Research On The Damage Mechanism And Protective Measures Of Bridge Caused By Explosion Based On Urban Digital Grid

Bridges are the lifeline of modern comprehensive transportation systems.As of 2022,the total number of bridges in China has exceeded 800000,including over 80000 urban bridges.In the context of digital infrastructure,big data applications,and intelligence,it is necessary to integrate traditional industries with "digital intelligence" to scientifically achieve the specific requirements of "increasing investment in infrastructure security protection and enhancing the security protection capacity of key infrastructure" in the strategic plan for a strong transportation country.It is necessary to integrate different disciplines and break through many key issues.The research on bridge explosion resistance protection in China started relatively late,and the cost of designing protection against extreme loads for all in-service bridges is extremely high.With big data application as the background,this paper introduces the concept of urban digital grid,combines cluster analysis algorithm,and uses intelligent methods to explore the distribution of risk source of urban explosion.On the basis of clarifying the mechanism of conventional bridge type explosion damage of urban bridges and the conceptual design of urban bridge anti explosion protection,this paper proposes the mechanism of bridge explosion damage and protection countermeasures based on urban digital grid.The main research content carried out in this article is as follows:(1)The KMeans clustering algorithm is introduced to classify the potential risk source in the designated area of the city according to the corresponding indicators.The internal logic of the KMeans clustering algorithm model is programmed to extract the distribution characteristics of the potential risk source of the city.Through the construction of the clustering model,the evaluation of the clustering effect and the analysis of the clustering results,the distribution and fortification conditions of some vulnerable bridges in the area are given.(2)By combining clustering results and feature analysis,potential high-risk bridges within the region were identified.The ANSYS/LS-DYNA numerical analysis program was used to perform dynamic analysis of explosion damage display for four common urban structural forms.The mechanism of explosion damage for conventional urban bridge types was obtained through structural damage characterization and key characteristic parameter time history curves.(3)Introducing the concept design of urban bridge explosion resistance,summarizing the application scenarios of explosion damage effects,proportional distance indicators,and fortification safety indicators that can be used for urban bridge explosion protection;Due to the frequent occurrence of local punching and shear failure of bridges under explosive loads,numerical simulation analysis was used to analyze the damage characteristics of different components such as beams,columns,and plates subjected to explosion.Five different reinforcement methods were studied to enhance the anti explosion performance of the components.(4)Based on the above work,a comprehensive analysis method and implementation process for bridge explosion protection based on urban digital grid are proposed.The research results can provide support for improving the level of urban bridge explosion protection and enriching the theory of urban bridge explosion protection.