| 摘要: |
| 【目的】针对陕南秦巴山区梯田垮坎严重，石坎、混凝土预制件坎等难以大面积推广的现状，探索PP织物袋筑坎的稳定性，为PP织物袋梯田田坎在不同高度、坡度和降雨强度等各因素组合影响下的构筑提供参考。【方法】以PP织物袋梯田筑坎作为研究对象，坡度设置65°～70°和70°～75° 2个处理，每个处理分有连接扣和无连接扣共4个处理，并对各个处理的田坎设置坎高1.0，1.2，1.4 m。对各处理分别在雨前和雨后进行试验，测定抗剪强度、抗滑力、抗倾覆力和土压力，然后分析各个处理的田坎稳定性。【结果】强降雨后，随着土压力的增大，PP织物袋田坎剪切强度显著增加，抗倾覆稳定系数和抗滑稳定系数显著减小；增加连接扣后抗剪切作用明显；强降雨后，在无连接扣的条件下发生剪切破坏的可能性更大，主要集中在坎高1.2～1.4 m的第2、3层；在有连接扣的条件下，田坎的剪切破坏多发生在坎高1.2～1.4 m的第3层，而且坡度越大破坏发生的可能性越大；当PP织物袋田坎的坡度为65°～75°、坎高≥1.2 m时，强降雨后容易发生滑动破坏，但基本不会发生倾覆破坏。【结论】PP织物袋梯田田坎在坎高≤1.0 m、坎坡65°～75°时都是稳定的；在有连接扣的条件下，当坎高≥1.2 m、坎坡为65°～75°时，强降雨后更容易发生滑动破坏。 |
| 关键词: PP织物袋 梯田 田坎 筑坎材料 田坎稳定性 陕南秦巴山区 |
| DOI： |
| 分类号: |
| 基金项目:西北农林科技大学大学生科技创新项目（20110631）；陕西省水土保持局重点科技示范项目（20101003）；水利部科技推广计划项目（TG1308） |
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| Stability of terraced ridges using polypropylene geotextile bags |
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BAI Zhen-feng,LI Guang-lu,LI Xiang,et al
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| Abstract: |
| 【Objective】To prevent the collapse of terraced ridges in Qinba mountainous area and overcome the limitation in the popularization of ridges built with rocks or concrete,this study focused on the stability of ridges built with polypropylene geotextile bags (PP bags) and investigated the effects of ridge height,slope and rainfall intensity.【Method】PP bags ridges with two slopes,A (slope 65°-70°) and B (slope 70°-75°),were conducted.Each slope had two treatments with and without connecting buckles.Effects of three ridge heights,1.0 and 1.2 and 1.4 m,were investigated,respectively.Anti-shear strength,sliding resistance,overturning force resistance and soil press of each treatment were measured before and after rain.【Result】After heavy rain,shear strength increased as the increase of soil press,in the contrary,anti-overturning strength and anti-sliding resistance coefficient were decreased.Buckles significantly increased the anti-shear strength.Without buckles,the ridges were more likely to collapse,especially in the second or third floor with ridge height of 1.2-1.4 m.With buckles,the collapse tended to happen in the third floor with height of 1.2-1.4 m.When the slope was 65°-75° and the ridge height was ≥1.2 m,sliding was more likely to happen than overturning.【Conclusion】When the ridge height was less than 1.0 m,and the slope was 65°-75°,the PP bags ridges were stable while when the slope was 65°-75° and the ridge height was ≥1.2 m,the ridges were likely to collapse even with buckles. |
| Key words: polypropylene geotextile bags terraces ridges ridges material ridges stability Qinba mountainous area |
