黄土细观界面形成演化机制试验研究

黄土界面是黄土形成演化过程中形成的产物，是黄土发生灾变的根源。同时平山造城、治沟造地和固沟保塬等重大工程建设过程中，也形成了众多堆填土与黄土之间的人工界面，在黄土界面控灾这一全新认识中，这些界面均是黄土细观界面发展演化的综合外在体现。本项目拟通过野外调研、室内土工试验、计算机图像处理技术、三轴加载协同实时CT扫描试验等研究手段开展以下三个方面的研究：（1）大量获取黄土细观界面数据，总结其成因与发育规律；（2）获取土样图像切片并构建三维数字模型，提取黄土细观界面的关键要素，分析其在加载过程中的变化趋势；（3）基于黄土细观界面动态发展过程和土体力学行为变化过程，分析土体损伤过程与土体强度的折减关系。从而搭建细观界面的基础数据库，重现细观界面形成演化过程，建立黄土细观结构损伤数学评价模型，初步揭示黄土细观界面形成演化机制。研究成果将为黄土界面控灾机制和黄土灾害预测预报研究提供数据支撑和理论依据。

Loess interface is formed during the formation and evolution of loess. It is the root cause of loess disasters. At the same time, many artificial interfaces between landfills and loess have also been formed during the construction of major projects such as Mountain Excavation and City Construction, Gully Stabilization and Land Reclamation, Gully Control and Highland Protection, etc. “Loess disasters was controlled by the loess interface” was a new understanding, in which these loess interfaces are the comprehensive external manifestations of the loess meso interface. This project intends to carry out the following three aspects of research through the methods such as field investigations, soil tests, computer image processing technology, real-time CT scanning tests in the condition of triaxial loading: (1) Collecting a large amount of data of loess meso interface, and summarize the inducing factors and development characteristics of the loess meso interface; (2) Collecting image slices of the soil sample and construct the 3D digital core models. Extracting the key elements of the loess meso interface, and analyze its changing trend during the loading process; (3) Based on the dynamic development process of the loess meso interface and the change process of the mechanical behavior of soil, the relationship between the damage process of the soil and the reduction of soil strength was analyzed. We aimed to build a basic database of the loess meso interface, reproduce the formation and evolution process of the loess meso interface, establish a mathematical evaluation model for the damage of the meso structure of loess, and initially reveal the formation and evolution mechanism of the loess meso interface. The results will provide data support and theoretical basis for the mechanism of “loess disasters was controlled by the loess interface” and the prediction of loess disaster.