College of Mechanical and Equipment Engineering, Hebei University of Engineering, Handan, 056038, China.
Environ Sci Pollut Res Int. 2019 Nov;26(31):32050-32064. doi: 10.1007/s11356-019-06379-1. Epub 2019 Sep 6.
This paper proposes a stress wave monitoring method for monitoring and locating leakage through the impervious layer at a landfill to resolve the "first pollution, then discovery" problem caused by the existing electrical monitoring method. The experimental results show that the linear distance to the geophones from the leak point should be less than 31.5 m to provide a well-defined rupture signal. The amplitudes of the stress wave signals generated during the yield and rupture stages of the high-density polyethylene (HDPE) film are more obvious and easily identified by the geophones; the rupture signal duration is approximately 100 ms, and the bandwidth is distributed within 0 kHz to 1 kHz. By studying the stress wave first arrival times calculated by the picking model, the average error of the picking model is approximately 0.35 ms, and the iteration of the model is ceased when the thresholds of the discriminating indices are 3.5 and 0.9. Experiments reveal that the positioning model should stop iterating when the absolute value of each element in the calibration vector is less than 140. The average positioning error is 0.248 m, and the maximum fiducial errors of the positioning model in the X-axis and Y-axis directions are 0.32% and 0.58%, respectively.
本文提出了一种基于应力波监测的方法，用于监测和定位垃圾填埋场防渗层的渗漏，以解决现有电监测方法存在的“先污染，后发现”的问题。实验结果表明，为了提供清晰的破裂信号，检波器与泄漏点的直线距离应小于 31.5 米。高密度聚乙烯（HDPE）膜在屈服和破裂阶段产生的应力波信号的幅度更为明显，更容易被检波器识别；破裂信号持续时间约为 100ms，带宽分布在 0kHz 到 1kHz 之间。通过研究由拾取模型计算的应力波首波到达时间，拾取模型的平均误差约为 0.35ms，当判别指数的阈值为 3.5 和 0.9 时，模型的迭代停止。实验表明，当校准向量中每个元素的绝对值小于 140 时，定位模型应停止迭代。平均定位误差为 0.248m，定位模型在 X 轴和 Y 轴方向上的最大基准误差分别为 0.32%和 0.58%。
