Study On Dynamic Response And Vibration Isolation Measures For Urban Archaeological Exploratory Pit Walls Under Traffic Load

With the continuous development of domestic archaeological work,more archaeological excavations are carried out in urban area under complex environment,triggering instable failure and huge threat to the safety of site cultural relics,working staff and the surrounding.Cracks,excoriation,and even collapse,induced by traffic load for its longevity and repetition,occur on excavation walls carrying with ancient information,research on dynamic response laws and controlling method for archaeological excavation walls under traffic load are therefore important.This paper investigates the archaeological excavation in Zhouqiao,Kaifeng,field measurement and numerical simulation are adopted to analyze the dynamic response and vibration isolation protection of urban foundation pit under automobile load,main conclusions are as follows:(1)Artifact properties are specified by relative reference and archaeological excavations in Zhouqiao relics.Through plenty site investigation,diseases in excavation are categorized and the causes are evaluated,which indicates that traffic load is the main causing of cracks and failure during excavations.(2)Based on Zhouqiao relics,field tests are conducted on dynamic response of archaeological excavations under traffic load.The results show that vertical vibration strength peaks at the crest and bottom of excavation pit,but the vibration strength at the position of pit wall,in normal direction along road,is apparently more intense than the other two directions.Vibration frequency ranges from 0 to 30 Hz,the strength decreases with excavation depth increase,and that of high frequency reduces faster.(3)Dynamic response laws of excavation walls under traffic load are estimated with finite element method,the conclusions indicate that heavier the automobile is,faster the speed is,less distant to the excavation unit is,more intense dynamic respond would be,the response of excavation pit wall peaks and exceeds the protection limit at the vehicle interchange under multiple automobiles,vibration isolation protection are therefore needed.Multivariate regression model of dynamic response on excavation pit wall under traffic load is established based on the dynamic response laws.(4)Continuous vibration isolation barriers are set with the effect of vibration characteristics and dynamic response laws,coordinate filling material,depth,width and locations are discussed for the influence on the protection,and a barrier with high polymer material grouting is proposed for urban archaeological excavations with the combination of simulation comparisons and urban artifact characteristics.