高土石坝心墙多场耦合演化规律

The measured earth pressure, deformation, excess pore water pressure and their developing processes are sometimes rather different from the expected ones for several high earth core rockfill dams under construction or operation. It is difficult to explain these phenomena by the present theories and methods. This project aims to address these problems in a certain extent. The hydraulic and mechanical properties of compacted clayey soil under complex conditions will be investigated with the improved triaxial shear-seepage apparatus, firstly. Then, the affecting mechanism of various factors on the properties will be analyzed, and a corresponding constitutive model and a practical numerical method will be developed. Furthermore, the evolution of the coupling of multi-fields, including physical state field, stress field, deformation field and seepage field, will be studied deeply. Finally, the proposed theory and method will be applied to an actual high earth core rockfill dam for verification. It is expected that, the results of this project will be useful for the design and safety assessment of this kind of dams.

目前多座高心墙土石坝在建设和运行过程中实测的心墙应力、变形和超静孔隙水压力及其变化过程与计算值相差较大。这些现象根据已有的理论和方法难以解释和模拟。本课题拟利用改进的三轴剪切渗流试验设备，研究非饱和压实粘性土在复杂条件下的渗透特性和力学特性的变化特点；分析多种因素影响的内在机理，建立相应的本构模型并开发实用的模拟方法；揭示心墙内物态场、应力场、变形场、渗流场等的耦合演化规律，并应用于实际工程进行检验。本项目是在高土石坝工程实践中凝练出的课题，创新点明确，研究成果对于揭示复杂应力条件下心墙多场耦合演化机理、优化设计方案以及合理评价高土石坝的安全性具有指导作用，因而本研究既具有较大的理论意义又具有广阔的应用前景。

心墙堆石坝是水利水电工程中优先采用的一种坝型。随着坝高的增加，大坝所表现出的行为与低坝有很大差异。多座高心墙土石坝在建设和运行过程中实测的心墙应力、变形和超静孔隙水压力及其变化过程与计算值相差较大。这些现象根据已有的理论和方法难以解释和模拟。本课题利用多种试验设备，研究了非饱和压实黏性土在复杂条件下的渗透特性和力学特性的变化特点；分析了多种因素影响的内在机理，建立相应的本构模型并开发了实用的模拟方法和计算程序；根据计算揭示了心墙内物态场、应力场、变形场、渗流场等的耦合演化规律，并应用于实际工程进行检验。本项目是在高土石坝工程实践中凝练出的课题，创新点明确，研究成果对于揭示复杂应力条件下心墙多场耦合演化机理、优化设计方案以及合理评价高土石坝的安全性具有指导作用，因而本研究既具有较大的理论意义又具有广阔的应用前景。