assessment of environmental effects: vibrations state ... estimated vibration levels were assessed...

Assessment of Environmental Effects: Vibrations

State Highway 3, Awakino Tunnel Bypass Peter Cenek

Assessment of Environmental Effects: Vibrations

State Highway 3,

Awakino Tunnel Bypass

Peter Cenek

© Opus International Consultants Ltd 2017

Prepared By Opus International Consultants Ltd

Peter Cenek Opus Research

Research Manager, Engineering Sciences 33 The Esplanade, Petone, 5012

PO Box 30 845, Lower Hutt 5040

New Zealand

Reviewed By Telephone: +64 4 587 0600

Paul Carpenter Facsimile: +64 4 587 0604

Vibrations Specialist

Date: 24 August 2017

Reference: 2-32705.00 Task 51AVT

Status: Final

SH3, Awakino Tunnel Bypass – Assessment of Vibration Effects i

2-32705.00 51AVT| May 2017 Opus International Consultants Ltd

Executive Summary

This report presents an assessment of ground-borne vibrations resulting from construction works

associated with the State Highway 3 (SH3) Awakino Tunnel Bypass Project and from traffic once

the Project is completed. The Project involves realigning SH3 to the north bypassing the tunnel,

requiring two bridges and a relatively complex retaining wall.

Particular emphasis has been placed on determining critical separation distances between

construction and Heavy Goods Vehicle (HGV) traffic vibration sources and receivers to ensure the

generated vibrations are not problematic from the perspectives of annoyance and structural

damage.

The assessment has been based on a desk study that involved the application of predictive models

in conjunction with specific inputs to estimate ground vibrations from road construction activity

and HGV traffic and how these vibrations attenuate with distance.

The estimated vibration levels were assessed from the perspectives of human comfort and cosmetic

building damage using guidelines given in:

• British Standard BS 5228 2:2009, Code of practice for noise and vibration control on

construction and open sites – Part 2: Vibration;

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

structures; and

• The Transport Agency’s State Highway Construction and Maintenance Noise and Vibration

Guide (2013).

The primary conclusions and recommendations arising from this assessment of ground vibrations

generated by the construction and operation of the proposed realignment of SH3 in the vicinity of

Awakino Gorge are as follows:

1. Vibration levels generated by construction are likely to be higher than those from traffic.

However, these construction-related vibrations will be temporary and of a limited duration.

2. The occupants of the dwelling closest to the earthworks and road construction (i.e. OTS

House 1) are likely to experience vibration levels from these activities that may cause

complaint but not damage to the dwelling. Therefore, because complaints typically arise

from interference with people’s activities or fear of property damage, it is important that the

contractor establishes open communication with the occupants so that any issues can be

identified and addressed expeditiously. However, the contractor should ideally take all

practicable measures to avoid excessive earthworks and road construction induced

vibrations near OTS House 1.

3. The analysis has identified that there is the potential for piling to cause damage to the

existing Awakino tunnel.

4. The adverse effects from construction can be appropriately mitigated through a

Construction Vibration Management Plan as the mitigation measures relate to selection of

equipment and processes and the location and operation of the equipment. In the unlikely

event of there being no practicable means for achieving the construction vibration criteria

stipulated in the Construction Vibration Management Plan, pre- and post-construction

SH3, Awakino Tunnel Bypass – Assessment of Vibration Effects ii


inspections of at risk structures and buildings will need to be performed and any damage

rectified.

5. A key aspect of this Construction Vibration Management Plan is for piling operations to be

used on the project to be trialled before construction proper commences to ensure short-

term vibration damage guidelines given in German Standard DIN 4150-3 are complied with

at the existing Awakino tunnel.

6. Once operational, traffic induced vibrations are unlikely to be perceived if the proposed

chipseal road surface can be laid so that it satisfies the Transport Agency’s roughness

specification of 70 NAASRA counts per km for new pavement construction. Furthermore, at

the closest separation distance from a dwelling of approximately 87 m, vibrations are

unlikely to be felt by occupants even when the road surface roughness reaches 110 NAASRA

counts/km, the Transport Agency’s trigger for road smoothing for roads classified as Rural,

Regional Strategic.

SH3, Awakino Tunnel Bypass – Assessment of Vibration Effects iii


Contents

Executive Summary .................................................................................................... i

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

2 Project Description ............................................................................................ 2

2.1 Overview ................................................................................................................................ 2

2.2 Key considerations from a vibrations perspective .............................................................. 3

3 Assessment Criteria ........................................................................................... 4

3.1 Background ............................................................................................................................ 4

3.2 Human Comfort .................................................................................................................... 4

3.3 Building Damage ................................................................................................................... 5

3.4 Vibration Guidelines Used by the Transport Agency ......................................................... 6

3.5 Screening Criteria Applied to Project .................................................................................. 8

4 Methodology ...................................................................................................... 9

4.1 Overview ................................................................................................................................ 9

4.2 Method for Calculating Attenuation Coefficient ................................................................. 9

4.3 Vibration as a Function of Distance ..................................................................................... 9

