微生物固化工程裸土抗风蚀扬尘性能试验研究

Experimental study on wind erosion and fugitive dust resistance of engineering bare soil using microbial consolidation

目的 岩土微生物技术在土木工程领域已广泛应用,本文基于微生物诱导碳酸钙沉积(MICP)固化土体技术,探究其固化土体的抗风蚀扬尘效果及固化机理。方法 利用巴氏生孢八叠球菌,对比分析微生物固化典型工程裸土建筑渣土和砂土试样和其洒水固化试样,通过风洞试验、表面强度测试、微观结构观测研究微生物固化试样抗风蚀扬尘性能,提出一种新型土壤抑尘措施。结果 根据风洞试验和表面强度测试结果发现:同比条件下,微生物固化试样风蚀质量累计损失远远低于洒水试样的,风洞试验后微生物固化试样表面强度虽有所下降,但其表面强度仍强于洒水试样,试验结果验证了微生物固化工程裸土提升其抗风蚀扬尘的可行性及其显著效能.基于电镜扫描和X射线能谱试验分析显示:渣土和砂土试样经微生物固化后,土颗粒表面和孔隙间均产生大量碳酸钙沉积,有效增强了土颗粒间黏结性能,但CaCO_(3)晶体结构在不同土壤中略有差异,在工程渣土试样中主要为片状结构、在砂土试样中为球状或球状堆积体结构。结论 微生物固化技术有效提升了土壤抗风蚀扬尘性能,且具备良好的时效性,对土壤防尘治理具有一定的参考价值。

Objectives Geotechnical microbial technology has shown a wide range of application prospects in the field of civil engineering.Based on the Microbial Induced Calcium Carbonate Precipitation(MICP) soil solidification technology,this paper explores the resistance to wind erosion and dust effect and the solidification mechanism of the solidified soil.Methods Using Sporosarcina pasteurii,a comparative analysis of microbial solidified typical construction bare soil,construction waste,and sand specimens and their watered specimens were conducted.The resistance to wind erosion and dust of microbial solidified specimens was studied by wind tunnel test,surface strength test,and microstructure observation,and a new soil dust suppression measure was proposed.Results According to the results of the wind tunnel test and surface strength test,it was found that the cumulative loss of wind erosion mass of microbial solidified specimens was much lower than that of watered specimens under the same conditions.Although the surface strength of microbial solidified specimens decreased after the wind tunnel test,its surface strength was still stronger than that of watered specimens.The test results verified the feasibility and significant efficiency of microbial solidified construction bare soil to improve its resistance to wind erosion and dust.Based on scanning electron microscopy and X-ray energy spectrum test analysis,after the soil specimen was solidified by microorganisms,a large amount of CaCO_(3) deposition was produced on the surface of the soil particles and between the pores,which effectively enhanced the bonding performance between the soil particles.The crystal structure of CaCO_(3) was slightly different in different soils.It was mainly a flaky structure in construction waste and a spherical or aggregated structure in sand specimens.Conclusions Microbial solidification technology effectively enhances soil resistance to wind erosion and dust,with good durability,thereby offering valuable insights for soil dust control measures.