废旧轮胎加筋土挡墙抗震性能及其工作机理研究

Waste tire reinforced soil is not only economic and environmental, but also can realize resource utilization and has good seismic performance. However, it has not been understood about the seismic response mechanism of waste tire reinforced retaining wall and slope, which restirct its application and development. This project includes the following content, strength and deformation properties of waste tire, hysteresis loop mode, dynamic and static strength, modulus, stress-strain characteristics, a certain analysis method with ultimate strength of waste tires reinforced soil elements, which are investigated by the monotonic and cyclic tensile tests, static and cyclic large triaxial tests. This project will discuss deformation mode, fracture mechanism and effective parameters of waste tire reinforced retaining wall, the derivation and calculation of overall shear stiffness, damping ratio etc., giving internal fracture index and its expression, differentiating deformation modes quantitatively, Generalization seismic performance and revelation seismic response mechanism of waste tire reinforced retaining wall under large scale model test of shaking table. On this basis, putting forward and validating a dynamic displacement analysis method of internal stability with reinforced soil retaining wall. Above results will provide the scientific evidences for utilization of waste tires, seismic design of waste tire reinforced soil, and improvement of reinforced soil theory and its calculation methods.

废旧轮胎加筋土结构具有良好的抗震性能，经济环保，可实现资源化利用。但是目前对废旧轮胎加筋土挡墙、边坡地震响应工作机理的认识尚不清楚，制约了其应用和发展。本项目拟通过单一、循环抗拉，动-静大三轴等试验，研究废旧轮胎筋材的强度和变形特性，确定适合的滞回圈模型，获得轮胎加筋土单元动-静强度、模量、应力-应变特性，提出一种确定轮胎加筋土单元极限强度的分析方法。通过振动台大比尺模型试验，分析轮胎加筋土挡墙变形模式、破裂机理及其有效控制参数，推导计算加筋土挡墙剪切刚度模量、阻尼比等动力响应性能指标及其规律，给出内部破裂指标及其表达式，定量研究和区分不同变形模式，系统归纳轮胎加筋土挡墙抗震性能，揭示其地震响应工作机理。在此基础上，提出一种基于位移分析的加筋土挡墙内部稳定性动力计算分析方法，验证其合理性。通过上述研究，为废旧轮胎的资源化利用，废旧轮胎加筋土挡墙抗震设计理论与方法的发展与完善提供科学依据。

数量庞大的废旧轮胎给环境造成了严重污染，其翻新率、回收率和利用率都处于较低水平，如何处理数量庞大的废旧轮胎已成为紧迫和严重的国际性社会经济问题和环境问题。将废旧轮胎用于加筋抗震，既能为废旧轮胎减量化、资源化利用开辟新的途径，又能为加筋土工程提供质优价廉、柔性环保的加筋材料。但目前对废旧轮胎加筋土结构在交通荷载和地震荷载作用下的变形模式、动力响应性能及其加筋工作机理，相应计算方法等认识不够清楚，制约了废旧轮胎加筋土结构在挡土墙、边坡工程中的应用和发展。本项目借鉴并发展传统土工合成材料加筋土的研究方法，通过废旧轮胎与不同填料土共同作用的动-静大三轴试验、大型拉拔和大比例尺模型加筋边坡和加筋挡墙等系列试验，研究轮胎加筋土结构中加筋单元体的筋材和土体动、静强度和变形特性；分析加筋土结构筋-土界面拉拔模式下的相互作用机理及其在交通荷载和地震荷载作用下变形模式和破裂机理；深入剖析加筋土结构在各种荷载作用下变形、破坏模式及其影响因素和规律等。通过本项目的研究，揭示废旧轮胎与不同固废填料土共同作用的工作机理，完善废旧轮胎加筋土结构稳定性计算方法和设计理论，发展加筋土结构的研究方法和实验手段，为废旧轮胎和固废填料加筋土的设计、工程应用、规范编制等提供科学依据，推进废旧轮胎和固废填料等资源化应用的发展。