Chronicle of construction of Nanjing Chang Weisan Road Tunnel
Nanjing Chang Weisan Road under-river tunnel
is one of the channels across the Yangtze River for Nanjing
the connection between the old downtown
and the new urban district
and the Jiangbei new urban area
it is the most convinient
and fastest way
this tunnel is located
at 5 kilometers upreach from the Nanjing Yangtze River Bridge
4 kilometers from
the established Nanjing Weiqi Road under-river tunnel
it's divided into S line and N line
consisting of
connection road
cut and cover road in north bank
the start work well in the north bank
the work well in the south bank
cut and cover road in the south road
the S line
starts from the work well in the north bank
passing through the Yangtze River embankment in north bank
the Qianzhou Island and Meizhou Island
reaching the south bank
and is connected to the Dinghuai Road
and the Jiangtong North Road
with a total length of 7.3 kilometers
the N line
starts from the work well in the north bank
passing through the Yangtze River embankment in north bank
Qianzhou Island
reaching the south bank
and is connected to the Yangtze River Road
with a total length of about 7 kilometers
Weisan Road under-tiver tunnel
has two layers
with eight lanes
this allows the city to make full use of the room
allowing more cars to pass
just as an old saying goes:Good tools are essential things
in order to solve a series of construction problems
the most important thing is the shield tunneling machine
Tianhe Mechanical Equipment Manufacturing CO., Ltd
accepted this order
to prodive the crossing-river tunnel construction
with two super large slurry air balanced mis shield machine
whose diameter is 14.98m
this giant shield tunneling machine
in terms of construction plan£¬design and idea
is totally different with
the small and medium-sized shield tunneling machine
Weisan Roand unde-river tunnel is
the first one China with complicated geology
it has to pass through
stratums such as mollisol,hard rock,sandy gravel
the working water pressure is 0.72 MPa
this means for Zhongjiao company
around the world
it can't find any case to learn
with 8 months' effort
they succeeded
here is the most complicated cutterhead in the world
the machine is with a total weight of about 5000 tons
in this giant cutterhead
there are 717 tools.
different color means different types of tools
these two giants
will dig
under the Yangtze River
at the same time
Zhongjiao company also developed
technology of extra long distance digging tools
the extension section of tools
the disc cutters
the first ever cutter changing technology
during the design of the giant TBM
Tianhe won 18 intellectual properties
9 patents for invention
by integrated innovation Tianhe
the company developed what is usually monopoled by foreign countries
the giant shield machine
and Tianhe became the only one
that can design and manufacture giant shield machine
on 20, July 2012
with the director's order
Tianhe No.1 began to work on the Nanjing Weisan Road
with the boom
the giant cutterhead was working in the dark undergorund
the soil with water digged out
would be delivered to the gound through mud pipes
it would dig a tunnel under the river
from the north bank of the Yangtze river to the south
on 1, 11 2012
the digging speed and angle of the TBM
went wrong
the cutterhead got stuck by unknown materials
it can't move forward
there were a lot of answers for it
some one said it was shipwreck
some said it was deadwood
at this key moment
the the extension section of tools created by Tianhe
helped solve the problem
the cutterhead can retract 10 cm
during the retraction
the cutterhead can cut the obstacles repeatedly
moving foreard step by step
later during checking
dredge pipe
the engineers found there were deadwood
problem continued to rise from one to the next
in January 2014
the digging speed went wrong again
from the mud from the dredge pipe
engineers found many big stones
this was really a problem for them
because according to the geology exploration
there were no such stones here
where did they come from
it turned out in the 1950s
to fight against the flood
the government of Nanjing organised citizens to
throw stones into the Yangtze river
after years
these stones with a diameter of about 50cm
now pile on the Yangtze River embankment
where the TBN need to dig
to pass this area
the engineers had to garantee the smooth of the dredge pipe
finally they
solved the problem
by circulation loop
Tianhe No.1, without changing cutters
digged 1100 meters
which set a world record
tail brush is designed to prevent
water from getting into tunnel
although this TBM had 5 tail brushes
after a while
they were wore out
the engineers used the method of circular frozen
using liquid nitrogen to freeze certain amount of water
to form a cryosphere
which can provide enough time
to change tail brushes
the engineers froze
waters of The Yangtze river
at the bottole the river,70 deep
for 10 days
to freeze Yangtze river water
sounds impossible
but engineers
succeeded
usint this method
they changed the tail brushes
to freeze Yangtze river water
is also the first time in China
in February 2014
the digging speed of the TBM
slowed down suddenly
the TBM came accross
the 500-long stratum
the rock strength is 120 MPa
while the normal concrete strenth is no more than
40 Mpa
high strength rock
made the cutters wear out very quickly
now
the TBM is at 63.049m below the Yangtze River surface
the deepest place of the crossing- river tunnel
with a water pressure of 0.72 Mpa
this is the first ever in the world
the biggest pressure for TBM
in this conditon
the cutterhead need to
be changed mannually
but to work under this water pressure
is out of the Chinese working standard
in other words, according to Chinese standard
to change cutters mannually is not allowed
finally engineers
found a German company
according to German standard
worker can workd under the wair pressure of 0.7Mpa
under the air pressure of 0.6Mpa
workers can't work for more than 50 minutes on time
during these minutes
more than 20 minutes is used to open and close the door
so engineer had an idea
to transport a space capsule into the tunnel
with special gas
and on the ground there is a hyperbaric chamber for living
these special workers should
live under pressure for a long time
so their body can get used to the environment
when they need to work
the living chamber will be transported into the tunnel
and connected to the working chamber
workers can get to the working chamber with same pressure
from the living chamber
the working can be extended to
more than 4 hours from 50 minutes
on 22, June 2015
the TBM Tianhe came out from the bottom of the river
from the soil
seeing the sunshine again
passing many diffulties
the cutterhead from a colored one
turned into silver grey
just like a young man
after going thorough many difficulties
finally grows up
on 2, July
Tianhe No. 1 also came out from the underground
Nanjing Chang Weisan Road crossing river tunnel was dig through
the good news spread across both sides of the Yangze River
if you have a bird`s view of NanJing-Yangze River Tunnel
you will find three majestical ventilation shafts
the surface of the north ventilation shaft
used constantly changing shapes
ups and downs
which shows
Nanjing`s rapid development
and constant innovations
as for the south ventilation shaft
it is located in the scenic area of Yangtze River
so while meeting the need of exhaust air and air supply
it adopted the shape of sail
meaning that everything is going smoothly
and is in harmony with
scenery sights along the banks
showing the rhythm and sense of wholeness
the most characteristic one
the Mei Zizhou island ventilation shaft
it looks like a granary
which means good harvests
It used the modern landscape design language
to show the old
and distinctive Nanjing culture
it is also a modern shaft
which is full of regional culature features
in the Weisan Road crossing river tunnel
various vehicles can move in it
the drivers can experience the new LED
which is very comfortable
It is also a symbol of energy conservation and environment protection
by porper layout data acquisition equipment of the field River Estuary
the powerful integrated monitoring system platform
can analyze, process and release many information
trying to attain automatic control of the reaffic flow
this realizes the concept of Intelligent Transportation of Zhongjiao
chieving the enterprise vision of making the world more smooth