城市公路隧道衬砌结构碳化寿命可靠度预测模型

Reliability Forecasting Model of Carbonization Durability of Tunnel Lining Structure of Urban Highway

影响城市隧道衬砌结构耐久性的因素复杂,保护层厚度、温湿度、CO2浓度以及混凝土强度等因素对衬砌结构服役寿命有着显著的影响。分析城市隧道衬砌结构耐久性服役寿命影响因素的概率分布特征,提出基于碳化经验公式的耐久寿命概率预测方法。根据可靠度理论,基于结构的可靠指标提出了结构的服役寿命预测方法,该方法弥补了现有模型在参数取值方面的不足,并且能够满足对结构整体寿命预测的要求。建立可靠指标与时间的关系,预测衬砌结构的失效时间,以此作为结构的耐久寿命,完善了混凝土结构的寿命预测方法。

Factors affecting durability of urban tunnel lining structure are complicated,and the factors,such as thickness of protective layer,the temperature,the humidity,CO2 concentration and concrete strength,etc.influence the service life of the lining structure obviously.The probability distribution characteristics of the factors affecting service life of urban tunnel lining structure was analyzed,and the forecasting method of the service life probability was proposed in the article based on the carbonization experiential formula.The service life forecasting method of the structure based on the reliable indexes of the structure was proposed according to the reliability theory,which made up for the shortage of the current model in parameters and could satisfy the requirements of forecasting whole service life of the structure.Moreover,the service life forecasting method of the concrete structure was perfected after setting up the relationship between reliable indexes and time,forecasting the failure time of the lining structure and taking it as the service life of the structure.