基于光纤感测技术的抽水回灌过程砂土变形室内试验研究

Study on sand deformation caused by water pumping and artificial recharge based on optic fiber sensing technique

将光纤感测技术应用于抽水及回灌过程中砂土变形规律室内模型试验研究。研发了特种应变感测光缆测量砂土内部变形,采用碳纤维内加热光缆测量了砂土内部含水率分布与地下水水位面变化,并用传统的千分表和测水头管对相关结果进行了对比分析。研究成果揭示了抽水及回灌过程中砂土变形对土体内部水分运移的响应规律和机理,为地面沉降潜在评估和预警预测探索了新方法。同时,研究成果也验证了光纤感测技术应用于砂土变形室内模型试验测量中的可行性。

Based on the previous studies,the model test in the laboratory with the optic sensing technique is used for the study on the sand deformation in the water pumping and artificial recharge. The specially designed strain sensing cables are buried in the soil mass to measure the internal deformation of the sand.The soil strains at different positions are measured by using the Pulse-Prepump Brillouin optical timedomain analysis( PPP-BOTDA) technique during the water releasing. The measurement data under the pre-drawing process have been analyzed to discuss the co-deformation between the different sensing cables and the soil mass. The results have a positive effect on the understanding of the ground subsidence mechanism caused by the water releasing,which could provide a guiding to the application of the optic fiber sensing technique on the soil deformation measurement in future.