Opus Research Report 5-P0843.06 XXX65/XXX66 Manawatū River … · 2019. 11. 19. · of Ruha Street and terminating on the opposite bank. The bridge has a proposed span of approximately

Opus Research Report 5-P0843.06 XXX65/XXX66

Manawatū River Pedestrian and Cycle Bridge Noise and Vibration Assessment

I.Kvatch, P.Cenek, I.McIver

Opus Research Report 5-P0843.06 XXX65/XXX66

Manawatū River

Pedestrian and Cycle

Bridge Noise and

Vibration

Assessment

I.Kvatch, P.Cenek, I.McIver

© Opus International Consultants Ltd 2016

Opus International Consultants Ltd

Opus Research

33 The Esplanade, Petone

PO Box 30 845, Lower Hutt 5040

New Zealand

Telephone: +64 4 587 0600

Facsimile: +64 4 587 0604

Date: August 2016

Reference: 5-Po843.06

Status: Final

Opus Research Report 5-P0843.06 XXX65/XXX66 i

| Opus International Consultants Ltd

Contents

1 Introduction ....................................................................................................... 1

2 The Existing Noise Environment ........................................................................ 2 2.1 Investigation Area and Monitoring Site Location ............................................................ 2 2.2 Local Noise Sources .......................................................................................................... 3

3 Noise Assessment Methodology ......................................................................... 4 3.2 Noise Measurements ......................................................................................................... 5 3.3 Weather Conditions .......................................................................................................... 5

4 Noise Assessment ............................................................................................... 5 4.1 The Existing Ambient Noise Levels in the Area ................................................................ 6 4.2 Anticipated Noise Levels from Construction Activities .................................................... 8

4.4 Ambient Noise Levels after Construction of the Bridge ................................................. 12

5 Vibration Assessment........................................................................................ 12 5.1 Assessment Criteria ........................................................................................................ 12 5.2 Estimation Procedures .................................................................................................... 15

5.3 Analysis ........................................................................................................................... 18

6 Conclusions ...................................................................................................... 20

7 References ........................................................................................................ 21

Appendix A ............................................................................................................... 22

Opus Research Report 5-P0843.06 XXX65/XXX66 1


1 Introduction

This report describes the assessment of noise and vibration levels around the proposed Manawatū

pedestrian and cycle bridge. The proposed bridge will span the Manawatū River, starting at the end

of Ruha Street and terminating on the opposite bank. The bridge has a proposed span of

approximately 195 m and a width of 4.5 m, with an impression of the bridge being shown in Figure 1

below.

Figure 1: Impression of the proposed Manawatū River Pedestrian and Cycle Bridge.

The noise assessment part of this report considers ambient noise levels in the area of Ruha

Street/Dittmer Drive and the Manawatū River bank. The assessment covers measurements of the

existing noise levels and an assessment of the bridge construction and operation impacts on the local

environment. It is anticipated that the post construction noise environment may be different in this

area, and some local residents have raised concerns that after construction of the bridge, ambient

noise levels may increase due to pedestrian and cycling activities, and students coming to the city

area from Massey University campus which is located on the opposite side of the river.

This assessment also considers possible effects from construction noise and vibration, which may

occur in the area over the period of construction activities. The image in Figure 2 shows the proposed

location of the site works at the Ruha Street end of the bridge along with the proposed location of the

bridge itself.

A desk study was employed to calculate the maximum probable ground vibrations arising from

construction traffic and construction activities such as earthworks and piling. The methods and

assumptions utilised have been validated for New Zealand conditions. Typically, they produce

conservative estimates of the maximum probable ground vibration. Therefore, the output from the

desk study can be regarded as representing the upper bound of expected ground-borne vibration

levels. Potential issues with the vibration behaviour of the bridge due to pedestrian and cyclist

loading once it becomes operational has also been covered.



Figure 2: Image showing the proposed locations of the earthworks at the Ruha Street end of the bridge and the proposed

bridge itself.

2 The Existing Noise Environment

2.1 Investigation Area and Monitoring Site Location

The proposed bridge will be constructed at the end of Ruha Street. The nearest residential dwellings

to the bridge will be residential units of Palmerston North Holiday Park and sections for caravan

parking. The nearest units and the reception of Holiday Park will be located about 70 – 100 m from

the Bridge.

The nearest houses will be those located at the end of Ruha Street and along Dittmer Drive. The

intersection of Ruha Street and Dittmer Drive will be about 80 – 100 m from the bridge.

The residential properties between 101 Dittmer Drive and 22 Ruha Street were considered in this

assessment. Four noise measurement sites have been chosen to assess ambient noise levels in the

area. Two sites, at 125 and 101 Dittmer Drive, were used for continuous 24 hour noise measurements.

And two sites, at 115 Dittmer Drive and at unit 29 within the Holiday Park, were short-term sites.

The location of the sound measurement sites is shown in Figure 3, and the site view for each location

is shown on photos in Appendix A.

Noise measurements on the opposite, southern, river bank (Massey side) were not carried out

because there was no free access to the river bank from the Massey Agricultural Experiment Station

(MAES) facilities. The reasonable assumption can be made that the noise levels measured at Unit 29

of the Holiday Park are comparable to the noise levels on the opposite side of the river. On-site



investigation shows that the local noise sources audible on the southern (Massey University) side

river bank are also audible on the northern side (city side).

Figure 3: Approximate location of the bridge and noise measurement sites.

