砂土地震液化评价方法的新老规范对比研究  

Comparative Study on the New and Old Codes for the Evaluation Method of Sandy Soil Seismic Liquefaction

作　　者：李小雷 李江 杨玉生[2,3] 刘斌云 宁保辉[4] 彭兆轩 LI Xiaolei;LI Jiang;YANG Yusheng;LIU Binyun;NING Baohui;PENG Zhaoxuan(Department of Urban Construction,Beijing University of Technology,Beijing 100124,China;China Water Resources and Hydropower Research Institute,Beijing 100048,China;Xinjiang Water Resources and Hydropower Planning and Design Administration,Urumqi 830000,China;Henan Water Resources Survey,Design and Research Co.,Ltd.,Zhengzhou 450047,China)

机构地区：[1]北京工业大学城市建设学部,北京100124 [2]中国水利水电科学研究院,北京100048 [3]新疆水利水电规划设计管理局,新疆乌鲁木齐830000 [4]河南省水利勘测设计研究有限公司,河南郑州450047

出　　处：《人民黄河》2023年第9期157-164,共8页Yellow River

基　　金：国家自然科学基金资助项目(51679264)。

摘　　要：坝基饱和砂土地震液化对水利工程产生严重危害,准确评价坝基砂土地震液化是工程设计的关键。结合某砂土坝基工程,基于现场标贯试验,采用现行规范和老规范对坝基自由场地、地下水位上升导致工程卸载、上部坝体影响导致工程加载等3种工况下的砂层开展地震液化评价,对比分析了3种工况下土体实测标贯击数校正值和液化临界标贯击数,评估了现行规范和老规范对砂土地震液化评价结果的差异。标贯试验时,坝基砂层不会发生液化;工程运行时,在工程加、卸载条件下坝基砂层均会发生液化。在工程加、卸载时,采用现行规范的地震液化判别结果与采用老规范的近震工况的液化判别结果基本一致。现行规范能更真实反映工程加载、卸载条件的影响。Seismic liquefaction of saturated sandy soil in dam foundation will cause serious harm to hydraulic engineering works and affect the safety of projects.Therefore,accurate evaluation of seismic liquefaction of sandy soil in dam foundation overburden is the key to engineering design.Combined with a sandy overburden dam foundation project,based on the site penetration test,this study adopted the current and old norms to carry out seismic liquefaction evaluation of the sand layer under three working conditions,namely,free site during the penetration test,engineering unloading due to rising groundwater level and engineering loading due to the influence of the upper dam body.The calibration value of the measured soil standard penetration number and the liquefaction critical boundary standard penetration number under three working conditions of engineering loading and unloading were compared and analyzed,and the difference of the evaluation results of seismic liquefaction of sand layer using the current and old codes was evaluated.The results show that liquefaction of dam foundation sand will not occur during the standard penetration test.Liquefaction occurs in dam foundation sand layer under loading and unloading conditions during project operation.During engineering loading and unloading,the discriminatory results of seismic liquefaction of sand layers with the current code are basically consistent with the discriminatory results of near⁃seismic conditions with the old code,while the liquefaction range is smal⁃ler than that of farseismic conditions with the old code.In the current code,the nonlinearity correction method is used instead of the linearity correction method in the old code to correct the penetration number of soil,which can more truly reflect the influence of engineering loading and unloading conditions.

关 键 词：砂土地基 地震液化评价 标贯试验 对比分析 

分 类 号：TU435[建筑科学—岩土工程]