地震作用下模块式面板土工合成材料加筋土挡墙的内部稳定分析

Internal stability analysis of segmental geosynthetic-reinforced soil retaining walls subjected to seismic loading

由于造价低廉,性能优良且外表美观,模块式面板土工合成材料加筋土挡墙在我国交通及城建等领域有着广泛的应用前景。大量的工程实践证明,土工合成材料加筋土挡墙的抗震性能良好,但仍有必要进行合理的抗震设计,而内部稳定校核是加筋土挡墙抗震设计的一个重要环节,它一定程度上决定了高烈度地震区加筋土挡墙的配筋方式及配筋密度。应用非线性动力有限元法分析不同加筋长度、加筋间距及不同地震作用下模块式土工合成材料加筋土挡墙在地震作用下的内部稳定,研究了筋材蠕变对加筋土挡墙动力内部稳定的影响,并将有限元分析的结果与国外规范建议的内部稳定校核结果进行比较。研究结果表明,在正常配筋密度条件下,各层筋材最大内力的位置与规范建议的位置有一定的区别,墙体下部更加远离面板;且筋材的最大内力沿高度的分布与该规范计算结果差别较大;而筋材蠕变使筋材的内力出现重分布。

Geosynthetic-reinforced soil （GRS） segmental retaining wall was developed with the increasing popularity due to its good performance, low price and aesthetic appearance. It had been proved by practices and experiments that GRS retaining wails exhibited good seismic performance, however, it was still necessary to conduct seismic design of the structure. The internal stability analysis is a critical step in the seismic design, which to certain extent determines the layout and density of reinforcements. Nonlinear dynamic finite element method was used to investigate the seismic internal stabilities of this kind of earth structures with different reinforcement densities and different earthquake excitations. The effects of reinforcement creep on the seismic internal stability were also analyzed. The results were then compared to those obtained using the suggested internal stability analysis method by NCMA. It was found that with regular reinforcement the locations of the maximum reinforcement loads from the FE analysis were different to those using the suggested method, with the lower portion farther away from the facing; the distributions of the maximum reinforcement load along the height direction were considerably different; the creep of reinforcement led to load redistribution in the reinforcements.