高速公路弃土场堆积边坡的生态防护试验

Ecological protection of spoil ground accumulation slope in expressway construction

高速公路弃土场边坡的生态恢复与水土保持是公路建设环境保护的重要内容。在京珠高速公路粤境南段3号弃土场开展试验,探讨弃土场堆积边坡的生态防护技术及其应用效果。结果表明:弃土场采用香根草(Vetiveria zizaniodes)生态护坡技术,香根草在无养护措施的情况下能够快速生长形成密集草带,并具先锋植物的优势,1年后坡面植被覆盖率达100%,乡土植物种类增加到16种以上;而对照坡面植被自然恢复缓慢,仅生长少量本地杂草,植被覆盖率只有15%。香根草护坡效果显著,坡面土壤流失量比对照小区减少95·41%,边坡稳定,在一定程度上可代替浆砌片石骨架植草护坡措施。因此,高速公路弃土场边坡可大力推广应用香根草生态护坡技术。

Ecological restoration and soil and water conservation of spoil ground slope are the key projects of environmental protection in expressway construction. In this paper, an in situ experiment was conducted at the No. 3 spoil ground of Beijing-Zhuhai expressway＇ s south section within the boundaries of Guangdong Province to approach the ecological protection techniques of spoil ground accumulation slope and their application effects. The results showed that planting Vetiveria zizaniodes had significant ecological effects. Under conditions without any conservation measures adopted, this plant species could grow fast to form a thick grass belt, and had the pioneer superiority. After one year＇ s V. zizaniodes growth, the vegetation coverage on the slope reached 100%, and the native plant species increased to 16 or more. On the contrary, the natural recovery of vegetation on the control plot was quite slow, only a few native weeds grew there, and the vegetation coverage was only 15%. Compared with control plot, the soil loss from the slope planted with V. zizaniocles was decreased by 95.41%, and the slope was quite stable. To a certain extent, planting V. zizaniodes could replace planting grass in mortar-rubble skeleton. It could be feasible to popularize V. zizaniocles planting to protect the spoil ground accumulation slope along expressway.