ANNEX C3 - Train Noise Impact Assessment

ANNEX C3 Train Noise Impact Assessment

Annex C3 : Procedures for noise calculation of EMU Train Noise

The rail noise level at the NSR is predicted by modelling the train as a line source. The procedures for railway noise calculations are as follows:

Obtain the reference Lmax of a train at 25m from a continuously welded rail at speed Vo. According to the KCRC information (Annex C3, Ref ERE/IF/EN102/tw-mos/000352, dated 23 Nov., 1999) the airborne Lmax of the MOS Rail train is assumed to be 81.2 dB(A) at 80kph measured at 25m away from the ballast track. The structure borne noise of MOS Rail train Lmax using Floating Slab Track at 25m at 80 kph is 56 dB(A). The air-conditioning (AC) noise of MOS train Lmax at 15m is 57 dB(A).

Determine the locations of the NSRs

Divide the railway alignment into different segments in accordance with the different speeds, orientation of railway

Determination of Lmax

Correction of track wear is 3.0 dB(A)

Correction for viaduct slab track reflection is 2.0 dB(A)

Increase of rolling stock levels due to points and crossings = 7 dB(A)

Determination of SEL

Determination of Leq

Total Leq

Table C3.1

Predicted Unmitigated and Mitigated Railway Noise Levels at representative NSRs

NSR	NSR 10-1				NSR 18-2
Floor	Unmitigated		Mitigated ¹		Unmitigated
	Leq	Lmax	Leq	Lmax	Leq	Lmax
1	56	72	51	67	40	55
5	58	74	53	69	42	58
10	58	73	53	69	47	62
15	57	73	53	69	53	68
20	57	72	52	68	53	69
25	57	72	52	67	53	68
30	56	71	51	67	53	68
35	56	71	51	66
40	56	70	51	66
42	56	70	51	66

Note :
BOLD = Predicted Noise Level exceeds the night-time Noise Criteria (55dB(A))
1 Mitigation = Provision of central plenum along twin viaduct secton (~ 60m)

Table C3.2 - Sample Calculation of Railway Noise at NSR 10-1 (4^th Floor) with operation of MOS Rail (Without Mitigaiton)

