Experimental study on long-term performance of new urban green space soil for sponge city construction

As existing urban green space soil (UGSS) will gradually become compacted and the permeability decreases with time, it will not meet the need of sponge city construction. Therefore, it is necessary to study the UGSS suitable for sponge city construction. In this study, a dry-wet cycle test is performed on a new urban green space soil (NUGSS), and the laws of its permeation rate, moisture capacity, organic matter content, and salinity with time are studied. The results show that the moisture capacity, permeation rate, organic matter content, and salinity of the NUGSS show a downward trend under the action of dry-wet cycles. The comprehensive performance of the NUGSS will decay rapidly within 4–6 years. After about 10 years of use, its comprehensive performance will not be able to meet the optimal requirements for the properties of UGSS for sponge city construction. Finally, this study discusses the current urban greening soil standards, sponge city soil protection and management and puts forward suggestions.