Numerical Simulation Study of Basement Water Discharge Pressure Relief Method under Rainstorm Conditions

The development and expansion of underground space has led to a continuous increase in both the occupied area and the burial depth of underground basements. Meanwhile, due to the inaccurate estimation of groundwater buoyancy, more and more anti-floating problems of underground basement caused by rainstorm have emerged. Combined with the principles of unsaturated seepage theory, this article uses Flac3d 6.0 software to conduct simulations on the influence of various significant factors on the effect of the water discharge pressure relief method, a novel approach to reduce buoyancy. The numerical results show that the water discharge pressure relief method can ensure the stability of the basement under rainstorm conditions compared with the basement without drainage holes. In order to improve the anti-floating efficiency of the water discharge pressure relief method in preventing floating, it is recommended to initially decrease the height and spacing of the drainage holes and follow by increasing the aperture of the drainage holes. The recommended spacing of the drainage holes is between 2 m and 3 m. The height of the drainage holes should be between 1 m and 1.5 m, and the aperture of the drainage holes should be no smaller than 100 mm. Furthermore, the water head of the basement floor is proportional to the permeability of the lower backfill and cushion, and it is not significantly influenced by the upper backfill soil when its permeability is within a low range. Finally, in order to achieve a satisfactory anti-floating effect, it can be attempted to reduce the longitudinal width of the lower backfill soil or moderately increase the thickness of the cushion.

This creative work has been published under the Creative Commons Attribution 4.0 International (CC-BY 4.0) license which allows copying, and redistribution as well as adaptation of the original work provided appropriate credit is given to the original author and the conditions of the license are met.