危拱坝改型后的特性（英汉对照）

PERFORMANCE OF RETROFITTED DETERIORATED ARCH DAM
By Avinash C. Singhal, Fellow, ASCE, and Larry K. Nuss

ABSTRACT: The Stewart Mountain Dam is a 212 ft (64.6 m) high multi-curvature thin arch dam. The structure was completed in 1930. It has experienced alkali-silica reactions within the concrete and exhibited no bond across horizontal construction lift surfaces. The dam could be subjected to upgraded maximum credible earthquake (MCE) or probable maximum flood (PMF) loadings. Alkali-silica reactions and expansions have caused visible surface cracking. Several measures for prevention of further deterioration and strengthening were considered. Post-tensioned cables were selected to provide seismic strengthening. Cable design uses the stiffness, and acceleration response spectra methods. Vertical post-tensioned cables were installed during 1990-92 construction phase. This paper summarizes various field and laboratory investigations, structural analyses, and design parameters needed for post-tensioning a deteriorated arch dam. Post-tensioned cables are found to be a viable solution for the dynamic stability of a thin-arch dam. Methodology presented in this paper is applicable to other deteriorated dams.
摘要：Stewart坝高64.6m，是双曲薄拱坝，于1930年完工建成。由坝体混凝土中的硅碱反应实验表明在其水平结构的上表面无粘聚力。该拱坝能经受住强化的可能最大地震荷载或者可能最大洪水荷载。硅碱反应和张拉实验会引起可见的表面裂缝。考虑了多种防止坝体进一步破坏和混凝土裂缝强化的措施后，预应力锚索被选为提供地震加固的材料。锚索由加速刚度光谱特性曲线设计而成。垂直预应力锚索在1990-92年被写入建筑用语。本文总结了不同领域和实验的调查研究，结构分析和设计参数在恶化的拱坝中需要用预应力。预应力锚索在薄拱坝动态稳定的解决方面是个切实可行的措施。本文中的方法对于其它类型恶化的坝体同样适用。