聚丙烯纤维加筋对高岭土固结压缩特性影响试验研究

工程中为了改良压实黏土的强度和抗干裂性能，将分散的聚丙烯纤维均匀掺入土体中制成纤维加筋土。利用聚丙烯纤维与高岭土在室内人工拌和并压制成纤维加筋土样，基于一维固结试验研究了控制干密度条件下纤维加筋掺量与长度对加筋高岭土固结、压缩特性的影响规律。研究结果表明，在控制干密度和纤维长度条件下，随着纤维掺量的增加，加筋土的固结系数和压缩模量均先增大后减小；掺量为0.2%时固结系数最大，掺量为0.1%～0.15%时压缩模量最大；在控制干密度和纤维掺量条件下，随着纤维长度的增加，加筋土的固结系数先减小后增大，纤维长度为10 mm时固结系数最小；当固结压力较高（≥400 kPa）时，加筋土的压缩模量随纤维长度增大而减小。此外，加筋土的压缩指数总体上随纤维掺量和纤维长度的增大而增大，但纤维掺量为0.15%～0.20%以及纤维长度为10 mm时压缩指数有一极小值。

Influence of polypropylene fiber-reinforcement on consolidation and compression characteristics of kaolin

To improve the strength and resistance to desiccation cracking of clayey soils in engineering practice, fiber-reinforced soils are made by mixing polypropylene fibers together with soils. The polypropylene fibers and kaolin are mixed together and statically compacted into fiber-reinforced kaolin in the laboratory. Then the influences of fiber incorporation on the consolidation and compression characteristics of the fiber-reinforced soil are studied by one-dimensional compression experiments. Test results indicate that both the coefficient of consolidation and compression modulus first increases and then decreases with the increase of the fiber content, under constant dry density and fiber length. When the fiber content is 0.2%, the coefficient of consolidation will reach a peak value. When the fiber content is 0.1%-0.15%, the compression modulus will arrive at a peak value. The coefficient of consolidation first decreases and then increases with the increase of the fiber length under constant dry density and fiber content. When the fiber length is 10 mm, a minimum value of coefficient of consolidation will be achieved. When the vertical pressure is relatively high (≥400 kPa), the compression modulus of the fiber-reinforced kaolin will decrease with the increase of the fiber length. Furthermore, generally the compression index of the fiber-reinforced kaolin increases with the increase of the fiber content. However, a minimum value of the compression index is found when the fiber content is 0.15%-0.2%, or the fiber length is 10 mm.