Abstract: The dispersive soil has the characteristics of dispersing and losing when encountering water. The buildings located in the dispersive soil often suffer from seepage deformation at the interface under the coupling effects of soils-water-buildings, which often leads to dangerous situations in water conservancy projects. By using different artificially dispersive soils, conducting dispersivity and impermeability tests, and considering the separation and void from the soils and buildings caused by factors such as uneven settlement and vibration, the crack erosion tests are conducted on the non-dispersive soil and dispersive soil in the void area at the upper and lower sides of the pipelines. The results show that: (1) With the increase of sodium carbonate content, the soil samples gradually change from non-dispersibility to dispersibility. The critical hydraulic gradient decreases from 120.0 to 12.9 and 14.7, and the impermeability decreases significantly. (2) The cracks (without buildings) of the dispersive soil and non-dispersive soil can be gradually healed under the protection of filter, and the crack section can bear a slope drop greater than 59.0 and 51.2, respectively at the end of the tests, the anti-permeability performance is significantly improved. (3) Under the same dry density, compared with those in the non-dispersive soil, the cracks in the dispersive soil heal faster and can quickly fill and block the seepage channel under low-speed flowing water. (4) When the cracks are located in the upper part of the buildings, the non-dispersive soil and dispersive soil can bear hydraulic gradients greater than 87.4 and 63.1, respectively, and they can gradually heal under the protection of the filter and have certain impermeability properties. When the cracks are located at the bottom of the buildings, the crack section basically does not bear the hydraulic gradient. It is difficult to heal under the protection of the filter, and it is prone to piping of the filter under high water head.