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微生物诱导碳酸钙沉积(MICP)加固土体是近年来受到学术界重视的问题,但是对实际土壤温度下MICP加固土体的可行性及效果研究未见报道。利用尿素水解菌ATCC 11859,进行了微生物诱导碳酸钙沉积的试管试验及一维砂柱试验,研究了不同温度下微生物诱导生成碳酸钙的特性及对土体的加固效果。试管试验表明温度越高生成的碳酸钙越多,在不同温度下微生物诱导生成的碳酸钙晶型无显著差异,但是温度对碳酸钙的生成速率有明显影响。一维加固试验表明MICP在一般土壤温度条件下都能够有效地加固土体,但低温下MICP加固的试样强度较低,渗透系数较高。
Microbial-induced calcium carbonate (MICP) soil reinforcement has been the subject of great academic attention in recent years. However, no study has been reported on the feasibility and effectiveness of MICP soil reinforcement at actual soil temperature. Using urea hydrolyzate ATCC 11859, a tube test and one-dimensional sand column test of microbial induced calcium carbonate deposition were carried out to study the characteristics of calcium carbonate induced by microorganisms at different temperatures and the reinforcement effect on soil. Test tube tests showed that the higher the temperature, the more calcium carbonate produced, the different forms of calcium carbonate crystals induced by microorganisms did not show any significant difference, but the temperature had a significant effect on the formation rate of calcium carbonate. One-dimensional reinforcement tests show that MICP can effectively reinforce soil under normal soil temperature conditions. However, MICP-strengthened specimens have lower strength and higher permeability coefficient at low temperature.