2.2 Local Noise Sources

On-site investigation shows that the dominant noise sources in this area are cars travelling along

Ruha Street and Dittmer Drive. Currently traffic flow on these roads consists of light passenger cars,

vans and caravans moving to and from the Holiday Park. The speed limit in this area is 50 km/h. It

is expected that during the construction period a number of heavy trucks will use these roads to

deliver construction materials to the bridge construction site. Heavy trucks will increase the number

of short-term high noise events and the day time ambient noise levels in the area, but this increase

is difficult to assess at this stage. The vehicle noise from SH57 is also audible in this area from time

to time, but this noise depends on wind direction and speed. The traffic noise from SH57 was also

audible under calm weather conditions, on the morning of 24th August 2016 when the noise

measurements were taken.

Lido Aquatic Centre with outdoor swimming pool is another noise source in the area. At the time of

this investigation, noise from children using the pool area was audible from time to time at the

Holiday Park entrance.

Additional noise sources, specifically at the Holiday Park site included birds, the wind in the trees and bushes,

some activities within the holiday park and a few cars driving on the park’s driveways. After construction of

Holiday Park

125 Dittmer Dr

115 Dittmer Dr

101 Dittmer Dr



the bridge the noise environment in this area can be changed. These changes may be related to the increased

number of pedestrians, cyclists and student groups using this bridge and connecting roads.

3 Noise Assessment Methodology

The noise monitoring sites were established along Dittmer Drive, where all residential dwellings have

an open view of the proposed bridge. These dwellings could potentially be affected by construction

noise and changes in ambient noise levels if the proposed bridge is constructed. At all sites the sound

meters were positioned 1.45 metres above the ground level and they were synchronised in time for

consistency and better interpretation of the noise monitoring results.

For noise assessments, there is a requirement that noise levels shall be assessed, predicted and measured in

accordance with the following two New Zealand Standards: “NZS 6801:2008 Acoustic - Measurement of

Environmental Sound” and “NZS 6802:2008 Environmental Noise”. Section 3.1 below provides a discussion

on the noise assessment criteria employed.

A 24 hour measuring period was chosen for the assessment because it was required to assess the

night time noise levels and noise variations over an extended period of time. The averaging interval

was 15 minutes. The measured noise levels are representative for the existing noise environment in

the area.

3.1 Noise Assessment Criteria

The bridge will be located in Conservation and Amenity Zone, but the Operative PNCC District Plan does not

have established noise limits applicable for this area. The bridge construction activities and the operational

noise after construction will affect properties along Dittmer Drive and at the end of Ruha Street. These

properties are located in Residential Zone and the Residential Zone noise limits specified in the Rule R 10.9.1

can be used as assessment criteria. With respect to the Rule R 10.9.1 the following noise limits are

recommended:

Sound emissions from any non-residential activity shall not exceed the following limits when measured

at or within the boundary of any land zoned for residential purposes in the residential area (other than

the land from which the noise is emitted and any road).

7:00 am to 10:00 pm 45 dBA L10

10:00 pm to 7:00 am 40 dBA L10 and 65 dBA Lmax

Refer also to Section 6: Noise.

These noise levels should be considered as indicative only, because this Section of the Operative District Plan

is under review. The noise limits for Conservation and Amenity Zone are specified in the District Plan Review

Residential Zone Noise Provision1 report, and will be established after consideration.

The Residential Zone noise limits are not applicable to construction activities and vehicle movements during

construction works. The recommended upper limits for construction noise are provided in “NZS 6803:1999

Acoustics – Construction Noise” and are discussed below in Section 4.2.

1 Acousafe – Consulting and Engineering. Sectional District Plan Review, Residential Zone Noise Provisions for Palmerston North City Council. 30 April 2015.



The current PNCC District Plan Residential Zone noise limits are based on the outdated noise standards “NZS

6801:1991 Measurement of Sound” and “NZS 6802:1991 Assessment of Environmental Sound”. This

means that the current noise limits for the Residential Zone, given in rule 10.9.1 of the District Plan, are given

as LA10 values.

The current New Zealand Standard “NZS 6802:2008 Acoustics – Environmental Noise”, which has

superseded the previous “6802:1991 Assessment of Environmental Sound” included in the District

Plan Review, specifies the recommended noise limits in LAeq. This is a time average noise level that

is equivalent to all of the instantaneous noises occurring within the defined period of time (15 min in

this assessment). In contrast, LA10 is the noise level exceeded for 10% of the relevant time period.

The results of noise measurements provided in this report are shown in LA10 and LAeq (15 min) noise

levels. However, it is more common to express noise levels as LAeq rather than LA10, for this reason

the assessment of construction noise and after construction operational noise is given in LAeq.

3.2 Noise Measurements

The LAeq (15 min average) noise levels are measured in decibel (dB) units and because the human

ability to detect sound varies with the sound frequency, the frequency components are weighted so

that the sound level measured matches what a person hears. The ambient noise is usually measured

in terms of an “A” weighting, therefore reporting is in dB LAeq units.

3.3 Weather Conditions

The weather data for the period of noise measurements 23 – 24 August 2016 were obtained from

New Zealand Metservice website http://www.metservice.com/national/home. Over this period of

time, weather conditions were acceptable for noise measurement with light winds between 8 - 12

km/h; ambient temperatures were between 10 and 15°C, and atmospheric pressure – 1015 – 1018

hPa.

4 Noise Assessment

The noise assessment was carried out to determine noise levels in the following environment:

The existing ambient noise levels in the area;

The anticipated noise levels during the period of construction activities; and

The ambient noise levels after construction.

Measured noise levels are representative of the existing noise environment, while the noise levels

from construction activities and those expected after construction were predicted using measured

noise levels and anticipated activities in the area.

http://www.metservice.com/national/home



4.1 The Existing Ambient Noise Levels in the Area

The results of noise measurements are shown in Table 1 and noise levels recorded at 24 hour sites

are shown in Figure 4 and Figure 5 below. Measured LAeq and L10 noise levels are shown for 15 min

intervals and LAmax noise levels are shown in 1 min intervals.

