【作者】 苏骏；

【导师】 蒋沧如； 余天庆；

【作者基本信息】 武汉理工大学 ， 结构工程， 2005， 博士

【摘要】 双面加筋挡土墙是一种新型支挡结构物,由同层高的两侧面板用一根或多根拉筋相互连接,并在两侧面板间分层填土而成,具有成本低、材料耗费少、少占耕地、构件轻,面板可由人工安装,填土可采用机械压实等特点,在人工填土边坡受限制地段和城市郊区铁路、高等级公路及城市道路方面具有明显的优势,具有广阔的应用前景。论文结合湖北省交通厅科技项目“双面直立互锚式高路堤公路新结构理论及计算机仿真研究”(批准号:鄂交科教[2003]570号)而开展研究。 通过模型试验测试分析,给出了墙背土压力及拉筋拉应变的分布规律及设计和有关计算所需的参数,得出了挡土墙土压力分布不同于经典土压力理论。在模型试验的基础上,一段总墙高为9.6米、长度为80米的双面加筋挡土墙首次应用于远(安)当(阳)国防公路扩建工程中,并对该挡土墙的变形和受力进行了现场原型观测,观测内容主要包括拉筋拉力、墙背面板的土压力、基底压力及墙体的水平位移等。观测结果表明,侧向土压力均随填土高度的增大而增大,并呈非线性分布,属于柔性结构的双面加筋挡土墙的变形受到墙后拉筋的限制,随着填土高度的增加,引起墙面位移的土压力与拉筋的抗拔阻力处于动态平衡中;由拉筋拉力换算的土压力和压力盒量测的土压力沿墙高的变化趋势一致,大多数实测土压力均介于静止和主动土压力之间;各层拉筋拉力随填土高度的增加而增大,不同高度处的拉筋拉力分布有所差异;分析表明,该挡土墙的受力和变形完全满足结构的强度、稳定和安全的要求。 由于对拉钢筋处于土石混合填料、水等较复杂的环境中,因此,解决对拉钢筋的防腐问题成为该结构能否推广应用的关键。通过对比试验和参考相关资料提出了以环氧树脂为主的防腐涂料,给出了涂料的最佳配方比,探讨了不同配方涂层的耐酸性、耐碱性以及耐盐性;通过MTS—810疲劳试验机测试不同配方涂层钢筋经加速腐蚀后的抗拉强度的变化;根据涂层的经济性、附着力、柔韧性、耐蚀性、应用性和力学性能等性能分析,提出一种适用于对拉钢筋的表面防腐的涂层配力,并制定出钢筋表面防腐处理工艺流程及注意事项。更多还原

【Abstract】 As a new retaining engineering structure, double reinforced retaining wall is built by filling earth between two concrete slabs, which are equal in height and connected by one/more pulling ropes. This structure is superior in low-costing, material-saving, less field-occupancy and lighter structure. Once slabs being installed, the filling and pressing of earth can be done by machine, which enlarges the wall’s application in sites where man-soil-filling is futile effort for their unfavorable location, such as suburban district railway, high-grade highways and city road. This dissertation is a further study of "New Structuring Theory of Double Vertical Co-arching Highway Embankment and Its Emulating Study " (a scientific project sponsored by Traffic Department of Hubei Province, ratification number [2003]570)Analyzing model experiment, it is obtained that the distributive laws of earth pressure on wall’s back and the pulling strain in mutually pulled reinforcement, the needed parameter of the design and the calculation concerned, it is found out that the distributive laws is different from the Rankin and Coulomb earth pressure laws. On the basis of model experiment, a segment of double reinforced earth retaining wall, with 9.6 meters in height and 80 meters in length, is built in the reconstruction engineering of Yuanan --Dangyang national defense highway. In order to research the deformation and stress of this structure, a testing study is made on full-scale, the testing contents mainly include tensile force of the reinforcements, lateral earth pressures on the facing, vertical earth pressures at the base and horizontal displacements of the facing. It’s disclosed that the lateral earth pressure is in non-linear distribution and changes with the thickness of earth filling, the deformation of such flexible double earth reinforced retaining wall is restrained by reinforcement. With the increasing of filling earth height, a dynamic equilibrium is formed between earth pressure causing wall’s deformation and pull-out frictionalforce of reinforcement. The earth pressure conversed by the tensile force of reinforcement has the identical change trend as that of earth pressure measured by earth pressure sensors. The majority of tested earth pressure is within the boundary of steady earth pressure and active one. The tensile force of each layer’s reinforcement increases continuously with the filling height and the distribution of reinforcement tensile force varies with its height. The researching result shows the wall’s strain endurance and deformation can fulfill the requirement of to be endurable, steady and safe.On the other hand, since mutual anchor reinforcement is used in complicated environment of earth-rock mixture and water, how to deal successfully with its anticorrosion becomes a key step to widen reinforcement’s application. By carrying out contrastive testing and consulting relative materials, it is offered that a new type of anticorrosion coating for reinforcement (which is mainly formed from epoxy resin) and the optimal proportion of anticorrosion coating. Moreover the acid resistance, alkali resistance and salt tolerance of different proportion coating are discussed. With the help of MTS-810 fatigue tester, it is measured that the jacking strength of different proportion coating reinforcements which are corroded rapidly. Taking the anticorrosion coating’s economical virtue, satisfactory bonding strength, flexibility, anticorrosion, application ability and mechanical properties into consideration, the author offers a better mix of the coaling which can be applied to mutual anchor reinforcement, then the technological process of coating reinforcements’ anticorrosion and mentions the matters needing attention are set forth.Adopting the general-purpose finite analysis program ANSYS, it was carried out that both two-dimension and three-dimension finite element analysis of double reinforced earth retaining wall built on soft soil, DP model is chosen to simulate the non-linearity of soil, the distribution law of the lateral earth pressures on the facing, the vertical stresses on the base, the displacements of the wall’s facing and theembankment settlements are analyzed and studied. The results of the finite element method (FEM) are in accordance with the in-site measurement, the results manifest the FEM is reasonable for analyzing the double reinforced earth retaining wall. It also shows that mutual anchor reinforcement can restrain embankment’s lateral deformation and foundation upheaval plays important role in reducing uneven settlement and raising the embankment integral stabilization. Due to mutual anchor reinforcement, each segment’s responding stress and displacement of double reinforced earth retaining wall can be obtained by FEM analysis. By optimization analysis of the parameter concerned, the analysis examines that the effect of changing foundation-soil character is more remarkable than that of changing filling soil character to the stress and deformation of earth retaining wall. The FEM analysis results can be applied to practical engineering as a reference for controlling strength and displacement.更多还原