基于三维激光扫描仪的青藏铁路风沙工程效益评价

Application of 3D Laser Scanning Technology in the Evaluation of Aeolian Sand Engineering along the Qinghai-Tibet Railway

三维激光扫描技术是近年来发展起来的新型空间信息测量技术。将三维激光扫描技术应用于青藏铁路沿线风沙工程防护体系的效益评价中,通过对铁路沿线典型防沙措施积沙形态特征、断面蚀积廓线以及蚀积量的精确测量发现：砾石方格内垂直铁路方向易形成稳定凹曲面,且方格两侧沙埂处积沙较多,中心部位积沙较少,固沙效果显著。阻沙栅栏有效防护距离为栅栏高度的12倍,单位宽度拦截沙量高达14.93 m3,设置防护体系时,阻沙栅栏间隔应保持其高度的9~12倍。研究结论为青藏铁路沿线风沙综合防护体系的措施选择、结构优化和合理布局提供技术支撑。

3 D laser scanning has been a new technology in measurement of spatial information in recent years. In this paper, this technology was applied tentatively to the efficiency evaluation of the protective system of sand drift control engineering along Qinghai-Tibet Railway. The sand control efficiency of the system was evaluated by accurately measuring the morphology of sand deposition over the typical sand drift control measures, aeolian erosion and deposition profiles of the cross-section and quantities of erosion and deposition using the 3D laser scanning technology. The concave surface of rocky checkerboard sand barriers easily formed along the perpendicularly direction to the railway. Sand accumulation occured more on the sides of rocky checkerboard than its center. The effective distance of sand fences was about 12 H and sand-blocking volume was 14.93 m^3 per 1 m width. Therefore, the space of sand fences should remain 9 - 12 H in the construction of protective systems. The objective of this study is to extend this technology to the measurement of sand disaster threatening other railways, buildings and engineering measures and to the evaluation of the protective efficiency of their control systems, thus eventually providing technical support to the measure selection, structure optimization and rational distribution of the integrative sand drift control system.