Load Limit Analysis Method for Highway Bridge Structures After Static Load Test Verification

In China, load testing is one of the important means to evaluate the safety and applicability of in-service bridges. However, the current evaluation regulations do not address the issue of bridge load limit analysis after static load test verification. To solve the problem, a highway bridge load limit analysis model considering the left truncated distribution characteristics of resistance is proposed for the verified short- to medium-span simply-supported RC bridges. Firstly, the live load to dead load ratios of RC beam bridges are introduced as the basic parameter in truck weight limit analysis, and the left-truncated distributions of resistances are constructed based on the left-truncated values of resistances relative to various test load to design load ratios in static load testing of highway bridges. Given that the resistance and dead load effect are independent random variables, an analytical model for back-calculating truck weight limit factors of highway bridges under different load levels is proposed in accordance with simplified truck weight limit model as used before. On the basis of this, the effect of test load to design load ratios on truck weight limit factors is discussed for bridges designed according to three bridge design codes of 85, 04 and 18 editions. The calculation results indicate that for the same bridge, the higher the load efficiency of the static load test used in the test, the larger the corresponding load limiting coefficient. The research results can provide scientific basis for formulating load limiting strategies for highway bridge structures after experimental verification.