摘要
大豆脲酶诱导碳酸钙沉积技术(SICP)是一种新型环保生物加固土体技术,黄原胶是一种新型环境友好型土体改良材料,将大豆脲酶诱导碳酸钙沉积技术与黄原胶相结合,对前者进行优化改进。通过表面强度试验发现,黄原胶能提高SICP固土所得表面强度,且表面强度随着大豆脲酶胶结液浓度和黄原胶浓度上升而上升。通过风沙吹蚀试验,测定试样在不同强度不含沙风蚀和含沙风蚀下的质量损失率并观测表面硬壳破损情况,发现仅用SICP技术处理的试样具有较好的抵抗风沙侵蚀能力,黄原胶的加入进一步优化了其抵抗能力,降低了试样质量损失率,且表面硬壳层保存更加完好。此外,试验考虑风夹带沙侵蚀作用,由于沙颗粒的冲击和磨蚀,含沙风蚀破坏作用强于净风吹蚀,处理所得强度最低的试样在15 m/s不含沙风蚀1 h工况下,质量损失率仅为3.8%,而在同等含沙风蚀工况下,质量损失率达66.7%,说明考虑风沙吹蚀是必要的。同时发现,经过处理的土体,其抗风能力和表面强度之间有较强的正相关性。通过SEM扫描电镜试验观察其微观结构,发现胶体的包裹黏结和持续硬化,可能使得碳酸钙与土颗粒之间的胶结更为紧密。
The technology of soybean urease-induced calcium carbonate precipitation(SICP)is a new environmentally-friendly soil improvement technology.Xanthan gum can also be used as a soil cementation material.This study combines the technology of soybean urease-induced calcium carbonate precipitation and xanthan gum to optimize the former.It is found that the xanthan gum can further improve the surface strength of SCIP-improved sand.The surface strength increases with the increase of the concentration of soybean urease and xanthan gum.The wind erosion tests are carried out on the sand samples with different treatment levels using pure wind and wind mixed with solid particles.The samples treated only by SICP technology have relatively strong resistance to wind sand erosion.The addition of xanthan gum further improves their resistance by showing a lower erosion rate of the samples.In addition,the results indicate that in the wind erosion tests,the presence of solid particles have a strong erosion effect on the deterioration of the sand surface.The erosion rate(mass loss%)of the samples with the lowest strength is only 3.8%under the wind of 15 m/s and 1 h in the tests with pure wind,while under the same condition,the erosion rate is 66.7%in the tests using wind mixed solid particles.It is also found that there is a strong positive correlation between the wind erosion resistance and the surface strength of the treated soil.The microstructure of the treated sand samples is investigated by the SEM.It is observed that the cementation between the calcium carbonate and the soil particles becomes stronger due to the binding and the hardening effects of the xanthan gum.
作者
吴敏
高玉峰
何稼
刘阳
WU Min;GAO Yu-feng;HE Jia;LIU Yang(Key Laboratory of Ministry of Education for Geomechanics and Embankment Engineering,Hohai University,Nanjing 210024,China)
出处
《岩土工程学报》
EI
CAS
CSCD
北大核心
2020年第10期1914-1921,共8页
Chinese Journal of Geotechnical Engineering
基金
国家自然科学基金面上项目(51978244,51979088,51608169)。
关键词
SICP
黄原胶
防风固沙
表面强度
风蚀试验
SEM扫描电镜试验
soybean urease-induced calcium carbonate precipitation
xanthan gum
windbreak and sand fixation
surface strength
wind erosion experiment
scanning electron microscopy
