基于双尺度耦合方法的土石混合料高填方边坡破坏机理及稳定性研究

In recent years, the construction of the airport in China is stepping into a high speed development stage, therefore a large number of soil-rock aggregate high backfill slope projects have been emerged in the newly expanded mountainous airports, of which its packings are of various components and extremely uneven structure from complex geological origin. Hence, correctly analyzing the failure mechanism and stability of the high backfill slope with soil-rock aggregate is the key to the airport construction. Thus, this subject is comprehensive knowledge of soil mechanics, rock mechanics, granular matter mechanics, continuum mechanics, energy principle, modern computer technology, self-organization theory and catastrophe theory. Meanwhile, it is adopted the combined method of laboratory test, theoretical analysis and numerical simulation, considering the actual project profile. In the subject, the macro and micro physical mechanical properties and the failure mechanism are keenly researched, the strength mechanism of soil-rock aggregate is deeply analyzed, too. The nonlinear strength criterion consideing the damage characteristics is proposed. In addition, the time and space evolution of energy in high backfill slope with soil-rock aggregate are obtained, and a corresponding catastrophe model for slope failure is proposed. Eventually, a fine discrete-continuous dual scale coupling method is developed, and the meso mechanical mechanism and macroscopic energy mechanism of high backfill slope with soil-rock aggregate in failure are revealed, which provide new ideas and methods for the stability analysis of high backfill slope with soil-rock aggregate.

近年来，我国机场建设正步入一个高速发展阶段，进而催生出大量山区机场超高填方边坡工程，其填料广泛采用地质成因复杂、组成成分多样和结构极端不均匀的土石混合料，如何正确分析土石混合料高填方边坡的破坏机理和稳定性已成为机场建设的关键问题。本课题综合土力学、岩石力学、颗粒物质力学、连续介质力学、能量原理、现代计算机技术以及自组织理论和突变理论等多门学科知识，结合山区机场土石混合料高填方边坡的实际工况，采用室内试验、理论分析和数值模拟等相结合的方法，重点研究土石混合料的宏细观物理力学特性和破坏机理，深入分析土石混合料的强度产生机制，建立考虑破坏特征的非线性强度准则，获得土石混合料高填方边坡变形破坏的能量时空演化规律，提出相应的边坡失稳突变模型，开发一种精细的离散-连续双尺度耦合方法，揭示土石混合料高填方边坡破坏的细观力学机理和宏观能量机理，为开展土石混合料高填方边坡稳定性分析提供新的思路和方法。

随着社会经济的发展，机场对地区竞争力的提升作用日益凸显。而西部地区的地形地貌主要是以山地和丘陵为主，这就要求对机场场地进行开山填谷、高填深挖等土石方工程，因此催生出大量超高填方边坡工程。本项目综合土力学、岩石力学、颗粒物质力学、连续介质力学、能量原理、现代计算机技术以及自组织理论和突变理论等多门学科知识，结合山区机场土石混合料高填方边坡的实际工况，采用室内试验、理论分析和数值模拟等相结合的方法，开发了土石混合料高填方边坡的离散-连续双尺度耦合方法，分析了高填方边坡的破坏机理和稳定性。主要研究成果有：得到了土石混合料剪切过程和剪切完成后的颗粒破碎形态及变化规律；获得了土石混合料剪切面的分形维数变化规律；分析了土石混合料剪应力-剪切位移关系曲线变化规律和破坏模式；研究了土石混合料各物理指标对强度参数的影响规律和机理；并建立了一个土石混合料非线性强度准则；提出了一种可以精确模拟土石混合料细观结构特征精细化建模方法；探索了土石混合料的细观力学特性和破坏机理；二次开发了边坡能量可视化计算程序，揭示了边坡变形破坏的能量时空演化规律，提出了相应的边坡失稳突变模型；验证了连续离散耦合方法在边坡工程中的适用性；提出了土石混合料高填方边坡的离散-连续双尺度耦合方法；揭示了土石混合料高填方边坡破坏的细观力学机理。研究成果可为开展土石混合料高填方边坡稳定性分析提供新的思路和方法，并为土石混合料填方边坡的设计和维护提供理论依据和技术支持。