Abstract Geosynthetic-encased stone column (GESC) has been proven as an effective alternative to reinforcing soft soils. In this paper, a series of centrifuge model tests were conducted to investigate the performance of GESC-supported embankment over soft clay by varying the stiffness of encasement material. The enhancement in the performance of stone columns encased with geosynthetic materials was quantified by comparing the test with ordinary stone columns (OSCs) under identical test conditions. The test results reveal that by encasing stone columns with geosynthetic material, a significant reduction in the ground settlement, relatively faster dissipation of excess pore pressure and enhanced stress concentration ratio was noticed. Moreover, with the increase in the encasement stiffness from 450 kN/m to 3300 kN/m, the stress concentration ratio increased from 4 to 6.5, which signifies the importance of encasement stiffness. In addition, a relatively lower value of soil arching ratio observed for GESCs compared to OSCs indicate the formation of a relatively strong soil arch in the GESC-supported embankment. Interestingly, under embankment loading, GESCs fail by bending while OSCs fail by bulging. The stress reduction method can be used to calculate the settlement of GESC-supported embankment with larger stress reduction factor than that in the OSC-supported embankment. Finally, the limitation of the construction of the embankment at 1 g was addressed.

中文翻译：

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软粘土上土工合成材料包封石柱支路堤的离心建模

摘要 土工合成材料包裹的石柱 (GESC) 已被证明是加固软土的有效替代方法。在本文中，进行了一系列离心模型试验，通过改变包裹材料的刚度来研究 GESC 支撑的路堤在软粘土上的性能。通过在相同的测试条件下将测试与普通石柱 (OSC) 进行比较，量化了用土工合成材料包裹的石柱性能的增强。试验结果表明，通过用土工合成材料包裹石柱，地基沉降显着减少，超孔隙压力消散速度相对较快，应力集中率提高。而且，随着装箱刚度从 450 kN/m 增加到 3300 kN/m，应力集中比从 4 增加到 6.5，这表明外壳刚度的重要性。此外，与 OSCs 相比，GESCs 观察到的土拱比值相对较低表明在 GESC 支持的路堤中形成了相对较强的土拱。有趣的是，在路堤荷载下，GESCs 因弯曲而失效，而 OSCs 因膨胀而失效。应力折减法可用于计算应力折减系数大于OSC 支持的路堤的GESC 支持的路堤的沉降。最后，解决了 1 g 路堤施工的限制。与 OSC 相比，GESC 观察到的土拱比值相对较低表明在 GESC 支持的路堤中形成了相对较强的土拱。有趣的是，在路堤荷载下，GESCs 因弯曲而失效，而 OSCs 因膨胀而失效。应力折减法可用于计算应力折减系数大于OSC 支持的路堤的GESC 支持的路堤的沉降。最后，解决了 1 g 路堤施工的限制。与 OSC 相比，GESC 观察到的土拱比值相对较低表明在 GESC 支持的路堤中形成了相对较强的土拱。有趣的是，在路堤荷载下，GESCs 因弯曲而失效，而 OSCs 因膨胀而失效。应力折减法可用于计算应力折减系数大于OSC 支持的路堤的GESC 支持的路堤的沉降。最后，解决了 1 g 路堤施工的限制。