Research On The Points Stability Analysis Methods In Deformation Monitoring Network

Purpose of deformation monitoring is to determine geometric status of the deformed body by measuring changes of size, shape and location of the object, and to analyze and evaluate the safe condition of the deformable body based on the information, and to discover and solve the potential safety hazard timely. The implementation of the deformation monitoring is inseparable from the deformation monitoring network, and how to judge and determine the steady control points is the basis of calculating deformation displacement of monitoring points and analyzing the deformation, and is the key technology of deformation monitoring work.There are many methods of the points stability analysis in deformation monitoring network, each one has its advantages and disadvantages. Currently looking for a universal and reliable method of the points stability testing is still a problem urgently to be solved in deformation monitoring field. This dissertation analyzes the research circumstance of the points’stability analysis methods in deformation monitoring network in recent years, and analyzes and discusses a number of problems existing in the stability analysis.The main content of this dissertation is as follows:1. This dissertation introduces and analyzes the reference system of the deformation monitoring network and free adjustment, and through the actual example analyzes several common methods of points’stability analysis in different reference datum. Results of the example show that not only results of same method in different reference datum but also results of different methods in the same reference datum are different. So analyzing points’ stability in actual engineering projects should choose the right reference datum consistent with the actual deformation.2. This dissertation analyzes and summarizes the advantages and disadvantages of several common methods of points’stability analysis in deformation monitoring network. Without stable benchmark for the deformation monitoring network, this dissertation improves the common mean spacing method. The basic idea is that firstly calculating the displacement and the coordinated factor matrix of every point after unified network datum by the similarity transformation of the result of rank-defect free network adjustment, and then calculating the stable matrix of various points during weeks through the right to choose iteration method, and then using the similarity transformation principle to calculate the displacement and the coordinated factor matrix under the datum correspond to the actual conditions, and then using the single point displacement method to determine relative stable point, and then using the similarity transformation principle to convert the result of rank-defect free network adjustment to the quasi-stable datum of the relatively stable point as a quasi-steady point,and then calculating the displacement and the coordinated factor matrix of every point, finally using the mean spacing method to analysis the stability of points. Comparing with the means pacing method under the gravity datum and stable datum, this dissertation confirmed the result of the modified means pacing method is best and the misjudgment of the stable point will not happen, the modified mean spacing method can satisfy the requirements of stability analysis of the general deformation monitoring network.3. Because there are some datum points in the deformation monitoring network have moved, the adjustment datum of the former is different from the latter’s, which leads to that the displacements under the gravity datum do not accord with actual deformations and the stability of points will be wrongly judged. In view of this problem, this dissertation improves the tolerance method under the gravity datum, namely difference matrix method, which uses the result of the rank-defect free net adjustment to calculate the difference of the measured height difference (vertical control network) or the measured difference of coordinates component (horizontal control network) of every two points, and then forms a 0-1 triangular matrix that contains only element 0 and 1 by comparing with the permissible error range, and then analyzes the stability of each point according to the judgement index. Comparing with other stability analysis method under the gravity datum, this dissertation confirmed that the misjudgment of the stable point will not happen in this method, and using this method to analyze the stability of points is better, and this method is especially suitable for the points’ stability analysis of linear deformation monitoring network.4. The author uses C# programming language to develop the deformation monitoring data processing and management system software in VS2010 platform. This software can complete the following works:(1) processing the observation data of vertical displacement and horizontal displacement monitoring network; (2) checking the data, adjusting and evaluating precision; (3) analyzing the reference points or monitoring points’stability.