Track		Air		Perpendicular	Vertical	Slant				Deck		Plenum			Air	Air	Train	Train		Air	Air
		Train Lmax	Speed	Distance	Distance	Distance	Angle	Angle Cor	Speed Corr.	Reflection	Poor Track	Correction	Barrier	Lmax	Distance Cor	SEL	Freq. / 30 mins	Freq. Corr	Façade	Leq 30 mins	Lmax
MOS Rail South Bound Segment 1	Air Borne	81.2	80	15	25	29.2	113	-2.0	0	+2	+3	-18	-0.1	66	0.7	74.9	5	-25.6	+2.5	51.9	68
	Structure	56.0	80	15	25	29.2	113	-2.0	0	0	0	0	0	54	0.7	62.9	5	-25.6	+2.5	39.8	56
	AC	57.0	80	15	25	29.2	113	-2.0			0	0	0	55	2.9	61.6	5	-25.6	+2.5	38.6	55
	Subtotal Leq																			52.3	68
MOS Rail South Bound Segment 2	Air Borne	81.2	80	18	25	30.8	12.5	-11.6	0	+2	+3	-18	-1.1	56	0.9	64.2	5	-25.6	+2.5	41.1	57
	Structure	56.0	80	18	25	30.8	12.5	-11.6	0	0	0	0	0	44	0.9	53.1	5	-25.6	+2.5	30.0	46
	AC	57.0	80	18	25	30.8	12.5	-11.6			0	0	0	45	3.1	51.8	5	-25.6	+2.5	28.8	45
	Subtotal Leq																			41.7	58
MOS Rail South Bound Segment 3	Air Borne	81.2	80	29	25	38.3	8.1	-13.5	0	+2	+3	-18	-6.9	48	1.9	55.6	5	-25.6	+2.5	32.5	48
	Structure	56.0	80	29	25	38.3	8.1	-13.5	0	0	0	0	0	43	1.9	50.3	5	-25.6	+2.5	27.2	43
	AC	57.0	80	29	25	38.3	8.1	-13.5			0	0	0	44	4.1	49.1	5	-25.6	+2.5	26.0	42
	Subtotal Leq																			34.3	50
MOS Rail South Bound Segment 4	Air Borne	81.2	80	46	26.2	52.9	8.2	-13.4	0	+2	+3	-18	-10.3	45	3.3	51.0	5	-25.6	+2.5	27.9	44
	Structure	56.0	80	46	26.2	52.9	8.2	-13.4	0	0	0	0	0	43	3.3	49.0	5	-25.6	+2.5	26.0	42
	AC	57.0	80	46	26.2	52.9	8.2	-13.4			0	0	0	44	5.5	47.8	5	-25.6	+2.5	24.8	41
	Subtotal Leq																			31.2	47
MOS Rail South Bound Sub-total Noise Level																				52.8	69
MOS Rail North Bound Segment 1	Air Borne	81.2	80	31	25	39.8	82.6	-3.4	0	+2	+3	-18	-7.1	58	2.0	65.3	5	-25.6	+2.5	42.2	58
	Structure	56.0	80	31	25	39.8	82.6	-3.4	0	0	0	0	0	53	2.0	60.2	5	-25.6	+2.5	37.1	53
	AC	57.0	80	31	25	39.8	82.6	-3.4			0	0	0	54	4.2	59.0	5	-25.6	+2.5	35.9	52
	Subtotal Leq																			44.1	60
MOS Rail North Bound Segment 2	Air Borne	81.2	80	37	25	44.7	17.3	-10.2	0	+2	+3	-18	-8.2	50	2.5	56.9	5	-25.6	+2.5	33.9	50
	Structure	56.0	80	37	25	44.7	17.3	-10.2	0	0	0	0	0	46	2.5	53.0	5	-25.6	+2.5	29.9	46
	AC	57.0	80	37	25	44.7	17.3	-10.2			0	0	0	47	4.7	51.7	5	-25.6	+2.5	28.7	45
	Subtotal Leq																			36.2	52
MOS Rail North Bound Segment 3	Air Borne	81.2	80	46	25	52.4	13.1	-11.4	0	+2	+3	-18	-10.0	47	3.2	53.3	5	-25.6	+2.5	30.3	46
	Structure	56.0	80	46	25	52.4	13.1	-11.4	0	0	0	0	0	45	3.2	51.1	5	-25.6	+2.5	28.1	44
	AC	57.0	80	46	25	52.4	13.1	-11.4			0	0	0	46	5.4	49.9	5	-25.6	+2.5	26.8	43
	Subtotal Leq																			33.4	49
MOS Rail North Bound Segment 4	Air Borne	81.2	80	56	26.2	61.8	10.1	-12.5	0	+2	+3	-0.0	-0.0	74	3.9	79.6	5	-25.6	+2.5	56.5	72
	Structure	56.0	80	56	26.2	61.8	10.1	-12.5	0	0	0	0	0	43	3.9	49.4	5	-25.6	+2.5	26.3	42
	AC	57.0	80	56	26.2	61.8	10.1	-12.5			0	0	0	44	6.2	48.2	5	-25.6	+2.5	25.1	41
	Subtotal Leq																			56.5	72
MOS Rail North Bound Sub-total Noise Level																				56.8	73
MOS Rail total Noise Level																				58.3	74
Note :
Lmax (Air) = Train Lmax (Air) + Speed Corr. + Angle Corr. + Barrier Corr. + Poor Track + Deck Reflection
Lmax (AC) = Train Lmax (AC) + Angle Corr. + Barrier Corr.
Lmax (Air) = Train Lmax (Air) + Speed Corr. + Angle Corr.
SEL (Air) = Lmax (Air) + 10Log(L/V)-10Log((4D/(4D2+1))+2tan-1(1/2D))+10.5+Dist. Corr.
SEL (AC) = Lmax (AC) + 10Log(L/V)-10Log((4D/(4D2+1))+2tan-1(1/2D))+10.5+Dist. Corr.
SEL (Str) = Lmax (AC) + 10Log(L/V)-10Log((4D/(4D2+1))+2tan-1(1/2D))+10.5+Dist. Corr.
Leq = SEL + Train Freq. Corr. + Façade Corr.
Segments 1 to 3 of MOS South Bound and North Bound are single viaduct with multi-plenum system
Segments 4 of MOS South Bound and North Bound are twin viaduct with multi-plenum system at both sides. But, there is no centre plenum at this segment
Therefore, there is no multi-plenum system for the North Bound Segment 4. The edge barrier is far away from the track segment.
Deck Reflection correction (+2 dB(A)) based on assessment methodology of West Rail EIA included.
Source of AC and the reference distance used is based on assessment methodology of MOS Rail EIA.

