Experimental research on characteristics of vertical dynamic load on bridge pier and pile foundation under heavy-haul railway train
Guo Fengqi1,2 Wang Pengjiao1,2 Yang Qi1,2 Yu Zhiwu1,2 Leng Wuming1,2 Chen Chen1
1. School of Civil Engineering, Central South University, Changsha 410075, China;
2. The Key Laboratory Heavy-Haul Railway Engineering Structures of the Ministry of Education, Central South University, Changsha 410075, China
Abstract：To investigate the dynamic load characteristics of bridge pier and pile cap under heavy-haul train with large axle load, long marshalling and intensive operation, field tests on vertical dynamic load (strain) of pier and pile foundation system under different heavy-haul train load were performed. The time domain and frequency domain analysis methods were applied to study the characteristics of dynamic load curve, the Kolmogorov method was used to test the normality of dynamic load amplitude, and the relationship between train parameters and load frequency domain characteristics was established; Based on the 3σ principle, statistical analysis was performed to obtain the dynamic load characteristic values (mean value, mean amplitude value and mean peak value) under different vehicles. The calculation formula for dynamic amplification factor of pier top was proposed, and the load spectrums and their parameter values of bridge pier top and pile cap were proposed. The results indicate that the time domain response of dynamic load can be divided into three stages: rapid increase, periodic action and rapid attenuation. Moreover, the excitation frequency range of 0~5 Hz has a significant effect on dynamic load, and the spectrum curves follow the frequency multiplication rule and amplitude modulation effect. Further, it is observed that the dynamic load amplitude follows the normal distribution. The mean peak value of dynamic load and the vibration energy decrease rapidly along the pier shaft, the peak dynamic load and the mean peak value increase with the increase of the axle load, and the amplitude value may decrease with the increase of the axle load. Based on analysis results, it is suggested to apply the formula φ=1+0.0045v to calculate the dynamic amplification factor of pier top, and the load spectrum of pier can be well fitted by the trigonometric series.
郭风琪 王鹏蛟 杨奇 余志武 冷伍明 陈琛. 重载列车作用下桥墩-桩基竖向动荷载特性试验研究[J]. 土木工程学报, 2021, 54(11): 79-90.
Guo Fengqi Wang Pengjiao Yang Qi Yu Zhiwu Leng Wuming Chen Chen. Experimental research on characteristics of vertical dynamic load on bridge pier and pile foundation under heavy-haul railway train. 土木工程学报, 2021, 54(11): 79-90.