Table 1: LA10 and LAeq noise levels measured at various locations

Monitoring Site

Locations

Period of

measurement

Averaging

interval

(min)

Noise level dB

Measured range

(day time)

Measured range (night

time)

LAeq LA10 LAeq LA10

101 Dittmer Drive 24 h 15 46 - 59 49 - 62 32 - 53 35 - 56

125 Dittmer Drive 24 h 15 44 - 60 47 - 61 32 - 52 35 - 55

115 Dittmer Drive 2 h 15 50 - 55 53 - 58 n/a n/a

Holiday Park, Unit 29 2 h 15 47 - 49 50 - 62 n/a n/a

The day time LAeq (15 min) ambient noise levels in the area of investigation were in the range 44 dBA

to 60 dBA, and the LA10 noise levels were in the range 47 to 62 dB, The noise levels depend on the

location and the time of measurements. Table 1 shows that currently noise levels at the residential

dwellings along Dittmer Drive are comparable and the dominant noise source is traffic on Dittmer

Drive.

The night time LAeq noise levels for the period from 22:00 to 7:00 were in the range of 32 – 53 dB,

the LA10 noise levels were in the range of 35 – 55 dB.

The night time LAmax noise levels were approximately in the range 32 – 55 dB. The limit of 65dB was

exceeded many times due to some high noise events and these exceedances occurred in the later

evening and earlier morning hours. On-site investigation shows that most of these noise events were

associated with traffic on Ruha Street and Dittmer Drive.

0.0

10.0

20.0

30.0

40.0

50.0

60.0

70.0

11

:36

12

:21

13

:06

13

:51

14

:36

15

:21

16

:06

16

:51

17

:36

18

:21

19

:06

19

:51

20

:36

21

:21

22

:06

22

:51

23

:36

0:2

1

1:0

6

1:5

1

2:3

6

3:2

1

4:0

6

4:5

1

5:3

6

6:2

1

7:0

6

7:5

1

8:3

6

9:2

1

10

:06

10

:51

No

ise

leve

l dB

101 Dittmer Drive LAeq and L10 (15 min) noise levels, 23 - 24 August 2016

LAeq 15 min L10 15 min



Figure 4: LA10 and LAeq noise levels (15 minute interval).

0.0

10.0

20.0

30.0

40.0

50.0

60.0

70.0

11

:15

12

:00

12

:45

13

:30

14

:15

15

:00

15

:45

16

:30

17

:15

18

:00

18

:45

19

:30

20

:15

21

:00

21

:45

22

:30

23

:15

0:0

0

0:4

5

1:3

0

2:1

5

3:0

0

3:4

5

4:3

0

5:1

5

6:0

0

6:4

5

7:3

0

8:1

5

9:0

0

9:4

5

No

ise

leve

l dB

125 Dittmer Drive LAeq and L10 (15 min) noise levels 23 - 24 August 2016

LAeq 15 min L10 15 min

05

101520253035404550556065707580

22

:00

22

:15

22

:30

22

:45

23

:00

23

:15

23

:30

23

:45

00

:00

00

:15

00

:30

00

:45

01

:00

01

:15

01

:30

01

:45

02

:00

02

:15

02

:30

02

:45

03

:00

03

:15

03

:30

03

:45

04

:00

04

:15

04

:30

04

:45

05

:00

05

:15

05

:30

05

:45

06

:00

06

:15

06

:30

06

:45

07

:00

No

ise

leve

l dB

125 Dittmer Drive LAmax noise levels (1 min) 23-24 August 2016

LAmax



Figure 5: LAmax noise levels (1 minute interval).

4.2 Anticipated Noise Levels from Construction Activities

Noise effects due to construction of the bridge will be minor if a Construction Noise Management

Plan is implemented. The noise from construction activities is regulated by “NZS 6803:1999

Acoustics – Construction Noise”, which requires the best practicable option for mitigation to ensure

that noise levels are reasonable. With regard to construction, “reasonable noise” needs to allow

construction to occur in an efficient manner and protect the adjacent community from high levels of

noise, especially when activities such as sleep are expected.

Experience shows that people will accept construction noise above regular noise levels, so long as the

higher noise levels are for a finite period and good noise management practices are being followed.

Usually high levels of construction noise are acceptable only during daytime and only on weekdays,

although construction noise on Saturdays can also be acceptable.

NZS 6803:1999 is a guideline for setting construction noise limits that are specific to a project being

undertaken and the situation in which that project is located. The current ambient noise levels

existing prior to construction can be used for setting the construction noise limits.

NZS 6803:1999 provides the table of recommended construction noise limits for application in

residential and rural areas and these noise limits are shown in Table 2. This table is a reproduction

of NZS 6803:1999 Table 2. These noise limits can be modified according to specific project

requirements and assist in the setting of upper limits for construction noise.

05

101520253035404550556065707580

22

:00

:00

22

:15

:00

22

:30

:00

22

:45

:00

23

:00

:00

23

:15

:00

23

:30

:00

23

:45

:00

0:0

0:0

0

0:1

5:0

0

0:3

0:0

0

0:4

5:0

0

1:0

0:0

0

1:1

5:0

0

1:3

0:0

0

1:4

5:0

0

2:0

0:0

0

2:1

5:0

0

2:3

0:0

0

2:4

5:0

0

3:0

0:0

0

3:1

5:0

0

3:3

0:0

0

3:4

5:0

0

4:0

0:0

0

4:1

5:0

0

4:3

0:0

0

4:4

5:0

0

5:0

0:0

0

5:1

5:0

0

5:3

0:0

0

5:4

5:0

0

6:0

0:0

0

6:1

5:0

0

6:3

0:0

0

6:4

5:0

0

7:0

0:0

0

No

ise

leve

l dB

101 Dittmer Drive LAmax noise levels (1 min) 23-24 August 2016

Lamax (1 min)



Table 2: Recommended upper limits for construction noise received in residential zones and dwellings in rural areas.

