| 摘要: |
| 为了揭示软质海崖的侵蚀机制, 现场利用量测方法研究了福建省平潭岛东北部软质海崖的蚀退特征、蚀退模式和影响因素, 并利用自制崩解仪测试了砂土和粉质黏土的崩解速率。结果表明, 软质海崖滑塌物体积、堆积距离均随海崖高度增加而增大, 每次滑塌海崖蚀退距离位于0.08～1.23 m; 滑塌物覆盖住崖脚后具有临时保护崖脚的作用, 但由于其受到扰动较易发生再次蚀退; 崖脚海蚀槽的形成对滑塌起到重要控制作用; 降雨、海洋水动力、强风和人为活动是造成蚀退的四大因素; 在土体抗侵蚀方面, 砂土的抗侵蚀能力最弱, 粉质黏土的居中, 黏土的最强; 现场干燥粉质黏土的崩解速率为2.4 cm/min。 |
| 关键词: 软质海崖 蚀退 崩解 |
| DOI：10.11759/hykx20140312003 |
| 分类号: |
| 基金项目:国家自然科学基金项目(41306051); 福建省自然科学基金项目(2015J01625) |
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| Study on the retreat of soft sea cliff in the northeast Pingtan Island, Fujian Province |
|
CHANG Fang-qiang
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| Abstract: |
| To reveal the retreat mechanism of soft sea cliff (SSC), the characteristics, retreat patterns, and influencing factors of the retreat of SSC in the northeast Pingtan Island, Fujian Province, were measured and studied. Moreover, the disintegration rate of the sand and silty clay of the island were tested using a developed disintegration instrument. The study found that the volume and accumulation distances of slumping soil increases with the height of the SSC and that each slump leads to a retreat distance of between 0.08 and 1.23 m. The covering slump at the foot of the SSC temporarily protects the cliff; however, it is more prone to erosion as it is disturbed when sliding. The sea cliff notch at the foot of cliff greatly controls slump formation. Rainfall, ocean waves, strong winds, and human activities are responsible for the retreat. The anti-erosion ability of soil proceeds from weak to strong in sand, then silty clay to clay. Moreover, the disintegration rate of dry silty clay in-situ is 2.4 cm/min. |
| Key words: soft sea cliffs retreat disintegration |
