黏合剂与纤维组合对喷播基质材料抗剪性能及植物生长的影响

Effect of different binder and fiber combinations on shear resistance of substrate and plant growth of spray seeding

摘要:

【目的】明确添加“黏合剂+植物纤维”对客土喷播初期基质抗剪性能和植物生长的影响，为工程实践提供参考。【方法】采用环刀法、直接剪切法和模拟坡面法，选择聚丙烯酰胺（PAM）和聚乙烯醇（PVA）2 种黏合剂与棕榈纤维（PF）、椰丝纤维（CF）、剑麻纤维（SF）、木纤维（WF）4 种植物纤维，探究黏合剂和纤维两两组合下喷播基质的孔隙度、抗剪性能及植被生长特征。【结果】1）PAM+SF 组合孔隙度表现最优，其总孔隙度和毛管孔隙度显著高于 CK（P＜0. 05），分别是 CK 的 1. 26 倍和 1. 37 倍； 2）添加 PAM 能够提高纤维-土复合体的抗剪强度，PAM+CF 和 PAM+SF 组合内摩擦角显著大于 CK 和其他处理组（P＜0. 05），分别是 CK 的 1. 71 倍和 1. 88 倍，PAM+PF 组合内聚力显著高于 CK（P ＜0. 05），是 CK 的 1. 14 倍。3）PVA+SF 组合的植物生长状况最优，总生物量与根冠比显著大于 CK（P ＜0. 05）。【结论】添加 PAM 的组合能够提高喷播基质的抗剪性能；2 种黏合剂相比，添加 PAM 的组合抗剪强度优于添加 PVA 的组合。并且喷播基质的抗剪性能变化由黏合剂和植物纤维共同影响。添加 “黏合剂+植物纤维”，对植被生长恢复友好。

Abstract:

【Objective】 To investigate the effect of adding “binder + plant fiber” on the shear performance and plant growth of the substrate during the early stages of guest soil spraying，and to provide reference for engineering practice.【Method】 The ring knife method，direct shear method and simulated slope method were employed. Two binders，Polyacrylic amide （PAM） and Polyvinyl alcohol （PVA），and four plant fibers，palm fiber （PF），coconut fiber （CF），sisal fiber （SF）and wood fiber （WF），were selected. The porosity，shear resistance and vegetation growth characteristics of sprayed substrates were investigated under the two combinations of binder and fiber.【Result】 The results showed that （1） PAM+SF exhibited the highest porosity，with total and capillary porosity significantly higher than CK （P＜0. 05），at 1. 26 and 1. 37 times higher than those of CK，respectively；（2） Addition of PAM enhanced the shear strength of the fibersoil composite，with internal friction angles of PAM+CF and PAM+SF significantly higher than those of CK and other treatment groups （P＜0. 05），at 1.71 and 1. 88 times higher than those of CK，respectively，while the cohesion of PAM+PF combination was significantly higher than that of CK （P＜0. 05），at 1. 14 times higher than that of CK；（3） PVA+SF combination showed the best plant growth condition，with total biomass to root crown ratio significantly greater than CK （P＜0. 05）.【Conclusion】 Combining with PAM can improve the shear resistance of the sprayed substrate； PAM exhibited better shear strength compared to PVA. Shear resistance of sprayed substrates was influenced by both binder and plant fiber. The "binder + plant fiber" combination promotes vegetation growth recovery.