Time of

week

Time period Duration of work

Typical (dBA) Short-term (dBA) Long-term (dBA)

Leq Lmax Leq Lmax Leq Lmax

Weekdays 0630-0730 60 75 65 75 55 75

0730-1800 75 90 80 95 70 85

1800-2000 70 85 75 90 65 80

2000-0630 45 75 45 75 45 75

Saturdays 0630-0730 45 75 45 75 45 75

0730-1800 75 90 80 95 70 85

1800-2000 45 75 45 75 45 75

2000-0630 45 75 45 75 45 75

Sundays

and public

holidays

0630-0730 45 75 45 75 45 75

0730-1800 55 85 55 85 55 85

1800-2000 45 75 45 75 45 75

2000-0630 45 75 45 75 45 75

With reference to Table 2, the duration descriptions represent the following as defined by NZS 6803:

Short-term duration means construction work at any one location for up to 14 calendar days;

Typical duration means construction work at any one location for more than 14 calendar days

but less than 20 weeks; and

Long-term duration means construction work at any one location with a duration exceeding

20 weeks.

The standard specifies typical LAeq noise levels for different construction equipment including

bulldozer, dump truck, excavator, compactor, hammer drive piling equipment, compressors, other

plant and machinery. Therefore, expected construction noise levels can be calculated for different

distances from the specific construction noise source. Table 3 shows the ambient noise levels

calculated for different distances from the construction site and related to different sets of the

construction equipment which could be applicable to this project.

Table 3: Ambient LAeq noise levels associated with operations of construction equipment and machines calculated for the different distances from the source

Equipment or machine combination in operation Noise levels, Leq (dBA)

10 m 25 m 50 m 80 m

2 trucks and excavator 83 75 67 63

Pneumatic hammer 89 81 74 68

Pneumatic hammer and bulldozer 91 83 75 71

Compaction rammer 80 82 74 69

Scraper 85 78 70 65

Asphalt spreader 79 71 64 58



The distance from the bridge construction site to the receptor sites (the nearest residential dwellings)

will be about 80 - 100 m. Calculated noise levels in Table 3 show that bridge construction activities

comply with the recommended construction noise upper limits where there is more than 50 metres

of separation between the main construction activity and the receiver. This calculation can be

considered as conservative because it assumes that the construction equipment is operating in close

proximity, in one location. However, where there are several items of plant or machinery working

together, they are usually spread over the immediate work area. This dispersal tends to reduce the

noise level of the combined plant or machinery compared to if they were all working clustered closely

together.

The noise calculations indicate that beyond a distance of 50 metres from the noise source,

construction noise levels will be within the limits shown in Table 2. There are no residential

dwellings located within the distance of 50 metres from where major bridge works, such as piling,

are likely to be undertaken.

4.2.1 Bridge Approach Construction Works

The bridge approach construction works will include construction of the raised table in the centre of

Dittmer Drive and Ruha Street intersection and the main pedestrian passway from this table to the

bridge. The construction equipment and machines will operate at the distance of 10 – 20 m from the

nearest houses at 131 Dittmer Drive and 22 Ruha Street. These construction works will be short in

duration, and it is understood will be undertaken during the day time from 7.30 am to 6.00 pm.

The noise levels generated from these construction operations will be comparable to the noise levels

from ordinary surfacing roadworks. For the short period of time construction noise levels can be

exceeded, but people normally accept this noise for a finite period of time if good liaison with local

residents and noise management practice are established. The Construction Noise Management Plan

will include consideration of these residential dwellings located at the intersection.

With construction works progressing away from the road and towards the bridge noise levels will

decline below the noise limits. The noise levels in Table 3 above are applicable to equipment and

machines assumed to be operating on construction sites at one group and at the same distance from

the receptor site. For real conditions, when equipment and machines are spread through the site and

moving, noise levels are below those shown in the table.

4.2.2 Recommended Construction Noise Limits

The recommended construction noise limits are shown in Table 4. This table has the same values as Table 2, for typical duration work giving a set of construction noise limits for the bridge construction activities.

Table 4: Recommended construction noise limits applicable for the residential dwellings at Dittmer Drive and Ruha Street.

Time Noise levels (dBA)

Weekday Saturday Sunday, public

holiday

LAeq LAmax LAeq LAmax LAeq LAmax

6:30 am through to 7:30 am 60 75 45 75 45 75

7:30 am through to 6:00 pm 75 90 75 90 55 85

6:00 pm through to 8:00 pm 70 85 45 75 45 75



Time Noise levels (dBA)

Weekday Saturday Sunday, public

holiday

LAeq LAmax LAeq LAmax LAeq LAmax

8:00 pm through to 6:30 am 45 75 45 75 45 75

There will be an increased number of heavy vehicles driving through Dittmer Drive and Ruha Street

over the construction period. The traffic noise from heavy vehicles on those roads is not subject of

this assessment, because traffic noise on public roads is under the control of the traffic regulations

for individual noisy vehicles.

The lower speed limits applicable at the intersection of Dittmer Drive and Ruha Street over the

construction period will also reduce noise levels from heavy vehicles involved in the bridge

construction.

