At present, the lack of detection technology in underground space area is the main constraint on the development and utilization of underground space. In order to solve the difficult situation of underground space exploration and evaluation, this paper presents a multi-frequency ultrasonic scanning detection technology, a large number of borehole detection data can be obtained by using the detection system to realize the accurate scanning and detection of cavity and the belly rock mass. The stability evaluation standard of cavity is established, which realizes the integration of cavity detection and stability evaluation. This paper provides an important reference for the detection of underground cavity. A scanning point position determination method based on multi-frequency ultrasonic pulse ranging is proposed in this paper, and the coordinates of scanning points are calculated accurately to realize the 3D visualization of cavity contours. Through the refined calculation of space volume, the precise control of space deformation is realized. Then, the characteristic parameters of borehole structural plane are determined after the geometrical feature combination of structural planes and the high-frequency acoustic reflection characteristics, a directional method for rock velocity measurement, is presented for the first time by means of low-frequency acoustic wave transmission. Based on the comparative analysis of echo wave characteristics, the integrity evaluation criteria of cavity are established. Finally, by analyzing the structural characteristics of cavity and upper rock mass, and the parameters which may influence the stability of cavity, combined with an engineering example, a stability evaluation system based on the multi-frequency ultrasonic scanning detecting technology of cavity in the test borehole is formed.

当前，地下空间区域探测技术的缺乏是制约地下空间开发利用的主要制约因素。为了解决地下空间勘探与评估的困境，提出了一种多频超声扫描检测技术，利用该检测系统可以获取大量的井眼检测数据，实现对腔体的精确扫描与检测。和腹部的岩体。建立型腔稳定性评价标准，实现型腔检测与稳定性评价的集成。本文为地下洞的探测提供了重要的参考。提出了一种基于多频超声脉冲测距的扫描点位置确定方法，并精确计算出扫描点的坐标，以实现腔体轮廓的3D可视化。通过空间体积的精细计算，实现了空间变形的精确控制。然后，在构造面的几何特征与高频声反射特征结合后，确定了井眼构造面的特征参数，首次提出了一种利用低频声波的定向测量方法。传播。在对回波特性进行比较分析的基础上，建立了腔体的完整性评价标准。最后，通过分析空腔和上部岩体的结构特征以及可能影响空腔稳定性的参数，