The Vibration Influence Of The Nanwan Great Wall By Train And The Evaluation Of Vibration Reduction Measures

Based on the protection and restoration of NanwanGreat Wall ruins of the Ming dynasty,the paper carried out researches on the vibration impact on the Ming Great Wall ruins introduced byneedle train operation and the effect evaluation of the vibration isolation barrier.Testing the influence of traffic load(such as trains,cars,etc.)vibration on the rammed earth wall was to verify the method of numerical simulation and actual measurement,which was as the comprehensive measure to test the damping effect of vibration isolation barrier,andwhich provided the reference for protection of rammed earth wallfrom vibration using types of isolation barrier.As a typical instance of class rammed earth wall of NanwanGreat Wall,the strong earthquake instrument was utilized to analyze the affected results by vibration through evaluation two types situation,which were construction along with testing and test after traffic opening.On this basis,the finite element software ANSYS was used to carry out the numerical simulation of Nanwan Great Wall,the researches are as follows:The main research content of the paper:(1)The basic analysis about the present situation of Nanwan Ming Great Wall,carried out the soil test qualitative analysisof the soil samples of the Ming Great Wall andthe soil samplesaround it.Using dynamic triaxial test to study the dynamic properties of soil,basis for the numerical simulation.(2)Using the Nanwan Ming Great Wall and the vibration isolation barrier as the research object.Before the railway was opened to traffic,we built the vibration isolation barrier through the hammering method,then analysis the attenuation law of vibration isolation barrier and the effect of vibration isolation.After the train passed,measured the vibration caused by the train,analysis the attenuation law of vibration and frequency distribution characteristics,then evaluation the vibration isolation effect.(3)Using the finite element analysis software for numerical simulation on barrier isolation of the Nanwan Ming Great Wall.Using the Large Mass Method simplify the train vibration model.Using the Transient Analysis analysisthe attenuation law of vibration and evaluated the effect of vibration isolationcaused by the train operation.It is conclude through the above analysis that,vibration isolation barrier is useful to reduce vibration impact on the rammed earth wall induced by transportation such as train.Vibration isolation barrier can effectively reduce the peak acceleration and peak speed caused by vibration,The attenuation of vibration isolation barrier is significantly faster than no barrier attenuation.The results from actual measurement and numerical simulation can be used as guidance for design traffic considering vibration of influence of therammed earth Great Wall,at the same time,which can also be used as applied way to evaluatethe effect of vibration isolation barrier.