摘要
在城镇地区开展重力调查时,建筑物对重力测量的影响往往被忽视。为了解决城市建筑物重力影响的校正问题,首先采用直立长方体来模拟建筑物模型,计算了单一建筑物的重力校正值随建筑物高度和校正半径的变化趋势,结果表明校正值在校正半径为0~250m之间时急剧增加,在校正半径达到250m以后逐渐趋近一常数。随后,以1∶25万区域重力调查为例,对比校正半径为50m、250m和1 000m的建筑物影响值,发现250m的校正范围既能满足近中区地形校正精度要求,又便于野外操作,要减小250m的校正范围以外建筑物的影响,采用简单易行的理论计算方法即可实现。最后给出了城市建筑物重力校正的野外观测方法和绘图式记录方式。该校正方法和方案能够消除城市建筑物对重力测量影响,有助于提高城镇地区重力异常精度。
This paper addressed the issues of gravity effects caused by artificial buildings in gravity surveys in urban district, which is always ignored. The vertical cuboid is used to establish city building simulation model. And that its gravity correction value of one single building changes with building height and correction radius is calculated. The results showed that the gravity effects of building increase rapidly in the range of 0-250 m, then approaching to a constant after the distance increased to 250 m. Subsequently, a case study of 1/250,000 gravity surveys is used, the gravity effects caused by city buildings are compared with respect to the correction radius of 50 m, 250 m, and 1000 m, respectively. The results suggested that the radius of 250 m can satisfy the accuracy requirements of gravity correction in mid-distance area, on the other hand the practical gravity measurement could benefit from this simple strategy. In the end, a reasonable scheme for field work including gravity measurement and data records is proposed. The method and strategy presented in this paper would diminish the gravity effects caused by city buildings, and assist in improving the accuracy of gravity measurements in urban district.
出处
《工程地球物理学报》
2015年第5期686-691,共6页
Chinese Journal of Engineering Geophysics
基金
中国地质调查局基础地质调查项目(编号:1212011221040)
关键词
区域重力调查
城市建筑物
重力校正
district gravity survey
city buildings
gravity correction
