Effect of Vehicle Cycle Load on Fatigue Life of Lightweight Cellular Concrete Expressway Embankment
摘要
Lightweight Cellular Concrete (LCC) embankments endure significant operational loads throughout the service life of expressways. This study explores the fatigue characteristics of LCC embankments under cyclic loading through experimental analysis and numerical simulation. Based on vehicular dynamic loads and other related factors, a simplified method for complex vehicular dynamic loads is proposed, and an in-depth analysis is conducted in conjunction with indoor accelerated aging tests. Under cyclic loading, the longitudinal strain of LCC undergoes three stages: rapid growth, slow growth, and rapid growth again, while the elastic modulus gradually decreases with increasing cycles. At the same cyclic life ratio, a smaller stress ratio results in a more pronounced strength reduction. An optimized formula is proposed based on the inverse power law model to predict the decay of LCC compressive strength. Furthermore, using the LCC embankment on the Guangdong-Fojiang Expressway as a case study, numerical analysis was performed to determine the stability and residual strength characteristics under various vehicular dynamic loads. The results indicate that a bearing capacity of 100 kPa and a frequency of 15 Hz represent not only the limit where the safety factor falls below 1 but also where the residual strength reaches 65% of the original strength. These parameters can be recommended as reference values for the maximum load-bearing capacity and traffic flow for LCC embankments on expressways.