Abstract

The strength, deformation and particle breakage behaviors of reinforced coral sand were analyzed by performing a series of large-scale consolidated drained triaxial tests on unreinforced and two-layer geogrid reinforced samples. Two grain size distributions, namely, the natural coral sand in the South China Sea (ISG) and the uniformly graded coral sand (UG), were used to investigate the effect of gradation on unreinforced and geogrid-reinforced specimens under dry and saturated conditions. The results indicated that the inclusion of geogrid offered a great improvement to the coral sand with respect to increasing its shear strength and reducing the shear dilation. The reinforcement effect of geogrid on dry sample was better than that on saturated one. Moreover, the UG sample exhibits high compressibility and distinct strain hardening behavior due to the significant particle breakage resulting from the lack of fine content compared with the ISG sample, which induced the better reinforcement effect of geogrid on ISG sample. The increase of particle breakage further led to the decrease of peak-state friction angle.

摘要

通过对未加筋和双层土工格栅加筋样品进行一系列大型固结排水三轴试验，分析了加筋珊瑚砂的强度、变形和颗粒破碎行为。两种粒度分布，即南海天然珊瑚砂 (ISG) 和均匀级配珊瑚砂 (UG)，用于研究级配对干燥和饱和条件下未加固和土工格栅加固试样的影响。结果表明，土工格栅的加入对珊瑚砂的抗剪强度增加和剪切膨胀降低都有很大的改善作用。土工格栅对干样的加固效果优于饱和样。而且，由于与ISG样品相比，UG样品由于缺乏细粒含量而导致明显的颗粒破碎，因此表现出高压缩性和明显的应变硬化行为，这导致土工格栅对ISG样品具有更好的加固效果。颗粒破碎的增加进一步导致峰态摩擦角的减小。