| 引用本文: | 田志锋,唐小微,修志龙,薛志佳.不同形式生物液加固砂土试验及机理分析[J].哈尔滨工业大学学报,2020,52(11):120.DOI:10.11918/201901012 |
| TIAN Zhifeng,TANG Xiaowei,XIU Zhilong,XUE Zhijia.Experimental study and mechanism analysis on sand reinforcement with different compositions of biological solution[J].Journal of Harbin Institute of Technology,2020,52(11):120.DOI:10.11918/201901012 |
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| 摘要: |
| 为研究用新鲜培养基重悬巴氏球菌菌体(RF)对砂土加固效果是否有促进作用及其作用机理,通过一系列溶液及砂柱试验对比分析4种不同形式生物液的尿素水解、诱导生成碳酸钙(MICP)及砂土加固能力.结果表明:培养完成后未经任何处理的原菌液(US)的尿素水解及MICP能力主要来源于菌体内脲酶,另一部分源于菌体裂解释放的游离脲酶；高菌液浓度时,用新鲜培养基重悬菌体可一定程度促进菌液中菌体的MICP能力,但由于RF制备时移除上清液(SS),造成脲酶损失,导致RF的总体MICP能力与原菌液基本相同；经原菌液加固的砂柱具有更高的抗剪强度及碳酸钙产量, 且原菌液中上清液和菌体的共存使砂颗粒间产生的胶结接触更有效.相比RF,原菌液兼顾简便、经济及高效性,因此,在MICP处理需快速加固的地基问题时原菌液应被优先选用. |
| 关键词: 碳酸钙沉淀 脲酶活性 生物加固砂 抗剪强度 有效胶结接触 |
| DOI：10.11918/201901012 |
| 分类号:TU44 |
| 文献标识码:A |
| 基金项目:国家重点研发计划(2016YFE0200100)； 国家自然科学基金重点项目(51639002) |
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| Experimental study and mechanism analysis on sand reinforcement with different compositions of biological solution |
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TIAN Zhifeng1,TANG Xiaowei1,XIU Zhilong2,XUE Zhijia3
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(1.State Key Laboratory of Coastal and Offshore Engineering(Dalian University of Technology), Dalian 116024, Liaoning, China; 2.School of Life Science and Biotechnology, Dalian University of Technology, Dalian 116024, Liaoning, China; 3.School of Highway, Chang'an University, Xi'an 710064, China)
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| Abstract: |
| To assess the possibility of promotion of fresh medium to resuspend thallus (RF) in sand reinforcement and its mechanisms, a series of solution and sand column tests were conducted to analyze the abilities of four biological solutions with different compositions in urea hydrolysis, MICP, and sand reinforcement. Results show that the ability of the original bacterial solution (US) without any treatment after the completion of culture in urea hydrolysis and MICP mainly derived from the urease in thallus, and the other part came from the free urease released by lysis of bacteria. With high concentration of bacterial solution, the resuspension of thallus by fresh medium could promote the MICP ability of thallus of the biological solution to some extent, however, the removal of supernate (SS) in preparing RF led to urease loss, which resulted in the total MICP ability of RF basically the same with that of the original bacterial solution. The sand column reinforced by original bacterial solution had more calcium carbonate precipitation and higher shear strength, and the co-existence of SS and thallus led to more effective cementation contact. Compared with RF, US has the characteristics of simple, low cost, and high activity, which can be preferred selected in the application of MICP in solving the foundation problem that requires rapid reinforcement. |
| Key words: calcium carbonate precipitation urease activity bio-reinforced sand shear strength effective cementation contact |
