Whole-body vibration exposure on earthmoving equipment operators in construction industries

Figures & data

Figure 1. Simplified mechanical system representing a body subjected to vibration (Rasmussen, 2009).

Figure 2. Basicentric axes of the accelerometer.

Table 1. Selected earthmoving equipment specification, speed and maintenance history

Equipment	S/N	Model	Average speed (m/s)	Maintenance history
Bulldozer	1.	CAT DN8	3.56	Several major maintenance
	2.	CAT DB2	2.76	Several major maintenance
Excavator	1.	CAT 320D L	0.22	Major overhauling done
	2.	CAT C966D	0.30	Major maintenance done
Pail loader	1.	CASE 721B	8.02	Several major maintenance
	2.	CAT P7X	7.98	Major overhauling done
Grader	1.	CAT C14G	8.34	Major overhauling done
	2.	CAT C14G	9.92	Several major maintenance
Vibrating roller	1.	CAT C815	4.61	Minor check-up
	2.	DYNAPAC CA250	4.49	No major maintenance
Backhoe	1.	CAT C14H	0.00	Major overhauling done
	2.	CASE CX130	0.70	Major overhauling done

Figure 3. Average RMS acceleration on the seat.

Figure 4. Average RMS acceleration on the floor.

Figure 5. Vibration dose value on the seat.

Figure 6. Vibration dose value on the floor.

Figure 7. SEAT using the GCDC accelerometer.

Figure 8. ISO 2631-(1997) and 2002/44/EC standard comparison.

Table

Equipment	A RMS (m/s^2)			Crest factor			VDV (m/s^1.75)			aw RMS (m/s^2)	Time to HGCZ (min)
											Lower		Upper
	x	y	z	x	y	z	x	y	z		RMS	VDV	RMS	VDV
Bulldozer	0.4	0.4	0.7	82.4	673.0	312.0	13.9	28.9	24.1	1.3	11.7	0.2	46.7	3.2
	0.4	0.4	0.6	12.2	7.3	30.1	17.9	29.9	24.4	1.3	35.1	0.9	140.4	14.3
Excavator	0.3	0.3	0.4	17.1	41.4	133.0	17.8	9.9	32.1	1.1	36.5	0.1	145.9	2.4
	0.2	0.3	0.4	243.4	129.3	38.3	17.3	32.7	26.0	1.0	88.3	6.9	353.4	11.0
Grader	0.4	0.4	0.6	107.0	266.0	72.9	13.7	21.7	27.5	1.3	7.1	0.1	28.5	2.2
	0.5	0.5	0.5	4.2	3.4	4.1	14.7	19.0	27.9	1.4	4.1	0.0	16.3	0.7
Pail loader	0.7	0.7	1.5	33.3	33.8	80.2	32.1	30.6	51.0	1.9	2.0	0.0	8.1	0.3
	0.3	0.4	0.3	12.1	14.6	53.8	15.5	17.1	48.8	1.2	29.9	0.1	119.4	1.8
Vibrating roller	0.3	0.2	0.4	42.7	128.0	137.0	11.0	10.2	34.3	1.1	26.5	0.1	106.0	1.6
	0.3	0.3	0.6	12.7	18.0	23.5	10.5	7.1	42.6	1.2	5.8	0.0	23.2	0.3
Backhoe	0.3	0.2	1.0	2.8	5.4	2.5	6.5	4.8	20.5	1.3	33.8	5.3	135.1	85.4
	0.3	0.3	0.5	81.1	12.6	13.8	24.8	15.7	36.2	1.2	29.9	0.1	119.4	1.8

Rasmussen, G. (2009). Human body vibration and its measurement. Journal of the Acoustic Society of America , 73(6). doi:10.1121/1.389513.

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International Standards Organization, (ISO) ISO 2631–1 . (1997). Mechanical vibration and shock. Guide for the Evaluation of Human Exposure to Whole-body Vibration, Part 1 . ISO 2631/1-1997.

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