高拱坝坝踵应力实测与计算的比较研究  

Determination of high arch dam heel stress:A comparison between monitoring and calculating methods

作　　者：周建平[1] 杜小凯[2] 张礼兵 周秋景[4] 

机构地区：[1]中国电力建设集团有限公司,北京100048 [2]水电水利规划设计总院,北京100120 [3]中国电建昆明勘测设计研究院有限公司,昆明650041 [4]中国水利水电科学研究院,北京100038

出　　处：《水力发电学报》2017年第12期87-94,共8页Journal of Hydroelectric Engineering

摘　　要：高拱坝坝踵应力状态是评价大坝安全可靠性的重要指标。由于拱坝超静定结构特性,施工期坝体升高、运行期水位变化及内外部温度变化等影响因素,致使坝踵应力分布及其变化过程极其复杂。安全监测和数值计算是获取坝踵应力的两种主要方法,然而两方法获取的数值往往并不一致,甚至还存在矛盾。本文论述了实测方法和计算方法对坝踵应力评价的影响;针对安全监测,分析了压应力计、应变计组工作原理,提出了坝踵有效应力评估、增设渗压计、压应力计和应变计组对应布置的建议;针对数值分析,研究了精细网格下坝踵等效应力与沿坝厚网格精度的关系,提出了计算拱坝坝踵应力的网格剖分的建议;两方法可有其自身影响因素,改进后的实测方法结合高精度数值计算可为评估高拱坝坝踵应力提供可靠依据。The stress state at high arch dam heel is an important index for evaluating dam safety, but its variation and influencing factors are complicated due to its statically indeterminate structure, concrete placement during dam construction, changes in water level during reservoir operation, and changes in the internal and external temperature of the dam. To determine the dam heel stress, in-situ monitoring and numerical analysis are two main methods, but they often produce significantly different results. This paper discusses the difference between these two methods in dam heel stress evaluation. For in-situ monitoring, through the analysis of the working principle of the compressive stress meter and strain gauge, we suggest the evaluation of effective stress at dam heel, and an improvement on the arrangement of osmometers, compressive stress meters and strain gauges. For numerical analysis, we examine the relationship of dam heel equivalent stress versus mesh size along dam thickness, and give suggestions for effective mesh partition in calculation of dam heel stress. Results show that although both methods have their own influencing factors, the improved monitoring method combined with the numerical calculation of high accuracy can give a satisfactory evaluation of dam heel stress.

关 键 词：高拱坝 坝踵应力 安全监测 数值分析 等效应力 

分 类 号：TV31[水利工程—水工结构工程]