Development Trend And Prevention Measures Of Vertical Cracks In T-beam Web Under Vehicle Load

Prestressed concrete T-beam bridge is widely used in bridge construction in China due to its advantages of good economy and convenient construction.In recent years,during regular inspections of this type of bridge,a series of vertical cracks of different lengths have been found at the web of many beam bodies.Scholars have conducted extensive research on the causes of such cracks,but there is still little research on the development trend of cracks in prestressed concrete T-beams with vertical cracks in the web under moving loads;The development of cracks has a significant impact on the bearing capacity of the entire bridge,which is also a topic of concern;At the same time,what maintenance or reinforcement measures should be taken for bridges with such cracks is also an urgent problem to be solved.This article mainly focuses on the following aspects of work:(1)Based on the detection of engineering crack diseases and the research and analysis of many scholars,the characteristics and laws of different existing crack diseases in T-beams are summarized,and the structural form of cracks is determined,laying the foundation for subsequent research on the development trend of vertical web plate cracks.(2)Based on the structural characteristics of the research object,a finite element model is established based on the total strain crack model.The correctness of the model is verified by experimental data validation;By simplifying the vehicle model and selecting a reasonable loading form,the stability of vertical cracks in the T-beam web under different moving load sizes and speeds is explored;At the same time,based on the investigation results of the actual geometric size of cracks,cracks with different size characteristics and positions are implanted to explore the development trend of web cracks under moving loads in different states.(3)Based on the theory of changes in structural stiffness and bearing capacity under fatigue load,this paper explores the degradation of the bearing capacity of existing web crack T-beams under continuous load,and proposes preventive measures.