摘要
针对上荆江典型二元结构河岸的崩塌问题,综合考虑近岸水流冲刷作用与河岸土体组成及力学特性,采用BSTEM模型分析了上荆江不同时期的岸坡稳定性,并对二元结构河岸的崩塌过程进行了模拟。结果表明:枯水期和汛前涨水期河岸稳定性较高,为崩岸较弱阶段;洪水期和落水期河岸稳定性较低,并伴随持续崩塌,属崩岸强烈阶段。此外分析还表明坡脚冲刷和潜水位变化对河岸稳定性有重要影响,两者分别是引起洪水期和落水期崩岸强度较大的重要原因。最后在综合考虑坡脚冲刷、潜水位变化和崩塌后土体在坡脚堆积等因素基础上,模拟了2009—2010年荆34断面右侧河岸的崩塌过程,河岸崩塌总宽度与崩塌后岸坡形态等模拟结果与实测结果符合较好。因此在模拟上荆江二元结构河岸崩塌过程时,必须同时考虑坡脚冲刷、潜水位变化和坡脚堆积等因素的影响。
Considering the nearbank fluvial erosion, the soil composition and mechanical properties,the degrees of riverbank stability for composite bank in the Upper Jingjiang Reach ( U JR) were analyzed during different water level periods using BSTEM ,and the process of bank failure was simulated. The results indicated that the degrees of riverbank stability are high during the periods of low waler level and waterlevel rising befire the flood season,which leads to the stage of weak bank failure,and they are low during the periods of high water level and waterlevel recession with the continuous bank (.ollapse occurring, which beh,ngs to the stage of inlensive bank failure. In addition,the effects of hank toe ernsion and water table variation on the degree of bank stability were investigated. This analysis indi cated that these two factors have an important influence on the process of bank failure,anti they can cause respectively intensive bank failure during the high water and recession periods. Finally, with the bank toe erosion, water table variation and deposition form of the collapsed hank soil being csidered in the alculation,the process of bank failure of the right riverbank at Jing34 section was simulated over the period from . 2008 to Oct. 2010. The ,nodelpredieted results were in well agreement th the measured data of the total bank retreat width and lhe collapsed bank shape. Therefore,these influencing factors should be included when simulating the process of eompsite riverbank failure.
出处
《四川大学学报(工程科学版)》
EI
CAS
CSCD
北大核心
2013年第3期69-78,共10页
Journal of Sichuan University (Engineering Science Edition)
基金
国家自然科学基金资助项目(51079103)
国家"973"重点基础研究发展规划资助项目(2012CB417001)
关键词
崩岸模拟
BSTEM模型
上荆江
坡脚冲刷
潜水位
modeling of bank failure
BSTEM
Upper Jingjiang Reach
toe erosion
water table