Identifying Gravel Layer Using Time-Domain Analysis Methods for Landfill Leak Repair

Drilling and grouting repair technology is an effective way to repair leaks in landfill which need to drill into gravel layer firstly, and then make grouting repair. So it is important to judge correctly the location of bit when drilling for avoiding damaging the HDPE membrane. For judging the location of bit, in this paper, we proposed three time domain methods to analyze the acceleration of vibration signal which are the waveform amplitude analysis method, the rolative sum of absolute values method and the sub-root-mean-square method. The results show that: all of the three methods can distinguish waste layer and gravel layer clearly, and the waveform amplitude analysis method is more intuitively than the other two methods, while the rotative sum of absolute values method and the sub-root-mean-square method can susceptively reflect the mutation and the probability distribution of the acceleration amplitude in unit time.