基于光纤传感技术的地裂缝物理模型试验
Model tests on the ground fissures based on the optical
fiber sensing technology
-
摘要: 苏南地区地裂缝成因机制较为复杂, 且灾害活跃。以光纤光栅传感器为监测手段, 建立基岩潜山条件下物理地质模型, 模拟抽水差异性沉降过程, 揭示地裂缝发育演化规律。试验结果表明:(1)地下水过量抽采导致的不均匀沉降是地裂缝发育的最直接因素, 地下水水位降深越大、抽采速率越快, 地面沉降越明显。(2)基岩潜山形态位置对地表沉降起控制作用;同时地面沉降最严重区域与地裂缝分布区域基本一致;基岩潜山的发育位置形态、地表的沉降曲线以及地裂缝分布情况基本一致。(3)模型试验结果与研究区地裂缝灾害发育规律基本一致。此次基于光纤技术的物理模型试验研究为地裂缝研究提供新的方法与手段。Abstract: The formation mechanism of ground fissures in southern Jiangsu is complicated, where disasters occur frequently, and they are threats to the living environment. In order to reveal the regular development pattern of ground fissures, a geophysical model is established under the buried-hill condition and the settlement process with the water-drawing variability is simulated by means of a fiber grating sensor. The experimental results show that (1) The non-uniform settlement caused by groundwater over-exploitation is the most direct factor of the development of ground fissures. The more the groundwater level drops and the higher the groundwater extraction rate is, the more obvious the land subsidence is. (2) The location of the buried-hill formation controls the ground settlement, and the areas suffering land subsidence mostly coincide with those with ground fissures. The ground settlement curve and the fissure distribution where the buried hills develop look basically the same. (3) Result of the model experiment corresponds to the evolution pattern of disasters in the studied fissures area. The experimental research with the physical model based on the fiber-optic technology provides new methods and means for ground fissure studies.