【作者】 景健；

【导师】 何昌荣； 张在杰；

【作者基本信息】 四川大学 ， 水利工程， 2002， 硕士

【摘要】 土是散粒矿物、水、空气的聚合物，具有很低或甚至没有抗拉强度。加筋土是一种在土体中加入抗拉材料而形成的复合土，它可以提高土体的强度和稳定性。加筋土技术应用于工程结构中就形成加筋土结构，加筋土支挡结构是加筋土结构中应用最广泛的一种型式。它具有良好的技术和经济性能。但是其理论研究和计算分析，在我国还是处于初级阶段。论文正是在前人研究的基础上，通过大量的试验和有关理论分析，探讨了加筋土工程性质及加筋支挡结构计算分析方法。主要工作和结论如下： 1．全面回顾阐述了加筋土及加筋支挡结构的发展及研究现状； 2．结合杨柳河整治工程实践，进行了大量的试验研究，通过对不同填料、填料在不同压实度及加筋带有无孔等情况下加筋土工程力学性质的对比，找出了如下： (1)筋带—填料之间的摩阻力与筋带—填料之间的相对位移有直接关系。在发生拉出破坏之前摩阻力随位移的增大而增加，但增长率却不断减小，减小到一定程度后就发生拉出破坏。筋带拉拔破坏后，筋土之间仍然存在一定的摩阻力。砂土加筋后具有较大的准粘聚力c值，这证实了关于加筋土原理中的“摩擦加筋理论”和“准粘聚力理论”。 (2)当垂直压力在一定范围内时，垂直压力越大，摩阻力越大；但当垂直压力超出一定范围后，其对摩阻力的影响逐渐减弱，f～σ曲线趋于平缓，且似摩擦系数随垂直压力的增大呈非线性减小。 (3)筋带相同时，填料不同其加筋土的摩擦性质也有所不同。砂土作为填料时，效果较好。砂卵石加筋后，其效果不是很明显，这与试验中四川大学工程硕士学位论文 中文摘要卵石的颗粒大小有关，实际应用中应注意控制好颗粒的组成，卵石颗粒之间应有不同的粒径，才能明显地增大筋土之间的接触面积，增大筋带与卵石之间、卵石颗粒之间的摩擦、咬合与剪胀作用。 （4）在筋带与填料相同的情况下，填料本身的物理状态明显影响筋土之问的摩阻力的发挥。填料密实度越大，摩阻力越大，准粘聚力和似摩擦系数也越高。 （5）试验结果用于实际工程。 3．在“应变相容”理论的基础上，得出了筋带参数与土体抗剪强度参数之间的关系，指出当筋带的极限拉伸应变与砂土的峰值剪切应变相等时，土体的抗剪强度就会充分发挥。 4．在极限分析理论的基础上，建立了加筋支挡结构的理论分析模型，研究了加筋支挡结构的强度特性及其主要影响参数。 5．在楔体破坏的基础上，探讨了加筋土支挡结构的侧向土压力分布规律，建立了一种加筋土支挡结构侧向变形分析的理论模型。并将理论分析结果与重庆米帮沦加筋土挡墙工程项目实测结果进行了比较，表明该模型具有实际的使用价值和较高的预测精度。 6．通过对国内外加筋土支挡结构失事实例的介绍、分析，探讨了目前加筋土支挡结构设计、施工及监测中存在的若干问题。 7．结合工程实践，深入而系统地研究了加筋土工程力学性质和似摩擦系数的变化规律，研究成果用于杨柳河整治工程设计和施工中，通过不 同方案对比，达到了预期的目的，取得了较好的经济效益。更多还原

【Abstract】 Reinforced earth is a new type earth,which is good in term of technology and economy. But the studies and applications of this new structure of reinforced earth are still in their preliminary stage in China. Based on the studies of predecessors,the strength,deformation characters of reinforced earth are discussed by great many of tests and theoretical analysis. The main work and conclusions are as fellow:1. Look back generally to elaborate, Reinforced soil to pay gear research present situation and the development of Reinforced earth retaining structure.2. Combining the YangLiu river realignment project,a great experimental research on reinforce earth has been completed. Some internal laws about the mechanical property of reinforced earth are obtained and described as follows:(1) The friction between reinforcement and filling has a direct relation to relative displacement between the two ones. The sand is provided with the pseudo- cohesion c by reinforcement,which verified "the frictional reinforcement theory " and " the pseudo -cohesion theory" ;(2) The vertical pressure can influent the friction only within certain limits;(3) The frictional performances of different filling withthe same reinforcement are different;(4) when the reinforcement and filling are similar,the development of the friction between reinforcement and filling is influenced by physical state of filling;(5) The achievement of experiment are applied to project.3. Present the concept of " strain compatible "was used in the thesis. Form the equation of FS and the concept of "strain compatible" itself,the important implications of this concept and its applications in design ware clarified in detail.4. The upper-bound method limit analysis approach is used to establish reinforced earth retaining waifs failure mechanism,which is characterized by yielding of strips. The theoretical model on reinforced earth retaining wall was given.5. A lateral displacement analysis model about reinforced earth retaining wall that treats the wall’s face panel as an elastic foundation beam has been presented. The relations between the lateral displacement and related parameters are studied.6. Several key points about design,construction and monitor of the reinforced earth retaining walls ware discussed also.7. Combining the YangLiu river realignment project, some internal laws about the mechanical property of reinforced earth were studied thoroughly. Applied the achievement to project design and construction,and achieved the expectant purpose.更多还原