基于高密度电阻率法的河床结构特征研究:以宿州新汴河为例

Study on Riverbed Structure Characteristics Based on High Density Resistivity Method:A Case Study of New Bianhe River in Suzhou

宿州新汴河位于安徽淮北平原、淮河北岸,是一条以排洪、除涝为主,结合灌溉、航运、供水等综合利用功能的人工河道。为保持河水的适当深度,维持河道畅通,需要及时了解河床的结构特征。基于高密度电阻率法,通过布设横跨河面的测线,得到了宿州新汴河典型地段的电阻率剖面。根据不同岩性电阻率的变化范围,并结合钻孔等资料,得到了河床的结构特征:新汴河东节制闸上游河床形态呈现典型的“蝶”形,河床深度变化范围较小,河床形态整体平整,局部略有起伏。河床结构纵向分层性好,自上而下为粉质黏土、含砂黏土和砂土,层厚变化范围较小;下游河床形态整体上呈现“横钩”形,起伏较大,北部河床的深度明显大于南部河床的,河床结构纵向分层性较好,层界面有起伏,自上而下为粉质黏土、含砂黏土和砂土,层厚变化范围较大。研究结果可为河床的稳定性评价和清淤保航提供技术支持。

The New Bianhe River in Suzhou is located in the Huaibei Plain of Anhui Province,on the north bank of the Huai River.It is an artificial river channel mainly used for flood discharge and waterlogging removal,combined with irrigation,shipping,and water supply.In order to maintain the appropriate depth of the river and keep the river smooth,it is necessary to understand the structural characteristics of the riverbed in time.Based on the high-density resistivity method,the resistivity profile of typical sections of New Bianhe River in Suzhou is obtained by laying survey lines across the river.According to the variation range of resistivity of different lithology and combined with drilling data,the structural characteristics of riverbed are obtained.The river bed in the upper reaches of the east sluice of New Bianhe River presents a typical“butterfly”shape.The variation range of riverbed depth is small,and the riverbed shape is flat as a whole,with slight fluctuation in some parts.The longitudinal stratification of riverbed structure is sound,including silty clay,sandy clay and sandy soil from top to bottom,and the variation range of layer thickness is small.On the whole,the downstream riverbed presents a“horizontal hook”shape with large fluctuation.The depth of the north riverbed is significantly greater than that of the south riverbed,the longitudinal stratification of the riverbed structure is good,and the layer interface fluctuates.From top to bottom,there are silty clay,sandy clay and sandy soil,with a wide range of layer thickness changes.The research results can provide technical support for riverbed stability evaluation and dredging and navigation.