工程土方量测算精度的主要影响因素分析  

Analysis on key factors of earthwork calculation accuracy

作　　者：阮晓光 谈秋英 

机构地区：[1]浙江公路技师学院,杭州310023

出　　处：《工程勘察》2017年第12期65-69,共5页Geotechnical Investigation & Surveying

摘　　要：为研究三维地形碎部点平均间距、格网间距等因素对工程土方量测量计算过程中的精度影响,主要通过TLS技术(Terrestrial Laser Scanning Technology,地面三维激光扫描技术)采集数据完整、图形规则、坡度分布均匀的22块大比例尺数字地形区域,以此作为土方量计算的基础数据,分析不同碎部点平均间距、格网间距对土方量精度的影响,得出如下结论:(1)碎部点间距或碎部点密度是影响土方量精度的最主要因素,实际工程中可根据土方量限差要求推求较为适宜的碎部点间距,以提高工作效率,降低生产成本。(2)TLS技术进行土方量测算,点云数据抽稀到5m即可保证相当高的计算精度并兼顾计算效率;全站仪和GNSS RTK技术测算土方量,地形点间距不宜大于15m。(3)对于不同地形测绘技术和不同比例尺情况,土方量计算所选取的格网间距均不应大于10m。(4)航空摄影测量、全站仪和GNSS RTK技术测算工程土方量,须在地形变化复杂区域有意识地增大点密度,以弥补对地形变化描绘的不足。In order to study the effect of the average interval of three-dimensional terrain detail points and the side-length of grid on the earthwork calculation accuracy,22 pieces of large scale digital terrain regions with complete data,regular shape and uniform slope distribution are acquired mainly by TLS technology,and then are used as the base data of earthwork calculation. Through the analysis of earthwork calculation accuracy with different average interval of detail point and the grid side-length,it is concluded that：（1）Detail point interval or sampling point density is one of the most important factors affecting earthwork calculation accuracy. In practical engineering,the suitable detail point interval can be calculated by the earthwork error limit,which can improve efficiency and reduce cost.（2） When the point cloud data acquired by TLS technology is diluted to 5 meters,it can ensure requirements of accuracy and efficiency.Topographic point interval should not be greater than 15 meters by total station and RTK GNSS technology.（3） No matter what kind of topographic mapping technology and scale,the grid side-length should be less than 10 meters.（4）For earthwork calculation by aerial photogrammetric technology,total station and RTK GNSS technology,it needs to consciously increase the detail point density in complex terrain change area,to make up for the problems of terrain changes.

关 键 词：土方量精度 碎部点间距 格网间距 TLS 

分 类 号：TU751[建筑科学—建筑技术科学]