4.4 Predictor Equations ............................................................................................................ 10

5 Results .............................................................................................................. 12

5.1 Soil Attenuation .................................................................................................................... 12

5.2 Critical Separation Distances .............................................................................................. 12

6 Assessment of Effects ........................................................................................14

6.1 Existing Environment ..........................................................................................................14

6.2 Construction Vibrations ....................................................................................................... 15

6.3 Operational Vibrations ....................................................................................................... 18

6.4 Mitigation Measures ........................................................................................................... 18

7 Conclusions and Recommendations .................................................................. 21

8 References ....................................................................................................... 22

SH3, Awakino Tunnel Bypass – Assessment of Vibration Effects 1


1 Introduction

This report presents the results of a desk study to calculate likely maximum ground vibrations

expected to occur in the vicinity of the State Highway 3 (SH3) Awakino Tunnel Bypass project (the

Project). The effects of these calculated vibrations on the existing Awakino Tunnel and nearby

dwellings and their occupants were assessed so that appropriate mitigation actions can be

implemented if necessary.

The vibration sources considered were:

• The operation of machinery during earthworks and laying of the road surface associated

with the construction of the realigned SH3;

• Piling associated with the construction of the two new bridges, which will cross the Awakino

River; and

• Operational road vehicle traffic on SH3, following the completion of the project.

The study 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 vibrations. Therefore, the output from the study can be regarded as

representing the upper value of expected vibration levels.

The estimated vibration levels were assessed from the perspectives of human comfort and cosmetic

building damage using guidelines given in:

• British Standard BS 5228 2:2009, Code of practice for noise and vibration control on

construction and open sites – Part 2: Vibration;

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

structures; and

• The New Zealand Transport Agency’s State Highway Construction and Maintenance Noise

and Vibration Guide (2013).

The report has been structured as follows:

• Section 2 presents an overview of the project and key aspects of the project from a

vibrations perspective.

• Section 3 details the criteria by which the estimated construction and traffic related

vibrations were evaluated from the perspectives of human comfort and cosmetic building

damage.

• Section 4 describes the methodology used for determining construction and operational

vibrations.

• Section 5 summarises the key findings from the vibration analysis undertaken.

• Section 6 identifies problematic vibrations and associated mitigation measures.

• Section 7 presents the main conclusions and recommendations resulting from the

assessment.



2 Project Description

2.1 Overview

The SH3 Awakino Tunnel Bypass project is located 50 km south of Te Kuiti, roughly half way

between Hamilton and New Plymouth, in the Waikato Region. The project will reduce fatal and

serious crashes and road closures, as well as improve the performance of the network. Parts of the

site are highly constrained by poor access, steep terrain and the narrow existing highway, as well as

the meandering Awakino River. The proposed two lane realignment to the north of the existing

single lane Awakino Tunnel will be about 2 km long (i.e. approximate start at SH3 RS133-B/0.4

and approximate end at SH3 RS118-B/13.07).

The preliminary design of the realignment involves:

• Approximately 2.3 km of new two lane road typically 10 m wide (plus batter slopes), which

bypasses the existing single lane Awakino Tunnel;

• Approximately 675 m of northbound passing lane and two truck pull off areas (one in each

direction);

• Two new bridges across the Awakino River;

• Approximately 190,000 m3 of earthworks cut up to about 30 m high, covering about 400 m

length of the new highway;

• Approximately 600 m length of embankment up to about 6 m high, including a section of

fill supported on timber piles due to underlying soft ground;

• Approximately 600 m length of new retaining walls up to about 8 m high at various

locations along the realigned highway;

• Changes to existing farm entrances and access tracks, including provision of a new farm

underpass;

• A rest area with a footpath to the tunnel and access to the river; and

• Landscape treatment and ecological enhancement planting.

At the time of preparing the report, there were no plans to employ blasting in making the 50 m

length of cut in the limestone at the southern end of the Project. However, if the successful

contractor wanted to do things differently, he/she would still need to comply with the vibrations

related criteria specified in the Construction Vibration Management Plan (CVMP) as well as any

vibrations related conditions that may be placed on the designation. Recommend criteria for

managing the effects of construction vibration and airblast are provided in the Transport Agency’s

“State Highway construction and maintenance noise and vibration guide” (NZTA, 2013), which has

been reproduced as Table 3.3 in this report for ready reference. Therefore, for the purposes of this

assessment of vibration effects, it has been assumed that no blasting will be employed for the

Project.

The existing alignment has an annual average daily traffic of 2269 vehicles per day (two way flow)

of which heavy commercial vehicles comprise 20% (i.e. 450 HCV’s per day). These traffic

characteristics are not expected to change as a result of the Project, with the exception of growth

estimated at 0.8% per annum based on historic trending and a maximum rate of 2.2% per annum

based on the last 5 years.



2.2 Key considerations from a vibrations perspective

The key considerations of the project from a vibrations perspective are as follows:

2.2.1 Operational Traffic

The Project will have an 80 km/h speed limit in place, which is 20 km/h less than the open road

(100 km/h) for the existing alignment of SH3. Therefore, a deterioration of the existing traffic-

induced vibration conditions can only occur if the Project brings traffic closer to neighbouring

buildings.

