沿空留巷巷旁混凝土充填体受到本区段采空区顶板下沉及下区段工作面推进的重复扰动影响，其自身稳定性对于保障沿空留巷围岩控制效果具有重要意义。本文采用理论分析、数值模拟、室内力学实验的方法，研究了采动影响下沿空留巷巷旁充填体应力分布，利用非线性超声波动理论确定了巷旁充填混凝土单轴加载过程中超声波特征参数，表征了巷旁充填混凝土承载性能劣化过程，并建立了多参数融合的预测模型，实现了巷旁充填混凝土承载性能的预测，主要研究结果如下：

（1）沿空留巷巷旁充填体应力分布受工作面顶板破断影响显著，重复采动影响下巷旁充填体垂直应力呈非对称性分布，其中在充填体中部最大、采空区侧次之、巷道侧最小；应力值总体随工作面推进单调增加，然后逐渐平稳，且处于较高的应力水平。

（2）分析了巷旁充填混凝土单轴加载过程中变形破坏特征和能量耗散规律，根据弹性应变能率和耗散能率极值点确定了单轴加载巷旁充填混凝土的裂纹闭合应力和损伤应力特征值，将巷旁充填混凝土试样损伤演化过程划分为四个阶段：初始损伤阶段、损伤稳定发展阶段、损伤加速发展阶段、破坏阶段。

（3）提取了巷旁充填混凝土单轴加载过程中超声波时频信号，定义了损伤因子、衰减系数、主频变异系数、非线性系数四个特征参数，各特征参数曲线随加载过程出现明显的阶段性特征，由阶段性特征综合确定了单轴加载巷旁充填混凝土的裂纹闭合应力和损伤应力特征值，实现了单轴加载巷旁充填混凝土承载性能劣化过程的表征。

（4）通过主成分分析法融合多源超声波特征参数（损伤因子、衰减系数、主频变异系数、非线性系数）构建了回归型支持向量机算法模型，具有较好的泛化性，预测结果误差在0.14%~12.19%之间，实现了巷旁充填混凝土受载状态和承载性能劣化程度的精准预测。

The roadside backfilling wall next to the gob-side entry retaining is affected by repeated disturbances of the roof subsidence of the gob and the advancement of the working face in the lower section, and its own stability is of great significance for ensuring the control effect of the surrounding rock of the roadway along the gob. This paper adopts the methods of theoretical analysis, numerical simulation, and laboratory mechanics experiment. The stress distribution of the backfilling wall along the gob-side entry retaining under the influence of mining is studied. The nonlinear ultrasonic dynamic theory is used to determine the ultrasonic characteristic parameters during the uniaxial loading of the roadside backfilling concrete, which characterizes the degradation process of the roadside backfilling concrete bearing capacity. A multi-parameter fusion prediction model has been established to realize the prediction of the bearing capacity of the roadside backfilling concrete. The main research results are as follows:
(1) The stress distribution of the roadside backfilling wall beside the roadway is affected by the breakage of the roof of the working face, and the vertical stress of the roadside backfilling is distributed asymmetrically under the influence of repeated mining, which is the largest in the middle of the roadside backfilling wall, second on the side of the goaf, and smallest on the side of the roadway. The vertical stress on each position generally increases monotonously with the advancement of the working face, and then gradually stabilizes at a higher stress level.
(2) The characteristics of deformation and failure and the law of energy dissipation during uniaxial loading of roadside backfilling concrete are analyzed. According to the extreme points of elastic strain energy rate and dissipated energy rate, the characteristic values of crack closure stress and damage stress of the roadside backfilling concrete under uniaxial loading are determined. The damage evolution process of the roadside backfilling concrete specimens is divided into four stages: the initial damage stage, the stable development stage of the damage, the accelerated development stage of the damage, and the failure stage.
(3) The ultrasonic time-frequency signal during the uniaxial loading process of the roadside backfilling filling concrete is extracted, and the damage factor, attenuation coefficient, main frequency variation coefficient, and nonlinear coefficient are defined. The characteristic parameter curves show obvious phased characteristics with the loading process. The crack closure stress and the damage stress of the uniaxial loading of roadside backfilling filling concrete are comprehensively determined from the characteristic change stage, and the characterization of the degradation process of the bearing capacity of the roadside backfilling concrete under uniaxial loading is realized.
(4) The regression support vector machine algorithm model is constructed by the principal component analysis method and the characteristic parameters(damage factor, attenuation coefficient, main frequency variation coefficient, and nonlinear coefficient) of multi-source ultrasonic waves has good generalization, and the error of the prediction results is between 0.14% and 12.19%, the accurate prediction of the loading state and the degradation degree of the bearing capacity of the roadside backfilling concrete is realized.

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