针对黄土高原北部砂黄土结构松散、颗粒间黏聚力较小,容易被雨水侵蚀产生破坏的问题,采用MICP技术进行覆膜防护。为探究钙源和处理轮次对砂黄土MICP覆膜效果的影响,选用氯化钙、乙酸钙、乳酸钙3种钙源在4种不同轮次下对坡面模型覆膜处理,并对覆膜后的试样进行碳酸钙含量测定、室内降雨冲刷试验和微型贯入试验。研究结果表明：不同钙源的覆膜形式不同,氯化钙和乙酸钙主要通过增加土颗粒间的黏聚力加固土体,而乳酸钙更多的是在土体表面生成硬壳层来保护土体。钙源及处理轮次对砂黄土MICP覆膜效果的影响主要体现在碳酸钙含量和固化深度两方面,且不同钙源在不同处理轮次下的覆膜效果存在差异。氯化钙作为钙源,处理3轮以上时,覆膜效果较好,但处理超过5轮后,覆膜效果增加不明显；乙酸钙作为钙源,处理1轮时覆膜效果较差,处理3到7轮时,随着轮次增加,覆膜效果增加明显；乳酸钙作为钙源,处理1轮时覆膜效果较好,处理3轮以上时,效果不如氯化钙和乙酸钙。研究成果可为鄂尔多斯地区砂黄土坡面侵蚀的防护提供一定的借鉴。

In view of the loose structure of sand loess in the northern Loess Plateau, the cohesion between particles is small, and it is easy to be damaged by rainwater erosion, MICP technology is used for film mulching protection. The effects of calcium source and treatment rounds on the MICP mulching effect of sandy loess were investigated. Three calcium sources of calcium chloride, calcium acetate and calcium lactate were selected to mulch the slope model under four different rounds. The calcium carbonate content, indoor rainfall scouring test and micro-penetration test were carried out on the samples after mulching. The results show that: Different calcium sources have different coating forms. Calcium chloride and calcium acetate mainly strengthen the soil by increasing the cohesion between soil particles, while calcium lactate is more likely to form a hard shell layer on the surface of the soil to protect the soil. The effects of calcium source and treatment rounds on the MICP coating effect of sandy loess are mainly reflected in the content of calcium carbonate and the curing depth. The effects of different calcium sources on film mulching under different treatment rounds were different. When calcium chloride was used as calcium source, the effect of film mulching was better when the treatment was more than 3 rounds, and the effect of film mulching was not obvious when the treatment was more than 5 rounds. Calcium acetate as a calcium source, the effect of film mulching was poor when treated for 1 round. When treated for 3 to 7 rounds, the effect of film mulching increased significantly with the increase of rounds. Calcium lactate as a calcium source, the effect of film mulching was better when treated for 1 round, but the effect was not as good as calcium chloride and calcium acetate when treated for more than 3 rounds. The research results of this paper can provide some reference for the protection of sand loess slope erosion in Ordos area.

TU45

内蒙古自然科学基金(2022LHMS05010)；内蒙古自治区直属高校基本科研业务费项目(JY2022096，ZTY2023058，ZTY2023056)