2.2.2 The Bridge Elements

The two new bridges have the potential to generate problematic vibrations from a number of

aspects:

• Ground improvement may be required to protect against liquefaction subsidence and

lateral spreading at the bridge abutments. A method, which is commonly used is

compacted or rammed stone columns. This may result in large ground vibrations,

depending on the energy required to ram the stone columns.

• Construction of the bridge piers will necessitate vibration inducing piling operations, which

have the potential to cause damage to nearby buildings because of the large impact forces

involved.

• Once operational, large ground vibrations will result if the transitions at the bridge

abutments and expansion joints aren’t sufficiently smooth to limit impact wheel loading

from heavy commercial vehicles.

2.2.3 General Road Construction

Typical road construction activity such as ground excavation and compaction has the potential to

cause problematic vibrations if it takes place in close proximity to buildings and structures.

2.2.4 Wooden piles – Hammonds Corner

Wooden piles may be used around the area of the realigned Hammonds Corner. These wooden

piles are expected to only be driven until they hit rock and as such are expected to generate smaller

vibration levels than possible piling activities related to bridge construction. As the location of the

wooden piles is further from the sensitive receivers than the bridge construction activities, it can be

expected that vibrations generated from the wooden piles will be of a low level, provided the

calculated vibration levels from piling related to bridge construction are acceptably low.



3 Assessment Criteria

3.1 Background

The Project covers land areas under the jurisdiction of the Waitomo District Council and the

Waikato Regional Council. The only specific reference to vibrations is made under clause 20.5.1.6

of the Waitomo District Plan-March 2009, Part 3: Section 20: Noise1. Under the Waitomo District

Plan, the Project area is zoned rural and the following rules apply:

While Waitomo District Plan vibration related rules do not directly apply to the designation, they

provide guidance as to the community’s expectations of what is reasonable vibration. Therefore,

any standards based criteria used to evaluate the significance of the calculated maximum probable

ground vibrations in the vicinity of the Project should ideally be consistent with the vibration

related rules contained in the Waitomo District Plan.

Current standards and guidelines considered appropriate in assessing the effects of vibration

caused by the Project from the perspectives of human comfort and damage to buildings are

discussed below. These standards and guidelines generally state ground vibrations in terms of

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

3.2 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 3-1 for ready reference. The

vibration levels in Table 3-1 are in terms of PPV, which is the vibration parameter routinely

measured when assessing potential building damage.

1 http://www.waitomo.govt.nz/Documents/Documents/District%20Plan/Part%20Three_General%20Provisions.pdf



Table 3-1: Guidance on effects of vibration levels (from British Standard BS 5228-2:2009, Annex B)

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.

3.3 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.

• Partitions become detached from load bearing walls or floors.

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

The DIN 4150-3 (1999) guideline values for evaluating short-term and long-term vibration on

structures are given in Table 3-2, where short-term vibrations are defined as those that do not

occur often enough to cause structural fatigue and do not produce resonance2 in the structure

being evaluated and long-term vibrations are all the other types of vibration.

With reference to Table 3-2, the German Standard DIN 4150-3 (1999) recognises 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.

2 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.



Table 3-2: Vibration guidelines from DIN 4150-3:1999 for assessing effects of vibrations on buildings

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.

3.4 Vibration Guidelines Used by the Transport Agency

3.4.1 Construction Related Vibrations

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

Guide (NZTA, 2013) have been used as a basis to manage construction related vibrations. These

criteria are reproduced in Table 3-3 below.

Table 3-3: Construction Vibration Criteria from NZTA, 2013

Receiver Details Category A Category B Location

Occupied

dwellings

Daytime 6: 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: am 0.3 mm/s PPV 1.0 mm/s PPV

Other

occupied

buildings

Daytime 6: 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 percent

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 3-3 refers to values from BS 5228.2 Table B2, which is reproduced below as Table 3-4 for

ease of reference.

With reference to Table 3-3, 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.

Table 3-4: 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

3.4.2 Operational Vibrations

For perception of traffic vibration, the criteria commonly used is taken from Annex B, table B.1 of

the Norwegian Standard NS 8176.E (2005) “Vibration and shock: Measurement of vibration in

buildings from land-based transport and guidance to evaluation of its effects on human beings.”

For new roads, the criterion for class C buildings is applied as it corresponds to the recommended

limit value for vibration in new residential buildings and in connection with planning and building

of new transport infrastructures. This criterion is in terms of statistical maximum value for

weighted velocity (Vw,95) and has a value of 0.3 mm/s. Weighted velocity is the root-mean-square

value (r.m.s) of vibration velocity measured by using a frequency weighting filter corresponding to

whole-body vibration in buildings, where the weighting is about 1 over the frequency range 1 to 80

Hz. The r.m.s integration time is 1 second and the statistical maximum is derived from the mean

and standard deviation of a minimum of 15 single passes of a Heavy Goods Vehicle (HGV) at a

measurement location.

