沿海混凝土结构耐久性设计中环境作用的分类分级

Classification of environment action on coastal concrete structure in durability design

为探讨环境作用在沿海混凝土结构耐久性设计中的影响程度,对沿海混凝土结构受到的海洋大气、沿海地质以及海水环境的作用进行分析.分析有关研究成果和工程测试表明,沿海大气环境作用应该考虑Cl-的沉降率、相对湿度、相对湿度大于80%的天数等影响.沿海地质环境除一般腐蚀因素外,还要考虑基础开挖引起海水向地基渗透对耐久性的影响.而海水环境根据海水飞溅区、海水潮差区、海水全浸区和海泥区的不同区域,要考虑海水中溶解氧、海水pH等的影响.结合2个沿海混凝土结构工程耐久性设计中的环境作用确定问题,讨论了沿海大气环境和地质环境作用的分类分级和确定方法,建议采用地理位置描述与环境因素、建筑因素相结合的方法.

To determine the environment action on the durability of coastal concrete structure, the effect of coastal atmospheric, geology and seawater environment on the coastal concrete structure was examined. Through analyzing the related research and in-site engineering inspection, it is shown that the coastal atmospheric environment should include the effect of Cl- settlement rate, relative humidity and the number of days with more than 80% relative humidity; the coastal geology environment should include the sea water infiltrating in the foundation construction besides the general corrosive factors; the seawater environment should include the dissolved oxygen, pH level and other factors in different position of the sea such as the splashing area, tidal range area, immersion area and the sea mud area. Associating the determination of environment action for two coastal concrete structure projects, the classification of atmospheric and geological coastal environment and the standards of the classification are discussed. It is suggested that the classification of the environment action should combine the description of geographic location with the environmental factors and building situation.