| 耿峻,张国新,张海龙,程恒,江晨芳.三峡实测坝前库水温与坝体温度场分析[J].水利学报,2025,56(8):991-1001 |
| 三峡实测坝前库水温与坝体温度场分析 |
| Analysis of measured reservoir water temperature and dam temperature field in the Three Gorges Dam |
| 投稿时间：2024-08-12 修订日期：2025-07-23 |
| DOI：10.13243/j.cnki.slxb.20240521 |
| 中文关键词: 三峡重力坝 安全监测 库水温 温度场 温差 |
| 英文关键词: the Three Gorges Gravity Dam safety monitoring reservoir temperature temperature field temperature difference |
| 基金项目:国家重点研发计划项目 （2016YFB0201000）；中国长江三峡集团有限公司项目（SXSN/4983） |
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| 中文摘要: |
| 温度是混凝土坝的重要监测项目，因为它直接关系到大坝的工作性态和安全。本研究基于三峡大坝典型坝段上游坝面及内部的实测温度数据，分析了三峡水库水温和大坝温度随时间和空间的演变规律，揭示了三峡水库这一多沙深库独特的坝前水温和坝体温度分布特征。研究发现：（1）三峡泄洪坝段和厂房坝段坝前年平均水温沿深度方向基本保持等温状态，库底温度稳定在18.4℃，而从淤沙高程到库表，平均水温在19.1~19.4℃之间小幅变化。（2）淤沙内温度接近恒温，淤沙高程以上水温则随季节变化，夏季温度高，冬季温度低，各月水温沿水深方向的分布接近一致，未见库水分层现象。（3）这种坝前库水温分布特征与三峡的库容径流比、各月来水的含沙量、泄洪引水建筑物的布置及调度方式有关。（4）坝体温度场方面，重点研究了最高和最低温度、稳定与准稳定温度场、基础温差和最大温差等关键温度指标的空间分布。由于上游平均库水温接近多年平均气温加辐射热，且与下游坝面温度相近，坝体稳定温度场接近等温状态，温度范围在18.5~21℃，其中坝体上游中下部的温度高于设计预测的15℃。（5）坝体内部最高温度出现在浇筑后的高温峰值时刻，最低温度为接缝灌浆温度。（6）坝体上游淤沙高程以上、下游及泄洪孔洞影响区的温度随季节周期性变化，实测的最高温度、最低温度、基础温差和最大温差等指标均显示出良好的规律性。由于实测淤沙温度和库水温与设计阶段的预测值差距较大，坝体实测稳定温度高于原设计预测值，稳定温度分布接近均匀等温场，使得坝体实际基础温差、上下游温差小于设计预测值，减小了由于温差导致的坝体拉应力，对混凝土防裂有利。 |
| 英文摘要: |
| Temperature is an important monitoring item for concrete dams，as it is directly related to the operational behavior and safety of the dams. Based on the measured temperature data from the upstream surface and interior of typical sections of the Three Gorges Dam，this study analyzes the temporal and spatial evolution laws of the water tem perature in the Three Gorges Reservoir and the dam temperature. It reveals the unique distribution characteristics of the water temperature in front of the dam and the temperature of the dam body in this multi - sand and deep reservoir. The research findings are as follows：（1）The annual average water temperature in front of the flood - discharge and powerhouse sections of the Three Gorges Dam remains basically isothermal along the depth direction. The bottom temperature of the reservoir is stable at 18.4°C，and the average water temperature slightly varies between 19.1°C and 19.4 ℃ from the sediment elevation to the reservoir surface.（2）The temperature in the sediment is close to a constant temperature. The water temperature above the sediment elevation changes with seasons，being high in summer and low in winter. The monthly water temperature distributions along the water depth are nearly the same，and no obvious water stratification phenomenon is observed.（3）Analysis shows that the distribution characteristics of the water temperature in front of the dam are related to the ratio of reservoir capacity to runoff in the Three Gorges，the sediment concentration of the monthly incoming water，and the layout and operation mode of the flood - discharge and water-diversion structures.（4）Regarding the temperature field of the dam body，the spatial distributions of key tem perature indicators such as the maximum and minimum temperatures，steady and quasi-steady temperature fields， foundation temperature difference，and maximum temperature difference are mainly studied. Since the average water temperature of the upstream reservoir is close to the average annual air temperature plus radiant heat and is similar to the temperature of the downstream dam surface，the steady temperature field of the dam body is close to an isothermal state，with a temperature range of 18.5°C to 21°C. The temperature in the middle and lower parts of the upstream side of the dam body is higher than the 15°C predicted in the design.（5）The highest temperature inside the dam body occurs at the peak moment after pouring，and the lowest temperature is the joint grouting temperature.（6）The temperatures above the upstream sediment elevation，downstream，and in the areas affected by the flood-discharge holes of the dam body change periodically with seasons. The measured indicators such as the highest temperature，lowest temperature，foundation temperature difference，and maximum temperature difference all show good regularity. Due to the significant differences between the measured sediment temperature and reservoir water temperature and the predicted values at the design stage，the measured steady temperature of the dam body is higher than the original design prediction. The steady temperature distribution is close to a uniform isothermal field，which makes the actual foundation temperature difference and the upstream-downstream temperature difference of the dam body smaller than the design predictions. This reduces the tensile stress of the dam body caused by the temperature difference，which is beneficial for preventing cracks in concrete. |
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