积石山地震对大河家水电站右岸砂砾石副坝震害影响分析  

Impact of Jishishan Earthquake on the Gravel Rockfill Dam on the Right Bank of Dahejia Hydropower Station

作　　者：蒲诚 刘关张 黄华 魏康康 孙海涛 PU Cheng;LIU Guanzhang;HUANG Hua;WEI Kangkang;SUN Haitao(PowerChina Northwest Engineering Corporation Limited,Xi'an 710065,China;Postdoctoral Research Station of PowerChina Northwest Engineering Corporation Limited,Xi'an 710065,China;Xi'an Key Laboratory of Clean Energy Digital Technology,Xi'an 710065,China)

机构地区：[1]中国电建集团西北勘测设计研究院有限公司,西安710065 [2]中国电建集团西北勘测设计研究院有限公司博士后科研工作站,西安710065 [3]西安市清洁能源数字化技术重点实验室,西安710065

出　　处：《西北水电》2024年第3期81-88,共8页Northwest Hydropower

基　　金：国家自然科学基金项目(42177158,11902249)。

摘　　要：通过现场调查及试验结果,结合监测资料对积石山地震后大河家水电站砂砾石堆石坝的震害特性进行分析,在对其震后安全性进行综合评判的基础上提出相应的处理措施。研究发现:地震后坝顶部位出现两条位于混凝土防渗心墙两侧沿坝轴线方向的裂缝,其中1号裂缝为连续主裂缝,是由于土体张裂导致的;2号裂缝为间断次生拉裂缝,是由于1号裂缝形成后,防渗墙顶部土体向上游变形导致的。防浪墙与上游坝坡、防浪墙与坝体基础面以及防渗墙与导向槽之间均接触紧密,无脱空现象。砂砾石堆石坝段震后坝顶沉降量在6.5~35 mm,靠近河床部位沉降量较大而岸坡部位沉降量较小;坝顶顺河向水平位移变化量在-2.51(向上游)~1.14 mm(向下游),河床部位向下游变形而岸坡部位向上游侧变形。综合分析后认为,虽然大河家水电站遭受了超标地震的袭击,但不影响坝坡的整体稳定,初步判断大坝处于安全可控状态;后续建议采用土工格栅分层敷设、储层碾压换填处理措施进行坝顶裂缝修复。Through field investigation and experiment results,combined with monitoring data,the seismic damage characteristics of the gravel rockfill dam of Dahejia Hydropower Station after the Jishishan earthquake are analyzed,and corresponding treatment measures are proposed based on a comprehensive evaluation of its post-earthquake safety.The study found that after the earthquake,two cracks appeared on the top of the dam,located on both sides of the concrete anti-seepage core wall along the dam axis.Crack No.1 is a continuous main crack caused by soil tension;Crack No.2 is an intermittent secondary tensile crack caused by the deformation of the soil on the top of the anti-seepage wall upstream after the formation of crack No.1.The parapet wall and the upstream dam slope,the parapet wall and the dam foundation surface,and the anti-seepage wall and the guide groove are in close contact without any void.The settlement of the gravel rockfill dam after the earthquake is 6.5~35 mm,with a larger settlement near the riverbed and a smaller settlement on the bank slope;the horizontal displacement change of the dam top along the river is-2.51 mm(upstream)to 1.14 mm(downstream),with the riverbed deforming downstream and the bank slope deforming upstream.After comprehensive analysis,it is believed that although the Dahejia Hydropower Station is hit by an earthquake exceeding the standard,it does not affect the overall stability of the dam slope.It is preliminarily judged that the dam is in a safe and controllable state;it is recommended to use geogrid layering and reservoir rolling replacement treatment measures to repair the dam top cracks.

关 键 词：积石山地震 大河家水电站 堆石坝 大坝震害 

分 类 号：TV698[水利工程—水利水电工程] TV641