Table C3.3a - Sample Calculation of Railway Noise at NSR 10-1 (7^th Floor) with operation of MOS Rail (With Mitigaiton)

Track			Air		Perpendicular	Vertical	Slant				Deck		Plenum			Air	Air	Train	Train		Air
		Mitigation	Train Lmax	Speed	Distance	Distance	Distance	Angle	Angle Cor	Speed Corr.	Reflection	Poor Track	Correction	Barrier	Lmax	Distance Cor	SEL	Freq. / 30 mins	Freq. Corr	Façade	Leq 30 mins
MOS Rail South Bound Segment 1	Air Borne		81.2	80	15	25	29.2	113	-2.0	0	+2	+3	-18	-0.1	66	0.7	74.9	5	-25.6	+2.5	51.9
	Structure		56.0	80	15	25	29.2	113	-2.0	0	0	0	0	0	54	0.7	62.9	5	-25.6	+2.5	39.8
	AC		57.0	80	15	25	29.2	113	-2.0			0	0	0	55	2.9	61.6	5	-25.6	+2.5	38.6
	Subtotal Leq																				52.3
MOS Rail South Bound Segment 2	Air Borne		81.2	80	18	25	30.8	12.5	-11.6	0	+2	+3	-18	-1.1	56	0.9	64.2	5	-25.6	+2.5	41.1
	Structure		56.0	80	18	25	30.8	12.5	-11.6	0	0	0	0	0	44	0.9	53.1	5	-25.6	+2.5	30.0
	AC		57.0	80	18	25	30.8	12.5	-11.6			0	0	0	45	3.1	51.8	5	-25.6	+2.5	28.8
	Subtotal Leq																				41.7
MOS Rail South Bound Segment 3	Air Borne		81.2	80	29	25	38.3	8.1	-13.5	0	+2	+3	-18	-6.9	48	1.9	55.6	5	-25.6	+2.5	32.5
	Structure		56.0	80	29	25	38.3	8.1	-13.5	0	0	0	0	0	43	1.9	50.3	5	-25.6	+2.5	27.2
	AC		57.0	80	29	25	38.3	8.1	-13.5			0	0	0	44	4.1	49.1	5	-25.6	+2.5	26.0
	Subtotal Leq																				34.3
MOS Rail South Bound Segment 4	Air Borne	semi-Enclosure	81.2	80	46	26.2	52.9	8.2	-13.4	0	+2	+3	-18	-20.0	35	3.3	41.2	5	-25.6	+2.5	18.2
	Structure		56.0	80	46	26.2	52.9	8.2	-13.4	0	0	0	0	0	43	3.3	49.0	5	-25.6	+2.5	26.0
	AC		57.0	80	46	26.2	52.9	8.2	-13.4			0	0	-20.0	24	5.5	27.8	5	-25.6	+2.5	4.8
	Subtotal Leq																				26.7
MOS Rail South Bound Sub-total Noise Level																					52.7
MOS Rail North Bound Segment 1	Air Borne		81.2	80	31	25	39.8	82.6	-3.4	0	+2	+3	-18	-7.1	58	2.0	65.3	5	-25.6	+2.5	42.2
	Structure		56.0	80	31	25	39.8	82.6	-3.4	0	0	0	0	0	53	2.0	60.2	5	-25.6	+2.5	37.1
	AC		57.0	80	31	25	39.8	82.6	-3.4			0	0	0	54	4.2	59.0	5	-25.6	+2.5	35.9
	Subtotal Leq																				44.1
MOS Rail North Bound Segment 2	Air Borne		81.2	80	37	25	44.7	17.3	-10.2	0	+2	+3	-18	-8.2	50	2.5	56.9	5	-25.6	+2.5	33.9
