Study On Vibration Isolation Effect And Non-Monotonicity Of Single Row Pile Under Continuous Load

With the development of national economy and comprehensive national strength,convenient means of transportation have become a wide range of objects at home and abroad.As the backbone of transportation,high-speed railway has the advantages of low energy consumption and high efficiency,which brings convenient benefits and travel conditions for cultural production and life.However,the environmental vibration problems caused by high-speed railway operation are increasing,and vibration isolation barrier is the most common way.Pile row has been widely used in engineering because of its strong adaptability and not restricted by topography.In this paper,the vibration isolation test of single row pile under continuous load in sandy soil foundation is studied,and the vibration isolation effect of single row pile and the non-monotonicity in the vibration isolation area are studied and discussed from two angles of two-dimensional plane and two-dimensional curve by controlling the single variable of pile spacing,pile diameter,pile length,frequency and vibration source distance.The ratio of acceleration after setting vibration isolation measures to that without vibration isolation measures(amplitude reduction ratio Ar value,smaller Ar value is better)is adopted as the evaluation index,and the following laws and suggestions are obtained:Firstly,the vibration isolation effect was analyzed from the two-dimensional plane Angle,and the following results were obtained:(1)single row piles under continuous load of vibration isolation effect,pile length,pile spacing,pile diameter,spacing and the frequency of vibration on the influence of the vibration isolation effect each are not identical,the pile length,pile diameter,the increase of the frequency can lead to single row piles under continuous load of vibration isolation effect is enhanced,pile spacing,the increase of the vibration source distance will lead to a single row piles under continuous load vibration isolation effect is weakened.(2)The vibration isolation effect will be enhanced obviously with the increase of frequency;When the pile length increased by 1.67 times,the vibration isolation area with Ar value less than 0.5 increased by 2.29 times.When the pile diameter parameter increases by 3 times,the vibration isolation area with Ar value less than 0.5 increases by 2.32 times.Therefore,the greater the pile length and pile diameter parameters are,the better the isolation effect will be.When the pile spacing increases by 3 times,the vibration isolation area with Ar value less than 0.5 decreases by 5.42 times.As the vibration source distance parameter is larger,the area with Ar value less than 0.5 is smaller,and the distance appears farther.Therefore,the smaller the pile spacing and the vibration source spacing parameters are,the better the isolation effect is.Secondly,non-monotonicity can be obtained by analyzing the 2d curve Angle:Under continuous load of single pile,pile length,pile diameter,pile spacing and the source distance on single pile isolation areas within the monotonicity has a certain influence,with the increase of pile length and pile diameter will area on the vibration isolation of monotonicity strong impact,increasing pile length and pile diameter will significantly extend the area of monotonicity inflection point on the vibration isolation and the location of the Ar again a value greater than 0.5,Ar value is less than0.5 covering length will increase.And it increases the difference between the maximum and the minimum.The increase of pile spacing and vibration source distance has little influence on the non-monotonicity in the vibration isolation area.The increase of pile spacing and vibration source distance will make the Ar value stay above 0.5 all the time.And the difference between the two inflection points is small.