摘要
【目的】坝踵应力是评价重力坝安全的关键性控制指标。重力坝设计时自重按一次施加,并未考虑施工期大坝实际浇筑过程及温度荷载,因此,【方法】以三峡重力坝工程泄2坝段为例,基于大坝设计资料和温度监测数据,对大坝混凝土的关键热学参数进行反演。在此基础上,模拟大坝施工过程、材料性能变化过程、气温变化过程、纵缝接缝灌浆过程、通水冷却过程以及表面保温措施,进行大坝施工期全过程工作性态仿真分析,研究施工期分层浇筑与温度荷载对大坝应力尤其坝踵应力的影响。【结果】结果显示:仿真计算得到的监测点的温度变化规律与实测值吻合较好;分层浇筑模拟时自重产生的坝踵竖向压应力为7.32 MPa,自重一次施加产生的坝踵竖向压应力为7.70 MPa;施工期温度荷载引起坝踵观测部位的竖向压应力增量最大值为1.1 MPa。【结论】结果表明:自重荷载的施加方式对重力坝坝踵应力影响较小,分层浇筑自重荷载引起的坝踵竖向压应力略小于自重荷载一次施加的情况;纵缝接缝灌浆后坝体温度回升导致中块挤压上块,进而引起坝踵部位产生较大竖向压应力,这可部分解释目前重力坝实测坝踵应力多为较大压应力的原因。
[Objective]Dam heel stress is a key control index to evaluate the safety of gravity dams.In the design of gravity dam,the gravity load is applied once,without considering the actual pouring process and temperature load during construction.Therefore,[Methods]based on the dam design data and temperature monitoring data,the key thermal parameters of dam concrete in No.2 spillway section of Three Gorges Gravity Dam Project are inverted.On this basis,simulating the dam construction process,material properties change process,temperature change process,longitudinal joint grouting process,water cooling process and surface insulation measures,the working behavior simulation analysis is carried out during the construction period of the dam,and the influence of layered pouring and temperature load on the dam stress is studied,especially the dam heel stress.[Results]The result show that the temperature variation of the monitoring points obtained by simulation is in good agreement with the measured values.In the simulation of layered pouring,the vertical compressive stress of dam heel caused by self-weight is 7.32 MPa,and the vertical compressive stress of dam heel caused by one-time application of self-weight is 7.70 MPa.The temperature load during the construction period causes the vertical compressive stress increment at the observation dam heel,and the maximum value is 1.1 MPa.[Conclusion]The result show that the application method of self-weight load has little effect on the dam heel stress of gravity dam,and the vertical compressive stress of dam heel caused by layered pouring self-weight load is slightly smaller than that caused by one-time application of self-weight load.The temperature rise of the dam after the grouting of the longitudinal joint causes the middle block to squeeze the upper block,which leads to a large vertical compressive stress in the dam heel,which can partly explain the reason why the measured heel stress of gravity dam is mostly large compressive stress.
作者
耿峻
程恒
张国新
童广勤
周秋景
丁宇
GENG Jun;CHENG Heng;ZHANG Guoxin;TONG Guangqin;ZHOU Qiujing;DING Yu(River Basin Complex Administration Center of China Three Gorges Corporation,Yichang443134,Hubei,China;China Institute of Water Resources and Hydropower Research,Beijing100038,China;State Key Laboratory of Simulation and Regulation of Water Cycle in River Basin,Beijing100038,China)
出处
《水利水电技术（中英文）》
北大核心
2024年第5期84-92,共9页
Water Resources and Hydropower Engineering
基金
国家重点研发计划(2021YFC3090102)
中国长江三峡集团有限公司资助(SXSN/4983)。
关键词
重力坝
施工期
自重
温度
坝踵应力
数值模拟
gravity dam
construction period
dead-weight
temperature
dam heel stress
numerical simulation
