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Vacuum formation and negative pressure transmission under a self-starting drainage process

Drainage can effectively control landslides that are caused by the infiltration of rainfall. Laboratory model tests were conducted in this study to investigate an efficient groundwater drainage method. The tests identified a drainage method that self-starts and creates a vacuum in the permeable section through siphoning. In addition, the value of the vacuum pressure in the permeable section is related to the difference in the height from the outlet of the drain to the permeable section. The greater the height, the greater the vacuum pressure generated in the permeable section. However, the vacuum pressure attenuates continuously in the process of transfer in the soil. It was also proved that there is a smaller attenuation of the amplitude in soil that has good permeability. Most importantly, the self-starting drainage method makes the surrounding soil form a vacuum seepage field and increases the seepage gradient, thereby improving the efficiency of the drainage.