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冰川冻土 ›› 2018, Vol. 40 ›› Issue (4): 756-763.doi: 10.7522/j.issn.1000-0240.2018.0405

• 寒区科学与技术 • 上一篇    下一篇

寒区大坝心墙土料冬季冻融与防控监测

穆彦虎1, 朱忻怡2, 岳攀3, 王新斌1, 任秀玲1,4, 张振宇1,4, 俞祁浩1   

  1. 1. 中国科学院 西北生态环境资源研究院 冻土工程国家重点实验室, 甘肃 兰州 730000;
    2. 兰州交通大学 土木工程学院, 甘肃 兰州 730070;
    3. 雅砻江流域水电开发有限公司 两河口建设管理局, 四川 成都 610051;
    4. 中国科学院大学, 北京 100049
  • 收稿日期:2018-01-15 修回日期:2018-03-23 出版日期:2018-08-25 发布日期:2018-10-08
  • 通讯作者: 俞祁浩,E-mail:yuqh@lzb.ac.cn. E-mail:yuqh@lzb.ac.cn
  • 作者简介:穆彦虎(1985-),男,新疆昌吉人,副研究员,2012年中国科学院寒区旱区环境与工程研究所获博士学位,从事冻土力学与寒区工程研究.E-mail:muyanhu@lzb.ac.cn
  • 基金资助:
    雅砻江流域水电开发有限公司科研试验项目(LHKA-G20160*);国家自然科学基金项目(41690144)资助

Monitoring investigation on winter freezing-thawing of dam core wall soils in cold regions

MU Yanhu1, ZHU Xinyi2, YUE Pan3, WANG Xinbin1, REN Xiuling1,4, ZHANG Zhenyu1,4, YU Qihao1   

  1. 1. State Key Laboratory of Frozen Soil Engineering, Northwest Institute of Eco-Environment and Resources, Chinese Academy of Sciences, Lanzhou 730000, China;
    2. School of Civil Engineering, Lanzhou Jiaotong University, Lanzhou 730070, China;
    3. Lianghekou Construction Administration, Yalong River Hydropower Development Company, Ltd., Chengdu 610051, China;
    4. University of Chinese Academy of Sciences, Beijing 100049, China
  • Received:2018-01-15 Revised:2018-03-23 Online:2018-08-25 Published:2018-10-08

摘要: 两河口水电站是雅砻江干流规划开发中的中游控制性龙头电站,大坝为300米级砾石土心墙堆石坝。由于地处川西高原气候区,冬季气候寒冷干燥,大坝心墙土料填筑过程中面临着冻融问题的困扰。基于一个完整冬季的现场监测,系统分析了这一寒区大坝心墙建筑过程中砾石土、接触黏土土料温度变化规律、冻融特征与影响因素以及现有保温措施防冻效果。结果表明,无保温措施条件下,砾石土、接触黏土均出现了负温冻结现象,其中砾石土最大冻结深度达20 cm,接触黏土达14 cm,土料冻结持续时间不超过1个昼夜,为短时冻土。土料降温冻结过程以与外界大气对流换热过程为主,受气温、风速条件影响显著,波动范围较大,而升温融化过程以太阳辐射增温过程为主,与有效辐射起始时间密切相关,因此波动范围较小。监测期内,采用三布两膜保温材料覆盖可有效防止心墙土料冻结的发生,有、无保温材料覆盖条件下浅层土料最低温度可相差约5℃。结合监测结果和现场实际,建议将现有心墙防渗土料半幅填筑方式转换为全幅填筑,并研发轻质、憎水保温材料及其快速收放机械设备,以提高填筑作业进度、强化防冻效果。系统完整的现场实测结果,可为未来寒区水电大坝建设提供基础数据和参考。

关键词: 冻融特征, 保温材料, 防渗土料, 心墙, 寒区大坝

Abstract: Lianghekou Hydropower Station is a control leading station in the middle reaches of the Yalong River. The dam of the station is a 300-m-high rock-fill dam constructed with gravel soil core wall. Because of the dry and cold climate in winter, filling of anti-seepage soil material is always affected by freezing-thawing. In this paper, based on monitored temperature of one winter in 2016/2017, the freezing-thawing characteristics and influence factors of gravel soil and clay soil and the effect of thermal insulation method were analyzed. The results showed that shallow gravel soil and clay soil without thermal insulation all experienced freezing during the monitored winter, but the freezing duration was less than 24 hours. The maximum freezing depth of gravel soil and clay soil could reach 20 and 14 cm, respectively. The freezing process of the soil was controlled by heat convection with ambient air, thus was heavily influenced by wind speed. The thawing process was controlled by heat radiation, thus the beginning of the thawing was closely related to the time of sun rise. During the monitoring period, coverage of thermal insulation material would effectively prevent freezing of the soil; the difference of the minimum temperature of soil was as much as 5℃ between the soils with and without thermal insulations. From the monitoring results and field conditions, one can see that light and hydrophobic thermal insulation materials are needed, as well as quick package machine for thermal insulation materials. Also, it is considered that whole surface filling of the dam core will be better than half surface filling. The monitored data in this paper will be useful for dam construction in cold regions in the future.

Key words: freezing-thawing characteristics, thermal insulation, anti-seepage soils, core wall, cold region dam

中图分类号: 

  • TV641.4+1