Controlling the swelling of expansive clay soils is always challenging for geotechnicians. In this study, the effect of hollow polyester fiber as an additive on the free swelling percentage and pressure reduction of bentonite clay is investigated experimentally. The fibers are employed in two forms of spread and concentrated. Fiber dosages of 0.2, 0.5, 1, and 1.5 are employed for the spread form and fiber columns with diameters of 1.2, 2 and 3.2 cm, are considered for the concentrated form with fiber column densities of 30 and 60 kg/m3. The obtained results show a significant improvement in the swelling behaviour of bentonite for both the spread and concentrated forms, with better performance for the later form. In which, higher densities and larger diameters of the fiber columns generally decreases the swelling percentage and pressure. The best improvement was observed in the concentrated form sample, with 60 kg/cm3 density and 3.2 cm diameter, with 19 and 57 percent reduction in swelling percentage and pressure, respectively.

控制膨胀粘土的膨胀对于岩土工程师来说始终是一个挑战。本研究通过实验研究了中空聚酯纤维作为添加剂对膨润土自由溶胀率和压力降低的影响。纤维以散布和浓缩两种形式使用。0.2、0.5、1 和 1.5 的纤维剂量用于展开形式，直径为 1.2、2 和 3.2 厘米的纤维柱被考虑用于纤维柱密度为 30 和 60 kg/m3 的浓缩形式。所得结果表明，膨润土的膨润土溶胀行为对于分散形式和浓缩形式都有显着改善，后一种形式具有更好的性能。其中，纤维柱的较高密度和较大直径通常会降低溶胀百分比和压力。