高拱坝坝踵应力实测与弹性计算结果差异原因分析  

Causing-analysis on the difference between monitoring and elastic calculating results of dam heel stress for high arch dams

作　　者：张国新[1] 周秋景[1] 

机构地区：[1]中国水利水电科学研究院结构材料研究所,北京100038

出　　处：《水利学报》2013年第6期640-647,共8页Journal of Hydraulic Engineering

基　　金：国家自然科学基金资助项目(50909105;51209235);水利部公益性行业科研专项(201201050);973科研项目(2013CB036406;2013CB035903);中国水利水电科学研究院专项(材集1353;材集1361;材集1309);"十二五"科技支撑项目(SQ2013BAJY4138)

摘　　要：坝踵应力是关系到混凝土坝是否开裂和安全的一个重要指标,不管是用结构力学法还是有限元法都能计算出坝踵有一定的拉应力,但实际监测中却很少出现。本文从定性和定量两个方面分析造成计算结果和实测结果差异的原因,以小湾特高拱坝为例分析影响计算精度的各项主要因素,在此基础上提出坝踵真实应力的仿真分析方法。结果显示,计算和实测应力差异原因主要在于以下3个方面:(1)坝踵位置的定义不同;(2)目前监测仪器和方法有局限性;(3)计算过程中的不当简化,如自重和水压的施加方式、坝体温度荷载的考虑、库水温度分布以及库盆水压的影响等。改进后的仿真分析结果与监测结果吻合良好,说明该方法能够给出合理的坝踵应力变化规律和比较精确的应力范围。最后,给出了坝踵应力监测仪器和方法的改进建议。Dam heel stress is a key indicator concerning concrete cracks and dam safety. Tension stress is generally got in a dam heel by structure mechanics or finite element methods, while seldom be monitored with instruments. The reason for the difference between simulation and monitoring results is analyzed qualita- tively and quantitatively. With Xiaowan arch dam, for example, the main factors affecting simulation accura- cy are studied and an improved simulation method is proposed to give more real and accurate dam heel stress. The results show that the reason mainly lie in the following： （1） different definition of dam heel be- tween simulation and monitor; （2） limitation of monitoring methods and instruments; （3） improper simplifi- cation in simulations, such as the way to preload self-weight and water pressure, to consider thermal loads in a dam and distribution of water temperature in reservoir, and impact of basin water pressure etc. The im- proved simulation results are in good agreement with the monitoring results of Xiaowan arch dam. Some sug- gestions for improving monitoring devices and methods are given.

关 键 词：高拱坝 坝踵应力 数值模拟方法 监测方法 

分 类 号：TV311[水利工程—水工结构工程]