生物基可降解聚乳酸沙障的蚀积特征

Characteristics of Erosion and Deposition of Biodegradable Poly Lactic Acid Checkerboard Barriers

[目的]分析不同铺设规格生物基可降解聚乳酸(PLA)沙障障格内风蚀稳定凹曲面形态特征、断面轮廓及蚀积效应等指标,为聚乳酸沙袋沙障规格优选提供理论依据。[方法]以内蒙古自治区吉兰泰盐湖周边流动沙垄铺设的0.5 m×0.5 m,1 m×1 m,1.5 m×1.5 m和2 m×2 m规格的聚乳酸沙袋沙障为研究对象,待风季后测量障格内稳定凹曲面蚀积形态,绘制凹曲面形态图并计算蚀积参数等。[结果] 4种规格沙障障格内均能形成稳定的凹曲面,且呈四周高中间低的整体格局。0.5 m×0.5 m,1 m×1 m,1.5 m×1.5 m和2 m×2 m障格内的净堆积强度分别为17.29,7.09,0.61,-8.2 g/cm^2。[结论]障格内稳定的凹曲面形成前,0.5 m×0.5 m和1 m×1 m障格内以堆积为主;1.5 m×1.5 m障格内风蚀堆积近乎平衡;2 m×2 m障格内部在布设初期呈风蚀状态,但稳定凹曲面形成后,仍可控制地表风蚀。

[Objective] Morphological characteristics, different orientation section profile characteristics, and erosion and deposition effects of concave surfaces of biodegradable poly lactic acid(PLA) checkerboard barriers with different sizes were analyzed to provide evidence on which to base the specification parameter selection of PLA checkerboard barriers. [Methods] The biodegradable sandbag checkerboard barriers laid on the edge of the Jilantai Salt Lake in the Inner Mongolia Autonomous Region were undertaken for research. The sizes of the checkerboard were 0.5 m×0.5 m, 1 m×1 m, 1.5 m×1.5 m, and 2 m×2 m. The shape of the concave surface was measured, pictures of the shape of the concave surface were drawn, and the parameters of the erosion and deposition after the wind period were calculated. [Results] A sand surface can form a stable concave surface for the four kinds of PLA checkerboard barrier. The center was lower than the surrounding parts in the PLA checkerboard barriers. The strengths of net deposition in the 0.5 m×0.5 m, 1 m×1 m, 1.5 m×1.5 m, and 2 m×2 m PLA checkerboard barriers were 17.29, 7.09, 0.61, and-8.2 g/cm^2, respectively. [Conclusion] Before the stable formation of the concave surface, the sand grains of the PLA checkerboard barriers of 0.5 m×0.5 m and 1 m×1 m were mainly deposition. The volume of erosion and deposition was close to equilibrium in the 1.5 m×1.5 m PLA checkerboard barriers. The sand surface was wind eroded at the initial stage in the PLA checkerboard barriers of 2 m×2 m, but when the sand surface formed a stable concave surface, the PLA checkerboard barriers could control wind erosion of the sand surface.