绢云母片岩填料在环境变化和应力耦合作用下颗粒组构演化特征及其力学效应

The metamorphic rock as a filler is prone to dynamic evolution of grain fabric under coupling effect of environmental change and load conditions, leading to strength and deformation characteristics attenuation of the metamorphic rock filler. The metamorphic rock filler is prone to great subgrade settlement, which is key technical problems that threat to subgrade normal operation and long-term stability. As a result, it has important theoretical and engineering value to study on grain fabric evolution and mechanical effect for sericite schist during coupling effect between environmental change and load conditions. The laboratory test method is taken and combination of theoretical analysis. CT technology will be used for real-time observation in the process of triaxial test. The sericite schist filler particles’ fabric dynamic change will be seen under environmental change and load conditions coupling effect. The relationship between dynamic evolution of grain fabric and macro mechanic parameter are find out. Forecast model for strength and deformation characteristics attenuation of sericite schist filler under coupling effect between environmental change and load conditions are built. Settlement calculation method for sericite schist filler under coupling effect of environmental change and load conditions is put forward, which provides theoretical basis and technical guidance for subgrade design and long-term stability analysis of subgrade in metamorphic soft rock areas.

变质软岩填料在环境变化和荷载耦合作用下发生了颗粒组构动态演化，导致变质软岩填料路基的强度与变形特性发生衰减，变质软岩填料路基易发生较大的沉降，是影响到路基正常运营和长期稳定的关键技术难题，为此研究变质软岩填料在环境变化和荷载耦合作用下中颗粒组构演化及其力学效应具有重要的理论和工程借鉴意义。采用室内试验、理论分析相结合的研究方法，利用CT三轴试验开展绢云母片岩填料颗粒组构和结构实时观测，弄清绢云母片岩填料在环境变化和荷载耦合作用下颗粒组构信息动态变化，探讨绢云母片岩填料在环境变化和荷载耦合作用下颗粒组构演化与宏观力学参数之间的关系，建立基于细观试验的宏观力学参数预测模型，提出绢云母片岩填料路基工后沉降计算方法，为变质岩地区路基的设计和路基长期稳定性分析提供理论和技术指导。

绢云母片岩填料在环境变化和荷载作用下易发生颗粒组构动态演化，从而导致绢云母片岩填料路基的变形特性发生衰减，引起路基发生较大的沉降，是影响到路基正常运营和长期稳定的关键技术难题。以鄂西山区谷竹高速公路绢云母片岩路基填筑段作为研究对象，通过试验研究与理论分析研究了绢云母片岩填料在环境变化和应力耦合作用下颗粒组构演化特征、力学效应及工后沉降。通过绢云母片岩填料在干湿循环作用及三轴试验前后的颗粒筛分试验分析，弄清了绢云母片岩填料在环境变化和应力耦合作用下组构动态演化特征；采用分形理论建立了绢云母片岩填料在环境变化及应力作用下填料颗粒组构演化的分形模型，揭示了绢云母片岩填料在环境变化和应力耦合作用下组构演化规律；通过室内试验查明了绢云母片岩填料强度与变形特性，建立了绢云母片岩填料颗粒组构分维数与宏观力学性质的关系，阐明了绢云母片岩填料在环境变化和应力作用下宏观力学指标的变化规律；基于分层总和法，通过理论分析提出了绢云母片岩填料路基附加沉降模型，并估算了绢云母片岩填料在环境变化和应力作用下工后沉降，为变质软岩路基的建设与安全运营提供了技术支持，同时也进一步拓宽了变质软岩可作为公路路基填料的应用范围。