混凝土新老结合面状态对大坝安全影响分析

混凝土新老坝面结合问题是南水北调丹江口大坝加高工程的主要技术难题之一。目前国内尚无混凝土坝加高的成熟经验和工程实例。新老结合面由于受到外界环境温度年际变化影响、运行期水力劈裂等多因素作用产生开裂，为大坝安全运行带来风险。通过有限元直接反力法计算内力．按重力坝规范方法计算分析1#坝段新老混凝土结合面完好、结合面开裂及结合面开裂进水3种情况下的安全度，并给出了处理建议。

Analysis of the New and Old Concrete Interfaces Influence to the Dam Safety

The new and old concrete dam interfaces problem is one of the main technical problems of Danjiangkou dam heightening project of South-to-North Water Transfer project. There is no mature experience and engineering examples on concrete dam heightening currently. The new and old dam interfaces cracking due to ambient temperature changes affect the age, operation period of hydraulic fracturing and other factors, the dam safe operation existed the risks. Calculated the internal forces by the finite element direct force method, according to the gravity specification method, calculated and analyed the safety degree of new and old concrete dam interfaces of dam No.l, under three kinds of situations：the surface in good condition, the surface cracking and the surface by water flooding, and gives suggestions for handling.