降雨条件下土工袋护坡抗冲刷试验研究

Experimental Research on the Anti-erosion Performance of the Slope Protection Using Soilbags under Rainfall Conditions

土工袋护坡是一种新型边坡加固技术,其单体强度和耐久性以及组合体的稳定性均可满足一般护坡的要求,但其抗冲刷能力尚未得到有效评估。为了探究土工袋护坡的抗冲刷能力,进行了大型边坡人工降雨冲刷试验,对比分析了土工袋护坡、石笼护坡及无防护砂土边坡的降雨入渗量和泥沙冲刷量。试验结果表明土工袋护坡能够有效减少雨水下渗量,并大幅降低边坡的土质流失量;土工袋护坡的坡面侵蚀主要集中在土工袋的间隙处,土工袋与边坡接触处无明显径流通道。土工袋的防冲刷机理可归结为压坡作用、消能作用、阻水作用和反滤作用4个方面。

The slope protection using soilbags is a new environment-friendly technology to reinforce the sand slope.To investigate the antierosion performance of the slope protection using soilbags,large-scale rainfall and erosion experimental tests are carried out on the soilbagprotected sand slope,the gabion-protected sand slope as well as the non-protected sand slope.The amount of rainwater infiltration and soil erosion of three slopes is measured.The test results show that the slope protection using soilbags can effectively intercept the infiltration of rainwater into the sand and greatly reduce the loss of soils.There is no obvious runoff channel at the contact area between the soilbags and the slope,while the non-protected slope forms lots of deep crisscrossed runoff channels.The erosion of soilbag-protected slope occurs mainly in the gaps between two rows of soilbags.The mechanism of anti-erosion performance in the slope protection by soilbags is summarized as four aspects:①pressuring the slope;②dissipating the energy of raindrops;③preventing the rainwater infiltrating into the soils of the slope;④filtering the ready-to-run-off soils.