The Deformation Monitoring And Analysis For Existing Subway Tunnel Under The Influence Of Traversing Engineering

During the traversing engineering, to monitor the existing subway tunnel deformation real-time is an important part of ensuring the safety of subway operation.The subway operation characteristics and the environment are considered the relevant theoretical approaches and key technologies about the subway tunnel structure deformation monitoring and deformation analysis are proposed where the subway tunnel is disturbed by the adjacent construction. Monitoring, identified risks and warning are the main research line. Though the key technology research subject the whole process of security control to the existing subway tunnel construction disturbance deformation is fulfilled. As a result we are successful in monitoring in the deformation, identifying risks on the analysis of key technologies, and early warning in the first place, which ensures the safe operation of the subway.The paper systematically summarizes the operating subway deformation theory and problems of monitoring and makes in-depth research on the benchmarks of precise monitoring, intelligent deformation prediction, automatic monitoring of feature points, subway deformation zone whole monitoring theory and methods. The research kernel and innovation of the paper are as follows.1. With the combination the traversing subway projects, the paper summed up that the disturbance deformation of operating subway caused by the adjacent construction is influenced by many factors, the monitoring data shows nonlinear and chaotic characteristics and it needs high-precision monitoring. On this basis, the paper focuses on the theory of building three-dimensional high-precision monitoring benchmark, and weighted seven-parameter space three-dimensional coordinate transformation model is constructed, and the mathematical model of precision monitoring the weight and adjustment is derived2. In view of the status that the subway monitoring reference point will have settlement with the whole urban ground subsidence the paper proposed the method to correct subway reference point settlement with the application of GPS dynamic monitoring. It constructs noise autocorrelation function with the use of noise autocorrelation in the high-frequency GPS coordinate time series, puts forward the Kalman filtering denoising model based on the fractal algorithm, and fulfills GPS subsidence deformation extract and the reference point coordinates settlement corrections.3. Because the subway benchmarks for monitoring needs high precision and real-time dynamic characteristics, a dedicated survey marks is developed. The coordinates of many sophisticated measure instruments are integrated such as laser tracking device, industrial total station, GPS, terrestrial3D laser scanner, measuring robots and so forth. A precision reference and the unity of the GPS space on a dynamic basis is achieved, and as a result the subway precise spatial and temporal integration benchmarks for monitoring is built.4. According to technical problems such as the subway monitoring data on the current is huge and the deformation analysis is difficult and the prediction has low accuracy, and according to the subway deformation data disturbed by adjacent construction is nonlinear and chaotic characteristics, the paper proposes the intelligent deformation prediction method based on the PBIL support vector machine (SVM). PBIL algorithm based on probability analysis is used to obtain the key parameters of support vector machine combinations (C,a,s). And in accordance with the characteristics of the deformation mechanism of the deformation direction and deformation rate, the particle swarm optimization (PSO) algorithm is introduced. Its update mechanism of both individual gain and groups’gain of the particle swarm optimization in particle flight direction and speed is used to guide the setting of optimal parameter combinations. Consequently the blindness of human choice of parameters is avoided and support vector machine prediction ability is improved. The deformation monitoring data of Guangzhou subway traversing project verifies that the deformation analysis has high accuracy predictive ability and practicability.5. The paper summarizes the theories and methods of using automatic monitoring measuring robot to the implementation the subway deformation characteristics points. View of the problem of disturbance in the subway monitoring, the principle of the automatic monitoring of the model based on micro corrections is put forward. Measuring robot subway automatic monitoring system is developed to achieve the automatic control of monitoring behavior, data management and intelligent forecast of monitoring data.6. To improve the identification of the threats and achieve the capability to fully monitoring subway deformation,3-D panoramic monitoring mode with the use of3D laser scanner is proposed. The panoramic three-dimensional monitoring station layout and scanning, the point cloud data processing principle are researched. The innovative point is the point cloud data deformation extraction model based on the NURBS surface, and engineering experiments are used to test the effectiveness of the model of deformation and extraction. View of the real-time characteristics of subway monitoring, either the large monitoring regional or the higher sampling rate will result in the huge time spending of point cloud processing and deformation extraction, this paper develops a subway tunnel safety and rapid assessment method based on slice-based fitting technique. It can use the shortest time to determine the area which has the overrun deformation, and the assessment of the subway tunnel safety can be implemented timely.The research results are applied on the existing subway tunnel deformation monitoring project such as Beijing subway line10, line1, line6and Guangzhou subway line2and Shenzhen subway line1, the validation, feasibility and high performance are fully proved.