Soil Compaction Measurements, Based On Signal Analysis

Soil compaction is a natural phenomenon which causes atmosphere and water to be not able to flow freely in soil because of the losing of pores among soil granules. Once the soil is compacted, it will be difficult to recover its initial state unless ultimate physical interference is carried out. Furthermore, the soil is very difficult to be recovered completely if some vegetation grows on it, and it will be taken a long time to regain proper soil condition if the soil only be depended on the plants growing on or on animals such as earthworms living in. Since soil compaction is of great impact to the crop production, the research about principles and application of soil compaction has been the focus of the relevant field. At present, it is a common concern on exploring the methods by which the degree of soil compaction can be measured accurately. The existing soil compaction measurement methods and devices mainly measure soil compaction, bulk density and porosity. Because of the great influence of outside world no the physical nature of the soil itself, most device can only measure roughly, and the measurements often involve much manual operation, which cause the process very complexity.This paper aims to look for a new method to measure soil compaction. First the paper studied on the existing variety of measuring instruments of soil compaction about their measuring principle, operations and their final results. In light of the needs of paper's experiment, soil compaction measurement system was designed based on impact. In this paper, acceleration sensor B&K4370 was used to measure the impact response on soil. By testing the soil impact response on the soil, signal analysis methods were used to compare the response among the different soil samples. Relation between impact signals of soil and its compaction was discussed. Through looking for the law of the experimental data about soil impact, and making linear regression by the least squares fitting principle of the impact response parameters and soil compaction, it was carried out that confirming the degree of soil compaction based on the impact signal of the soil.In this study the measurement of soil impact response involves large amounts of data. This paper developed a numerical approach which can get the degree of soil compaction by processing and calculating the data measured. This paper also designed an interface program using Visual C++, which can be used to read a measured document, and display the waveform of the impact signal. The interface program enables the corresponding impact signals more intuitive displayed to the users.Through the application of a new type of soil compaction measurement devices and the pilot studies on processing system of impact signal analysis, we can see first, at the same impact effect, integral to the time of the shock value and soil compaction degree show linear correlation. Second, measuring method of existing measurement devices involves the participation of people, so the results of soil compaction are affected in varying degrees. Third, in this paper, the study on method of soil compaction measurement is some originality. The device designed can basically meet the needs of the measurement of soil compaction, which has simple structure and is easy to use and greatly reduces the human factors and error source.