Study On Three-Dimensional Control Network Adjustment In Engineering Survey

In the traditional progress of layout, measuring and data-processing of control network, the three-dimensional spatial position is separated into two parts, two-dimensional plane position and elevation. This method is something unreasonable in theory. The observations, such as horizontal direction, zenith angle and slope distance show the geometric relationship among the control points. And the spatial position is a three-dimensional integrity composed by plane position and elevation. So the observations also have the unity. It will be imprecise to separate the observations into two-dimensional plus one-dimensional data-processing. Three-dimensional control network adjustment is superior to the separate adjustment of plane position and elevation. This thesis studied on three-dimensional control network adjustment in engineering survey.Firstly, observation equations were derived from the raw data of three-dimensional engineering control network. Secondly, the methods of weight-matrix determination of different observations were studied and the weight-matrix of three-dimensional control network was determined using Helmert variance component estimation. Then the effect of vertical deflection and astronomical refraction on the precision for three-dimensional control network was studied. Thirdly, a program of three-dimensional control network adjustment is work out. Finally, the thesis discussed the application of three-dimensional control network measuring and adjustment in three-dimensional deformation monitoring of side slope.Based on the study of three-dimensional control network adjustment, the corresponding programming and the verification with experimental data, three-dimensional control network can be used in engineering survey, especially in deformation monitoring of mountain area.