摘要
脲酶诱导碳酸钙沉积是一种新型的土体加固技术,该技术通过脲酶催化尿素水解,生成碳酸钙晶体,起到充填、胶结岩土材料的作用,本研究将该技术用于风积沙的表面固化,通过室内试验研究其效果和机理.脲酶从大豆中提取,与等量的氯化钙和尿素溶液混合后喷洒于试样表面,在试样表面形成薄层硬壳.通过测试试样的表面强度、风蚀率、保水性、渗透性和碳酸钙生成量,检验该技术的防风固沙效果.结果表明,经碳酸钙胶结形成的表层硬壳可以达到兆帕级强度,试样保水性较未处理试样提高了60%,风蚀率和渗透速率显著降低,生成碳酸钙含量约为0.6%.通过与仅喷洒盐溶液和仅喷洒酶液的试样对比,表明盐分和酶都具有一定的防风固沙效用,但胶结液可以综合两者的作用机理,且生成的碳酸钙使颗粒胶结更为耐久.
Calcium carbonate precipitation induced by urease is a new soil consolidation technology,which catalyzes the hydrolysis of urea to produce calcium carbonate crystal and plays the role of filling and cementing geotechnical materials.In the study,the technology was applied to the surface solidification of aeolian sand,and its effect and mechanism were studied through laboratory experiments.Urease extracted from soybean was mixed with equal amount of calcium chloride and urea solution.The surface of the sample sprayed with the mixed solution formed a thin hard layer.The wind-proof and sand-fixing effect of the technology was tested by testing the surface strength,wind erosion rate,water retention,permeability and calcium carbonate production.The results show that the surface hard shell formed by calcium carbonate cementation can reach MPa magnitude strength,the water retention of the sample is60%higher than that of the untreated sample,and the wind erosion rate and the permeation rate are significantly reduced.The mass ratio of resulting calcium carbonate is about 0.6%.Compared with samples only sprayed with salt solution and enzyme solution,it showed that both salt and enzyme have a certain effect of wind break and sand fixation.However,the cementing solution possesses the two mechanism,and the calcium carbonate formed makes the particle cementation more durable.
作者
刘阳
高玉峰
何稼
亓永帅
LIU Yang;GAO Yufeng;HE Jia;QI Yongshuai(Key Laboratory of Geomechanics and Embankment Engineering,Ministry of Education,Hohai University,Nanjing 210024,China)
出处
《河南科学》
2019年第11期1784-1789,共6页
Henan Science
基金
国家自然科学基金（51608169）
关键词
大豆脲酶
防风固沙
表面强度
风蚀率
保水性
soybean urease
wind break and sand fixation
surface strength
wind erosion rate
water retention
作者简介
刘阳(1995-),女,硕士研究生,主要研究方向为生物岩土技术;通信作者:高玉峰(1966-),男,教授,博士生导师,主要研究方向为岩土与地震工程。
