instalacion
TRANSCRIPT
Doc No: DPD073.GN
Revision: March-09
© 2009
This document has copyright, which is owned by Sonneville International Corporation (SIC) and may not be reproduced, in whole, in part, or in any form whatsoever without
prior written authority from SIC. This document has been submitted on the understanding that it will not be used in any way against the interest of SIC.
LOW VIBRATION TRACK (LVT)
New construction
SONNEVILLE INTERNATIONAL CORPORATION
8109 Tis Well Drive, Suite 513
Alexandria, VA 22306, USA
Tel. +1 703 619 1530
Fax +1 703 619 1534
E-mail [email protected]
www.sonneville.com
Doc No: DPD073.GN
Revision: March-09
Low Vibration Track (LVT) – New construction Page 2 of 10
Distribution and assembly
LVT support delivery
LVT support distribution
After the civil works are surveyed, the pre-assembled LVT
supports are transported and distributed along the alignment.
The rails are then pulled or pushed over the LVT supports on
rollers, lowered on the previously positioned rail pads and
secured in place with the rail fastenings.
The entire track distribution can take place by rail, a work train
carrying the LVT supports and rails advancing over the track as
the work progresses. This method is particularly advantageous
for long single bore tunnels with limited access points.
Rail distribution
Doc No: DPD073.GN
Revision: March-09
Low Vibration Track (LVT) – New construction Page 3 of 10
Rail distribution as a first step
LVT support distribution
Rail threading
If logistically preferable, the rails are first distributed along the alignment, followed by the LVT supports. The rails are then
threaded onto the LVT supports and the rail fastenings installed.
Doc No: DPD073.GN
Revision: March-09
Low Vibration Track (LVT) – New construction Page 4 of 10
Option to pre-assemble rail strings
Option to pre-assemble track panels
Short or long rail strings may also be entirely pre-assembled at the staging area, transported and distributed along the alignment.
Doc No: DPD073.GN
Revision: March-09
Low Vibration Track (LVT) – New construction Page 5 of 10
The track can be used for work train traffic as soon
as it is distributed, assembled and secured with
temporary gauge bars.
Once the rails are connected longitudinally with temporary fish plates or permanent welds and secured transversally with
temporary gauge rods (and lateral props if necessary), the track resting below its final level can immediately be used for work
train traffic to advance the trackwork and simultaneously perform E&M and other works by rail.
Doc No: DPD073.GN
Revision: March-09
Low Vibration Track (LVT) – New construction Page 6 of 10
Final track adjustment prior to concreting
Once a track section is scheduled to be concreted, temporary
gauge bars that accurately and rigidly set the track gauge and
rail inclination are installed between the rails, typically at three
or four LVT support intervals.
Vertical screws incorporated into the temporary gauge bars
permit to adjust the vertical alignment including superelevation
in curves and a lateral adjustment mechanism built into each (or every second) temporary gauge bar permit to adjust the
horizontal alignment.
Alternative methods such as the one developed by Rhomberg
Bau have also proven very effective.
Doc No: DPD073.GN
Revision: March-09
Low Vibration Track (LVT) – New construction Page 7 of 10
Track geometry verification
The track geometry is checked and, if necessary, corrected and checked again before the track concrete placement is authorized
to proceed, thus eliminating any need for post-concreting adjustments.
Doc No: DPD073.GN
Revision: March-09
Low Vibration Track (LVT) – New construction Page 8 of 10
Concreting equipment
Concrete placement
The concrete is brought to site from the nearest access point by high rail or rubber tyred ready-mix trucks, belt conveyors, pumps
or a combination thereof. Upon discharge, preferably through an intermediate chute, the concrete is vibrated and directed to
flow under and around the LVT supports in a consistent manner.
Doc No: DPD073.GN
Revision: March-09
Low Vibration Track (LVT) – New construction Page 9 of 10
Option of encasing the base of every 4th pair of
LVT supports prior to final concreting.
In order to speed-up the recycling of the temporary gauge
bars, thereby reducing their quantity, and to provide for
unobstructed access during track concrete placement, the
same principle as illustrated earlier can be implemented but
only the base of every 4th LVT support encased in concrete
after the track is placed to its final line and level.
The track can then be used for work train traffic again as soon
as the resulting intermediary encasement concrete hardens
and the temporary gauge bars are removed. The final track concrete placement is subsequently simplified and accelerated.
Doc No: DPD073.GN
Revision: March-09
Low Vibration Track (LVT) – New construction Page 10 of 10
Provision for conductor rail anchoring
For lines with third rail electrification, the insulator supports or anchoring inserts can be precisely located in the track concrete
with temporary brackets affixed to the running rails. These brackets are removed and recycled at the same time as the temporary
gauge bars and the contact rail is then installed from a work train.