基于工程类比的小湾拱坝安全评价

 将工程类比法推广到拱坝极限承载力的研究，对于小湾拱坝等超高拱坝，由于其条件复杂，工程规模巨大，简单按照规范设计是不够的，应该以已建工程为对比对象，通过类比研究确定合理的安全标准。基于相同网格尺寸、相同材料模型以及相同计算软件，以已建工程二滩和Kolnbrein加固前后作为类比研究对象，对小湾拱坝的坝踵开裂及极限承载力进行研究。以超大规模精细有限元模型精确模拟坝体的底缝和地基的地形、断层、蚀变带加固措施以及建基面卸荷带，以全面评估地质条件对极限承载力的影响。分析结果表明：小湾拱坝极限承载能力要明显强于Kolnbrein加固前后，略逊于二滩。但正常工作条件下帷幕的安全裕度不大。

ANALOGICAL PROJECT COMPARATIVE STUDY OF SAFETY EVALUATION FOR XIAOWAN ARCH DAM

An analogical project comparative study method for super-high arch dams is presented since simple standard design is not enough due to the complexity and large scale of super-high arch dams. The safety evaluation for super-high arch dams under design could be performed by comparative study with constructed dams. Choosing Ertan and Kolnbrein Arch Dams as analogical projects，the cracking at dam heel and the ultimate bearing capacity of Xiaowan Arch Dam are studied based on similar mesh size，same material model and same finite element software. The refined Xiaowan finite element model including the simulation of the bottom joint of dam body，terrain，faults，alteration zone，reinforcement measures and unloading zone of the foundation is adopted to evaluate the effects of these factors on the ultimate bearing capacity of the dam. The conclusions are drawn as follows：the ultimate bearing capacity of Xiaowan Arch Dam is higher than that of Kolnbrein Dam and slightly lower than that of Ertan Dam. The safety for grouting curtain in Xiaowan has a narrow safety margin under normal operation.