降雨条件下微生物技术治理崩岗侵蚀

Mitigating Erosion of Collapsing Gully by Microbial Technology under Rainfall Conditions

崩岗是中国花岗岩地区危害最大的一种土壤侵蚀方式,坡面防护是崩岗侵蚀治理的重要措施。为研究微生物诱导碳酸钙沉淀(MICP)技术在花岗岩崩岗侵蚀区冲刷防护中应用的可行性,以福建省崩岗最为发育的安溪县官桥镇花岗岩土质覆盖层为研究对象,进行降雨条件下微生物治理崩岗的模型试验研究。采用喷洒加固法对崩岗坡面进行处理,然后利用降雨模拟系统冲刷坡面,最后分析了MICP加固技术对泥沙产量及坡面侵蚀深度的影响。结果表明:与未加固边坡相比,MICP固化边坡泥沙产量由未加固的7648.43 g下降至266.61 g,较加固之前降低了96.51%;最大侵蚀深度由未加固的60 mm下降至除个别侵蚀坑外边坡表面基本未发生侵蚀。

Collapsing gully is the most serious soil erosion phenomenon in granite region in China.Slope surface protection is an important measure to control the erosion of collapsing gully soil.Collapsing gully soil in Guanqiao town in Anxi county,one of the most developed areas in Fujian Province,was investigated in this study and a model experiment was carried out to investigate the feasibility of the application of microbially induced carbonate precipitation(MICP)technology on the slope surface erosion protection.The MICP spraying technology was used to treat the surface of the collapsing gully soil slope.Then,the slope was flushed by an artificial rainfall simulation system.The impacts of the MICP technology on the amount of substance in the effluent and erosion depth on the slope surface were analyzed.The results show that the amount of matter in the effluent of treated slope decreased from 7648.43 g to 266.61 g,which was 96.51%lower than that before treatment;the erosion depth decreased from 60 mm to no obvious erosion except for individual erosion hole compared with untreated slopes.The current work shows that the MICP technology can effectively reduce the erosion of residual soil slope in collapsing gully region.