world and they are widely employed in various engineering projects. Behavior of such kinds of soils is not sufficiently understood and our knowledge about the fundamental behavior of saprolites is to a far less extent than the sedimentary soils. Owing to the limited knowledge, many problems occurred in the engineering applications that used saprolites as a construction material. This study presents results of a set of conventional drained and undrained triaxial compression shearing tests on the granitic saprolites in both the disturbed and undisturbed conditions. This study showed that the soil fabric was the paramount factor governing on the soil stress–strain response rather than the soil bonds. Under the drained shearing condition, the undisturbed soil revealed a strain-softening behavior with a dilative response at the low consolidation stress level, while a contractive response was present at the high consolidation stress levels. However, the disturbed soil showed a strain-hardening behavior with a contractive response, regardless of the consolidation stress levels during the drained shearing. The undrained response was complicated, as the soil showed both the contractive and dilative responses with phase transformation points, regardless of the soil condition (i.e., disturbed or undisturbed) and the consolidation stress levels. The bond effect of the intact soil persisted during the consolidation stage; however, its effect did not extend to the large strain-controlled shearing stage, where the tangential stiffness suddenly decreased at the axial strain of 1.5%.

中文翻译：

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扰动和未扰动的花岗腐泥土的试验研究

花岗岩腐泥土遍布世界许多地区，并广泛用于各种工程项目中。对此类土壤的行为还没有足够的了解，我们对腐泥土基本行为的了解远远少于沉积土壤。由于知识有限，在使用腐泥土作为建筑材料的工程应用中出现了许多问题。这项研究提出了在扰动和未扰动条件下对花岗岩腐泥土进行的一组常规排水和不排水三轴压缩剪切试验的结果。这项研究表明，土壤结构是决定土壤应力－应变响应而不是土壤结合力的最重要因素。在排水剪切条件下，原状土壤在低固结应力水平下表现出应变软化行为，并具有扩张反应，而在高固结应力水平下表现出收缩反应。然而，扰动的土壤表现出具有应变响应的应变硬化行为，而与排水剪切过程中的固结应力水平无关。不排水的响应是复杂的，因为无论土壤条件（即受干扰还是不受干扰）和固结应力水平如何，土壤都显示出具有相变点的收缩和扩张响应。在固结阶段，完整土壤的粘结作用持续存在。但是，它的作用并没有扩展到大的应变控制剪切阶段，在该阶段，切向刚度在轴向应变为1.5％时突然降低。