【作者】 刘泽；

【导师】 杨果林；

【作者基本信息】 中南大学 ， 土木工程， 2012， 博士

【摘要】 生态型加筋土挡墙是集现代加筋土技术与植被护坡技术于一体的新型支挡结构,在实际工程得到越来越广泛的应用。但针对生态型加筋土挡墙的相关研究很少,设计时也是套用传统加筋土挡墙的相关理论与方法,使得理论研究落后于工程实践,制约了生态型加筋土挡墙的推广应用。本文结合湖南省交通科技项目“高速公路加筋土结构应用技术与示范工程”(编号：200612)和浙江省交通科技项目“柔性生态挡墙在高速公路中应用的专题研究”(编号：2010H08)的研究,以绍诸高速公路加筋土挡墙实体工程为依托,以绿色加筋格宾挡墙和土工格栅包生态袋加筋土挡墙为代表,通过理论分析、室内外试验研究和数值模拟对筋土相互作用机理、生态型加筋土挡墙的破坏失稳机理、动力特性、稳定性分析方法和耐久性进行了系统地研究。主要研究内容有：1、通过不同筋材加筋粘土的大三轴试验、直剪试验和拉拔试验,对加筋粘土的强度和筋土界面特性进行研究,分析了平面网状筋材的加筋特点,获得了含水量、加筋间距对加筋粘土抗剪强度影响的计算公式、粘土与不同筋材间的摩擦系数,为工程设计提供了参数。2、通过模型试验研究了不同工况(普通工况、半挖半填工况)、不同结构(绿色加筋格宾挡墙和土工格栅包生态袋加筋土挡墙)的生态型加筋土挡墙在交通重复荷载作用下的动力特性。获得了不同荷载幅值、频率和加载次数下生态型加筋土挡墙不同部位的加速度、动土压力响应规律,挡墙的竖向和水平向变形的累积变形规律以及筋材累积拉应变增长规律。3、通过模型试验和数值分析研究了不同工况、不同结构形式的生态型加筋土挡墙的静力特性,获得了生态型加筋土挡墙的变形规律、筋带应变的分布与发展规律、极限承载力、挡墙的失稳破坏方式。4、以绍诸高速公路K38+325-k38+485路段的绿色加筋格宾挡墙实体工程为原型,通过数值分析研究了车辆荷载作用下生态型加筋土挡墙的动响应特征。5、在对土工合成材料耐久性损伤规律进行研究的基础上,分析了加筋土挡墙耐久性的主要影响因素,并基于筋材应变控制和加筋土结构侧向变形控制要求,提出了加筋土结构耐久性评估准则,建立了加筋土结构寿命预测方法。6、基于塑性极限分析的上限法理论,分析了普通工况和半挖半填工况生态型加筋土挡墙的破坏失稳机制,获得了两种工况生态型加筋土挡墙的承载能力计算公式。7、基于结构系统可靠性理论,建立了加筋土挡墙在不同失效模式下的极限状态方程,分析了各失效模式之间的逻辑关系,提出了加筋土挡墙结构系统可靠度计算方法,并进行了实例分析。8、提出了加筋土结构稳定性分析的点安全系数法。推导了岩土体、筋材和筋土界面的点安全系数计算公式,建立了筋材的抗拉、抗拔安全系数计算方法,给出了点安全系数法在FLAC3D中实现的步骤和FISH命令,并进行了实例分析。9、对绿色加筋格宾挡墙进行了现场试验,测试了施工过程中绿色加筋格宾挡墙基底不同方向的土压力、墙内竖向土压力,面墙后侧向土压力、筋材拉应变以及挡墙侧向变形的发展规律。10、结合试验研究、现场测试和调研成果,对生态型加筋土挡墙的工程应用提出了一些建议。更多还原

【Abstract】 Eco-reinforced earth retaining wall is a new type support structure which is combined with the technology of reinforced soil and bioengineering techniques for slope protection, and widely used in actual engineering. However, the relevant research has not been done sufficiently and traditional theory of reinforced earth retaining wall was adopted for design. The theoretical study of eco-reinforced earth retaining wall dropped far behind its practice which restricted its popularization.Supported by the transportation scientific research project of Hunan province-"Application Technique and Demonstration Engineering of Highway Reinforced Soil Structure"(No.200612) and transportation scientific research project of Zhejiang province "Special Study on Application of Flexible Ecology Retaining Wall in Highway"(No.2010H08), and based on the projects of the green reinforced gabion retaining wall and reinforced earth retaining wall with geogrid and eco-bag in Shaozhu Expressway, the reinforcement mechanism, failure mechanism, dynamic property, stability analysis method and durability of eco-reinforced earth retaining wall was studied systematically by the means of theoretical analysis, laboratory and field test and numerical simulation in this paper.The main research conclusions and innovation points were as follows:1. Based on the triaxial test, direct shear test and pullout test of reinforced clay with different reinforcements, the characteristics of shear strength and interface relationship between clay and reinforcement have been studied. The formula for calculating shear strength of reinforced clay, which considers the influence of water content and reinforced spacing, and the friction coefficient of clay with different reinforcements has been gotten, which provides parameters for engineering design.2. By the model tests, the dynamic characteristics of eco-reinforced earth retaining wall in different working conditions (common type and digging and stowing one) and structure forms (green gabion reinforced earth retaining wall and reinforced earth retaining wall with geogrid and eco-bag) under traffic load were studied. It has been gotten that the laws of acceleration, dynamic earth pressure, vertical and horizontal accumulated deformation, accumulated tensile strain of reinforcement under cyclic loading with different amplitudes and frequencies.3. The static characteristics of eco-reinforced earth retaining wall in different working conditions and different structure forms were studied by model tests and numerical analysis. The laws of deformation, tensile strain of reinforcement, ultimate bearing capacity and failure models of walls were obtained.4. The dynamic response characteristics of eco-reinforced earth retaining wall under traffic load had been studied by numerical analysis where green gabion reinforced earth retaining wall in the section K38+325-k38+485of Shaozhu Expressway was taken for prototype.5. Based on the analysis of durability injury law of gesynthetics, the durability influence factors of reinforced earth retaining wall were studied, its evaluation criterions were provided according to reinforcement strain controlling and lateral deformation controlling of the reinforced soil structure respectively, and the lifetime prediction method for reinforced soil structure has been set up.6. Based on the upper bound method of plastic limit analysis theory, the failure mechanisms of eco-reinforced retaining wall in common conditions and cutting with filling conditions have been studied, and the respective calculation formulas for their bearing capacity have been gotten.7. Based on the system reliability theory, the limit state equations of various failure models of reinforced soil retaining wall were set up and their logical relationships were analyzed, and the structural system reliability calculation model was established and a practical project was analyzed.8. The point safety factor method for reinforced soil structure stability analysis was proposed. The formulas for point safety factor of rock and soil, reinforcement unit and interface were derived out. The calculation method for anti-breack and anti-pullout factors of reinforcement were provided. The steps and FISH command flow for the method to implement in FLAC3D were analyzed and a practical project was analyzed.9. Field test was implemented for green gabion reinforced earth retaining wall. Its earth pressures in different directions in bottom of the base, vertical and horizontal earth pressures in wall, tensile strain of reinforcement and its lateral deformation were monitored during construction. 10. Some rationalization proposals for the application of eco-reinforced earth retaining wall were put forward according to the results of test studies, in-situ test and field investigation.更多还原