Research On Collapse Mode Of Earthen Sites Under Earthquake Action

Earthen relics are non-renewable cultural heritage with high historical,artistic,archaeological and scientific value.The Silk Road,as the main road of economic and cultural exchange between China and foreign countries in history,has a large number of earthen sites along the route.The earthen ruins and the local geological environment are closely dependent on each other.After thousands of years of wind and rain,the wall cracking,collapse,cavity,spalling,soil erosion and other diseases are common.Disease is the reason that affects the stability and preservation life of earthen sites,we need to clarify the relationship between disease,but also to study which disease has the most significant impact on the stability of earthen sites.Therefore,the study of the relationship between the disease of earthen sites,to find the most unfavorable disease for the stability of earthen sites,and based on the most unfavorable disease,the static and dynamic numerical simulation is carried out,the results are helpful to find the weak links of earthen ruins and to improve the form of earthen ruins.In this paper,the research status of earthen relics protection,collapse index and collapse model is analyzed.Through the investigation of earthen relics diseases along the Silk Road,the correlation of each disease is calculated and analyzed,the most disadvantageous disease affecting the stability of earthen ruins was found.Ansys is also used to calculate the influence of erosion disease on the stability of earthen sites under static load,and then seismic analysis is carried out for earthen sites with erosion disease by LSDYNA software,according to the analysis results,the collapse process of earthen ruins is described,and the ultimate seismic load that earthen ruins can bear is given:(1)Based on the references and field investigations,the typical disease types of earthen ruins along the Silk Road are analyzed,and the correlation between the diseases is analyzed,it is confirmed that the erosion disease is the most significant disease causing the collapse of earthen ruins,which can provide reference for the treatment of earthen ruins in the future.(2)Based on the ANSYS static calculation results,the influence of erosion disease on the safety of earthen sites is presented,and the change of earthen sites caused by erosion disease is determined to be 50% of the wall thickness.(3)LSDYNA software is used to calculate the collapse mode of earthen ruins under earthquake dynamic action,and to calculate the dynamic response of rammed earthen ruins with weak layer and plant interlayer under earthquake dynamic action,the results show that the existence of plant interlayer can strengthen the earthen site and improve the seismic performance of earthen site.Based on the analysis of the process of the collapse of earthen sites with different depth of erosion,it is determined that the ultimate seismic acceleration of the collapse of earthen sites with different depth of erosion decreases exponentially.