4.3 Construction Noise Management Plan

NZS 6803 provides extensive guidance on good practice to manage construction noise and its effects.

Much of this guidance is typically captured in a Construction Noise Management Plan (CNMP) which

is prepared in association with each specific construction project.

A CNMP may include:

Description of the works, anticipated equipment processes/durations;

Identification of the noise-sensitive receivers likely most affected by construction noise of

specific construction activities;

“Construction noise upper limits” determined with regard to the receiving noise environment

and including daily/weekly scheduling considerations, and with regard to any specific

consent/designation requirements, and this may also take into account where particular

noise-sensitive receivers are recently subject to other construction noise sources;

Assessment of likely construction noise levels and scheduling, with appropriate noise

mitigation measures to be implemented;

Establishing a monitoring regime which targets both the more noisy activities and their

potential occurrences near noise-sensitive locations;

Staff training/awareness programme;

Procedures for maintaining contact with local residents, including informing them when

noisy activities may occur and providing summary reports of monitoring and investigations

of any noise complaints;

Process for managing noise complaints; and

Contact telephone numbers for key construction staff, staff responsible for noise assessment

and Council offices, plus a single point of contact for immediate advice of concerns about

noisy activities.



The CNMP will outline management practices to accompany construction activities with noise levels

within the “construction noise upper limits”. While the constructor is expected to make practicable

efforts to comply with the construction noise upper limits recommended for a project,

NZS 6803:1999 recognises there may still be occasions where, even with application of the best

practicable options for noise avoidance or mitigation, the construction activity will not comply with

the recommended construction noise upper limits. Therefore, the CNMP will also outline more

intense and/or additional management practices that will be used for those activities which are

expected to exceed the construction noise limits.

4.4 Ambient Noise Levels after Construction of the Bridge

After construction of the bridge, the ambient noise levels can be assessed as indicative only. It is

expected that changes in the local noise environment, if they occur, will be related to the increased

number of pedestrians and sport activities (running and biking) in this area, increasing the number

of high noise events.

The existing LAeq (15 min) ambient noise levels are in the range of 44 – 60 dBA depending on the

location and time. These noise levels may increase slightly by 2 – 3 dBA, but according to various

noise studies, changes of up to 3 dBA are perceived by people as “no change” in the noise

environment. If the noise levels will increase more than 3 dBA, these changes may be noticeable by

some local residents and result in noise complaints.

5 Vibration Assessment

The aim of the vibration assessment is to identify potential adverse vibration effects resulting from

the proposed project on nearby properties, so that appropriate actions can be implemented if

necessary.

The vibration sources under consideration include:

Construction related traffic; and

The operation of earthworks and piling machinery during the construction of the project.

The desk study has involved the application of predictive models in conjunction with New Zealand

specific inputs to estimate ground vibration from road construction activity and traffic, and how

these vibrations attenuate with distance. Typically, this approach produces conservative estimates

of the maximum probable ground vibration.

5.1 Assessment Criteria

5.1.1 Background

There are no specific vibration provisions related to construction and traffic in the Horizons Regional

Council (HRC) and the Palmerston North City Council (PNCC) District Plans. Therefore, the most

relevant criteria by which to evaluate the significance of the maximum probable ground vibrations

in the vicinity of proposed bridge are the appropriate international standards and New Zealand

Transport Agency guidelines. These standards and guidelines generally state ground vibration in

terms of peak particle velocity (PPV) for assessment of effects on humans and structures.



5.1.2 Human Comfort

The British Standard, BS 5228.2, 2009, “Code of practice for noise and vibration control on

construction and open sites – Part 2: Vibration,” is a current standard that is commonly adopted in

New Zealand to provide guidance on the response of humans to vibration levels. Guidance on effects

of vibration levels from BS 5228.2 is reproduced below as Table 5. The vibration levels in Table 5 are

in terms of peak particle velocity, PPV (mm/s), which is the vibration parameter routinely measured

when assessing potential building damage.

Table 5: Guidance on effects of vibration levels (from British Standard BS 5228-2:2009, Annex B)

5.1.3 Building Damage

The German Standard DIN 4150-3 (1999) “Structural vibration – Part 3: Effects of vibration on

structures” provides guideline vibration levels which, “when complied with, will not result in damage

that will have an adverse effect on the structure’s serviceability.” For residential buildings, the

standard considers serviceability to have been reduced if:

Cracks form in plastered surfaces of walls;

Existing cracks in the building become enlarged; and

Partitions become detached from load bearing walls or floors.

These effects are deemed ‘minor damage’ in DIN 4150-3.

The DIN 4150-3 guideline values for evaluating short-term and long-term vibration on structures

are given in Table 6 where short-term vibrations are defined as those that do not occur often enough

to cause structural fatigue and do not produce resonance in the structure being evaluated and long-

term vibrations are all the other types of vibration. Resonance is the condition occurring when a

vibrating system is subjected to a periodic force that has the same frequency as the natural

vibrational frequency of the system; at resonance, the amplitude of vibration is a maximum. The

standard recognises that commercial buildings can withstand higher vibration levels than residential

and historic buildings. Also, the guideline values for short-term vibration increase as the vibration

frequency increases.

Table 6: Vibration guidelines from DIN 4150-3:1999 for assessing effects of vibrations on buildings

Vibration level Effect

0.14 mm/s

Vibration might be just perceptible in the most sensitive situation for most vibration

frequencies associated with construction. At lower frequencies, people are less

sensitive to vibration.

0.3 mm/s Vibration might be just perceptible in residential environments.

1.0 mm/s It is likely that vibration of this level in residential environments will cause complaint,

but can be tolerated if prior warning and explanation has been given to residents.