Because of this need to apply a weighting, the class C and D building criteria of NS 8176.E (2005)

can only be applied to measurements of traffic-induced vibrations, not values calculated from

predictive models.

NS 8176.E states that about 15% of the affected persons in class C dwellings can be expected to be

disturbed by traffic induced vibration.

For existing roads, the criterion for class D buildings is applied as it corresponds to vibration

conditions that ought to be achieved in existing residential buildings. This criterion is in terms of

statistical maximum value for weighted velocity (Vw,95) and has a value of 0.6 mm/s.

NS 8176.E (2005) states that about 25% of the affected persons in class D dwellings can be

expected to be disturbed by traffic induced vibration.



3.5 Screening Criteria Applied to Project

To identify where construction and operation 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.

• 2.5 mm/s PPV for damage to buildings arising from traffic (i.e. long term vibration).

• 5 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 either the Waitomo District

Council or the 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.



4 Methodology

4.1 Overview

The methodology adopted in making the assessment involved the application of predictive models

in conjunction with specific inputs to estimate ground vibrations from road construction activity

and HGV traffic and how these vibrations attenuate with distance. These predictive models are

detailed below.

4.2 Method for Calculating Attenuation Coefficient

The soil attenuation coefficient, α, is used as a measure of the decrease in measured vibration with

increasing distance from the road.

With reference to Cenek et al (2012), maximum scala readings have been shown to be very good

predictors of soil attenuation. Therefore, estimates of soil attenuation coefficient were calculated

from scala readings presented in the 2017 SH3 Awakino Tunnel Bypass DBC Geotechnical Factual

Report used in combination with equation 4-1, taken from Cenek et al (2012).

�(5��) = 0.0351 ��.�� (Equation 4-1)

where: �(5��) = soil attenuation coefficient (m-1) for a frequency of 5Hz

�� = maximum scala reading (blows/50mm)

Attenuation of vibrations is dependent on the frequency of the vibrations. Equation 4-2 can be used

to convert the attenuation coefficient to a frequency independent value relating to the soil type.

fπ

αρ = (Equation 4-2)

where: α is the attenuation coefficient [m-1]

ρ is the frequency independent material property of the soil [s/m]

f is the dominant frequency of the ground vibration [Hz]

4.3 Vibration as a Function of Distance

The soil attenuation coefficient derived as outlined in section 4.2 can be used to estimate the

magnitude of ground vibrations at any distance from source using equation 4-3 below, taken from

Cenek et al (2012). 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.



!� = !" #$"$�%�.& �α(')×()*�)+) (Equation 4-3)

where: V" = the measured or estimated peak particle velocity (mm/s) at distance R" (m)

V� = the peak particle velocity (mm/s) at distance R� (m) from source

�(.) = soil coefficient for the dominant frequency . (Hz)

4.4 Predictor Equations

4.4.1 Vibrations from Heavy Commercial Vehicles

The probable maximum ground vibrations 2m from the lane edge arising from HCV traffic were

calculated using an approach developed for the US Federal Highway Administration (FHWA) by

Rudder (Rudder, 1978). This allows the effect of vehicle speed, vehicle mass, vehicle suspension

type, surrounding soil type and road roughness on the calculated ground vibration level to be

investigated.

For the project, the following inputs were used with the FHWA model:

• Mass of vehicle = 50 tonnes

• Suspension = leaf spring/walking beam

• Speed = 80 km/h

• Road roughness:

Minimum = 70 NAASRA counts/km

Maximum = 110 NAASRA counts/km

The minimum roughness value coincides with the Transport Agency’s roughness specification for

the construction of new chipseal surfaces (NZTA, 2006).

The maximum roughness value coincides with target maximum values adopted by the Transport

Agency for state highways classified as “Regional Strategic.”

4.4.2 Vibrations from Road Construction Equipment

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 soil types expected along the route of

Section C.

For the Project, the source vibration representing construction activity for use with equation 4-3

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

distance of 10 m, with a frequency of 20 Hz. With reference to the vibration levels from mechanical

plant given in Cenek et al 2012, a vibration level of 5.4 mm/s PPV corresponds to the 80th

percentile value, i.e. only 20% of the mechanical plant monitored generated a vibration level

greater than 5.4 mm/s PPV at a distance of 10 m.



4.4.3 Piling Operations

Predictor equations provided in Table E.1 of BS 5228-2:2009 for vibrated stone columns,

percussive (drop mass) piling and vibratory piling have been used. These have been reproduced

below for ready reference. In all cases, the 5% scaling factor has been adopted, so there is only a 5%

probability of the predicted value being exceeded.

