Study On The Auto Select Dimension Model Of Grey And Its Application In Tunnel Deformation Monitoring

By now，Grey system theory is already from static to dynamic development. Thedynamic grey forecast model further elucidates ethylene the grey model. It follows the newinformation priority principle and makes dynamic choice in the selection. The traditionaldynamic model insists the new information priority and fixed dimension. The former caneffectively guarantee the prediction results is more close to the actual situation, althoughthe latter ensures equal proportion of new and old data, mandatory to abandon oldinformation make the high precision among different dimension inevitable. The choice ofdimension has not been effectively resolved. For this problem, a new dynamic grey modelwas proposed, th is Automatic dimension selection grey model.In view of the situation, I sum up a new dynamic grey model, which is “Auto SelectDimension Model of Grey”. It built in the preprocessing of the Grubbs criterion ofdata,estimate the best dimesion,select the dimension of the highest accuracy to set a model,at the same time,combined with the trend chart of deformation, analysis the deformationstage,define minimum dimensions,in order to improve、optimize and make a perdition.Finally,verify the advantages of the model by comparing with the other grey dynamicmodel and the predictions of the tunnel vault subsidence data.This paper is based on the grey theory, mainly discusses its application in themonitoring of tunnel deformation. It has completed the followings：1) Analyze the theory and method of deformation monitoring of the tunnel, comparedifferent prediction models and study the composition and characteristic of the predictionmodel.2) For deformation data access, especially on the selection of monitoring points, itmakes a progress. Th proposed geological prediction of tunnel and set up the monitoringpoints in the place of easy deformation. It reflects the deformation. 3) For sorting through the data, in order to get away bad values of deformation data,it needs to preprocess. According to the characteristics of tunnel deformation data, chooseGrab J criterion as the pretreatment of data, and make it in order.4) Using MATLAB GUI software interface for the platform, to create a convenientrepeatable operation interface, it can use automatic selection of grey model to forecastdata.5) Compare with other dynamic gray model, discuss the influence of dimension ofthe model, give some advice on improvement and optimization model. Finally, make aprediction and verify the automatic choice of grey model can be used in tunneldeformation.In the end, pose questions of the automatic selection dimension dynamic grey modeand look forward to improve the next step.