	Structure		56.0	80	37	25	44.7	17.3	-10.2	0	0	0	0	0	46	2.5	53.0	5	-25.6	+2.5	29.9
	AC		57.0	80	37	25	44.7	17.3	-10.2			0	0	0	47	4.7	51.7	5	-25.6	+2.5	28.7
	Subtotal Leq																				36.2
MOS Rail North Bound Segment 3	Air Borne		81.2	80	46	25	52.4	13.1	-11.4	0	+2	+3	-18	-10.0	47	3.2	53.3	5	-25.6	+2.5	30.3
	Structure		56.0	80	46	25	52.4	13.1	-11.4	0	0	0	0	0	45	3.2	51.1	5	-25.6	+2.5	28.1
	AC		57.0	80	46	25	52.4	13.1	-11.4			0	0	0	46	5.4	49.9	5	-25.6	+2.5	26.8
	Subtotal Leq																				33.4
MOS Rail North Bound Segment 4	Air Borne	Semi-Enclosure	81.2	80	56	26.2	61.8	10.1	-12.5	0	+2	+3	-0	-20.0	54	3.9	59.6	5	-25.6	+2.5	36.5
	Structure		56.0	80	56	26.2	61.8	10.1	-12.5	0	0	0	0	0	43	3.9	49.4	5	-25.6	+2.5	26.3
	AC		57.0	80	56	26.2	61.8	10.1	-12.5			0	0	-20.0	24	6.2	28.2	5	-25.6	+2.5	5.1
	Subtotal Leq																				36.9
MOS Rail North Bound Sub-total Noise Level																					45.7
MOS Rail total Noise Level																					53.5
Note :
Lmax (Air) = Train Lmax (Air) + Speed Corr. + Angle Corr. + Barrier Corr. + Poor Track + Deck Reflection
Lmax (AC) = Train Lmax (AC) + Angle Corr. + Barrier Corr.
Lmax (Air) = Train Lmax (Air) + Speed Corr. + Angle Corr.
SEL (Air) = Lmax (Air) + 10Log(L/V)-10Log((4D/(4D2+1))+2tan-1(1/2D))+10.5+Dist. Corr.
SEL (AC) = Lmax (AC) + 10Log(L/V)-10Log((4D/(4D2+1))+2tan-1(1/2D))+10.5+Dist. Corr.
SEL (Str) = Lmax (AC) + 10Log(L/V)-10Log((4D/(4D2+1))+2tan-1(1/2D))+10.5+Dist. Corr.
Leq = SEL + Train Freq. Corr. + Façade Corr.
Segments 1 to 3 of MOS South Bound and North Bound are single viaduct with multi-plenum system
Segments 4 of MOS South Bound and North Bound are twin viaduct with multi-plenum system at both sides. But, there is no centre plenum at this segment
Therefore, there is no multi-plenum system for the North Bound Segment 4. The edge barrier is far away from the track segment.
Enclosure is proposed for North Bound Segment 4 and South Bound Segment 4.
Deck Reflection correction (+2 dB(A)) based on assessment methodology of West Rail EIA included.
Source of AC and the reference distance used is based on assessment methodology of MOS Rail EIA.