Vibrated stone Vibrated stone Vibrated stone Vibrated stone columnscolumnscolumnscolumns !=>? = 95A".B (Equation 4-4)

where: !=>? = predicted resultant peak particle velocity (mm/s) with 5% probability of value being exceeded

A = distance measure along the ground surface (m), 8≤ A ≤100 m

VibratVibratVibratVibratory pilingory pilingory pilingory piling (all operations)(all operations)(all operations)(all operations) !=>? = 266A".B (Equation 4-5)

where: !=>? = predicted resultant peak particle velocity (mm/s) with 5% probability of value being exceeded

A = distance measure along the ground surface (m), 1≤ A ≤100 m

PercussivePercussivePercussivePercussive pilingpilingpilingpiling (a(a(a(at refusal)t refusal)t refusal)t refusal) !=>? ≤ 5 L√NO".� P (Equation 4-6)

where: !=>? = predicted resultant peak particle velocity (mm/s)

N = nominal hammer energy , in joules (J), 1,500≤W≤85,000

O = slope distance from pile toe (m), where O� = �� + A�

�, pile toe depth (m) (1≤ �≤27) and

A, distance measured along the ground surface (m) (1≤ A≤111)



5 Results

5.1 Soil Attenuation

Results of the soil attenuation coefficients for the 3 locations where scala penetrometer readings

were made from the surface are given in Table 5-1. Because of the small variability in the

maximum scala readings over the 3 locations, a ρ value of 1.40×10-3 s/m was adopted for the

project, this being the average.

Table 5-1: Soil Attenuation Estimates along Project Route

Test Pit ID

SCALAmax

(blows/50mm) α(5Hz) ρ

AS201 1.5 0.0246 1.57E-03

AS202 2 0.0219 1.39E-03

AS203 2.5 0.0195 1.24E-03

Av 2 0.0220 1.40E-03

With reference to Table 5-2 below, a ρ value of 1.40×10-3 s/m corresponds to weak or soft soils.

This is consistent with the Project’s Geotechnical Factual Report, which shows that the soil to a

depth of 2.5 m comprises of silt and fine to medium sand.

Table 5-2: Attenuation Characteristics of Various Soil Types (adapted from Amick, 1999)

5.2 Critical Separation Distances

Table 5-3 tabulates the calculated critical separation distances for key construction operations and

HGV traffic once the Project becomes operational. The vibration levels corresponding to

perception, complaint, damage from long term vibrations and damage from short term vibrations

are as presented in section 3.5.

The estimates of critical separation distance given for percussive piling in Table 5-3 assumes the

maximum hammer energy permitted for use with Equation 4-6, i.e. 85,000 J, and a pile toe depth

of 12 m. To put these two values in context, the hammer energy of 85,000 J corresponds to a 9

tonne hammer with an approximately 1m drop height. Such energy was considered to be sufficient

Class Description of Soil Attenuation Coefficient,

αααα, at 5 Hz (m-1)

Frequency Independent

Soil Property, ρρρρ (s/m)

I

Weak or soft soils (soil penetrated easily); loess soils, dry or partially saturated peat and muck, mud, loose beach sand and dune sand, recently ploughed ground, soft spongy forest or jungle floor, organic soils, topsoil

0.01 - 0.03 6x10-4 - 2x10-3

II Competent soils (can dig with shovel): most sands, sandy clays, silty clays, gravel, silts, weathered rock

0. 003 - 0.01 2x10-5 - 6x10-4

III

Hard soils (cannot dig with shovel, must use pick to break up): dense compacted sand, dry consolidated clay, consolidated glacial till, some exposed rock

0.0003 - 0.003 2x10-5 - 2x10-4

IV Hard, competent rock (difficult to break with a hammer): bedrock, freshly exposed hard rock

< 0.0003 < 2x10-5



to drive a concrete plug at the base of piles for the Wigram Magdala Link Bridge, which was part of

the Christchurch Southern Motorway project (Hayes, 2015).

For the Project, the retaining walls at the western tie-in are bored concrete piles into the underlying

rock. Similarly, the bridge piles will be bored piles into the underlying rock. Construction of these

bored piles may involve temporary steel casings. The methodology for driving the casing is

undetermined at this stage so could be either vibratory, percussive or a combination of both so

both piling options have been considered in Table 5-3.

It should be noted that critical separation distances tabulated in Table 5-3 for damage are

indicative only as no account has been taken of the dominant frequency of the ground vibrations.

Table 5-3: Estimated Critical Separation Distances for Key Construction Activities and HGV Traffic

Vibration Source

Separation Distance from Vibration Source (m)

Perception Complaint Damage

(Long Term Vibrations)

Damage (Short Term Vibrations)

50T Truck @ 80km/h, 70 NAASRA counts/km

4.2 0.5 <0.1 -

50T Truck @ 80 km/h, 110 NAASRA counts/km

7.7 1.2 0.2 <0.1

Excavator 43.8 28.4 - 10.7

Vibrated Stone Columns 61.0 25.8 - 8.1

Vibratory Piling 127.3 53.9 - 17.1

Percussive Piling 683.8 270.6 - 77.7



6 Assessment of Effects

6.1 Existing Environment

There are only two dwellings in the vicinity of the Project located within 100 m of each other.

These two dwellings will be referred to as OTS House 1 and OTS House 2 for consistency with the

Noise Assessment Report. OTS House 1 is to the north of OTS House 2, the approximate location

of these 2 dwellings along SH3 being RS 118-B/14.008 (OTS House 1) and RS 118-B/14.108 (OTS

House 2). Figure 6-1 shows an aerial view of the two dwellings and their proximity to SH 3.

