纤维掺量对椰丝纤维加筋土强度特性影响试验研究

Experimental study on the effect of fiber dosing on the strength characteristics of coconut fiber reinforced soil

为改善边坡浅层土体抗剪强度不足的问题,对椰丝纤维开展不同围压下的不固结不排水三轴试验,研究纤维掺量对椰丝纤维加筋土抗剪强度的影响及其加筋机理。结果表明:(1)椰丝纤维可以显著提高土体的强度和抵抗变形的能力。(2)主应力差呈现随纤维掺量的增长先增高后降低的趋势,纤维掺量为0.55%时主应力差最高。(3)围压对主应力差影响显著,相同条件下,围压越高,加筋效果越差。(4)纤维掺量对黏聚力影响显著,随纤维掺量的增加呈现先上升后下降的趋势,平均提升幅度为139.8%;对内摩擦角影响不大,在4.3°以内变化。

In order to improve the problem of insufficient shear strength of shallow soil on slope,the unconsolidated undrained triaxial test was carried out on coconut fiber under different surrounding pressure to study the effect of coconut fiber on the shear strength of soil and its reinforcement mechanism at 0.35%,0.55%,0.75%and 0.95%fiber admixture.The results show that:(1)The incorporation of coconut fiber into the pulverized clay can significantly improve the strength and resistance to deformation of the soil.(2)The main stress difference showed a trend of increasing and then decreasing with the increase of fiber admixture,and the highest main stress difference was found when the fiber admixture was 0.55%.(3)The surrounding pressure has a significant effect on the main stress difference,and the higher the surrounding pressure,the worse the reinforcement effect under the same conditions.(3)The fiber admixture has influence on the cohesion and internal friction angle of reinforced soil.The effect on cohesion is significant,and the cohesion of reinforced soil specimens is increased compared with that of plain soil specimens,showing a trend of increasing and then decreasing with the amount of fiber,with an average increase of 139.8%;the effect on the internal friction angle is not significant,and it varies within 4.3.