The Research On The Compactness Measure Of Roadbed Using Dynamic Testing Methods

As the government increased the infrastructure investment in the recent years, the construction of road is developing at a fantastic speed. The compactness of roadbed and embankment is the key control factor in the construction of road and quality control. But the testing methods in use waste too much time and labor, not to mention any technical specification for rockfill embankment. It's an urgent requirement of the current situation in the construction of road to develop a rapid and convenient testing methods to measure the compactness of roadbed. Based on the summarized relevant achievements both domestic and abroad, this paper studied the application of SASW (Spectral Analysis of Surface Waves) in the measuring of compactness for fill roadbed and the application of other dynamic testing methods for rockfill embankment.In-situ testing results obtained by SASW method was compared with those of the sand replacement method in this paper, and a regressive equation was presented. Further research on several forward modeling algorithms for solution of a roadbed model were discussed.This paper put forward a new method to establish the relationship between parameters and compactness by parameter identify through frequency response function. This method applied complex mode theory on multidegree-of-freedom modal. This method shows it's applicability in less control on excitation energy.Base on the results of a series of experiment on backfill ground, this paper summarized the variation tendency of parameters obtained by four dynamic testing methods during the compact process.This paper also studied the application of dynamic test on rockfill embankment. Experiment was conducted on an indoor model of rockfill embankment, variation tendency between parameters and settlement was presented by qualitative analysis of the data, regressive equation of additive mass method was also presented by comparison with the result of water replacement method. We also presented regressive equations based on additive mass method and parameter identify method in in-situ testing, tentatively validate the two methods.