废旧轮胎加筋土结构加筋机理研究

A large number of waste tires have caused serious pollution to the environment and have become a pressing environmental problem. Waste tires can be used for soil reinforcement, which can dispose a lot of waste tires and provide high quality and low price reinforced materials. But there is not enough understanding on the working mechanism of waste tires in reinforced soil, which severely restricted the application and development of waste tire recycling. Based on the development tradition research method of geosynthetics reinforcement, some analysis are carried out through the plane strain shear, large direct shear, large drawing and large scale reinforced model tests of interaction between waste tire and soil, including the stress and deformation characteristics of unit reinforced material and soil, the interaction mechanism between reinforcement material and soil, such as shear transfer properties , resistance to tensile failure and pull out etc. There are discussions of the whole deformation, failure mode, influencing factors and regularity of reinforced structure. The purpose of this project is to reveal reinforced mechanism of waste tire reinforced structures, set up stability calculation method of waste tire reinforced slope, which can enrich research method and calculation theory, provide scientific evidence for engineering applications and standard establishment of waste tire reinforced soil structures, and promote the development of waste tire recycling utilization.

数量庞大的废旧轮胎给环境造成了严重的污染，已成为一项紧迫的环境问题。将废旧轮胎用于土体加筋，既能消纳大量的废旧轮胎，又可为加筋土提供质优价廉的加筋材料。但目前对废旧轮胎加筋土的工作机理认识不清，严重制约了这种废旧轮胎资源化利用加筋方式的应用和发展。 本项目借鉴并发展传统土工合成材料加筋土的研究方法，通过废旧轮胎与土共同作用的平面应变剪切、大型直剪、大型拉拔和大比例尺模型加筋边坡等系列试验，研究轮胎加筋土结构中加筋单元体的筋材和土体应力-变形特性；分析加筋土筋土界面剪力传递特性、拉拔模式下轮胎筋材抗拉断和抗拔出等筋土相互作用机理；深入剖析加筋土结构整体变形、破坏模式及其影响因素和规律等。通过本项目的研究，揭示废旧轮胎加筋土结构的加筋机理，建立废旧轮胎加筋边坡稳定性计算方法，丰富加筋土结构的研究方法和计算理论，为废旧轮胎加筋土的工程应用、规范编制等提供科学依据，推进废旧轮胎资源化应用的发展。

废旧轮胎用于岩土工程加筋，不但可以消纳、处理大量的废旧轮胎，减轻废旧轮胎造成的环境问题，而且可以为大量的加筋土工程提供质优价廉的加筋材料。但目前对废旧轮胎加筋土的工作机理认识不清，严重制约了这种废旧轮胎资源化利用加筋方式的应用和发展。本项目主要研究内容及成果有：.轮胎加筋对于路堤边坡应力演化有显著影响，加筋路堤破坏时相对素土边坡没有出现明显整体变形破坏，应力值没有出现陡降；轮胎加筋可显著降低靠近轮胎单元体正下方及其附近砂土承担的竖向附加应力，且顶层加筋轮胎与加载板距离越小，附加应力值减小越明显；轮胎加筋对减小路堤沉降量效果明显，且荷载越大效果越显著；加筋路堤中，顶部轮胎层距离加载板越近、轮胎加筋层间距越小，路堤模型沉降越小，初始密度较小时，路堤加筋效果较好；路堤边坡加筋前后破坏形态存在明显差异，对于路堤边坡剪出口位置的影响较大，顶部轮胎位置对于路堤边坡破坏形态作用较明显。.废旧轮胎-土工格室复合加筋路堤比土工格室加筋路堤能更好的提高承载力和降低沉降量。与素土路堤相比，加筋路堤不但使附加应力变得较为均匀，而且有效限制了路堤侧向变形，减少了不均匀沉降，废旧轮胎-土工格室复合加筋路堤这种特征更明显。加筋路堤能有效增强其稳定性。.不同强度轮胎条与砂土界面内摩擦角和黏聚力均大于单/双向土工格栅。随法向应力增大，筋土界面摩阻力不断增大，且在整个拉拔过程中抗拉拔能力明显优于土工格栅。法向应力越大，筋土界面摩阻力越大，轮胎条相对位移与应变越大。在拉拔初始阶段，主要由前端轮胎条与土体作用，提供界面剪应力；拉拔后期，后半部分轮胎条提供界面剪应力的作用不断增大。.通过本项目的研究，揭示了废旧轮胎加筋土结构的加筋机理，建立废旧轮胎加筋边坡稳定性计算方法，丰富加筋土结构的研究方法和计算理论，为废旧轮胎加筋土的工程应用、规范编制等提供科学依据，推进废旧轮胎资源化应用的发展。