Study On The Geological Engineering Division Of Holocene Ancient River Sediments In Xuzhou City

The ancient river sediments are mainly composed of the sand gravels with loose structure,weakly resist compression and large subsidence,which have an important impact on construction sites.This paper,in terms of the complexity of the engineering characteristics and the cause of the ancient river channels,carried out the sedimentary characteristics and engineering characteristics of the ancient river channels in Xuzhou area.Based on the collection of a great variety of practical engineering investigation reports,analyzing the data of drill holes and geotechnical tests,then selecting and counting these 214 typical data,this paper analyzes and researches the periods of the sedimentation of the ancient rivers,the revolution of the ancient rivers,and the ancient rivers sediments in terms of sedimentary sequences,engineering properties,and potential engineering geological problems.According to the researches of urban development,river flooding and city relics in Xuzhou,the different sedimentary periods of ancient rivers in Xuzhou are divided.On this basis,the ancient rivers sediments in different characteristics and different periods are identified,thus the historical form of ancient river channels are reduced and the features of sedimentation of the ancient rivers are determined.Based on the data of 214 boreholes,the engineering characteristics of ancient rivers sedimentary layers are studied,and the geotechnical characteristics,sand liquefaction and physical and mechanical properties of the ancient rivers sediments are statistically analyzed.Combined with practical engineering experiences,the preventions of potential engineering geological problems due to the ancient rivers sediments are given.This paper analyses the distribution and engineering characteristics of the ancient river sediments in Xuzhou area,which is helpful to effectively avoid some negative geological phenomena and safety accidents caused by the sedimentary layer of the ancient rivers and have guiding significance for the future construction of this area.