糯扎渡高心墙堆石坝心墙砾石土料变形参数反演分析

采用室内中型三轴试验和现场碾压载荷试验对糯扎渡高心墙堆石坝心墙砾石土料的变形特性进行了研究。试验结果表明，采用掺入35％花岗岩碎石的风化混合土料作为心墙防渗土料是合适的，掺入的碎石料可显著提高心墙土料的变形模量，这对减少心墙和堆石体的不均匀沉降和拱效应，防止心墙发生水力劈裂是十分有益的。对现场载荷试验进行了基于神经网络和演化算法的位移反演分析，在有限元计算中提出了通过给定加载函数初始值来描述坝料由碾压过程所致的初始超固结状态的方法。研究结果表明，对糯扎渡心墙砾石土料，由室内三轴试验和现场载荷试验得到的变形特性基本一致。

The back-analysis of deformation parameters of core gravelly soil of the Nuozhadu high rock-fill dam

The deformation properties of core gravelly soil of the Nuozhadu high rockfill dam are studied by using medium-scale triaxial tests and the field loading tests. The test results show that the gravelly soil composed of weathered soil mixed with 35% men-made granite gravel is suitable for core material. The mixed gravel can enhance the deformation modulus of core material, which is very helpful to reduce the unequal settlement and arching effect between core wall and rockfill as well as to prevent the hydraulic fracture in the core wall. The field loading test is carried out by using the displacement back-analysis based on neural network and evolutionary algorithm. A method to describe the over-consolidated condition resulted from the roller compaction process is proposed by setting the initial value of loading function in the finite element analysis. The study result indicates that the deformation properties of core clay from the triaxial tests are well agreed with those from the field loading tests.