排桩几何参数对其隔振半径的影响试验研究

通过室外试验的方法、从二维角度入手并将排桩参数与瑞利波波长建立联系研究了几何参数变化时隔振半径的变化。结果表明:单排桩可取得整体性的隔振特点,并且隔振效果最佳的区域在桩后较近的距离;桩长增加可使其隔振效果提升且隔振半径随桩长与波长比值的增加而增加,当桩长与波长比值小于0.320时,隔振半径为0;随比值增加到0.820左右,隔振半径增加到约0.680 m。桩间距的增加可使其隔振效果变差,隔振半径随桩间距与波长比值增加而降低,当比值达到0.300~0.430时,隔振半径长度降为0。振源距离增加可使得排桩隔振效果增强,而隔振半径随振源距与波长比值增加而增加,当比值在0.165~0.305的范围内时,隔振半径为0;随比值增加到0.808左右,隔振半径的长度增加到约0.512 m。

Experimentaltest for impact of geo-metric parameters of row piles instal-lation on radiation isolation radius

Based on the spot-field test and starting from the 2-D view-points,the given paper intends to set up and confirm the geometric parameters of the row piles as is related to the wavelength of the Rayleigh waves. It is necessary just for the said purpose that we have carefully traced the changes of the influential radii with the necessary changes of the geometric parameters,which is beneficial to the vibration isolation of the project. As is well known,single row of piles can help to achieve the overall vibration isolation,it can also help to keep the best vibration isolation effect of the area within a certain distance behind the piles. On the other hand,the increase of the pile length can help to heighten its vibration isolation effect so as to increase the vibration isolation radii with the increase of the ratio of the pile length to the wavelength. For instance,when the ratio of the pile length to the wavelength is less than 0. 320,the vibration isolation radius has to be 0. However,when the ratio has increased to about 0. 820,the affecting radius may increase to about 0. 680 m. And,therefore,it is preferably recommended to set the pile length reasonably in the actual project to be protected. And,on the contrary,the objective pile would be made within the radius of impact,and in turn,the increase of the pile spacing would bring harm to the vibration isolation effect. The influential radius may decrease with the increase of the pile spacing to the wavelength ratio. To be exact,in case the ratio reaches 0. 300-0. 430,the impact radius length would decrease to 0,which makes us recommend to set a small pile spacing to keep us a nice vibration isolation effect to count against the effect of the radius length. Nevertheless,with the increase of the distance of vibration source,it would be possible to enhance the isolation effect of the pile row,which can help to increase of the ratio of the vibration source distance in wavelength. To be exact,if the ratio is within the range of 0. 165-0. 305,the vibration isolation radius would be 0,and,in such a situation,with the increase of the ratio by about 0. 808,it can be expected to increase the length of the vibration isolation radius just about 0. 512 m.