PVA纤维改良软土的工程特性研究  

Experimental Study on Engineering Properties of Soft Soil Modified by PVA Fiber

作　　者：余浩 余振锡 YU Hao;YU Zhenxi(School of Civil Engineering and Architecture,Anhui University of Technology,Maanshan 243000,Anhui,China)

机构地区：[1]安徽工业大学建筑工程学院,安徽马鞍山243000

出　　处：《水力发电》2021年第7期48-54,88,共8页Water Power

基　　金：安徽高校自然科学研究重大项目(KJ2016SD08)。

摘　　要：为解决软土地区承载力不足、沉降过大等问题,使用水溶性聚乙烯醇(PVA)纤维改良安徽地区软土,并将其与水泥改良土进行对比,探讨PVA纤维的改良效果。通过不同掺量PVA纤维和水泥的基本物理力学试验,对比PVA纤维的改良效果,选取3个代表性试样进行动三轴试验,验证其路用性能,并通过压汞和扫描电镜试验研究其改良机制。结果表明,PVA纤维可使软土的最佳含水量、液限、塑限增大,膨胀性降低,最大干密度无显著影响,且可以同时显著增大软土的无侧限抗压强度、动强度和阻尼比;PVA纤维主要通过其凝聚作用改善土体的力学性能,并未填充土体孔隙,可以一定程度保持土体的透气性。In order to solve the problems of insufficient bearing capacity and excessive settlement in the soft soil area,the water-soluble PVA fiber is used to improve the soft soil in Anhui Province and that is compared with the cement improved soil to further explore the improvement effect of PVA fiber.Firstly,the improvement effect of PVA fiber is compared through the basic physical and mechanical tests of the improved soil with different dosage of PVA fiber and cement.Secondly,three representative samples are selected to conduct triaxial test to verify the road performance.Finally,the improvement mechanism is studied by MIP and SEM.The test results show that the PVA fiber can increase the optimal water content,liquid limit and plastic limit of soft soil,reduce the swelling property of soft soil,and have no significant influence on the maximum dry density of soft soil.The PVA fiber can significantly increase the unconfined compressive strength,dynamic strength and damping ratio of soft soil.The PVA fiber improves the mechanical properties of soil by its condensation,and it does not fill the pores of the soil and can maintain the air permeability of the soil to some extent.

关 键 词：土工试验 改良软土 工程特性 细观机制 水溶性聚乙烯醇纤维 

分 类 号：TU411[建筑科学—岩土工程]