微生物砂浆防护粉土坡面的强度与抗侵蚀性影响因素分析

发布时间：2018-09-05 10:00

【摘要】：微生物砂浆表面防护处理是处理粉土边坡扬尘与水流侵蚀问题的新技术。采用微生物砂浆层对粉土表面进行防护处理试验,通过微型贯入试验、水稳定性试验以及模拟降雨冲刷试验,分析了微生物砂浆防护层厚度、CaCl_2和尿素混合胶结溶液浓度、喷洒处理遍数等参数变化对微生物砂浆表面防护层的强度、水稳定性和土壤剥蚀率等性能的影响规律。结果表明,微型贯入仪可用于微生物砂浆表面防护层的强度测定,防护层的强度、水稳定性随胶结溶液浓度和喷洒处理遍数的增长而提高,最小有效厚度为5 mm。采用浓度为0.50 mol/L胶结溶液喷洒4遍,厚5 mm的防护层能够达到贯入阻力310 kPa,防护强度比77.5,崩解率2.3%,浸水强度损失率5.4%,具备较高的强度和较好的抗崩解性与强度水稳定性。粉土边坡在微生物砂浆防护前后,土壤剥蚀率能够从大于29.6降至6.8 g/(m~2·s)以下。该研究表明,微生物砂浆层用于粉土表面防护具有较好的抗冲刷性;微生物诱导结晶的方解石形成包裹砂颗粒的胶结微结构,能够使表面防护砂浆层具备良好的抗水流侵蚀性。
[Abstract]:Surface protection of microbial mortar is a new technique to deal with dust and water erosion of silt slope. The microorganism mortar layer was used to protect the silt surface. The concentration of mixed cement solution of CaCl2 and urea was analyzed by micro-penetration test, water stability test and simulated rainfall scour test. The effects of the parameters such as the number of times of spraying treatment on the strength, water stability and soil erosion rate of the surface protective layer of microbial mortar were studied. The results show that the micro penetration instrument can be used to measure the strength of the protective layer on the surface of microbial mortar. The strength and water stability of the protective layer increase with the increase of the concentration of cemented solution and the number of spraying times. The minimum effective thickness is 5 mm.. The protective layer with a concentration of 0.50 mol/L cementing solution was sprayed for 4 times, and the protective layer with a thickness of 5 mm could achieve the penetration resistance of 310 kPa, the ratio of protection strength to the ratio of 77.5 kPa, the disintegration rate of 2.3%, the loss rate of immersion strength of 5.4 times, which had higher strength, better resistance to disintegration and better stability of strength and water. The soil erosion rate of silt slope can be reduced from 29.6 to 6.8 g / (m ~ 2 s) before and after microbial mortar protection. The results show that the microbial mortar layer has good scour resistance when it is used for the surface protection of silt, and the microorganism induces the crystallization of calcite to form the cemented microstructure of the coated sand particles, which can make the surface protective mortar layer have good resistance to water flow erosion.
【作者单位】：南京林业大学土木工程学院;江苏省水土保持与生态修复重点实验室;
【基金】：国家自然科学基金项目(51578293) 江苏高校优势学科建设工程资助项目(PAPD2015) 国家大学生实践创新训练计划项目(201510298005Z)
【分类号】：S157.1

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