Research On On-line Monitoring And Prediction Method For Differential Settlement Of Large Storage Tanks

The hundred thousand cubic meter floating roof tanks are widely used in the field of oil and gas storage in petroleum and chemical industry.In order to facilitate storage and transportation,for the convenience of storage and transportation,large tanks are built in the coastal areas along the river.This will cause the storage tank to produce different degrees of settlement deformation.In particular,the differential settlement of the tank can seriously affect the storage tank structure.This research monitored differential settlement around tank wall by advanced on-line monitoring technology.Obtained the actual settlement data of the field,combined with the new method of predicting the foundation settlement of storage tank.The harmonic curve fitting curve is obtained by processing and analyzing the settlement data.And the finite element analysis method is used to analyze the stress and displacement of the floating roof tank under the measured uneven settlement.The main research work includes:(1)Setting up a set of on-line monitoring method for differential settlement of large storage tanks.And carried out on-line monitoring method for differential settlement of 9floating roof tanks in a reserve reservoir in Dalian.A stable and reliable settlement monitoring data is obtained.(2)Through studying the principle and modeling process of grey prediction method and BP neural algorithm,put forward a new method to predict the foundation settlement of the storage tank,discrete grey neural network model based on improved BP algorithm.Compared with the other two methods,the new prediction method has higher prediction accuracy.(3)Raised a new fitting method for the differential settlement around tank wall.Load the fitting curve into the floating roof tank ANASYS model,and obtained the displacement curve of the joint of the bottom of the tank,the line matched with the measured settlementvalues of each monitoring point.It shows that the settlement curve fitting method proposed can simulate the settlement change of the tank bottom great.(4)Analyzed the influence of the harmonic order and the height of liquid storage on the deformation of storage tank under the differential settlement around tank wall.The analysis shows that with the increase of the harmonic order,the maximum radial displacement on the wall is also increased,and the maximum radial displacement of the top of the tank is always the greatest;as the height of the storage liquid rises,the maximum value of the radial displacement of the tank and the maximum stress of von Mises increase gradually.