10 mm/s Vibration is likely to be intolerable for any more than a very brief exposure to this level.



Type of Structure

Vibration Thresholds for Structural Damage, PPV (mm/s)

Short-Term Long-Term

At Foundation Uppermost

Floor

Uppermost

Floor

0 to 10

Hz

10 to 50

Hz 50 to 100 Hz

All

Frequencies

All

Frequencies

Commercial /industrial 20 20 to 40 40 to 50 40 10

Residential 5 5 to 15 15 to 20 15 5

Sensitive/Historic 3 3 to 8 8 to 10 8 2.5

Note: When a range of velocities is given, the limit increases linearly over the frequency range.

5.1.4 Construction Vibration Guidelines Adopted by the Transport Agency

Vibration criteria given in the State Highway Construction and Maintenance Noise and Vibration

Guide (NZ Transport Agency, 2013) have been used as a basis to manage construction related

vibrations, as listed in Table 7.

Table 7: Construction Vibration Criteria

Receiver Details Category A Category B Location

Occupied

dwellings

Daytime 6:00 am to 8:00 pm 1.0 mm/s PPV 5.0 mm/s PPV Inside the

building

Night time 8:00 pm to 6:00 am 0.3 mm/s PPV 1.0 mm/s PPV

Other

occupied

buildings

Daytime 6:00 am to 8:00 pm 2.0 mm/s PPV 10.0 mm/s PPV

All buildings Transient vibration 5.0 mm/s PPV BS 5228.2

Table B2 values

Building

foundation

Continuous vibration BS 5228.2

50 % of

Table B2 values

Underground

Services

Transient vibration 20mm/s PPV 30 mm/s PPV On pipework

Continuous vibration 10mm/s PPV 15 mm/s PPV

Table 7 refers to values from BS 5228.2 Table B2, which is shown here as Table 8.

Table 8: BS 5228.2 Table B2 values



Type of building Peak component velocity in frequency range of predominant pulse

4 to 15 Hz 15 Hz and above

Reinforced or framed structures

Industrial and heavy commercial

buildings

50 mm/s 50 mm/s

Unreinforced or light framed structures

Residential or light commercial

buildings

15 mm/s at 4 Hz

increasing to 20 mm/s at 15 Hz

20 mm/s at 15 Hz

increasing to 50 mm/s at 40

Hz and above

With reference to Table 7, if measured or predicted vibration levels exceed the Category A criteria

then a suitably qualified expert shall be engaged to assess and manage construction vibration to

comply with the Category A criteria. If the Category A criteria cannot be practicably achieved, the

Category B criteria shall be applied.

If measured or predicted vibration levels exceed the Category B criteria, then construction activity

shall only proceed if there is continuous monitoring of vibration levels and effects on those buildings

at risk of exceeding the Category B criteria by suitably qualified experts.

5.1.5 Screening Criteria Applied to Project

To identify where construction of the project may create significant adverse impact, the following

criteria has been applied to the output of modelling used to provide estimates of ground-borne

vibrations:

0.3 mm/s PPV for disturbance of building occupants;

1 mm/s PPV for complaint by building occupants; and

3 mm/s PPV for damage to buildings arising from construction (i.e. short term vibration).

These criteria have been derived from BS 5228.2, 2009 and DIN 4150-3 (1999) and have deliberately

been made more stringent than the criteria used by the NZ Transport Agency because they are being

applied to modelled estimates of ground vibrations and not measured ground vibrations. This

approach will yield slightly more conservative effects assessments, which is considered preferable.

5.2 Estimation Procedures

5.2.1 Vibration as a Function of Distance

With reference to Hunaidi (2000), vibration amplitudes and the predominant frequencies are

influenced significantly by the soil type and stratification. The lower the stiffness and damping of the

soil, the higher the vibration. For impact loads, ground vibrations are highest at the natural

frequencies of the site. At these frequencies, the soil, like any structural system, offers the least

resistance and therefore the greatest response to loads. For soils, the natural frequencies depend on

stiffness and stratification.

Vibration amplitudes decrease with distance from the vibration source. The decay is faster in softer

soils than stiffer soils. Also vibrations of a higher frequency decay faster than those of lower



frequency. However, because of the complex nature of soil characteristics, attenuation relationships

are site-specific.

Equation 5-1 below, taken from Cenek et al (2012), was used to estimate the magnitude of ground

vibrations at any distance from source. This allows estimation of critical separation distances

required to ensure that the guideline vibration levels for human comfort and building damage given

in BS 5228-2:2009 and DIN 4150-3:1999 are not exceeded.

𝑉2 = 𝑉1 (𝑅1

𝑅2

)0.5

𝑒−(𝑓)×(𝑅2−𝑅1) (Equation 5-1)

where: V1 = the measured peak particle velocity (mm/s) at distance R1 (m)

V2 = the peak particle velocity (mm/s) at distance R2 (m) from source

𝛼(𝑓) = soil coefficient for the dominant frequency 𝑓 (Hz)

5.2.2 Soil Characteristics

An attenuation coefficient of 0.024 at 5 Hz has been assumed in all the vibration attenuation

calculations. This value of attenuation coefficient has been derived from geotechnical advice received

that the soil conditions in the vicinity of the earthworks area comprise of very loose sand to a depth

of 3.3 m BGL. Below the very loose sand, there is dense silty or sandy gravel to more than 10 m depth.

From the NZGS publication “Field Description of Soil and Rock” Table 2.8, very loose was taken to

correspond to 2 blows per 100mm. This average scala penetrometer reading was applied to equation

8.2 in Cenek et al (2012) to obtain the estimate of the site soil attenuation coefficient.

