Shock and Vibration

Research Article

Vibration-Isolation Performance of a Pile Barrier in an Area of Soft Soil in Shanghai

Table 6

Summary of parametric investigation.


Group	Variable				Other key parameters/configuration	Maximum displacement (nm)	RMS displacement (nm)	Note

I	Pile body material	Foam plastics	ρ (kg/m³)	700	D = 0.8 actm; D₀ = 0.8 m; L = 45 m; n = 1; d = 20 m	950.41	208.59	Effect of pile body material
			E (MPa)	2000
				0.38
		C20 concrete	Ρ (kg/m³)	2500		865.29	191.57
			E (MPa)	26,000
				0.2
		C30 concrete	Ρ (kg/m³)	2500		825.02	190.27
			E (MPa)	30,000
				0.2
		C40 concrete	Ρ (kg/m³)	2500		827.58	190.28
			E (MPa)	33,000
				0.2
		C50 concrete	Ρ (kg/m³)	2500		828.87	190.29
			E (MPa)	35,000
				0.2
		Foam concrete	Ρ (kg/m³)	800		942.4	207.53
			E (MPa)	400
				0.21
II	Hollow ratio (r)	0	D (m)	0.8	ρ = 2500 kg/m; E = 26,000 MPa; = 0.2; L = 45 m; n = 1; d = 20 m	865.29	191.57	Effect of hollow ratio, r
			D₀ (m)	0.8
		0.39	D (m)	0.8		441.62	125.75
			D₀ (m)	0.65
		0.25	D (m)	0.8		506.84	133.37
			D₀ (m)	0.6
		0.19	D (m)	0.8		505.48	133.43
			D₀ (m)	0.575
		0.14	D (m)	0.8		511.35	134.12
			D₀ (m)	0.55
		0.06	D (m)	0.8		511.28	135.13
			D₀ (m)	0.5
III	Filling material	Loose field soil	ρ₀ (kg/m³)	1000	D = 0.8 m; D₀ = 0.65 m; ρ = 2500 kg/m; E = 26,000 MPa; = 0.2; L = 45 m; n = 1; d = 20 m	765.61	159.64	Effect of filling material
			E₀ (MPa)	50
				0.3
		Dense field soil	ρ₀ (kg/m³)	1900		785.67	159.64
			E₀ (MPa)	100
				0.3
		Foam	ρ₀ (kg/m³)	45		565.77	134.29
			E₀ (MPa)	2.94
				0.3
		Cement-soil	ρ₀ (kg/m³)	1850		826.16	164.11
			E₀ (MPa)	1000
				0.2

IV	Pile length, L (m)		10		D = 0.8 m; D₀ = 0.8 m; ρ = 2500 kg/m; E = 26,000 MPa; = 0.2; n = 1; d = 20 m	979.58	227.42	Effect of pile length, L
			20			938.49	219.07
			30			918.67	217.26
			40			872.22	191.74
			50			836.84	187.94
			60			836.84	186.92

V	Pile diameter, D (m)		0.3		D₀ = 0.8 m; ρ = 2500 kg/m; E = 26,000 MPa; = 0.2; n = 1; d = 20 m	881.9	195.8z	Effect of pile diameter, D
			0.4			879.35	195.03
			0.5			873.6	192.9
			0.6			870.36	192.35
			0.7			867.26	192.02
			0.8			865.29	191.57

VI	Distance from hard-X-ray tunnel, d (m)		5		D = 0.8 m; D₀ = 0.8 m; ρ = 2500 kg/m; E = 26,000 MPa; = 0.2; L = 45 m; n = 1	850.06	182.34	Effect of the distance from hard-X-ray tunnel, d
			10			828.88	180.69
			20			865.29	191.57
			30			843.43	191.83
			40			742.48	177.78
			50			734.31	167.26
			60			862.36	185.32

VII	Pile row number, n		1		D = 0.8 m; D₀ = 0.8 m; ρ = 2500 kg/m; E = 26,000 MPa; = 0.2; L = 45 m; C = 2.5	865.29	191.57	Effect of pile row number, n
			2			829.73	189.2
			3			823.27	186.3
			4			787.53	184.36

VIII	Row spacing, c (m)		2		D = 0.8 m; D₀ = 0.8 m; ρ = 2500 kg/m; E = 26,000 MPa; = 0.2; L = 45 m; n = 2	827.36	187.69	Effect of row spacing, c
			2.5			829.73	189.2
			3			843.26	191.62
			4			849.73	192.96
			5			878.36	193.42
			6			891.68	195.92

Note: D and D₀ are the outer diameter and inner diameter of the tunnel, respectively.