China is one of the countries with the most serious soil erosion disaster, especially in Loess Plateau region. A new strategy for loess surface erosion control using MICP technology in terms of spraying was proposed. The feasibility, mitigation mechanism and the effects of MICP treatment cycle and cementation solution (CS) concentration were investigated through the rainfall erosion test and penetration test. It is found that the proposed MICP technique shows the ability to mitigate the rainfall erosion of loess. Final accumulative soil erosion weight could reach a maximum reduction of 200 times after only 3 cycles of MICP spaying treatment and almost no soil loss was observed since 5 cycles of treatment. The mitigation mechanism can be attributed to the MICP induced double layer structure, namely the upper hard crust layer on soil surface and the lower weak cemented layer, which is attributed to the bonding effect of the precipitated calcium carbonate (CaCO₃) between soil particles and the filling effect in pores. The high structure strength of the hard crust can resist the impact of raindrops as well as can resist runoff erosion. The low permeability of the hard crust effectively prevents the rainwater infiltration to soft the subsurface weak cemented layer and deep uncemented soil. With increasing MICP treatment cycles, the amount CaCO₃ and the thickness of the hard crust layer increases accordingly, leading to higher soil structure strength and erosion resistance. The CaCO₃ content generally decreases with increasing depth. It is also found that the loess treated by 1.0 M CS presents the highest CaCO₃ content, hard crust layer thickness and soil structure strength as compare with the samples treated by 1.5 M and 0.5 M CS. Taking into account the overall effectiveness, efficiency and cost, 5 cycles of MICP treatment with 1.0 M CS is optimal for the mitigation of the rainfall erosion of the tested loess.

我国是水土流失灾害最严重的国家之一，尤其是黄土高原地区。提出了一种利用MICP技术喷洒防治黄土表面侵蚀的新策略。通过降雨侵蚀试验和渗透试验研究了MICP处理周期和胶结溶液(CS)浓度的可行性、减缓机制和影响。结果表明，所提出的 MICP 技术显示出减轻黄土降雨侵蚀的能力。仅3个周期的MICP喷施处理后，最终累积的土壤侵蚀重量最多可减少200倍，并且5个周期以来几乎没有观察到土壤流失。缓解机制可归因于 MICP 诱导的双层结构，₃ ) 土粒间与孔隙中的充填作用。坚硬的地壳结构强度高，既能抵抗雨滴的冲击，又能抵抗径流侵蚀。硬地壳的低渗透性有效地阻止了雨水的渗透，软化了地下的弱胶结层和深层未胶结的土壤。随着MICP处理周期的增加，CaCO ₃的含量和硬壳层的厚度相应增加，导致土壤结构强度和抗侵蚀能力提高。CaCO ₃含量通常随着深度的增加而降低。还发现1.0 M CS处理的黄土呈现出最高的CaCO ₃与 1.5 M 和 0.5 M CS 处理的样品相比，含量、硬壳层厚度和土壤结构强度。考虑到整体效果、效率和成本，1.0 M CS 5 个周期的MICP 处理对于缓解测试黄土的降雨侵蚀是最佳的。