6 Groundborne Noise and Vibration
124. A railway project such as Crossrail is expected
to generate certain levels of noise and vibration. Understandably,
many Petitioners were concerned about this issue as they live
or work above the proposed tunnels. The local authorities presented
a joint case to express their concerns about vibration and groundborne
noise and the impact on the properties above the railway. We were
keen to establish what measures the Promoter proposed to put in
place to control the effects of groundborne noise and vibration
that might otherwise arise from the construction and operation
of the railway. We spent time with several noise experts measuring
the noise levels of the District Line on London Underground to
provide us with a better understanding of the issues.
125. Where we thought it necessary, we have asked
the Promoter to provide additional measures to protect certain
Petitioners from unreasonable levels of disruption. However, it
is our view that the undertakings given by the Promoter on these
issues will generally provide adequate protection for those impacted
by the railway.
126. Groundborne noise could arise from the movement
of trains or tunnelling equipment in Crossrail tunnels, during
construction of the railway, during commissioning of the railway,
or once the railway is operating passenger services. There are
no UK legislative standards or criteria that define when groundborne
noise becomes significant. Crossrail has therefore drawn upon
available experience in constructing new underground railways,
for example the Jubilee Line Extension, Thameslink and the Channel
Tunnel Rail Link. All of these projects adopted a threshold of
significance for groundborne noise in residential properties of
40dBLAMax,s.
127. This criterion was therefore adopted to assess
the significance of potential groundborne noise impacts in residential
properties during both construction and operation of Crossrail.
In the case of buildings used as reference libraries, lecture
theatres, auditoria, theatres, hospitals, churches, schools and
similar buildings, the use of which is particularly sensitive
to noise or vibration, either the same or more stringent assessment
criteria were adopted.
128. Crossrail has set out a series of mitigation
measures which the nominated undertaker would be required to take.
The potential impact of Crossrail trains running through tunnels
during construction and operation of the railway has been assessed
and the findings reported in the Environmental Statement. The
running of both the construction and permanent railways is not
forecast to cause vibration impacts which will be felt by those
occupying the buildings above. Vibration from the passage of the
tunnel boring machines may be perceptible. However, this will
be a transient effect lasting only a few days at any one location
and will not cause damage to buildings.
129. A detailed explanation of the technical arguments
can be found in Crossrail Information Paper D10 - (Groundborne
Noise and Vibration)[33]
and in the transcripts of our hearings.[34]
33 http://billdocuments.crossrail.co.uk/80256FA10055060F/ pages/informationpapers Back
34
Paragraphs 2322-2367 [Mr D Elvin QC, Mr R Thornely-Taylor] Back
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