Experimental Study On Ultrasonic Brazing And Microbial Solidification Based On Loess Erosion

The national strategy of ecological protection and high quality development in the Yellow River Basin has brought new opportunities and challenges to soil and water conservation.Soil erosion is serious in the Loess Plateau,and soil erosion monitoring and prevention is the focus of soil and water conservation work.This study based on relevant theories of the loess erosion,soil erosion of newly developed ultrasonic pin test have been carried out to verify the accuracy and reliability of the monitoring equipment,the technical basis is provided for the equipment improvement and application,and carried out microbial solidified loess experimental study to improve the performance of resistance to erosion,provides a new technology for the loess erosion prevention.The main conclusions are as follows:(1)The absolute error range of ultrasonic soil erosion monitoring is 0～2.1mm,and the absolute error does not increase with the increase of soil erosion thickness.When the absolute error is allowed within the range of 0～2mm,the accuracy of monitoring data is 90%.(2)The analysis of ultrasonic brazing data error,standard deviation SD and standard error SE shows that the measurement accuracy of ultrasonic brazing is as follows:No.6 test bit 90.11%,no.3 test bit 80.02%,No.1 test bit 72.90%,No.9 test bit 70.94%,No.4 test bit 70.22%,No.7 test bit 68.63%,No.5 test bit 68.06%,No.8 test bit 67.61%,the average accuracy is 73.56%;(3)The correlation analysis of Pearson linear regression showed that there was a strong positive linear correlation between the soil erosion monitored by ultrasonic drilling and the soil erosion measured by artificial drilling,with a confidence interval of 95%.Ultrasonic brazing monitoring has good accuracy and reliability,and can replace manual measurement in indoor artificial simulation of rainfall erosion.(4)According to runoff scour test of microbial cured loess,when the scour flow rate was 4L/min,the sediment yield of MICP-cured soil samples was significantly lower than that of non-MICP soil samples,and the sediment yield of MICP-cured soil samples on 5°,15° and 25° scour slopes was reduced by 73.61%,94.10%and 81.53%,respectively.Compared with non-MICP soil samples,the anti-impact coefficient of MICP-cured soil samples on 5°,15° and 25° scour slopes increased by 1.26 times,6.67 times and 1.92 times,respectively.