特高心墙坝堆石料缩尺试验与变形特性验证分析  

Scale Test and Deformation Characteristic Verification Analysis of Extra-high Core Rockfill Dam

作　　者：朱晟[1,2] 孙安 杨娱琦 何顺宾 张丹 ZHU Sheng;SUN An;YANG Yuqi;HE Shunbin;ZHANG Dan(State Key Laboratory of Hydrology,Water Resources and Hydraulic Engineering,Hohai University,Nanjing 210024,Jiangsu,China;College of Water Conservancy and Hydropower Engineering,Hohai University,Nanjing 210024,Jiangsu,China;PowerChina Chengdu Engineering Corporation Limited,Chengdu 610081,Sichuan,China)

机构地区：[1]河海大学水文水资源与水利水电工程科学国家重点实验室,江苏南京210024 [2]河海大学水利水电学院,江苏南京210024 [3]中国电建集团成都勘测设计研究院有限公司,四川成都610081

出　　处：《水力发电》2023年第8期65-71,78,共8页Water Power

摘　　要：基于坝料现场与室内缩尺试验相结合和粘弹塑性固结有限元法,结合长河坝原型监测资料,研究了缩尺方法对大坝变形预测的影响;根据堆石料碾压试验资料,讨论了堆石体单一孔隙率标准存在的问题。结果表明:采用分形缩尺方法和与现场相同的相对密度制样,坝料室内三轴试验成果可以较好反映超径堆石料的力学特性,计算变形与原型大坝监测值吻合较好;混合法缩尺的坝料室内三轴试验成果计算变形明显偏离原型大坝监测值;由于长河坝坝料级配优良,采用33 t振动碾碾压4遍,堆石体孔隙率即可达到规范不大于21%的要求,但此时相对密度为0.52,尚未达到密实状态,坝体分区变形协调性较差,且坝顶将出现蓄水开裂现象;实际施工时堆石体采用33 t振动碾碾压6遍,孔隙率提高到不大于19%,相对密度为0.65,基本达到密实状态,即可避免坝顶出现蓄水开裂,也有利于提高大坝的抗震性能。高心墙堆石坝的变形协调设计需考虑级配效应的影响,应采用孔隙率和相对密度双控填筑指标。Based on the combining field and indoor scaling tests of dam material and the finite element method of viscoelastic-plastic consolidation,the influence of scaling method on dam deformation prediction is studied combined with actual monitoring data of Changheba Dam.Based on the rolling test data of rockfill,the problems of single porosity standard of rockfill are discussed.The results show that:(a)by using fractal scale method and taking same relative density to prepare test samples,the results of laboratory triaxial test of dam material can better reflect the mechanical properties of ultra-diameter rockfill,and the calculated deformation is in good agreement with dam monitoring value;(b)based on the results of laboratory triaxial test of dam material with mixed scaling method,the calculated deformation is obviously different from the monitoring value of prototype dam;(c)due to the excellent grading of dam material,the porosity of the rockfill can reach the specification requirement of no more than 21%by rolling it four times with a 33 t vibratory roller,but the relative density is only 0.52,which has not yet reached the dense state,the coordination of dam area deformation is poor and the dam crest will crack after reservoir impounding;and(d)after the rockfill body is rolled by a 33 t vibrating roller for six times in actual construction,the porosity is increased to no more than 19%and the relative density is 0.65,and in this state,it basically reaches a dense state,which can avoid dam crest cracking after impounding and is also conducive to improving the seismic performance of dam.The effect of dam material grading should be considered in deformation coordination design of high core rockfill dam,and the filling index should be controlled by both porosity and relative density.

关 键 词：分形理论 堆石料 缩尺效应 压实 变形协调 孔隙率 相对密度 砾石土心墙堆石坝 长河坝水电站 

分 类 号：TV641.41[水利工程—水利水电工程]