盐沼泽腐蚀区桥梁桩基竖向承载特性分析及其防腐技术研究

发布时间：2018-03-04 22:03

本文选题：桥梁桩基础　切入点：盐沼泽　出处：《长安大学》2015年硕士论文　论文类型：学位论文

【摘要】：盐沼泽是地表过湿或季节性积水、土壤盐渍化并长有盐生植物的地段。盐沼泽地表呈碱性、土壤中盐分含量较高,表层积累有可溶性盐。位于盐沼泽区内土体或水体中的盐类对桩身混凝土的化学、物理作用,使桥梁桩基础出现混凝土溶蚀、剥落等腐蚀损伤现象,腐蚀损伤的发生,影响桥梁的正常承载性能且极易诱发工程病害。公路桥涵设计通用规范(JTGD60-2004)规定公路桥涵结构的设计基准期是100年。然而受工程服役环境作用的影响,盐沼泽区内的公路桥梁结构物的服务年限很难达到设计要求。本文依托青海在建德香高速公路盐沼泽区的桥梁工程项目,针对盐沼泽区复合盐类对桥梁下部结构腐蚀问题开展研究。主要研究工作如下:(1)对工程沿线盐沼泽区域气候特点、地貌特征、地表水文条件和水文地质条件等环境进行调查与分析;总结提出了盐沼泽区内引起桥梁桩基础腐蚀的岩土体及水体类型。并对相似工程环境中已发生腐蚀病害的桥涵相关结构进行调查分析,为数值模拟的计算工况设计提供参考。(2)采用室内试验手段分析了盐类腐蚀发生与作用的机理;以依托工程现场土体与水体中所含单盐类型与离子浓度为参考,配制腐蚀溶液,开展腐蚀试验,对试验成果进行分析。(3)基于有限元仿真方法对腐蚀前、后桥梁桩基础进行建模,分析相关盐类腐蚀桩身混凝土,剥落厚度与桩身受腐深度的变化情况下,桥梁桩基础的竖向承载力特性及其变化规律。(4)从隔离、抗裂、密实及钢筋阻锈等技术层面提出了针对性强的腐蚀防治措施,并对每种防腐技术的防腐机理进行阐述,总结提出了防腐的关键技术手段。
[Abstract]:Salt swamp is an area where the soil is salinized and has halophytes. The salt swamp is alkaline, and the salt content in the soil is high. Soluble salt accumulates on the surface. The chemical and physical effects of the salt in the soil or water body of the salt swamp area on the concrete of the pile body make the concrete corrosion damage phenomena such as concrete dissolution and exfoliation of the bridge pile foundation and the occurrence of the corrosion damage. The general code for highway bridge and culvert design (JTGD60-2004) stipulates that the design reference period of highway bridge and culvert structure is 100 years. However, it is affected by the effect of engineering service environment. The service life of the highway bridge structure in the salt swamp area is very difficult to meet the design requirements. This paper relies on the bridge project of Qinghai Province in the salt swamp area of Jiande Xiang Expressway. The main research work is as follows: (1) the climatic and geomorphological characteristics of salt swamp region along the engineering line are studied. The surface hydrological conditions and hydrogeological conditions were investigated and analyzed. In this paper, the types of rock, soil and water body that cause corrosion of bridge pile foundation in salt swamp area are summarized, and the related structures of bridge and culvert that have been corroded in similar engineering environment are investigated and analyzed. The mechanism of the occurrence and action of salt corrosion is analyzed by laboratory test method, and the corrosion solution is prepared by relying on the single salt type and ion concentration in the soil and water body of engineering site. The corrosion test is carried out, and the test results are analyzed. (3) based on the finite element simulation method, the bridge pile foundation before and after corrosion is modeled, and the concrete of the correlating salt corroded pile body is analyzed under the condition of the variation of the spalling thickness and the corrosion depth of the pile. The vertical bearing capacity characteristics of bridge pile foundation and its variation rule. (4) from the technical aspects of isolation, crack resistance, compaction and steel bar corrosion prevention and control measures are put forward, and the anticorrosive mechanism of each kind of anticorrosion technology is expounded. The key technical means of anticorrosion are summarized and put forward.
【学位授予单位】：长安大学
【学位级别】：硕士
【学位授予年份】：2015
【分类号】：U443.15

【参考文献】