聚苯乙烯塑料泡沫(EPS)用于膨胀土渠道水下坡面的混凝土衬砌板下，发挥其减载、防水和保温功能，可减小作用于衬砌板上的膨胀压力，同时能保持膨胀土的基质吸力，从而对维护渠坡稳定起到十分积极的作用。为了更深入地研究EPS在受压时的力学特性，开展了3种密度EPS无侧限的单轴压缩与蠕变试验。结果表明EPS单轴压缩的应力-应变关系呈明显的非线性特征，据此提出了能完整描述其受压过程的本构模型;3种EPS即使在较小压缩应力的长期作用下，也会发生明显的蠕变。进一步指出了在寒区膨胀土渠坡衬砌结构应用的EPS选择中，应综合考虑EPS密度对其减载、防水和保温特性的不同影响;同时也应考虑EPS的压缩蠕变效应对于衬砌结构的影响。
Abstract
Expanded polystyrene (EPS) geofoam is a novel geosynthetic material with some prominent features, including light weight, good compressibility, water resistance and heat preservation. It can be used as a lining structural layer under the concrete lining slab of underwater slope of expansive soil canal to release the expansive pressure acting on the concrete slab and to maintain matrix suction of expansive soil, thus stabilizing the canal slope. In order to further explore the mechanical characteristics of EPS under compression in this application, one dimensional compression tests and compressive creep tests on EPS of different densities (14.7 kg/m 3, 17.05 kg/m 3 , 23.4 kg/m 3) were conducted. Results show that the uniaxial stress strain relationship of EPS is significantly nonlinear and the creep strain is significant even under longterm small loading. On the basis of the test results, a constitutive model describing the whole uniaxial compression process of EPS is proposed. It is further pointed out that the influences of EPS density on its deloading property, water resistance and heat preservation properties should be taken into account when selecting EPS for lining structure of canal slope in cold region. Meanwhile, the influence of compression creep of EPS on lining structure of canal slope should also be considered.
关键词
膨胀土渠坡 /
边坡稳定 /
聚苯乙烯塑料泡沫 /
压缩 /
蠕变
Key words
expansive soil canal slope /
slope stability /
expanded polystyrene (EPS) /
compression /
creep
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参考文献
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基金
国家自然科学基金资助项目(50979080)；交通部西部交通建设科技项目(2011318785760)
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