基于BOFDA的砂—黏土互层垂向变形物理模型试验研究

地面沉降作为一种常见地质灾害对城市发展造成巨大威胁，有效监测土层的垂向变形过程是地面沉降防治的一项重 要工作。文章采用布里渊光频域分析（BOFDA） 技术，利用室内地面沉降模型，对砂—黏土互层土体在排灌水循环中的垂 向变形进行分布式监测，并结合固结压缩试验对土体的垂向变形进行分析。结果表明：黏土层为地面沉降的主要变形层； 在排灌水循环中，土体也会经历压缩—回弹的循环。此外，BOFDA分布式监测技术可以有效地捕捉砂—黏土互层土体在排 灌水状态下的垂向变形情况，实现对地面沉降发育过程中土体垂向变形的实时监测。研究结果可为实现地面沉降的有效防 治措施提供一定的参考依据。

Physical Model Test of Vertical Deformation of Sand-Clay Layers Based on the BOFDA

Land subsidence as a common geological hazard poses a great threat to urban development. Effective monitoring of vertical deformation process of soil layers is an important task for land subsidence prevention and control. In this paper, Brillouin Optical Frequency Domain Analysis (BOFDA) technology is used to monitor the vertical deformation of sand-clay layers in draining-recharging cycles by using an indoor land subsidence model. Moreover, a compression test is used to analyze the vertical deformation of the soil. The results show that the clay layer is the main deformation layer. In the draining-recharging cycles, the soil also experiences compression-rebound cycles. In addition, BOFDA technology can effectively capture the vertical deformation of sand-clay layers in draining-recharging cycles and monitor in real-time the soil vertical deformation in the process of land subsidence development. The research results provide some reference for the effective prevention and control of land subsidence.