School of Earth Sciences and Engineering, Hohai University, No. 8 Focheng West Road, Jiangning District, Nanjing, 210098, China; Department of Civil Engineering, University of Victoria, 3800 Finnerty Road, Victoria, BC, V8P 5C2, Canada.
School of Earth Sciences and Engineering, Hohai University, No. 8 Focheng West Road, Jiangning District, Nanjing, 210098, China.
J Environ Manage. 2022 Dec 15;324:116209. doi: 10.1016/j.jenvman.2022.116209. Epub 2022 Sep 23.
External-soil spray seeding (ESSS) is a method often used for the ecological restoration of bare rock slopes. However, the direct use of ESSS is normally less satisfactory due to the erosion of sprayed soil and low survival rate of the plants on rock slopes. This study proposes a novel approach to addressing this issue through the combined use of ESSS with polyvinyl acetate (PVA) based soil stabilization. The PVA solutions are added to the soil to stabilize soil and improve soil strength while possessing high water and nutrient retention favorable for plant growth. A series of experimental tests on the mechanical properties, water stability, erosion resistance, water retention, and plant growth of the PVA-stabilized soil were conducted to assess the efficacy of the proposed method. The results showed that the proposed method could be promising for rock slope ecological restoration. A proper curing time (e.g., >3 days) was required to achieve beneficial effects of PVA on the soil properties. A shorter curing time would otherwise result in the decrease in the strength with the increased PVA content. It was found that the optimum PVA content was 3% for achieving the maximum water stability, erosion resistance, water retention, and plant growth. The cohesion increased by up to 50% and the internal friction angle increased by 3.5° compared to the natural soil. The disintegration rate of the stabilized soil was generally < 3e-3%/min. The maximum reduction in erosion was up to 83% when the PVA content ≥3%. The mechanisms behind the findings are also discussed.
坡面外源土壤喷播（ESSS）是一种常用于裸岩边坡生态恢复的方法。然而，由于喷播土壤的侵蚀和岩质边坡上植物的成活率低，直接使用 ESSS 通常不太令人满意。本研究提出了一种通过将 ESSS 与聚醋酸乙烯酯（PVA）基土壤稳定化相结合来解决这一问题的新方法。将 PVA 溶液添加到土壤中，以稳定土壤并提高土壤强度，同时具有高的保水和保肥能力，有利于植物生长。对 PVA 稳定土的力学性能、水稳定性、抗侵蚀性、保水性和植物生长进行了一系列实验测试，以评估所提出方法的效果。结果表明，该方法有望用于岩质边坡的生态恢复。需要适当的养护时间（例如，>3 天）才能实现 PVA 对土壤性质的有益效果。较短的养护时间会导致强度随 PVA 含量的增加而降低。发现 3%的 PVA 含量是实现最大水稳定性、抗侵蚀性、保水性和植物生长的最佳含量。与天然土壤相比，粘聚力增加了 50%，内摩擦角增加了 3.5°。稳定土的崩解率一般<3e-3%/min。当 PVA 含量≥3%时，最大减蚀率高达 83%。还讨论了研究结果背后的机制。