5.2.3 Source Traffic Vibrations

The probable maximum ground vibrations at the road verge arising from traffic is calculated using

an approach developed for the US Federal Highway Administration (Rudder, 1978), which provides

a value for the peak particle acceleration two metres from the edge of the road. Standards used for

evaluating the effect of vibrations in terms on humans and buildings are formulated around peak

velocities. Therefore, the following transformation was employed:

f)π(2

)(m/s acclpeak 1000(mm/s) peak vel.

2n

(Equation 5-2)

where: f = axle bounce frequency (Hz)

The typical axle bounce frequency for heavy commercial vehicles ranges between 8-15 Hz for

“walking beam” suspensions and 10-15 Hz for air suspensions. For this analysis, an axle bounce

frequency of 10 Hz was assumed as this corresponds to the lowest frequency that covers both

suspension types. With reference to Equation 5.2 above, a low bounce frequency will give “worst

case” (i.e. conservative) estimates of peak velocities.



Vehicle weight and speed and a factor related to the roughness of the road surface are required as

inputs to the predictive model. For this investigation, the maximum permitted weight of 44 tonnes

and a vehicle speed of 50 km/h, corresponding to the sign posted speed limit have been assumed.

The roughness level of the road was assumed to be 150 NAASRA counts/km, this being considered

representative of local roads.

The resulting source traffic vibration levels calculated at 2metres from the road edge were as follows:

0.66 mm/s PPV for a 44 tonne truck travelling at 50 km/h

0.42 mm/s PPV for a 44 tonne truck travelling at 30 km/h

0.44 mm/s PPV for a car/SUV travelling at 50 km/h

These results show that if the truck travel speed is reduced from 50 km/h to 30 km/h, the resulting

traffic vibrations will be imperceptible from those generated by car traffic.

5.2.4 Construction Vibrations

The operation of construction equipment causes ground vibrations that spread through the ground

and diminish in strength with distance. Buildings and structures in the vicinity of the construction

site respond to these vibrations with varying results ranging from no perceptible effects at the lowest

levels, perceptible vibrations at moderate levels and slight damage at the highest levels (Hanson et

al, 2006). Construction equipment that generate little or no ground vibrations are air compressors,

light trucks, hydraulic loaders etc. whereas construction activities that typically generate the most

severe vibrations are pile-driving, vibratory compaction, and drilling or excavation in close proximity

to vibration sensitive structures.

With regard to the proposed bridge project the two construction activities that have the most

potential to generate troublesome vibrations are piling associated with the construction of the bridge

piers and general earthworks. These are expanded on below.

5.2.4.1 Pile Driving

Two methods are commonly used in New Zealand for driving piles into soil to provide foundation

support for bridge structures, these being the impact or recursive hammer and the vibratory

hammer. Because the method of piling to be used on the bridge project has not yet been identified,

empirically based predictor equations provided in Table E.1 of BS 5228-2:2009 have been used to

determine what critical separation distance will be required to ensure the resulting ground vibrations

do not exceed the disturbance threshold of 1 mm/s PPV and the short term damage threshold of 3

mm/s PPV.

Cenek et al (2012) showed that application of both the BS 5228-2:2009 percussive and vibratory

piling predictor equations provided estimates of ground vibration levels which were in close

agreement with NZ measurements for representative piling operations and so can be used with

confidence.

5.2.4.2 General Earthworks

Table 4.1 in NZTA Research Report 485 “Ground vibration from road construction” (Cenek et al,

2012) summarises ground vibration data from construction sites throughout New Zealand acquired



for representative mechanised construction equipment operating on a range of soil types. The

specific equipment monitored comprised, twelve rollers, three dozers, two excavators, one grader

and one stabiliser. This table was used to identify the type of mechanical plant that would generate

the highest magnitude vibrations when operating on the soil type expected in the earthworks area

for the bridge project.

The source vibration selected to represent construction activity, for use with equation 5-1, was taken

to be a Sumitomo SH120 Excavator, giving a vibration level of 5.4 mm/s PPV at a distance of 10

metres, with a frequency of 20 Hz.

To assist the assessment, the separation distances required for (1) building occupants to complain

about the vibration levels and (2) minor building damage to occur from use of the excavator were

calculated. This was achieved by using the “Goal Seek” function in Microsoft Excel with equation 5-

1 to determine what distance from source would be required to achieve the complaint threshold value

of 1 mm/s PPV and short–term structural damage threshold value of 3 mm/s.

5.3 Analysis

5.3.1 Critical Separation Distances

Table 9 lists the calculated critical separation distances for construction traffic and general

earthworks activity.

Table 9: Critical separation distances for traffic and general earthworks

Vibration Source Separation Distance from Vibration Source (m)

Perception Complaint Damage

44 T Truck @ 50 km/h 6.4 1 0.12

44 T Truck @ 30 km/h 3.4 0.4 -

Excavator 34 23 14

Table 9 shows that vibrations from earthworks machinery have the potential to be more problematic than general construction traffic.

5.3.2 Construction Traffic

Residential buildings along both Ruha Street and Dittmer Drive are at their closest 6 m from the

road edge. Therefore, it is unlikely that occupants of these buildings will notice any change in

vibration levels to those presently experienced as 6 m is close to the 6.4 m required for traffic

vibrations to be perceived.

However, if residential streets need to be used to gain access to the bridge construction site, imposing

a speed limit of 30 km/h on the construction related HCV traffic will ensure that any vibrations

induced will be at the same level as those generated by cars/SUV’s.



5.3.3 Earthworks

The extent of the area earmarked for earthworks is shown in Figure 2. The closest residential

buildings to the earthworks area are 131 Dittmer Drive and 22 Ruha Street, which are about 12 m

and 16 m away respectively from the nearest earthworks area boundary.

