三峡库区重庆段塌岸预测研究

STUDY ON FORECASTING OF CHONGQING SEGMENT IN THREE GORGES RESERVOIR

三峡水库蓄水将会引起库区两岸变形再造,为了研究重庆段库岸塌岸变形,通过对重庆段重点库岸段的详细地质调查,总结出重庆库岸段存在如下三种主要的塌岸模式:冲蚀磨蚀型、坍(崩)塌型、滑移型;其中冲蚀磨蚀型约占调查总长的54%,坍(崩)塌型约占42%,滑移型仅占4%左右。在调查的基础上,针对不同的库岸塌岸模式和岸坡结构,采用不同的塌岸预测方法和预测参数开展了重庆段重点库岸段的塌岸预测,得出重庆段80%的库岸再造范围在20 m以内,而再造变形范围大于20 m的库岸段大多表现为滑移型。以上为重庆段库岸塌岸的防治措施提供了理论依据。

Bank collapsing of reservoir will happen after three gorges reservoir impounds. In order to study bank-collapsing, the geology about bank-collapsing of Chongqing segment is investigated. It is sum up that three main bank-collapsing types： wash and abrasion type, soil collapse （rock sliding） type, slope type, and the length of wash and abrasion type mainly occupies 54 ~, soil collapse （rock sliding） type mainly occupies 42%, and slope type is only 4%. Base on investigation, in view of different bank-collapsing types and different riverbank structures, corresponding bank-collapse forecasting method and parameters is adopted. The forecasting result shows that total length of bank-collapsing zone less than 20m is about 80%, and zone of bank-collapsing of slope is mostly more than 20m. All these are helpful to frame an treatment measure for the bank-collapsing in Cehongqing segment.