潭衡西高速公路支挡结构现场试验与设计方法研究

【作者】 许桂林；

【导师】 杨果林；

【作者基本信息】 中南大学 ， 岩土工程， 2010， 硕士

【摘要】 湘潭至衡阳西线高速公路途经红砂岩地区,边坡防护工程大且必须重视生态防护。而目前,国内外公路在支挡结构与边坡生态防护结合形式单一。经各方面综合考虑,最终采用三种新型的支挡结构形式—加筋格宾组合式挡墙、柔性网面土工格栅加筋土挡墙和加筋格宾桥台。因此,研究红砂岩的工程地质特性、新型加筋材料特性、筋土界面摩擦特性以及加筋格宾挡墙设计,对今后新型土工合成材料、新型支挡结构的研究、设计、施工及应用等均具有重要意义。本文结合导师科研课题湖南省交通厅科技项目(200612)：“高速公路新型加筋土结构技术研究与示范工程”,以湖南湘潭至衡阳西线高速公路三种支挡结构实体工程为依托,在进行了一系列土工试验,现场试验和理论分析的基础上,全面系统地分析和研究了该项新型加筋土技术,为今后设计和施工同类型的加筋土挡墙提供依据和参考,主要工作和结论如下：1.归纳和总结了红砂岩的工程地质特性,并通过室内土工试验及现场大型水平推剪试验得到了红砂岩风化土的物理力学特性,通过室内粗粒土三轴试验研究了素红砂岩、加筋红砂岩在不同含水量、不同加筋材料、不同加筋层数条件下的强度及变形特性。结合现场所采用的施工工艺,对红砂岩填料进行了可行性分析。2.详细介绍了工程背景及相关材料特性。在室内模型试验的基础上,结合格宾和格栅材料的拉伸试验以及加筋土的拉拔摩擦试验,获得了两种格宾和格栅筋材的物理力学参数,得到了它们与红砂岩的界面摩擦参数,研究了加筋格宾材料的耐久性及影响因素。3.介绍了格宾结构及其组合结构、柔性网面土工格栅加筋土挡墙和加筋格宾桥台的组成和技术特点。根据试验段的工程地质情况,确定了现场监测方案,在湘潭至衡阳西线高速公路第十二合同段的三个典型断面进行了现场监测,研究了这三种新型支挡结构墙背土压力沿墙高的变化及分布规律、拉筋及格宾笼的变形规律、潜在破裂面形式和墙面板的水平位移变化规律,充分研究了这三种新型支挡结构的工作机理。4.归纳和总结了加筋格宾挡墙的组成部分和技术特点、设计方法,结合实际工程,并借助相关程序,研究了常规的定值设计法(安全系数法)和结构可靠度理论(Rosenblueth法)在加筋格宾挡墙稳定性分析中的应用,深入探讨了抗剪强度等相关参数对加筋格宾挡墙稳定性的影响。更多还原

【Abstract】 As Xiangtan to Hengyang express highway cross the red sandstone,slope protection engineering has huge amount of work and must pay attention to the ecological protection.So far,the combining form of supporting and retaining structure and ecological slope protection is single in common use at home and abroad.By comprehensive consideration,three new type support structures-compound reinforced gabion retaining wall, geogrid reinforced earth retaining wall(flexible mess), reinforced gabion abutment were adopted.Therefore,the study on the engineering geological characteristics of red sandstone,the material properties of new type geosynthetics,the interaction characteristics between reinforced materials and soils and the design and construction technology of reinforced gabion retaining wall, have important significance in study,design,construction and application of this new geosynthetics and new type support structure.Combining scientific research task supported by Hunan provincial communications department and science & technology department-the technology research on these new type reinforced earth structures and the demonstration project in Xiangtan to Hengyang express highway in Hunan province,a series of soil test,field tests and theoretical analysis were carried out.And this article comprehensively and systematically analysed this new reinforced earth technology,providing basises and references for design and construction the same type reinforced earth retaining wall.The main couclusions were as follows:1. The engineering characteristics of red sandstone was concluded and summarized.By the ways of field sampling and the horizonal push-shear in-situ tests, the major physics and mechanics indexes of red sand silty clay were obtained.Large-scale triaxial tests were carried out and the characteristic of strength and the deformation of reinforced and non-reinforced red sandstone soil with different reinforcement layers, different compaction and different water content, were studied. This paper analyzed the feasibility of red sandstone as a filling on the basis of construction technology.2. Engineering background and material properties were introduced in detail.Combined with the laboratory model tests, the tensile test of gabion and geogrid and the pull-out friction test of reinforced earth, the physical and mechanical characteristics of gabion and geogrid and the interaction characteristics between reinforced materials and soils, has been studied deeply.And This paper deeply researched the durability of the reinforced gabion material and its influencing factors.3. Components, technical features of the gabion structure and its composite structures, geogrid reinforced earth retaining wall (flexible mess), reinforced gabion abutment were presented. Based on the engineering geological conditions of the test section, systematic in-situ testing scheme was established.And the distribution and variation law of the lateral pressure on the facing, the vertical earth pressure with filling height and time, the tied-reinforcement and gebion deformation, the shape of rupture surface and the horizontal deformation of face panel of the wall, were studied through on-site monitoring three typical sections of Xiangtan to Hengyang express highway in Hunan province. The working mechanisms of three new supporting and retaining structures were sufficiently studied.4. Components, technical features, and design method of the reinforced gabion retaining wall were analyzed and summarized.Combining with practical project, the application of deterministic design method (Safety factor method) and structural reliability theory (Rosenblueth method) in the stability analysis of the reinforced gabion retaining wall were studied by means of relative program. Finally, the influences of parameters of shear strength on the stability of reinforced gabion retaining wall were deeply discussed.更多还原