基于现场载荷试验的压实土石填筑料变形参数反演  

Back Analysis of Deformation Parameters for Compacted Soil-Rock Mixture Based on in-Situ Plate Load Test

作　　者：陈洪春 王珊 段玉昌 王柳江[3] 梁睿斌 徐祥 沈超敏[3] CHEN Hongchun;WANG Shan;DUAN Yuchang;WANG Liujiang;LIANG Ruibin;XU Xiang;SHEN Chaomin(Jiangsu Jurong Pumped Storage Co.,Ltd.,Jurong 212400,China;Bureau of Water Affairs of Jiangning District,Nanjing,Nanjing 211112,China;College of Water Conservancy&Hydropower Engineering,Hohai Univ.,Nanjing 210024,China)

机构地区：[1]江苏句容抽水蓄能有限公司,江苏句容212400 [2]南京市江宁区水务局,南京211112 [3]河海大学水利水电学院,南京210024

出　　处：《三峡大学学报（自然科学版）》2023年第1期22-27,共6页Journal of China Three Gorges University：Natural Sciences

基　　金：国家自然科学基金(U1765205,51979091,52009036)。

摘　　要：为了解现场压实土石填筑料的变形特性,开展了5组不同土石填筑料的平板载荷试验,并采用改进加速遗传算法对试验结果进行了反演分析,得到了“薄层重碾”作用下压实土石填筑料的邓肯E-B模型参数.在此基础上,对句容抽蓄上水库库盆填筑过程进行了数值模拟.结果表明:现场压实后的土石填筑料处于超固结状态,其在初始加载阶段产生的沉降较小;由于缩尺效应影响,室内三轴试验试样与现场原级配土石填筑料的力学性状存在较大差别,现场压实土石填筑料的K和K_(b)更大,卸荷模量系数K_(ur)为K的1.56~2.33倍,加载函数初值S_(0)在0.3~0.42之间;利用三轴试验参数计算得到的库盆测点沉降明显大于实测值,而基于反演参数的计算结果与实测值基本一致,说明基于平板载荷试验结果反演确定现场压实土石填筑料变形参数的方法是合理可行的.In order to study the deformation behaviour of soil-rock mixture under field compaction,the plate loading tests were conducted on five different types of soil-rock mixture.Then,the back analysis was conducted with improved accelerated genetic algorithm to obtain parameters of Duncan E-B model.After that,the numerical simulation of filling construction of dam and reservoir basin was conducted for the upper reservoir of Jurong pumped storage power station.The result indicates that the soil-rock mixture after field compaction is in the state of over-consolidation,which leads to the smaller settlement occurs in the initial loading stage.Due to the influence of scale effect,the mechanical behaviour of the triaxial test sample is different with that of naturally graded soil-rock mixture.The parameters K and K_(b) for the naturally graded soil-rock mixture under field compaction are obviously larger,while the parameter K_(ur) is 1.56 to 2.33 times larger than K.In addition,the initial loading function S_(0) is in the range of 0.3 to 0.42.Finally,it is found that the predicted settlement of reservoir basin after filling construction is larger than the measured value by using the parameters obtained from the triaxial tests.However,the predicted settlement by using the parameters through the back analysis is very closed to the measured value.Thus,the method of using plate loading test combined with back analysis to determine the deformation parameters of the soil-rock mixture under filed compaction is reasonable and acceptable.

关 键 词：土石混合料 薄层重碾 平板载荷试验 变形特性 反分析 

分 类 号：TV213.4[水利工程—水文学及水资源]