Figure 6-1: Aerial image of the only dwellings in vicinity of the project

The average lane roughness levels of SH3 along the frontages of these two properties as measured

on 23rd of November 2016 as part of the Transport Agency’s annual high speed condition survey

was 65 NAASRA counts/km in the near (southbound) lane and 88 NAASRA counts/km in the far

(northbound) lane.

OTS House 1 is setback from the edgeline of SH3 by about 33 m whereas OTS House 2 is setback

even further at 55 m. Therefore, with reference to the HGV vibration data provided in Table 5-3, it

can be inferred that vibrations presently induced by SH3 traffic are unlikely to be perceived by

occupants of either OTS House 1 or OTS House 2.



6.2 Construction Vibrations

6.2.1 Background

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 Project, the six construction activities that have the most potential to generate

troublesome vibrations are:

i. bored piling associated with the construction of the bridge piers,

ii. bored piling associated with the retaining walls at the western tie-in;

iii. ground improvement that may involve vibrated stone columns;

iv. wooden piling associated with Hammonds corner;

v. general road construction; and

vi. construction machinery startup and shutdown in set-down areas.

These are expanded on below after a consideration of distances between the various vibration

sources and the critical receivers. For this Project, the critical receivers with regard to vibrations

are the two OTS houses shown in Figure 6-1. Also, the Awakino tunnel could be considered a

critical receiver as it is unlined and if large vibrations were to be created nearby, there could be

some risk of increased rockfall from slopes in the vicinity of the tunnel.

6.2.2 Building and Tunnel Setbacks

The distances of the nearest occupied buildings and the Awakino tunnel to

earthworks/piling/blasting associated with the Project, as determined from Google Earth, are

summarised in Table 6-1. Figure 6-2 spatially shows how the location of the two dwellings are

related to the key construction activities.

By comparing the distances against the critical separation distances provided in Table 5-3, the

expected construction vibration effects can be readily inferred.



Table 6-1: Nearest Scaled Distances

Vibration Source Receiver Estimated Nearest Distance

(m)

Piling:

Western tie-in

Awakino Tunnel 90

Nearest OTS House 630

Piling:

Bridge Abutments/Pylons

Awakino Tunnel 35


Timber Piling: Hammonds Corner

Awakino Tunnel 1,100


General Construction Awakino Tunnel 35


Site Storage Awakino Tunnel 110


Figure 6-2: Aerial image showing the approximate location of the various construction activities: (A) Possible piling activities related to bridge construction. (B) Nearest earthworks activities to a dwelling (C) Nearest road construction/sealing activities to a dwelling. (D) Possible wooden piles associated with realignment of Hammonds Corner.

6.2.3 Earthworks and General Road Construction

The minimum separation distance between where earthworks and road construction is indicated to

take place and the two dwellings is 30 m (OTS House 1) and 70 m (OTS House 2). It is therefore

unlikely that the occupants of OTS House 2 will be able to distinguish vibrations generated from

earthworks and road construction activity from ambient vibrations as, with reference to Table 5-3,

a separation distance of less than 44 m is required for these vibrations to be perceived. However,



at OTS House 1, vibration levels will approach the level that will cause complaint in residential

environments. Therefore, because complaints typically arise from interference with people’s

activities or fear of property damage, it is important that the contractor establishes open

communications with the occupants so that any issues can be identified and addressed

expeditiously. As a minimum, this communication should include written information on the

planned works (nature, working hours, and anticipated duration) plus a helpline to respond to

queries and complaints.

Ideally, the contractor should take all practicable measures to avoid using earthworks and road

construction equipment near OTS House 1 that generate excessive ground vibrations.

The Awakino tunnel is 35 m away at its closest from earthworks and road construction activity. As

a consequence, the magnitude of ground vibrations induced by this activity will be insufficient to

cause damage to the tunnel or soil settlement in its vicinity.

6.2.4 Piling

The two dwellings are at least 300 m away from any piling operations and stone column based

ground improvement works. Therefore, irrespective of what piling technique is used, this distance

is more than sufficient to prevent annoyance of the occupants and damage to the buildings.

Regarding the Awakino tunnel, the closest piling operations are likely to get to the Awakino Tunnel

from Table 6-1 is 35 m. With reference to Table 5-3, no damage is expected to occur if vibratory

piling is selected for driving steel casings or the concrete piles associated with the construction of

the bridge. However, if percussive piling is selected instead, there is a possibility that vibrations

could cause damage depending on the hammer energy used and the structural integrity of the

tunnel.

For example, the estimated critical separation distance for avoiding damage from percussive piling

of 78 m given in Table 5-3 has been predicated on a maximum hammer energy of 85 kJ and the

Awakino tunnel having reduced integrity so that it approximates a residential building. If we

assume the structure has adequate structural integrity so that it approximates a commercial

building, the vibration level for onset of damage increases from 5 mm/s PPV to 20 mm/s PPV

allowing the critical separation distance to reduce from 78 m to 27 m, if a maximum hammer

energy of 85 kJ is assumed.

