动力扰动作用下地质聚合物充填膏体蠕变损伤特性研究

Cementitious materials of filling mining with paste develops from cement to geological polymer gradually, after using geological polymer to finish the work of filling mining with paste, the creep damage of filling paste and creep disturbance caused by dynamic action has an important impact on long-term effects of filling. Using orthogonal design with project scientific proportioning method to make paste filling of geopolymer of high performance, triaxial creep test of filling paste with dynamic and static triaxial testing machine of the type of FST-200 carried out to test the creep deformation, elastic modulus, cohesion, internal friction angle and poisson's ratio change with time. Based on disturbance triaxial creep test, threshold of viscoelastic deformation and visco-plastic deformation caused by disturbance, disturbance sensitive range around the threshold and parameters of damage evolution creep can be got. The FST-200 type of dynamic and static The calculation results and measured datas are compared and analyzed to correct the constitutive model of dynamic disturbance based on the platform of FLAC3D to make further development and numerical calculation. The constitutive model established to predict the long-term effect of backfill mining. The constitutive model established to predict the long-term effect of backfill mining. The research results will reveal the creep damage characteristics of filling body under dynamic perturbations and provide theoretical support and technical guidance for the long-term effects of paste filling mining.

膏体充填开采使用的胶凝材料逐渐从水泥向地质聚合物发展，采用地质聚合物充填膏体进行充填开采后，充填膏体的蠕变损伤及其受到动力作用产生的蠕变扰动效应对充填长期效果有重要影响。项目采用正交设计手段进行科学配比，制备出高性能的地质聚合物充填膏体，并采用FST-200型动静三轴试验机进行充填膏体的三轴蠕变试验，测试充填膏体的蠕变变形、弹性模量、黏聚力、内摩擦角和泊松比随时间的变化规律，在此基础上进行三轴蠕变扰动试验，测试充填膏体在扰动作用下粘弹性变形与粘塑性变形的阈值、阈值附近的扰动敏感范围和蠕变参数的损伤演化规律，建立动力扰动作用下充填膏体的蠕变损伤本构模型并以FLAC3D为平台进行二次开发和数值计算，将计算结果与试验数据进行对比，修正该本构模型。项目建立的本构模型可预测充填开采的长期效果，研究成果将揭示地质聚合物充填膏体在动力扰动作用下的蠕变损伤特性，为膏体充填开采的长期效果提供理论支持和指导。

采用粉煤灰地质聚合物充填膏体进行充填开采后，充填膏体在静载作用下的蠕变及其在动力作用产生的蠕变扰动效应对充填长期效果有重要影响。项目采用现场调研、试验研究、理论分析与数值模拟相结合的方法开展研究，取得了以下研究成果：（1）提出了一种新型的地质聚合物膏体充填材料拌和工艺，并使用该工艺在使用较少胶凝材料的情况下制备出了满足要求的膏体充填材料，通过正交试验，获得了地质聚合物充填膏体的最优配合比，采用SEM和EDS相结合的方法对充填膏体的微观结构和化学成分进行了分析，揭示了充填膏体的强度形成机理。（2）采用单轴压缩试验与白光数字散斑相关方法相结合的手段，揭示了充填膏体在加载过程中的变形场演化特征、泊松比演化规律及能量释放规律。（3）开展了充填膏体的蠕变试验研究，获得了充填膏体的蠕变变形规律，将分数阶Burgers模型与一个应变触发的非线性黏壶串联，建立了充填膏体的蠕变本构模型。（4）自主研发了一种基于多场耦合的动力扰动试验机，利用该试验机开展了分级加载方式下的蠕变扰动效应试验；探索了充填膏体的蠕变扰动规律，建立了符合充填膏体变形特征的蠕变扰动本构模型。（5）采用C++语言基于FLAC3D平台对项目建立的蠕变本构模型进行了二次开发，开发后计算的结果与试验数据吻合较好，可以描述充填膏体的蠕变特性与蠕变扰动效应。研究成果揭示了粉煤灰地质聚合物充填膏体在动力扰动作用下的蠕变规律，为膏体充填开采的长期效果提供理论支持和指导。