PSD Correction Method for Removing Background Vibration from Traffic Environmental Vibration Observation
Wang Fu-tong1,2;Tao Xia-xin1;Zheng Xin1,3; Cui Gao-hang4;Chen Xian-mai5
1. School of Civil Engineering, Harbin Institute of Technology, Harbin, Heilongjiang, 150090; 2. School of Civil Engineering and Architecture, Heilongjiang University, Harbin, Heilongjiang, 150001; 3. School of Engineering, Heilongjiang Bayi Agricultural University, Daqing, Heilongjiang 163319; 4. School of Civil Engineering, Northeast Forestry University, Harbin, Heilongjiang, 150040; 5. School of Civil Engineering and Architecture, Central South University, Changsha, Hunan, 410075
Abstract：Abstract: Background vibrations typically reside in field observation data for recording traffic-induced environmental vibration in surrounding areas, and may disturb the true vibration signals excited by traffic transportations. A method of PSD revising is suggested here to remove the background vibration from field observed records. Based on the assumption that the true vibration and the background vibration are mutually uncorrelated stochastic processes, calculating formulae of the method were deduced. A group of data was then taken as an example to demonstrate the capability of the method. First, a vibration curve was set as the true vibration data, and was superimposed on a background one to synthesize a filed observation record. Then the true vibration was supposed to be unknown, and was estimated by the vibration level revising approach, the Fourier amplitude revising approach and the proposed PSD revising approach, respectively. The feasibility and accuracy of these approaches were examined by comparing the true vibration setting data with the estimated ones. The results of the example show that the time history and the PSD obtained with the PSD revising approach resemble their setting curves very well, and the errors are smaller than that of Fourier amplitude revising approach. The vibration level calculated by the PSD revising approach or the vibration level revising approach is almost the same as its setting value, but the calculated value by the Fourier amplitude revising approach is relative smaller. It can be concluded that the proposed approach behaves more accurately than the Fourier amplitude revising approach, and produces more types of true vibration data, i.e., time histories and PSDs, than that obtained by the vibration level revising approach.
2011, Vol. 30 
