To study the characteristics of infrasonic wave response during the failure process of concrete samples and analyze the feasibility of infrasonic wave prediction for the failure of concrete structures in underground spaces, rock mechanics loading devices and infrasonic wave acquisition devices were used to carry out infrasonic wave test experiments on concrete samples during uniaxial loading. With the help of MATLAB numerical simulation software, the test results are processed and analyzed by constructing band-pass filtering program, wavelet denoising program and time–frequency analysis program. The analysis results show that: there is infrasound wave during the loading process of the concrete sample; During the loading process, the change of infrasonic wave presents stage characteristics, which can be divided into three stages: the initial stage when a certain amount of infrasonic events occur, the middle stage when there are few infrasonic events and the later stage when infrasonic events increase rapidly and reach a peak. These stages respectively correspond to the compaction deformation stage, elastic deformation stage, plastic deformation and later stage of concrete sample deformation, and there is a good corresponding relationship between them. When the concrete sample is damaged by the peak value, the frequency and amplitude of the infrasound wave have abnormal changes. Therefore, in the early stage of the failure of the concrete structure, when the local failure occurs, there is also an abnormal response of infrasonic wave and the failure of the concrete structure can be predicted based on the abnormal change. At the same time, the infrasound wave, as a kind of low-frequency wave, has the advantages of long propagation distance, small attenuation and flexible position arrangement and has stronger adaptability to the complex underground space environment. It is of great significance to improve the accuracy of underground space concrete structure failure prediction.

为研究混凝土样品破坏过程中的次声波响应特征，分析次声波预测地下空间混凝土结构破坏的可行性，采用岩石力学加载装置和次声波采集装置进行次声波测试。混凝土样品单轴加载过程中的实验。借助MATLAB数值仿真软件，通过构建带通滤波程序，小波去噪程序和时频分析程序来处理和分析测试结果。分析结果表明：混凝土样品加载过程中存在次声波。在加载过程中，次声波的变化呈现出阶段性特征，可以分为三个阶段：最初的阶段是发生一定量的次声事件，中间阶段是次声事件很少，而后期则是次声事件迅速增加并达到峰值。这些阶段分别对应于混凝土样品变形的压实变形阶段，弹性变形阶段，塑性变形阶段和后期阶段，它们之间具有良好的对应关系。当混凝土样品被峰值破坏时，次声波的频率和幅度会发生异常变化。因此，在混凝土结构的破坏的初期，发生局部破坏时，也会发生次声波的异常响应，能够根据该异常变化来预测混凝土结构的破坏。同时，次声波 作为一种低频波，传播距离长，衰减小，位置布置灵活，对复杂的地下空间环境适应性强。对于提高地下空间混凝土结构破坏预测的准确性具有重要意义。