IF articles

Noise and vibration evaluation of a floating slab in direct fixation turnouts in “Haidari & Anthoupoli extentions” of Athens metro lines 2 and 3


This paper describes the work performed

for the last two extensions on lines 2 and 3 of the Athens

Metro: (a) extension of line 3 from Aegaleo to Haidari and

(b) extension of line 2 from AgiosAntonios to Anthoupoli,

and on the respective turnout (TO) locations 3-02,3-03 and

2-55,2-66. The aim of the ground borne noise and vibration

evaluation presented hereafter is to determine the required

mitigation measures in order to guarantee, in each turnout

location along these extensions, allowable ground borne

noise and vibration levels in nearby sensitive buildings. In

order to reach this objective, within the initial N&V study

the whole extensions were divided into homogeneous sections,

i.e. sections along which the tunnel and soil types,

depth and distance from nearby buildings and presence or

not of a switch can be considered as constant, with particular

emphasis on section with turnouts on direct fixation in

order to assess the expected noise and vibration levels from

Metro operation. Then in order to achieve the requested

criteria, a vibro-acoustic measurement programme was executed

in Madrid Metro network in order to evaluate the vibration

emissions in similar TO implementation and then

based on those results a Floating slab track (FST) solution

was evaluated in the above Athens Metro (AM) TO locations

ensuring a complete ground borne and vibration attenuation

with an insertion loss of -20dBV with respect to

the predominant excitation (40 to 125 Hz). For the proposed

FST implementation solution the estimated expected

noise level at the soil surface were calculated and proven

considerably lower from the given criterion.

  • Giugno
Num. 6
Pag. 533