Table C3.3b -Sample Calculation of Railway Noise at NSR 10-1 (4^th Floor) with operation of MOS Rail (With Mitigation)

Track			Air		Perpendicular	Vertical	Slant				Deck		Plenum			Air	Air	Train	Train		Air
		Mitigation	Train Lmax	Speed	Distance	Distance	Distance	Angle	Angle Cor	Speed Corr.	Reflection	Poor Track	Correction	Barrier	Lmax	Distance Cor	SEL	Freq. / 30 mins	Freq. Corr	Façade	Leq 30 mins
MOS Rail South Bound Segment 1	Air Borne		81.2	80	15	25	29.2	113	-2.0	0	+2	+3	-18	-0.1	66	0.7	74.9	5	-25.6	+2.5	51.9
	Structure		56.0	80	15	25	29.2	113	-2.0	0	0	0	0	0	54	0.7	62.9	5	-25.6	+2.5	39.8
	AC		57.0	80	15	25	29.2	113	-2.0			0	0	0	55	2.9	61.6	5	-25.6	+2.5	38.6
	Subtotal Leq																				52.3
MOS Rail South Bound Segment 2	Air Borne		81.2	80	18	25	30.8	12.5	-11.6	0	+2	+3	-18	-1.1	56	0.9	64.2	5	-25.6	+2.5	41.1
	Structure		56.0	80	18	25	30.8	12.5	-11.6	0	0	0	0	0	44	0.9	53.1	5	-25.6	+2.5	30.0
	AC		57.0	80	18	25	30.8	12.5	-11.6			0	0	0	45	3.1	51.8	5	-25.6	+2.5	28.8
	Subtotal Leq																				41.7
MOS Rail South Bound Segment 3	Air Borne		81.2	80	29	25	38.3	8.1	-13.5	0	+2	+3	-18	-6.9	48	1.9	55.6	5	-25.6	+2.5	32.5
	Structure		56.0	80	29	25	38.3	8.1	-13.5	0	0	0	0	0	43	1.9	50.3	5	-25.6	+2.5	27.2
	AC		57.0	80	29	25	38.3	8.1	-13.5			0	0	0	44	4.1	49.1	5	-25.6	+2.5	26.0
	Subtotal Leq																				34.3
MOS Rail South Bound Segment 4	Air Borne		81.2	80	46	26.2	52.9	8.2	-13.4	0	+2	+3	-18	-10.3	45	3.3	51.0	5	-25.6	+2.5	27.9
	Structure		56.0	80	46	26.2	52.9	8.2	-13.4	0	0	0	0	0	43	3.3	49.0	5	-25.6	+2.5	26.0
	AC		57.0	80	46	26.2	52.9	8.2	-13.4			0	0	-0.0	44	5.5	47.8	5	-25.6	+2.5	24.8
	Subtotal Leq																				31.2
MOS Rail South Bound Sub-total Noise Level																					52.8
MOS Rail North Bound Segment 1	Air Borne		81.2	80	31	25	39.8	82.6	-3.4	0	+2	+3	-18	-7.1	58	2.0	65.3	5	-25.6	+2.5	42.2
	Structure		56.0	80	31	25	39.8	82.6	-3.4	0	0	0	0	0	53	2.0	60.2	5	-25.6	+2.5	37.1
	AC		57.0	80	31	25	39.8	82.6	-3.4			0	0	0	54	4.2	59.0	5	-25.6	+2.5	35.9
	Subtotal Leq																				44.1
MOS Rail North Bound Segment 2	Air Borne		81.2	80	37	25	44.7	17.3	-10.2	0	+2	+3	-18	-8.2	50	2.5	56.9	5	-25.6	+2.5	33.9
	Structure		56.0	80	37	25	44.7	17.3	-10.2	0	0	0	0	0	46	2.5	53.0	5	-25.6	+2.5	29.9
	AC		57.0	80	37	25	44.7	17.3	-10.2			0	0	0	47	4.7	51.7	5	-25.6	+2.5	28.7
	Subtotal Leq																				36.2
MOS Rail North Bound Segment 3	Air Borne		81.2	80	46	25	52.4	13.1	-11.4	0	+2	+3	-18	-10.0	47	3.2	53.3	5	-25.6	+2.5	30.3
	Structure		56.0	80	46	25	52.4	13.1	-11.4	0	0	0	-0	0	45	3.2	51.1	5	-25.6	+2.5	28.1
	AC		57.0	80	46	25	52.4	13.1	-11.4			0	0	0	46	5.4	49.9	5	-25.6	+2.5	26.8
	Subtotal Leq																				33.4
MOS Rail North Bound Segment 4	Air Borne	Central Plenum	81.2	80	56	26.2	61.8	10.1	-12.5	0	+2	+3	-13	-0.0	61	3.9	66.6	5	-25.6	+2.5	43.5
	Structure		56.0	80	56	26.2	61.8	10.1	-12.5	0	0	0	0	0	43	3.9	49.4	5	-25.6	+2.5	26.3
	AC		57.0	80	56	26.2	61.8	10.1	-12.5			0	0	-0.0	44	6.2	48.2	5	-25.6	+2.5	25.1
	Subtotal Leq																				43.7
MOS Rail North Bound Sub-total Noise Level																					47.4
MOS Rail total Noise Level																					53.9
Note :
Lmax (Air) = Train Lmax (Air) + Speed Corr. + Angle Corr. + Barrier Corr. + Poor Track + Deck Reflection
Lmax (AC) = Train Lmax (AC) + Angle Corr. + Barrier Corr.
Lmax (Air) = Train Lmax (Air) + Speed Corr. + Angle Corr.
SEL (Air) = Lmax (Air) + 10Log(L/V)-10Log((4D/(4D2+1))+2tan-1(1/2D))+10.5+Dist. Corr.
SEL (AC) = Lmax (AC) + 10Log(L/V)-10Log((4D/(4D2+1))+2tan-1(1/2D))+10.5+Dist. Corr.
SEL (Str) = Lmax (AC) + 10Log(L/V)-10Log((4D/(4D2+1))+2tan-1(1/2D))+10.5+Dist. Corr.
Leq = SEL + Train Freq. Corr. + Façade Corr.
Segments 1 to 3 of MOS South Bound and North Bound are single viaduct with multi-plenum system
Segments 4 of MOS South Bound and North Bound are twin viaduct with multi-plenum system at both sides. But, there is no centre plenum at this segment
Therefore, there is no multi-plenum system for the North Bound Segment 4. The edge barrier is far away from the track segment.
Enclosure is proposed for North Bound Segment 4 and South Bound Segment 4.
Deck Reflection correction (+2 dB(A)) based on assessment methodology of West Rail EIA included.
Source of AC and the reference distance used is based on assessment methodology of MOS Rail EIA.