海蚀槽发育导致的软质海崖滑塌计算与分析

对福建省平潭岛东北部软质海崖进行现场调查和量测,在约1 km的岸线上发现9处滑塌,滑塌物的堆积距离、堆积高度和滑塌物体积均随海崖高度的增大而增大.滑塌包括剪切破坏和顶部破坏两种类型,剪切破坏的破坏面几乎完全垂直,顶部破坏的破坏面呈L形.针对这两种滑塌类型,分别建立理论计算模型.结果表明:经理论计算模型得到的海蚀槽最大槽深(蚀退距离)为0.51~1.30 m;海崖稳定性随槽深的增大而降低;海崖顶部破坏的滑塌临界水深为0.22~0.61 m.

Collapse Calculation and Analysis of Soft Sea Cliff Induced by Sea-Eroded Notch Development

The soft sea cliffs at northeast of Pingtan Island in Fujian Province are investigated and measured in situ. Nine collapses are found on the length of about 1 km cliffs. The deposition distance, deposition height and volume of collapse increase with cliff height. There are two types of collapse: shear failure and top failure. The failure surface of shear failure is almost vertical, and the failure surface of top failure is L-shaped. For both types of collapse, the theoretical calculation models are established. The results show the maximum depths of sea-eroded notch(retrograded distance)are 0.51-1.30 m calculated by the theoretical calculation models. The stability of cliffs decreases with the increase of the depths of sea-eroded notch. The critical water depth of collapse on the top of cliffs are 0.22-0.61 m.