| Luoshan,located in the transition zone of northern part of the Dabie Mountains and the Huaihai plain,has the Huaihe River main stream and two main tributaries.There are many geological disasters such as the collapse of the bank,soil erosion and soil desertification caused by Huaihe River in flood season each year.These geological disasters have brought great economic loss to the local residents.In order to better understand and prevent geological hazards,we have collected the previous geological data,carried out the remote sensing interpretation investigation and the comprehensive investigation of the environment and geology,and found out the basic parameters and general conditions of the natural geography,the economy and the main rivers in the working area,as well as the meteorology,topography,lithology and geological structure of the river area.Characteristics of the development of the disaster body have been awakened one by one.From the point of view of prevention and control,a typical case of the collapse of the river bank(Dayuwan)of the Huaihe village of Gan town is detailed analyzed and studied.On the basis of the study of the geological environment and the characteristics of the disaster development of the main rivers,using the advanced theoretical analysis methods of home and foreign countries and using the comprehensive evaluation method,the types of the bank slope of the main rivers in Luoshan were divided according to the engineering geological rock,structure and lateral support conditions of the bank slope.In this work,23 sections of the rocky bank slope are identified,the total length is 221.2km,and the total length of the 15 slopes of the soil bank is 313.2km.There are 5 geological disasters in rock slope and 19 geological hazards in soil slope.In addition,the evaluation models of the stability of the rock slope and the soil slope are established according to the formation conditions of the slope collapse and the debris flow,the factors that lead to the stability and the trend of development.The evaluation model of rock slope has taken into account the characteristics of engineering geology.It selects 9 control factors such as lithology,slope,bank slope structure type,geological structure,new tectonic activity and earthquake,human engineering activity and external dynamic action,slope height,three day maximum rainfall,and bank slope deformation.The evaluation model of soil bank slope considers 9 factors such as soil type,thickness of soil thickness,slope,slope structure type,three day maximum rainfall,slope height,new tectonic activity and earthquake,human engineering activity and external dynamic action,and slope deformation and failure characteristics.On the basis of the model,the stable bank length 38.1km is quantified by the normalization and weight assignment,which accounts for 7.13% of the total length;the long 99.2km with a better stability is 37.28%;the long 217.0km with relatively poor stability is 40.61%,and the poor stability of the bank section is 80.1km,accounting for 14.99%.The main river and Zhugan river in Huaihe,which has poor stability,will collapse along with the erosion of the river,resulting in soil erosion,the destruction of the good fields.The river section with poor stability may cause secondary geological disasters in the flood and heavy rainfall weather.At last,we put forward four countermeasures and suggestions to strengthen dynamic monitoring,prevent the infiltration of precipitation and surface water,prevent river erosion and protect development and utilization. |
PDF Full Text Request