原泽, 晏长根, 陶悦, 等. 2023. 骨架防护黄土边坡坡面冲蚀模型试验研究[J]. 工程地质学报, 31(6): 1989-1998. doi: 10.13544/j.cnki.jeg.2022-0118.
    引用本文: 原泽, 晏长根, 陶悦, 等. 2023. 骨架防护黄土边坡坡面冲蚀模型试验研究[J]. 工程地质学报, 31(6): 1989-1998. doi: 10.13544/j.cnki.jeg.2022-0118.
    Yuan Ze, Yan Changgen, Tao Yue, et al. 2023. Erosion model test of loess slope with framework protection[J]. Journal of Engineering Geology, 31(6): 1989-1998. doi: 10.13544/j.cnki.jeg.2022-0118.
    Citation: Yuan Ze, Yan Changgen, Tao Yue, et al. 2023. Erosion model test of loess slope with framework protection[J]. Journal of Engineering Geology, 31(6): 1989-1998. doi: 10.13544/j.cnki.jeg.2022-0118.

    骨架防护黄土边坡坡面冲蚀模型试验研究

    EROSION MODEL TEST OF LOESS SLOPE WITH FRAMEWORK PROTECTION

    • 摘要: 西部黄土地区高边坡多采用骨架结构进行防护,但其服役期间容易产生土体侵蚀破坏,造成防护效力的局部丧失,严重者甚至可诱发垮塌灾害。通过开展人工模拟降雨冲蚀模型试验,对比分析了裸坡和骨架边坡的坡面冲蚀过程、含沙量、径流量及累计冲蚀量,探讨了骨架结构的防护效果,厘清了骨架关键部位处的坡面冲蚀规律,揭示了强降雨诱发骨架防护边坡侵蚀破坏机制。试验结果表明:骨架结构具有一定防护效力,但其框格边缘土体容易侵蚀破坏;随着降雨时间增长,裸坡和骨架边坡的含沙量、径流量及累计冲蚀量均逐渐增加。相比于裸坡,冲蚀60 min时骨架边坡的含沙量降低25%(坡比1 ︰ 1.5),21.4%(坡比1 ︰ 1.75),径流量降低33.6%(坡比1 ︰ 1.5),31.4%(坡比1 ︰ 1.75),累计冲蚀量降低43.6%(坡比1 ︰ 1.5),40.0%(坡比1 ︰ 1.75);骨架关键部位,尤其是尖角边缘土体所承受的雨水冲刷作用较强,其冲蚀演化历程归纳为:溅蚀-片蚀-细沟侵蚀-切沟侵蚀(初次冲蚀),或溅蚀-片蚀-切沟侵蚀(再次冲蚀);骨架结构可限制土颗粒运移、削弱径流冲蚀,起到截流、挡水及分流作用,但也会在骨架关键部位处产生较为明显的边缘汇流现象,容易使得骨架支撑土体的侵蚀破坏,造成骨架结构的局部悬空。研究成果可为黄土地区路堤边坡拱形骨架防护的优化设计与现场施工提供参考。

       

      Abstract: The high slopes in the western loess area are mostly protected by skeleton structures. During its service,the structure is prone to erosion and damage of slope soil,resulting in partial loss of protective effectiveness. Moreover,it can even induce collapse disasters in severe cases. This paper carries out a series of artificial simulated rainfall erosion model tests. The slope erosion process,sediment content,runoff,and cumulative erosion amount of bare slope,and skeleton slope are compared and analyzed. The protective effect of the skeleton structure is discussed,and the slope erosion law of the key parts of the skeleton is clarified. The mechanism of erosion and damage to skeleton protection slope induced by heavy rainfall is revealed. The results show the follows. The skeleton structure has a certain protective effect,but the soil at the edge of the sash is easy to be eroded and damaged. With the increase in rainfall time,the sediment content,runoff,and cumulative erosion of bare slope and skeleton slope gradually increase. Compared with the bare slope,the sediment content of the skeleton slope at erosion for 60 min is decreased by 25%(slope ratio 1 ︰ 1.5),21.4%(slope ratio 1 ︰ 1.75),and the runoff is decreased by 33.6%(slope ratio 1 ︰ 1.5),31.4%(slope ratio 1 ︰ 1.75),the cumulative erosion amount is decreased by 43.6%(slope ratio 1 ︰ 1.5),40.0%(slope ratio 1 ︰ 1.75). The key parts of the skeleton structure,especially the soil at the sharp corners,are strongly eroded by rainwater. The erosion evolution process can be summarized as from splash erosion to sheet erosion, to rill erosion, to cutting ditch erosion(primary erosion),or from splash erosion to sheet erosion, and to gully erosion(erosion again). The skeleton structure can limit the migration of soil particles,weaken the runoff erosion,and play the role of interception,water retention,and diversion. However,there would also be a relatively obvious edge confluence phenomenon at the key parts of the skeleton. It is easy to cause erosion and damage to the soil below the vertical support of the skeleton,making the skeleton partially suspended. The research results can provide a reference for the optimal design and site construction of arched skeleton slope protection for embankment slopes in loess areas.

       

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