纤维加筋对土体力学特性的影响

Effect of Fiber Reinforced Soil on Mechanical Properties

纤维加筋技术用于提升土体的强度和抗变形特性。本文分别选取两种不同纤维材料(工业聚丙烯纤维和天然麦秸秆),通过无侧限抗压强度试验来研究纤维种类、掺量及长度对于土体强度和变形的影响。试验结果表明:相较于未加筋土,聚丙烯纤维加筋土的峰值强度得到较大程度的提升,长度为12 mm、掺量为0.2%时加筋效果最好,强度可达到素土的2.2倍;麦秸秆纤维加筋后,尽管土体强度略低于未加筋土,但无论是掺加聚丙烯纤维还是麦秸秆纤维,纤维土的破坏应变均大于素土,且在峰值强度过后纤维土均表现出较大的残余强度,可见加入纤维可以明显改善土体的抗变形性能。主要是因为纤维与土颗粒之间的摩擦作用为土体提供了更大的摩擦力。

Fiber reinforced technology was applied to improve the strength and deformation resistance of soil. Two kinds of different fiber material （industrial polypropylene fiber and natural wheat straw） were selected, the effects of different fibers, content and length on soil strength and deformation were studied by unconfined compressive strength test.Experimental results show that compared with soil without fiber, polypropylene fiber reinforced soil have great improvement on the peak strength, the reinforcement effect with length of 12 mm and content of 0.2% is best and the peak strength can reach 2.2 times of soil without reinforcement. With wheat straw fiber reinforced, while the soil strength is slightly lower than soil without fiber, but whether it is mixed with polypropylene fiber or wheat straw fiber, the failure strain of fiber reinforced soil is greater than soil without any reinforced materials, and after peak intensity, the residual strength of fiber reinforced soil is higher.Therefore, we can draw a conclusion that fiber can improve the deformation resistance of soil obviously. The main reason is that the occlusion between fiber and soil particles provides soil with greater friction.