岩土预应力锚固结构服役寿命研究

岩土预应力锚固技术在交通、水利和建筑工程中得到了广泛应用，但工程实践表明，预应力索（杆）体由于使用环境和条件的特殊性，如长期埋置于潮湿的环境中和承受张拉作用力，存在着失效破坏现象。在相关研究的基础上，通过对比分析影响预应力锚固结构服役寿命的主要因素，确定杆体材料应力腐蚀是决定正常使用条件下预应力锚固结构服役寿命的根本因素。在利用流变力学理论和实际监测数据建立预应力长期变化模型、依据室内快速腐蚀试验和现场腐蚀监测数据建立杆体材料应力腐蚀发展模型基础上，以杆体材料变化的极限承载能力为判据，提出岩土预应力锚固结构服役寿命预测方法，可为岩土预应力锚固结构失效风险预防和处置提供指导作用。将研究成果应用于工程实践，预测了实际工程的服役寿命。

Study of service life of geotechnical prestressed anchorage structure

The geotechnical prestressed anchorage techniques have been widely used in the traffic, hydraulic and construction engineerings. But the engineering practice has shown that the prestressed anchorage cable/bolt could happen to fail because of the special service environment and condition, such as the long-term moist environment and the effect of high-tension stress. Based on the present related experiment results, and through the comparison and analysis of the principal factors that can influence its service life, it is shown that the stress corrosion of rod body materials is the basic factor that determines its service life under normal use conditions of geotechnical prestressed anchorage structures. Utilizing the model test which can forecast the long term prestressing force variation by combining the rheological mechanics with the actual monitoring data and the quantificational formula of the development rule of the stress corrosion established from the indoor accelerated corrosion test and the related field-testing data, the method of forecasting service life for the geotechnical prestressed anchorage structures is presented, which utilizes the ultimate bearing capacity of rod body material as a criterion. This method can guide the risk prevention and treatment of the prestressed anchorage system. Finally, the research result is applied to an actual engineering; and the service life of the project is put forward.