摘要
对温州市台风地质灾害分析,发现乔木类滑坡最为典型。以物理模型试验再现其演化过程,归纳总结变形破坏特征,分析台风引发裸坡和乔木类斜坡变形破坏现象的联系,再综合分析,初步得到台风滑坡的变形破坏机制。研究表明,坡体在强降雨作用软化后更易在台风与植被耦合下破坏。与一般类型斜坡变形破坏在诱发机制方面显著不同,台风对斜坡的作用主要包括暴雨的冲蚀、软化作用和大风的动力作用等。台风来袭时,当乔木根系在滑带之上则不利于斜坡的稳定,可能导致前缘小部分土体失稳。风振液化是以脉动风的反复循环荷载形式通过植被作用于根部土体,使土体液化,加剧植被的风倒和斜坡的变形破坏。将台风滑坡的变形破坏机制归纳为:暴雨冲蚀→土体软化→风的作用→植被摇曳→土体松动→裂缝发展→前缘土体失稳→滑坡形成。
This paper analyzes the geological hazards induced by typhoon in Wenzhou.The landslide with arbor was most typical.Physical model experiments well reappear the the slope deformation-failure process caused by typhoon. The connection of failure phenomena between bare and arbor slope was analyzed after the induction and summarization on the characteristics of deformation and failure.Then a comprehensive analysis is made.The deformation and failure mechanism of typhoon landside is initially obtained.The results show that the slope is more likely to be damaged coupling typhoon with arbor after soil is softened by stronger rainfall.The main actions of typhoon to slope are the rain wash and softening caused by rainstorm with dynamic effect of gale,which is significantly different from general landside.When arbor roots are above the sliding zone,the roots go against the stability of slope under typhoon calamity.Soil mass failure may be caused in slope front areas.A phenomenon of'wind liquefaction' is found in the model testing.The reason is that soil liquefaction is formed with the cyclic loading of fluctu ating wind to soil around root.It aggravates the wind throw of trees,makes the slope destruction complicated. Therefore,the deformation and failure mechanism of typhoon landslide is summarized as'the rain wash→soil softening→ wind action→arbor swinging→soil loosening→crack development→front soil failure→landslide formation'.
出处
《工程地质学报》
CSCD
北大核心
2013年第2期297-303,共7页
Journal of Engineering Geology
基金
国家自然科学基金项目(40772177)
国家重点基础研究发展计划(973)项目(2011CB013501)
长江学者和创新团队发展计划项目(IRT0812)
关键词
台风滑坡
乔木类斜坡
模型试验
变形破坏机制
风振液化
Typhoon landslide,Arbor slope,Model test,Deformation and failure mechanism,Wind liquefaction
