黄土坡面的微生物矿化加固及抗侵蚀性能试验研究

[目的] 研究黄土坡面的微生物矿化加固及抗侵蚀性能，为该区域坡面土壤侵蚀的防治提供防治技术。[方法] 采用微生物矿化技术对黄土坡面进行加固，通过光学显微镜和扫描电子显微镜(SEM)，从微观角度探究微生物诱导碳酸钙沉淀(MICP)技术对黄土坡面矿化加固的作用机制，并结合室内人工模拟降雨测试分析了加固坡面的抗侵蚀性能。[结果] 采用微生物矿化技术固化黄土坡面，能够有效提高坡面的抗侵蚀性能；随着固化处理次数的增加，固化层厚度逐渐增加，坡面渗透性逐渐降低，坡面总产流量逐渐增加，从38.5 L/h增加到44.4 L/h，增加了15.6%，而坡面总产沙量逐渐减少，从480.64 g/h减少到17.1 g/h，减少了96.5%。固化处理7次及以上的坡面，经雨强为120 mm/h的降雨持续冲刷1 h，坡面均没有发生明显的土壤侵蚀，坡面径流量与径流含沙量几乎不随降雨历时的增加而变化，分别稳定在0.72～0.74 L/min和0.001～0.002 g/ml之间。固化处理次数达7次及以上时，固化处理次数对总产沙量有显著影响，随着固化处理次数的增加，总产沙量不断减小。[结论] MICP技术可为黄土丘陵沟壑区临时和永久边坡土壤侵蚀的防治，黄土坡面的加固提供新方法和新技术，具有较广阔的实际应用前景。

Experimental Study on Microbial Mineralization Reinforcement and Erosion Resistance of Loess Slope Surface

[Objective] The microbial mineralization reinforcement and erosion resistance of loess slope were studied in order to provide technology for the prevention and control of slope soil erosion in this region. [Methods] Microbial mineralization technology was used to reinforce a loess slope. The mechanism of microbially induced calcite precipitation (MICP) technology on the mineralization and reinforcement of a loess slope was determined from a microscopic point of view with the use of an optical microscope and a scanning electron microscope. Erosion resistance of the reinforced slope was analyzed combined with an indoor simulated rainfall test. [Results] The erosion resistance of a loess slope could be effectively improved by using microbial mineralization technology to solidify the loess slope. As curing times increased, the thickness of the cured layer gradually increased. The permeability of the slope gradually decreased, and the total production flow gradually increased from 38.5 to 44.4 L/h, with an increase ratio of 15.6%. At the same time, total sediment yield gradually decreased from 480.64 to 17.1 g/h, with a decrease of 96.5%. No obvious soil erosion occurred on the slope after seven solidification treatments and one hour of continuous scouring with a rainfall intensity of 120 mm/h. The runoff and sediment concentration on the slope hardly changed with increased rainfall duration, and were stable between 0.72 and 0.74 L/min and between 0.001 and 0.002 g/ml, respectively. When the number of curing treatments reached seven or more, the number of curing treatments had a significant effect on total sediment yield, and total sediment yield decreased with increasing number of curing treatments. [Conclusion] MICP technology provides a new method and technology for reinforcement of loess slopes in the loess hilly and gully region that will prevent and control soil erosion on temporary and permanent slopes. This technology would be certain to have practical applications.