Modification Treatment And Mechanical Properties Simulation Of Repair Materials For Silt Sites In Northwest China

China is a great country with an ancient civilization.It has a history and culture of more than 5,000 years and remains numerous historic relics.Historical relics have important historical value and social significance.The northwest region is the starting point of the ancient silk road in China,and historical relics are widely distributed,among which there are many famous soil sites.The soil site is a special kind of cultural relics,and its main carrier is soil such as Chang’an City during the Han Dynasty and Tongwan city.Most of the sites of the earth cover a wide area,belonging to the category of large sites,and the environmental impact is quite obvious.Protection of existing soil sites in China is not optimistic,and many relics are badly damaged and need to be repaired.Therefore,it is necessary and urgent to carry out research on the protection and repair of soil sites as soon as possible.In light of this,this article takes the typical silt sites in the north of Shaanxi as the research object,based on the research thought of using local materials,repairing soil sites with soils,take the modification of soil as the main research means,in order to explore newly suitable method to repair and protect silt site,and to test its feasibility by conducting experiment.Considering the soil remains as cultural relics,it is not advisable to carry out too many experiments.Therefore,on the basis of the experiment,the mechanical properties of silt sites and its imitated soil are simulated,and the simulation results and the measured data are compared and analyzed.Different from traditional chemical and physical repairing and consolidation method,the soil near the site was chosen as the main restoration material,single mixed modification experiments were carried out after the environmental-friendly materials were screened and added respectively.According to the experimental results,materials with better effect were chosen and then the dual-mixed modification experiments were carried out,and the best mixing material and mixing proportion were adopted to imitate original soil sites.Engineering properties of modified imitation soil samples were tested and compared with the original site to test the feasibility of the test results.On the basis of this,a model based on UH theory is established,and the stress-strain relationship between modified imitation soil samples and original site soil samples is verified.The results of the modified test show that: For single mixing test of repairing materials,the modified samples which were prepared by adopting 6% hydraulic lime or 8% lignin,the engineering properties were close to or slightly superior to the original site,considering the economic feasibility,the two materials were suggested to use them in partial restoration and protection of soil sites;For dual-mixing test of repairing materials,the modified samples which were prepared by adding 0.25% polypropylene fiber in mixed soils(lime:silt,2:8)or5% starch ether in mixed soils(lime:silt,1:9),the engineering properties were close to or slightly superior to the original site,and due to the lime is traditional used as modification materials and its obvious price advantage,and the two materials were suggested using in large scale restoration and protection of soil sites.The mechanical properties of soil site and its modified repair materials were simulated based on the equivalent pre-consolidation pressure and UH model,and the model calculation curve and experimental data were more consistent,which provides the model foundation for the finite element calculation of soil site.This paper conducted a series of experiments and theoretical work aim at the restoration and protection of soil sites,and the research results will provide a theoretical basis and experimental support for the restoration and protection of soil sites,and have significantly application value and practical significance.