摘要
鄂尔多斯地区的砂状非典型黄土具有遇水土体结构破坏、强度降低的特性,极易发生水土流失。该文采用微生物诱导碳酸钙沉积(microbial induced carbonate precipitation,MICP)技术对砂状非典型黄土进行覆膜防护处理,并探究钙源和喷洒顺序对覆膜强度的影响。首先,开展不同钙源反应效率试验,探究钙源对碳酸钙生成量、生成速率及晶型的影响。然后,进行不同喷洒顺序下的微生物覆膜试验,并测定不同条件下的覆膜强度。研究结果表明,不同钙源条件下,碳酸钙的生成效率和晶体形态表现出显著的差异。以乳酸钙为钙源时,碳酸钙生成量出现快速增长阶段,主要晶型为方解石。氯化钙和乙酸钙为钙源时,碳酸钙的生成量呈线性增长。氯化钙为钙源时,主要晶型为方解石,乙酸钙为钙源时,主要晶型为球霰石。因此,可选择乳酸钙作为覆膜钙源。改变喷洒顺序可以提高覆膜的表面强度,但机理不同。氯化钙、乙酸钙为钙源时,采用先喷洒胶结液后喷洒菌液的顺序,会延长表面强度增长期的时间,强度比原喷洒顺序分别提高了16%和20%。乳酸钙作为钙源时,采用先喷洒胶结液后喷洒菌液的喷洒顺序,可以在注入菌液时再溶解一部分乳酸钙到土体内,碳酸钙含量提高了45%,覆膜强度增加了33%。该研究可为鄂尔多斯砂状非典型黄土水土流失的防治提供试验依据。
The sandy atypical loess in Ordos area is prone to soil erosion due to its structural damage and strength reduction when exposed to water.The microbial induced carbonate precipitation(MICP)technology was used to protect sandy atypical loess with film coating,and the effects of calcium source and spraying sequence on film coating strength were also investigated.First,the reaction efficiency test of different calcium sources was carried out to explore the influence of calcium sources on the amount of calcium carbonate generation,the formation rate and the crystal form.Then the microbial film coating test was carried out under different spraying sequences,and the film coating strength was measured under different conditions.The results showed that,the formation efficiency and crystal morphology of calcium carbonate were significantly different under different calcium sources.When calcium lactate was used as the calcium source,calcium carbonate production increased rapidly,and the main crystalline form was calcite.When calcium chloride or calcium acetate was the calcium source,the amount of calcium carbonate produced increased linearly.When calcium chloride was the calcium source,the main crystal type was calcite,and when calcium acetate was the calcium source,the main crystal type was vaterite.Therefore,calcium lactate could be selected as the calcium source for the film.Changing the spraying sequence could improve the surface strength of the film,but the mechanism was different.When calcium chloride or calcium acetate was used as the calcium source,the duration of the surface strength growth period was prolonged by spraying the cement solution first and then the bacterial solution,and the strength was increased by 16%and 20%respectively.When calcium lactate was used as the calcium source,part of the calcium lactate could be dissolved into the soil when the cement solution was sprayed first and then the bacterial solution was sprayed,so the content of calcium carbonate was increased by 45%and the coating strength was increased by 33%.This study could provide experimental basis for the prevention and control of soil erosion in Ordos.
作者
杜强
刘旭梅
曲立强
刘超凡
李佳良
DU Qiang;LIU Xumei;QU Liqiang;LIU Chaofan;LI Jialiang(School of Civil Engineering,Inner Mongolia University of Technology,Hohhot 010051,China;Key Laboratory of Geological Hazards and Geotechnical Engineering Defense in Sandy and Drought Regions at Universities of Inner Mongolia Autonomous Region,Hohhot 010051,China;Inner Mongolia Engineering Research Center of Geological Technology and Geotechnical Engineering,Inner Mongolia University of Technology,Hohhot 010051,China)
出处
《自然灾害学报》
北大核心
2025年第5期181-191,共11页
Journal of Natural Disasters
基金
内蒙古自然科学基金项目(2022LHMS05010,2025MS05004)
内蒙古自治区直属高校基本科研业务费项目(JY2022096,ZTY2023058,ZTY2023056)。
