Exerimental Study On Cracking Mechanism Of Sanxingdui Soil Site In Humid Environment

The complex diseases caused by humid environment have long been the difficulties in the protection of soil sites in south areas.At present,the domestic research on damp area sites stays at qualitative description and analysis of influence factors.Therefore,a quantitative description of the relationship between moisture migration and cracks,and the research on cracks rules and morphology distribution are of great significance in the protection of soil sites in humid areas.Based on sanxingdui soil site,the thesis is mainly divided into two parts: field monitoring and laboratory experiment.The first part is outdoor experiment,three modes of cracking are analyzed by investigating the disease of soil site.The dynamic changes of water content,which were obtained by embedding the ECH2 O soil moisture monitoring system into the moon-bay wall,are used to analyze the influence factor on moisture content of soil.Using the temperature and humidity recorder to monitor the temperature and humidity of the moon-bay wall for nine months,the temperature and humidity curves of the surrounding environment of the moon bay were obtained.The second part is the indoor experiment,the density,specific gravity,free swelling ratio,water ratio limit,grading curve(hydrometer method),Soil mineral composition and soil-water characteristic curve etc.are aquired by geotechnical experiment.Using matlab combined with photoshop software to process crack images,which are obtained by shrinkage and drying-wetting cycles experiment without considering the gravity.Thus,fracture rate,moisture content,fracture length,fracture width,intersection angle of cracks and the number of intersections etc.are obtained to analyze the relationship between fracture rate,crack forms and moisture content,time,the size of soil sample and boundary condition.Using matlab combined with photoshop software to process crack images,which are obtained by shrinkage and drying-wetting cycles experiment with the gravity.Therefore,the relationship between fracture rate and time in humidification process is obtained.And the change of fracture rate and crack forms in drying-wetting process under gravity is obtained.