唐飞跃

摘 要：为了研究加筋聚苯乙烯轻质膨胀土的膨胀与强度特性，将聚苯乙烯颗粒与膨胀土混合，聚丙烯纤维作为加筋材料，开展了包括密度、无荷膨胀率、膨胀力以及饱和快剪等室内试验。结果表明，聚苯乙烯颗粒和聚丙烯纤维的掺入可有效抑制膨胀土的膨胀特性，表现为无荷膨胀率与膨胀力的显著减小;聚苯乙烯颗粒主要起到体积置换作用，土样密度以及膨胀力随聚苯乙烯颗粒掺量增加线性减小;随着聚苯乙烯颗粒的增加，混合土内摩擦角持续增大，黏聚力先增加后降低;随着纤维掺量的增加，混合土的黏聚力得到有效增长。因此，加筋聚苯乙烯轻质土在改良膨胀土方面具有良好的应用价值。

关键词：岩土力学;聚苯乙烯;轻质;纤维加筋;膨胀土;膨胀特性;强度

中图分类号：TU443 文献标识码：A

Abstract：In order to study the swell potential and shear strength of reinforced expensive soil mixed with expanded polystyrene， polystyrene particles and expansive soil were mixed. Polypropylene fibers functioned as reinforcement material. Density， swelling ratio， swelling pressure and direct shear strength were determined by indoor test. The results indicate that the incorporation of polystyrene particles and polypropylene fibers can effectively suppress the expansion of expansive soil. Swelling ratio and swelling pressure are decreased significantly. Polystyrene particles majorly play a role of volumereplacing， the soil density and swelling pressure decrease linearly with the increase of dosage of polystyrene particles. With the increase of polystyrene particles， the internal friction angle of the mixed soil is dramatically increased， and the cohesive strength increases firstly and then decreases. With the increase of fiber content， the cohesion of mixed soil increases obviously. The test shows that reinforced expensive soil mixed with expanded polystyrene has a good application prospect in the treatment of expansive soil.

Keywords：geomechanics; polystyrene; light weight; fiber reinforced; expansive soil; swell potential; strength

聚苯乙烯（EPS）颗粒混合轻质土是将原料土、EPS颗粒、固化材料和水混合搅拌而成。EPS颗粒轻质土具有密度小、压缩模量大、流动性好、环保性强的优点，主要用于减小软弱地基沉降和挡土墙侧向压力、管道填埋、陡坡施工等方面[18]。日本率先于20世纪80年代進行了EPS颗粒混合轻质土的研究，并成功应用于路基填土、港口工程中。中国对EPS轻型土的研究尚处于起步阶段。2004年，在新安江电厂8870开关站道路的建设工程中，为了解决边坡稳定问题，进行了200 m3的废弃泡沫颗粒混合轻质土的换填工程，运行状况良好[9]。相关研究发现[1013]，淤泥、砂土和黏土都可以作为EPS轻质土的原料土。……