Study On Theories And Methods Of Subsidence Monitoring Network Displacement Analysis

Purpose of deformation monitoring is to obtain geometric status information of the deformable body through measuring changes of shape and size of the object. On this account we can analyze and evaluate the safe condition of the monitored object.We mostly build deformation monitoring network in order to obtain deformation information. The stability analysis for deformation monitoring network is the basic premise and an important content of the deformation analysis.Subsidence monitoring is an important content of deformation monitoring. This paper combines some building project of subsidence monitoring to analyze and discuss a number of important problems of the stability analysis for deformation monitoring network. The main contents show as follows.(1) This paper not only introduces the free network adjustment and datum transformation theory but also summarizes the three adjustment datum unified equation containing datum weight:STPxx=0. and deduces the free network adjustment unified formula with the datum equation containing datum weight constrainting.(2) According to the similarity of the statistical model,in this paper it introduces the detailed derivation process of the Hannover method and the single-point inspection method by the means of the linear hypothesis method. In addition, combined with the Hannover method, the single-point inspection method and quasi-stable adjustment it gives an analytical solution of the stability of reference network.(3) It will make an adverse effect on displacement analysis because of model error produced by using the same reference when we do the estimate of two stages displacement. Two stages of observation data containing the same system error will also exert an adverse influence on displacement analysis. We preliminarily discuss on these problems in this paper.(4) Do a research on application of iteration method with variable weights widely used in robust estimation to displacement analysis. combining the characteristics of displacement analysis, try to construct a weight function and give the corresponding explanation.(5) The data processing and analysis of two examples of subsidence monitoring project are done to verify the relative methods and formula above-mentioned. KEYWORDS:free network adjustment; datum weight; datum transformation;...