Abstract:During the long-term use of urban road greenbelts, caused by factors such as continuous action of motor vehicle loads and mixing of subgrade fillers, the soil of the greenbelts generally faces the problems such as increased bulk density, compact and hard structure, weakened water permeability and insufficient nutrient supply. By analyzing the internal mechanism of soil physical property degradation in urban main road greenbelts, an improvement technical scheme that combines bentonite zeolite powder composite improvement material with blind pipe drainage system is proposed. Based on laboratory experiments, the optimal ratio combination of the improvement material is determined, a hydraulic calculation model of the blind pipe drainage system is constructed, and the proposed technology is applied to the greenbelt construction project of an urban expressway. The results of engineering application show that this technology can reduce the soil bulk density by more than 0.25 g/cm3, increase the saturated hydraulic conductivity to 3.5 times that of the original soil, and raise the survival rate of green plants to more than 92%, providing a technical path of practical application value for the restoration and management of urban road greenbelt soil.
