桥梁上部结构几何线形的无接触检测

Non-contact Surveying Method for Geometric Configuration of Bridge Superstructure

桥梁上部结构的几何线形测量受客观条件的制约,使许多常规的测量方法无用武之地。本文提出一种"虚拟"的自交会测量方法:首先确定仪器中心相对于结构物轴线的平面位置,并将仪器零方向与结构物轴线方向设为一致;然后通过方向交会来求得结构物轴线上任意照准点的平面坐标,进而由三角高程方法求得其高程;最后由离散化的多个测点拟合出结构物的几何线形。新方法的精度与传统的前方交会法相当,但无需设置测量标志,可实现高效的无接触测量。

The survey for geometric configuration of bridge superstructure is often restricted by objective conditions,so that many conventional survey methods can not be used.A 'fictitious' self-intersection method was put forward in this paper.First,the instrument center is positioned relative to structure axes of bridge,and the zero direction of instrument is oriented to structure axes.Afterwards,the coordinate of discretional collimation point on structure axes can be computed by direction intersection method,and then its height can be calculated by trigonometric leveling.Finally geometric configuration of bridge superstructure is fitted based on a number of discrete survey points.The results show that the precision of the new method is equivalent to traditional forward intersection,but it doesn't need to set survey signs.Non-contact surveying for bridge superstructure can be realized by the new method.