细观损伤理论在地下工程结构耐久性研究中的应用

Research on Underground Structure's Durability with Meso Damage Theory

隧道与地下工程的开挖扰动造成应力的不平衡和重新分配。岩石(土)与衬砌结构两者皆可视为弹塑性体,并且构成相互作用的共同体以抵抗外荷载。岩石与衬砌结构在受到外荷载、地下水渗流、侵蚀性离子的作用时将发生损伤劣化,并进而影响其耐久性与可靠性。详细分析和总结损伤理论应用于混凝土及地下工程结构耐久性研究的现状,探讨和分析Gurson细观损伤模型应用于地下工程混凝土结构的方法、模式及步骤,并结合某工程案例分析和描述典型地下结构(构件)在受力情形下及腐蚀侵入后引起钢筋锈蚀的损伤应力数值计算方法,分析结构的耐久性状况及预测其寿命。

Excavation of tunnelsor underground projects will cause imbalance and redistribution of the stress in them. The rock （soil） and the lining structure both can be regarded as elastic--plastic body, and come into being the in- teraction community to resist external loads. Damage and deterioration will occur in rock and lining structure when sub- jected to the effect of external loads, groundwater seepage and erosive ions, which further affect their durability and reli- ability. In this paper, the current situation of damage theory being used in the durability research of concrete structures and underground projects was analyzed and summarized in detail. Then, Gurson meso-- damage-- model was discussed and analyzed about its application in underground engineering structures in terms of the method, model and steps. Com- bined with an engineering case, numerical calculation method of damage stress was analyzed and described about the typical underground structure （component） subjected by corrosion of steel bars under the effect of loads and ion ero- sion, so that the durability status and life of structure can be analyzed and predicted.