The Research On Preventive Maintenance Of The Expansive Soil Slope On Shiyan-Tianshui Expressway Operation Period

Shiyan-Tianshui Expressway of the xixiang-lueyang section distribution have a large number of expansive soil slope,the slope body side,retaining engineering and drainage system during the opening operation in the deformation and failure,brought slope maintenance problem,research along the disease mechanism of expansive soil slope and preventive maintenance technology is of great significance.Based on Shiyan-Tianshui Expressway of the xixiang-lueyang section operating period of expansive soil slope as the research object,through data collection,field investigation,laboratory test,field test and theoretical analysis,the distribution characteristics and failure mechanism of slope disease and preventive maintenance technology are studied,the following research results:(1)Through to the Shiyan-Tianshui Expressway period of Xi-Lue cut slope along the site investigation,Analysis for the section of the geological survey,along the slope body,structures and drainage system of disease type,size,deformation and failure characteristics and distribution rule.(2)The formation mechanism of disease was obtained through laboratory experiments and theoretical analysis.Expansive soil with high content of montmorillonite,it’s under the influence of water filtration contraction,dry-wet circulation for a long time after the fracture increase soil shear strength decreases,and under the effect of dry-wet cycles,the slope with cracks,ballooning,the phenomenon such as slip;Slope body structure and other structures in the expansive force under the action of repeated,compressive zone height decreases,and neutral axis,deflection,stiffness degradation,strength is reduced,when the decrease of strength of structure to withstand expansion force,deformation and even damage;The formation of the disease of drainage system is the result of the combination of maintenance failure,design defect and expansive soil characteristics.(3)Through the field test and combining with the monitoring results on the control effect evaluation,on the basis of study and put forward "inclined shop geogrids","wedge structure","old tires" three kinds of scheme of expansive soil slope diseases are various technologies of construction technology,after effects,and the suitable conditions.(4)Slope protection structure and slope drainage system two plates curing idea,gives the plate of main disease prevention and treatment measures and the corresponding preventive maintenance plan,provide technical guidance for later maintenance.Thesis research will strengthen highway maintenance personnel for shiyan-tianshui of expansive soil slope in the process of traffic operation damage rule understanding of disease,improve the technical ability of maintenance personnel,for shiyan-tianshui of expansive soil slope of freeway disease management to provide theoretical support and technical guidance,so as to reduce the incidence of slope damages.