BRIDGE 12 - STANWAY VIADUCT – KING-POST GROUND
STABILISATION PROJECT – work completed.
Following the
completion of the new King-post sleeper walls, the old sleeper walls were
removed.
This left the north end more or less completed, as in these two pictures.
The south end proved to be a bit more problematical because of the gabion
baskets on the upside, close to which were two signal cables. This did not
leave much room to feed the 450mm diam auger between the two but it got done
with slight disruption to the back of the gabion baskets. On the downside things were slightly easier.
Once the steel
columns were concreted in the concrete sleepers were dropped in on both sides, then the tie bar installation was started.
This involved
trenching between the sleepers.
The tie bars are to there to anchor the
tops together, which enabled a shorter length for the steel posts to be
used. Without the tie bars the
resistance to the outward movement of the track bed fill and ballast would be
entirely provided by sidewards ground resistance against the concrete casings
to the steel posts.
To simplify
the installation, the tie bars were in 3 pieces with couplings to fasten them
together.
One of the problems encountered in one section,
was where cement grout had been mixed with the ballast to create a large
concrete lump which had to be broken out to allow the trench to be dug.
After the tie bars had
been tightened up the side trenches were filled to restore the ballast levels
back to the original and the ground outside the new walls could be regraded.
At the north end,
the difference between the track level and the original ground was greater, as
can be seen from the step down from inside to out. There was
limited scope for levelling there.
The final task was
to try to locate the Inspection chambers for the viaduct drainage.
Unfortunately, by installing the track down the centre of the viaduct, they
were all buried preventing any maintenance.
With no real details of where they
were we dug down to find one.
Finally, the above two photographs show the completed stabilisation works.
Photos courtesy of Alastair Watson, John Balderstone
& Peter Muir.***
The pictures in this blogpost have been removed on request.
The pictures in this blogpost have been removed on request.
8.3.2019 - JOHN BALDERSTONE
great work on the viaduct , most impressive and good luck at Stanton , john M.
ReplyDeleteI assume, that with regard to the Tiebars, consideration has been given to the depth that tamper tines go down below sleeper bottom.
ReplyDeleteI think that another version of this sort of retaining work was undertaken on the Kent and East Sussex railway a few years back, but they used Highway Armco barrier instead of sleepers.
Good work though.
On the approach to Cranbrook Road.
DeleteThe tie-bars are a excellent aspect.
ReplyDeleteNoel
Our P-Way Dept. advised that the tines only extend 150mm below the bottom of the sleepers. We have placed the tie bars 450 below, for extra security. The scheme was prepared by the Engineer along similar lines to what was done on the Severn Valley Railway, some years ago. As we had quite a lot of un-useable concrete sleepers, they were the obvious choice and are very robust and weather resistant.
DeleteNot a glamorous aspect to railway maintenance but at the same time vitally important to keep on top of so much infrastructure now owned privately. With each line here alone in the UK comes a whole host of civil engineering responsibilities that can't be ignored.
ReplyDeleteThe SVR has a mighty task ahead of them, too.
What is the problem at Stanway Viaduct that stopped trains running to Broadway from Wednesday this week, please? Terry
ReplyDeleteJo, Are you the person to speak to about a pile of used concrete sleepers (Pandrol type fittings like the ones here at the viaduct.
ReplyDeletePowli Wilson
Powli Wilson
I can direct you further. Drop me a line:
Deletebreva2011 (at) hotmail.co.uk