麦秆纤维加筋土的抗冲蚀性及其防护效果试验研究

Experimental research on anti-eroding property and protection effect of reinforced soil with straw fibers

为了研究天然纤维加筋土的抗冲蚀性能及其防护效果,选取麦秆纤维为加筋材料,并加入定量石灰,制备麦秆纤维加筋土试样,进行直剪试验、崩解性试验及模拟降雨冲刷试验。试验结果表明:麦秆纤维加筋提高了土体的抗剪强度,主要表现为黏聚力随龄期增长明显,最大黏聚力增长率约为400%,内摩擦角增长较小,最大内摩擦角增长率约为50%,石灰+麦秆纤维加筋土的强度增长率高于纯麦秆纤维加筋土,纤维加筋率的增加可以明显提高加筋土的抗剪强度;麦秆纤维加筋有效降低土体的崩解性,崩解速率降低系数平均约为4.83,石灰的加入可以进一步提高纤维加筋土的水稳定性;麦秆纤维加筋土的防护效果明显,含泥量和径流量均比较稳定,含泥量平均降低约40%,且随着降雨历时的增长,防护效果更明显。本研究结果对于麦秆纤维加筋土应用于黄土边坡坡面防护具有指导意义。

For the purpose of investigating the anti-eroding property and protection effect of natural fibers reinforced soil,straw fibers were used for the reinforcement material in this study. Straw fibers reinforced soil samples were prepared with quantitative lime,and direct shear tests, disintegrating tests, and simulated rainfall tests were performed. Test results show that: the reinforcement with straw fibers improves shear strength of soil. It mainly displays that the cohesion increases significantly with age and the maximum increment of cohesion reaches about 400%; the increment of internal friction angle is small, and the maximum increment of internal friction angle reaches approximately 50%. The strength increment of reinforced soil with straw fibers and lime is higher than that of reinforced soil with straw fibers. The shear strength of reinforced soil increases obviously with the fiber content. Reinforcement with straw fibers reduces effectively disintegration rate of soil, the decrease coefficient of disintegration rate is 4.83 on average. The inclusion of lime improves further the stability in the water of reinforced soil with straw fibers. The protection effect of reinforced soil with straw fibers is remarkable. Mud content and runoff of slope with protection keep at a stable range, mud content decreases by about 40% on average, and the protection effect exhibits much better with the increase in rainfall hours. The findings of this study are instructive for application of reinforced loess with straw fibers in loess slope protection.