Research On Sea-crossing Bridge Main Pier Pile Foundations Damage Analysis And Detection Evaluation Technology

The main pier foundation of the sea-crossing bridge is usually in a harsh environment,which is influenced by the marine environment and geological conditions.It is very important to evaluate the damage accurately and effectively.Based on the environmental and damage characteristics of the main pier foundation of the sea-crossing bridge,this paper established the damage analysis model which was suitable for the foundation of the bridge,and gave the method of identification damage and basic scouring identification of the main pier foundation of the sea-crossing bridge.The main pier pile foundations damage index system and damage evaluation model were establlished,and formed a cross-sea bridge main pier foundation damage analysis and testing and evaluation of complete sets of technology for the main bridge pier design,maintenance management to provide technical support.In the aspect of damage analysis,the damage analysis model of pile foundation in water and soil were studied respectively.Firstly,based on the model of Park and Ang’s two-parameter damage model,the damage curvature model of the main pier foundation of the sea-crossing bridge was established,and the quantitative basis of the five damage degree distributions were given.Based on the study of load transfer theory of super-long bored pile foundation,combined with 23 soil-concrete friction damage test and 6 sets of pile-soil friction damage test,the main pier foundation of the sea-Damage analysis model of pile-soil contact surface under load was proposed.In the aspect of detection and identification,the surface inspection and basic scouring identification were studied.Based on the comparison and selection of the three-dimensional imaging sonar test theory,it was recommended to use the unmanned detection technology based on the three-dimensional imaging sonar to carry out the damage detection of the main pier foundation of the sea-crossing bridge,and compared with the traditional underwater camera technology.The feasibility and superiority of the technology were verified by the test,and the design of the new man-pier foundation of the main pier foundation of the sea-crossing bridge can be realized.Considering the foundation mold of the main pier of the sea-crossing bridge in this paper,the scour identification technology of the main pier foundation of the sea-crossing bridge was proposed based on the modal method.For the natural frequency,modal curvature and modal flexibility of the whole bridge,the dynamic fingerprints are obtained.The quantitative relationship between the different dynamic fingerprints and the basic damage degree and the sensitivity to the change of the basic scouring.The feasibility and accuracy of the bridge foundation damage identification method were verified by field test of the Hangzhou Bay Bridge.In the aspect of damage evaluation,the damage mechanism of various damage indexes is studied according to the environment of the main pier foundation of the sea bridge,and the index system for the damage assessment of the main pier foundation of the sea bridge was constructed the damage assessment model of the main pier foundation of the sea-crossing bridge was established by the analysis of the load deformation characteristics of the damage of the main pier foundation of the large-scale cross-sea bridge.The damage evaluation system was established and the specific evaluation method,process and evaluation standard wer given.Finally,the applicability of the evaluation model is verified by the engineering example.