复杂条件下高滩守护工程岸坡渗流破坏影响因素

针对荆江河段岸坡渗流破坏情况,结合破坏案例分析岸坡渗流破坏原因,确定岸坡渗流破坏主要影响因素——地质因素、水文因素和降水因素。荆江河段岸坡地质结构主要分为3类,即单一砂性土地质结构、上黏性土下砂性土双层地质结构以及由黏性土和砂性土组成的互层、夹层等结构土体。荆江河段地下水和江水补给关系复杂——汛期江水补给地下水,枯水期地下水补给江水。三峡蓄水后,汛后退水速度进一步加快,地下水和江水之间的渗流坡降进一步增加。荆江河段强降水天气分布出现频次和范围仍较高。在此基础上,进一步揭示高滩守护工程区域岸坡渗流破坏机理。

Influential factor of bank slope seepage failure of high beach protection under complicated condition

In view of the bank slope seepage failure in Jinjiang river reach,we analyze the reasons for the failure based on a practical case and find out the main influential factors for the failure,i.e.geologic factor,hydrologic factor and meteorological factor.The geological condition of Jingjiang reach includes single sandy soil structure,upper layer clay and lower layer sand,as well as interlayer and cross layer which consists of sand and clay.The supply relationship between groundwater and river water was complex.River water supplies groundwater in the flood season,and groundwater supplies river water in the dry season.After the impoundment of the Three Gorges reservoir,water level dropping speed was accelerated,and the seepage gradient between groundwater and river water was increased.The occurrence frequency of heavy precipitation weather is still high,and its range keeps still large.Finally,the bank slope seepage failure mechanism of Jingjiang beach is revealed