Because of the uncertainties associated with the method of piling and the structural condition of

the Awakino Tunnel and its sensitivity to soil settlement, it will be prudent to treat the Awakino

Tunnel as a vibration sensitive structure. This will require pre and post construction condition

surveys of the Awakino Tunnel and possibly monitoring of ground vibrations during the

construction period to ensure the magnitude and frequency of the resulting ground vibrations in

the vicinity of the tunnel are as expected.

6.2.5 Equipment Storage Areas

As powered construction equipment starts up or shuts down, the vibrations generated change

frequency. As a result, the vibration levels at start up and shut down may be considerably higher

than under normal running. Therefore, it is advisable to carefully plan where construction

equipment should be left parked.



With reference to Table 5-3, start-up and shut-down of equipment is unlikely to cause problematic

vibrations if this can take place at least 45 m away from the two occupied dwellings or the Awakino

tunnel. The indicated storage areas for the project are at least 110 m from the Awakino tunnel and

220 m from the dwellings so the critical separation distance of 45 m is exceeded by some margin.

6.3 Operational Vibrations

Both the dwellings and the Awakino tunnel will be at least 30 m way from the realigned SH3.

Therefore, if the proposed chipseal road surface can be laid so that it satisfies the Transport

Agency’s roughness specification of 70 NAASRA counts per km for new pavement construction3

then traffic induced vibrations are unlikely to be perceptible at these locations. Furthermore,

vibrations are unlikely to be felt in the dwellings or the Awakino tunnel even when the road surface

roughness reaches 110 NAASRA counts/km, the Transport Agency’s trigger for road smoothing for

roads classified as Rural, Regional Strategic. The modelling assumes a maximum vehicle mass of

50 tonnes and a vehicle speed of 80 km/h, so high productivity motor vehicles (HPMV’s) have been

covered.

6.4 Mitigation Measures

6.4.1 Piling and General Construction

The analysis has identified that there is the potential for percussive (i.e. drop mass) piling to cause

damage to the existing Awakino tunnel. Therefore, it is recommended that if percussive piling is

used on the Project, appropriate trials be carried out to ensure vibrations at the Awakino tunnel

will comply with the short-term vibration guidelines given in DIN 4150-3 and reproduced in

Table 3-2 of this report.

This will place more certainty around the impact of the percussive piling operations as the

assessment in this report is based on a predictor equations which does not take into account soil

characteristics. However, vibration amplitudes and the predominant frequencies are influenced

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

higher the vibration.

The Project will also entail a significant amount of compaction work, with conventional sheepsfoot

compaction of the silty soils expected for the embankments and vibratory compaction of granular

soils expected for retaining wall backfill and pavements. Like percussive piling, compaction has

the potential to generate large magnitude ground vibrations. Furthermore, there is considerable

variability in the magnitude and frequency of ground vibrations generated between different makes

and models of equipment used for compaction. Therefore, before commencing construction, it will

be prudent that the contractor performs trials with the compaction equipment to demonstrate that

the short-term vibration guidelines given in DIN 4150-3 will be complied with at the Awakino

tunnel and disturbance of the occupants of OTS House 1 is minimised.

These trial measurements should be performed either at an off-site location with soil properties

that are similar to the construction site or preferably on-site during first use of the equipment with

the on-site location of first use being chosen to be least sensitive to adjacent land uses.

3https://www.nzta.govt.nz/assets/resources/roughness-requirements-finished-pavement/docs/guide.pdf



Both the piling and compaction trials can be best addressed through a Construction Vibration

Management Plan (CVMP), which recognises the Awakino tunnel as a vibration sensitive structure.

The CVMP’s objective is to minimise annoyance and damage due to construction vibration by all

reasonable and feasible means possible. Therefore, it should specifically address:

a. The procedure for measuring vibrations.

b. The criteria for assessing vibrations.

c. Hours of operation, including times and days when high-vibration machinery would be

used.

d. List of machinery to be used.

e. Requirements for vibration measurements of relevant machinery prior to construction or

during their first operation, to confirm that the vibrations they generate will not be

problematic.

f. Requirements for building condition surveys of critical dwellings prior to and after

completion of construction works and during the works if required.

g. Requirements for identifying any existing infrastructure assets (services, roads etc) which

may be at risk of vibration induced damage during construction.

h. Roles and responsibilities of personnel on site.

i. Construction operator training procedures, particularly regarding the use of excavators and

vibratory compactors.

j. Construction vibration monitoring and reporting requirements.

k. Mitigation options, including alternative strategies where full compliance with the Project

Criteria cannot be achieved.

l. Methods for receiving and handling complaints about construction vibration.

m. Procedures for managing vibration damage to existing services such as roads and

underground pipelines.

Guidance on preparing a CNVMP is provided in the Transport Agency’s publication “State highway

construction and maintenance noise and vibration guide.”4

6.4.2 Bridge Joints

Bridge joints can be problematic because of the vibration generated by vehicles traversing the joint,

which is transferred to the surrounding ground via the bridge’s piers and also felt by occupants of

the vehicles. This vibration is caused by impact loads generated by vehicles encountering a

localised discontinuity in road surface level at the joint.