With reference to Table 7, there is the potential for both complaint and damage if earthworks

machinery is operated closer than 11 m from the indicated northern earthworks boundary. Should

this be the case, the Construction Noise and Vibration Plan must consider how earthworks

machinery will be selected, operated and parked to ensure vibrations will not be problematic for

occupants of 131 Dittmer Drive and 22 Ruha Street.

Vibrations from earthworks are unlikely to impact on the Palmerston North Holiday Park as the

closest building to the proposed earthworks area is about 44 m away.

5.3.4 Piling

Two methods are commonly used in New Zealand for driving piles into soil to provide foundation

support for bridge structures, these being the impact or recursive hammer and the vibratory

hammer. Because the method of piling to be used on the bridge project has not yet been confirmed,

empirically based predictor equations provided in Table E.1 of BS 5228-2:2009 have been used to

determine what critical separation distance will be required to ensure the resulting ground vibrations

do not exceed the short term damage threshold of 3 mm/s PPV.

Cenek et al (2012) showed that application of both the BS 5228-2:2009 percussive and vibratory

piling predictor equations provided estimates of ground vibration levels which were in close

agreement with NZ measurements for representative piling operations and so can be used with

confidence.

For vibratory piling, the minimum separation distance will need to be 32 m for a 5% probability that

the resulting ground vibrations are 3 mm/s PPV or less.

For percussive piling, the situation is slightly more complicated because the estimated ground

vibrations are a function of both hammer energy and slope distance from the pile toe. Therefore, if

the vibratory piling separation distance of 32 m is maintained, the maximum hammer energy that

can be applied is 5.9 kJ for the pile at refusal. This assumes the upper limit pile toe depth of 27 m

allowed for by the BS 5228-2:2009 percussive piling predictor equation, giving a slope distance of

41.9 m.

Currently, the closest residential properties to the proposed bridge are 22 Ruha Street at 52 m away

and 131 Dittmer Drive, at 58 m away. Therefore, there is sufficient space in which to locate the closest

landbased bridge pier to minimise any likelihood of structural damage to nearby buildings from pile

driving operations required for the construction of the pier. The two other bridge piers pose less of a

concern as they are much further away, being in the river itself.

5.3.5 Concluding Remark

From the above analysis, it appears that the only potential vibration issue is if earthwork operations

take place close to the northern boundary of the proposed earthworks area. However, a Construction

Vibration Management Plan that recognises 22 Ruha Street and 131 Dittmer Drive as vibration

sensitive buildings, will be sufficient to address any potential detrimental vibration effects.



6 Conclusions

The ambient noise levels measured in the assessment area are indicative of the existing noise

environment. It is anticipated that the local noise environment will change after construction of the

bridge, but these changes will be insignificant due to the considerable distance of 80 - 120 m between

the noise source (the proposed bridge and associated pedestrian pathways) and houses at Ruha

Street and along Dittmer Drive. Therefore, the effect on residential dwellings will be minimal.

Because noise and vibration effects due to construction are very much dependent on the equipment

used and on its condition, the assessment has had to be based on noise and vibration levels

representative of New Zealand construction practices. Using this approach, only two residential

buildings have been identified where there is some potential for construction vibrations to cause

complaint and even damage. These are 22 Ruha Street and 131 Dittmer Drive. However, it is

expected that any potential adverse noise and vibration effects at these two properties can be

addressed through the preparation and implementation of a combined Construction Noise and

Vibration Management Plan (CNVMP) as the mitigation measures relate to selection of equipment

and processes and the location and operation of the equipment.



7 References

British Standard, BS 5228.2:2009. Code of practice for noise and vibration control on construction

and open sites – Part 2: Vibration.

Cenek, P.D., Sutherland, A.J. and McIver, I.R.(2012) Ground Vibration from Road Construction,

NZ Transport Agency Research Report 485, downloadable from:

http://www.nzta.govt.nz/resources/research/reports/485/index.html

Dowding, C.H. (2000) Construction Vibrations. Second Edition. ISBN 0-99644313-1-9. Prentice

Hall Engineering/Science/Mathematics, Upper Saddle River, NJ.

German Standard, DIN 4150-3:1999. Structural Vibration – Part 3: Effects of vibration on

structures.

Hanson, C.E., Towers, D.A. and Meister, L. D. (2006) Transit Noise and Vibration Impact

Assessment. Report FTA-VA-90-1003-06, Office of Planning and Environment, Federal Transit

Administration.

Hunaidi, O. (2000) Traffic Vibrations in Buildings. Construction Technology Update No. 39.

Institute for Research in Construction, National Research Council of Canada. ISSN 1206-1220.

NZTA (2013). State Highway Construction and Maintenance Noise and Vibration Guide.

http://www.nzta.govt.nz/resources/sh-construction-maintenance-noise/

http://www.nzta.govt.nz/resources/research/reports/485/index.html

http://www.nzta.govt.nz/resources/sh-construction-maintenance-noise/



Appendix A

125 Dittmer Drive 24 hour site

101 Dittmer Drive 24 hour site



115 Dittmer Drive short-term site

Holiday Park Unit 29

Opus International Consultants Ltd 33 The Esplanade, Petone PO Box 30 845, Lower Hutt 5040 New Zealand t: +64 4 587 0600 f: +64 4 587 0604 w: www.opus.co.nz

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Opus Research Report 5-P0843.06 XXX65/XXX66 Manawatū River … · 2019. 11. 19. · of Ruha Street and terminating on the opposite bank. The bridge has a proposed span of approximately