预应力碳纤维约束高路堤边坡与沉降新技术的研究

【作者】 李洁；

【导师】 唐英旺；

【作者基本信息】 湖南大学 ， 道路与铁道工程， 2002， 硕士

【摘要】 “预应力碳纤维约束高路堤沉降和边坡稳定新技术”课题是针对当前高速公路建设中高路堤不断增多，而高路堤又常常产生过大或不均匀沉降、边坡稳定性差等常见病害而提出的。本课题第一次将预应力碳纤维技术应用于路基工程中，利用碳纤维的高抗拉强度和高耐腐蚀性，对其施加预应力，使路基土体处于三向受压应力状态中，从而加强路堤填料的密实程度、减少路堤的总沉降、增加边坡的稳定性。 本论文首先介绍室内材料试验和锚固张拉试验。通过对十余种碳纤维制品的抗拉试验，选择出“性价比”较高的碳纤维布作为试验路段的筋材，并初步研制出与之配套的环氧树脂胶和锚固张拉系统。 接着论文介绍了试验路段的修筑和实地观测情况，并总结出预应力碳纤维路堤施工的合理工序。通过试验路段的试验以及竣工后一段时间的定期观测，表明侧向施加的预应力能减少路堤总沉降，缩短工后沉降稳定期，提高路堤的承载力。 论文还对预应力碳纤维路堤的工作机理进行了较全面的分析，从理论上证实侧向施加的预应力能提高路堤的承载力、抗剪强度和抗变形能力，并推导出计算总沉降的修正公式。 对预应力碳纤维路堤的稳定性分析是本论文的另一个重点。文中根据该结构的受力情况对瑞典条分法进行了改进，对路堤边坡进行了稳定性分析。墙面板后土压力的分布变化情况直接关系到拉筋的拉力计算，论文通过对几种计算方法进行分析比较，给出了较合适的推荐计算方法。更多还原

【Abstract】 In order to solve problems that frequently happen in today’s construction of expressway, such as excessive or asymmetrical settlement, poor side slope stability, a research project on the application of prestressed carbon fiber to control high fill settlement and improve side slope stability is carried out. This is the first time to apply prestressed carbon fiber to roadbed engineer in the world. The high tensile strength and corrosion-resisting property of prestressed carbon fiber make it possible that the soil is in triaxial state of stress. Therefore, the embankment fill can be compacted, the settlement can be reduced and side slope stability can be improved.In this thesis, experiment on material and anchorage-tension system are first introduced. Comparing the tension test results of a series of carbon fiber products, the one with the best price-performance ratio is picked out among them to be used in the field experiment. The corresponding epoxy resin binder both and anchorage-tension system are also developed.Then the rational construction procedure of CFRP restrain fill is proposed based on field tests of experimental road in the thesis. The data captured in field tests and observations both prove that crossrange prestressing can effectively reduce roadbed settlement, shorten the roadbed compression and stabilization period, and increase the capacity of roadbed.Working mechanism of prestressing CFRP restrain fill has been analyzed comprehensively in the paper, moreover which also been proved in theory that crossrange prestressing can raise the strength of load-bearing and shock, enhance the shear resistance.Another focal point of the thesis is the stabilization analysis of prestressing CFRP restrain fill. In order to analyze the stabilization of slope, Swedish slice method has been improved. Earth pressure distribution back of wall has a bearing on tensile force calculation of CFRP belt. Through analyzing and comparing several calculation methods, one kind is be recommended at last.更多还原