Bridges and associated joints are usually immediately above water or other roads, and the footprint

of embankments and slip lanes can create separation between joints and the nearest dwellings. In

these cases, while cars and trucks traversing bridge joints may cause vibration to be felt inside the

vehicles, there is a relatively limited effect experienced in the wider environment.

4 https://www.nzta.govt.nz/assets/resources/sh-construction-maintenance-noise/docs/construction-maintenance-noise-vibration-guide.pdf



In the case of the proposed 2 bridges over the Awakino River, the nearest existing dwelling is some

300 m away. Therefore, ground vibrations generated by HGV traffic passing over the bridge joints

will not be an issue and so no specific mitigation measures are needed. However, if in the future

residential dwellings are to be constructed in close proximity (20 m) to the bridge, it would be

desirable to have any surface discontinuities as small as practicably possible.

Application of a theoretical method provided in Nelson (1987) for estimating vibration from a

surface discontinuity indicates that the difference in levels between the road and abutment should

be kept below 2 mm for vibrations to be below the perception threshold of 0.3 mm/s PPV and

7 mm to be below the complaint threshold of 1 mm/s PPV for HGV traffic travelling at 80 km/h.



7 Conclusions and Recommendations

Vibrations have been assessed in the vicinity of the SH3, Awakino Tunnel Bypass Project through a

desktop study. The vibration sources under consideration include earthwork and piling operations

during the construction of the Project, and operational road vehicle traffic following the completion

of the Project. The key conclusions and recommendations arising from this assessment are as

follows:

1. Vibration levels generated by construction are likely to be higher than those from traffic.

However, these construction-related vibrations will be temporary and of a limited duration.

2. The occupants of the dwelling closest to the earthworks and road construction (i.e. OTS

House 1) are likely to experience vibration levels from these activities that may cause

complaint but not damage to the dwelling. Therefore, because complaints typically arise

from interference with people’s activities or fear of property damage, it is important that the

contractor establishes open communication with the occupants so that any issues can be

identified and addressed expeditiously. However, the contractor should ideally take all

practicable measures to avoid excessive earthworks and road construction induced

vibrations near OTS House 1.

3. The analysis has identified that there is the potential for piling to cause damage to the

existing Awakino tunnel.

4. The adverse effects from construction can be appropriately mitigated through a

Construction Vibration Management Plan as the mitigation measures relate to selection of

equipment and processes and the location and operation of the equipment. In the unlikely

event of there being no practicable means for achieving the construction vibration criteria

stipulated in the Construction Vibration Management Plan, pre and post construction

inspections of at risk structures and buildings will need to be performed and any damage

rectified.

5. A key aspect of this Construction Vibration Management Plan is for piling operations and

compaction equipment to be used on the project to be trialled before construction proper

commences to ensure short-term vibration damage guidelines given in German Standard

DIN 4150-3 are complied with at the existing Awakino tunnel.

6. Once operational, traffic induced vibrations are unlikely to be perceived if the proposed

chipseal road surface can be laid so that it satisfies the Transport Agency’s roughness

specification of 70 NAASRA counts per km for new pavement construction. Furthermore, at

the closest separation distance from a dwelling of approximately 87 m, vibrations are

unlikely to be felt by occupants even when the road surface roughness reaches 110 NAASRA

counts/km, the Transport Agency’s trigger for road smoothing for roads classified as Rural,

Regional Strategic.



8 References

Amick, H. (1999) A Frequency-Dependent Soil Propagation Model. Presented at SPIE

Conference on Current Developments in Vibration Control for Optomechanical Systems, Denver,

Colorado, July 20, 1999. Retrieved from http://www.vulcanhammer.net/geotechnical/Amick-

SPIE99.pdf

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

and open sites – Part 2: Vibration.

British Standard, BS 7385:Part2:1993. Evaluation and measurement for vibration in buildings, Part

2. Guide to damage levels from ground-borne 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.

Hayes, G. (2015) Wigram Magdala Link: Vibration Assessment

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.

Nelson, P. M. (1987) Transportation Noise. Reference Book, Butterworth & Co (Publishers), Ltd.

Norwegian Standard NS 8176.E:2005 Second Edition Vibration and Shock. Measurement of

vibration in buildings from landbased transport and guidance to evaluation of its effects on human

beings, Standards, Norway, 2005. English translation version, 2006.

NZTA (2006). Network Operations Technical Memorandum No: TNZ TM7003 v1, Roughness

Requirements for Finished Pavement Construction.

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

downloadable from: https://www.nzta.govt.nz/resources/sh-construction-maintenance-noise/

Opus (2017). Geotechnical Factual Report No HA16/031 – SH3 Awakino Tunnel Bypass DBC.

Rudder,F.F. (1978) Engineering Guidelines for the Analysis of Traffic-Induced Vibration. Report

No FHWA-RD-78-166, US Department of Transportation, Washington, D.C.