Study On Damage Diagnosis For High-pile Wharf Based On Residual Force Vector

In the port engineering, the high-pile wharf is one of the widely used structure. It iscommon problems that the pile of high-pile wharf is damaged by the bank slope deformation,ship impact, using load and natural environment effect. As foundation of the upper structureof high-pile wharf, the pile plays a vital role in the safety of high-pile wharf. The research ofthe pile which contains upper structure is very few on damage diagnosis at home and abroad,and then a practical and feasible test method cannot be found. Therefore, it is a very worthy ofstudy of the subject based on the dynamic of high-pile wharf pile damage diagnosis. In thispaper, physical model modal test based on the stochastic subspace method of high-pile wharfmodal identification and finite element numerical simulation technology based on residualforce vector method of the pile of high-pile wharf are researched on the theory for a high-pilewharf structure section in Tianjin port. This article mainly research contents and results are asfollows:1.Firstly, damage diagnosis methods of the pile of high-pile wharf are summarized.Secondly, several methods which can be applied in the high-pile wharf group pile damagediagnosis based on power are introduced. Thirdly, the present situation of the structuraldamage diagnosis technology and its limitations are analyzed and the area of research isprospected.2.According to some high-pile wharf in Tianjin port, the physical model is made basedon Ansys finite element model. Firstly, carrying on the modal analysis, work out the modelbasic modal parameters such as frequency and vibration mode. And then testing the high-pilewharf physical model, obtain the model basic modal parameters. Comparing the modalparameters which are identified for physical model based on the stochastic subspace methodof modal identification program with the modal parameters which base on finite elementmodel, the analysis results show that the results of two methods for modal parameters aresimilar, the errors are small, and prove that the method of finite element model establishmentis accurate and reliable.3.According to the vibration differential equation, the residual force vector expression isdeduced in detail, and then the residual force vector for structural damage index is defined.With a single pile as the research object, the damage location diagnosis is realized by the numerical simulation of single pile, which proved the residual force vector method has highreliability. By establishing high-pile wharf frame finite element model and using the residualforce vector method, run the numerical simulation for the pile of high-pile wharf damagediagnosis in a variety of conditions. The simulation results show that the finite element modelbased on residual force vector of the pile of high-pile wharf damage detection is feasible,which provides scientific basis in the actual engineering of the pile of high-pile wharf damagediagnosis.