The bridge erecting machine is the equipment to place the prefabricated beam on the prefabricated pier. The bridge
erecting machine belongs to the category of crane, because its main
function is to lift the beam, then transport it to the position and
put it down.
Bridge erecting machine is very different from crane in general
sense. It requires harsh conditions, and there is a beam on the
line, or called longitudinal movement. Bridge erecting machine is
divided into highway bridge, conventional railway bridge and
passenger dedicated railway bridge.
It is a kind of bridge construction machinery which runs on highway
and railway track and is used for erecting small span beam. Because
of its high efficiency, it is considered as the design principle in
the standard design of railway bridges in China. The fuselage is
huge and beyond the railway transportation limit, so it must be
disassembled and transported, and then assembled and used after
arriving at the construction site.
There are three kinds of bridge erecting machines in China, most of
which are used for erecting reinforced or prestressed concrete
beams.
Single beam bridge erecting machine
One of the bridge construction machinery, its boom is a box beam,
which overhanging forward, in front of which there is a folding
column (composed of left and right legs). The machine can drive
into the bridge position automatically under no-load condition, and
then straighten the front column and support on the front pier.
When the supported beam (or the whole beam) moves along the boom,
the boom is close to the simply supported beam. When erecting a
bridge, the machine can drive into the bridge position
automatically under no-load condition. First, the beam pieces must
be transferred from the railway flat car to the special beam
carrier by using the special gantry crane, and then the beam
carrier and the rear end of the bridge erecting machine are
aligned, and the beam pieces are lifted by two beam trolleys
running on the crane arm of the bridge erecting machine, and then
they move forward along the crane arm to reach the bridge position
and drop the beam. In order to adapt to curved bridge erection, the
boom of the crane can swing a little in the horizontal plane. The
positioning method of the beam is the same as that of the double
cantilever bridge erector (moving the beam or moving the track).
The advantages of the machine are: canceling the balance weight, no
need of locomotive pushing, no need of bridge fork line for beam
feeding, improved mechanization degree and improved safety
performance. The Shengli Bridge Erecting Machine with a lifting
capacity of 130 tons is of this kind.
Double cantilever bridge erecting machine
This type of bridge construction machinery was used earlier in the
Soviet Union. When it was introduced in 1948, its front and rear
arms were made of steel plate beams, with lifting weights of 45
tons and 80 tons. In the 1950s, the double arms were changed into
frames, and the lifting capacity was developed to 130 tons.
This kind of bridge erecting machine can't be driven by itself, so
it needs to be pushed by locomotive. The forearm is used to lift
the beam, and the rear arm is used to lift the balance weight, so
the front and rear arms can not swing in the horizontal plane. When
erecting a bridge, it is often necessary to use a special 80 ton
flat car to transport the beam under the hook of the forearm of the
bridge erecting machine (called "beam feeding"); In order to make
shunting operation convenient, it is necessary to lay bifurcated
line at bridge head. After the girder is lifted by the bridge
erecting machine, the axle load will increase, and the new
embankment at the bridge head is relatively soft. Therefore,
reinforcement measures must be taken for the section where the
girder is lifted by the bridge erecting machine, such as using
heavy vehicles to press the road, adding sleepers, etc.
Double beam bridge erecting machine
Hongqi type bridge erecting machine and Liaoyuan type bridge
erecting machine belong to this kind, and the lifting weight is
also 130 tons. The boom is composed of left and right box girders,
which run through the fuselage and extend forward to the rear end.
There are folding columns composed of two legs at both ends. The
middle distance between the two beams of Hongqi type is 3.4m, while
that of Liaoyuan type is 4.8m. There are two truss cars across the
two box girders, which can travel along the boom longitudinally.
The trolley is placed on the truss car and can travel along the
truss car. The beam to be erected (or the whole beam) can be
directly sent to the rear arm of the bridge erecting machine by the
railway flat car, lifted by the beam trolley, moved forward by the
truss trolley, then moved horizontally by the beam trolley, and
then dropped into place. The front and rear ends of this kind of
bridge erecting machine can lift and drop beams; When changing the
direction of beam erection, there is no need to turn around; In
order to adapt to the curve beam, both the front and rear arms can
swing in the horizontal plane; When erecting in pieces, the beam
can be in place without moving the beam or shifting the track“
"Beam feeding" also does not need the bridge branch line or special
beam carrier.
Track laying should be done immediately after girder erection, so
that the bridge erecting machine can continue to work forward. The
latter two kinds of bridge erecting machines can generally hoist
the pre assembled track rows in place, so that the beam erecting
work will not be delayed due to track laying.
In addition to the above-mentioned standing bridge erecting
machines, the construction unit sometimes makes various temporary
bridge erecting machines as required. For example, during the
construction of the approach bridge on the South Bank of Jiujiang
Bridge, a special bridge erecting machine capable of lifting 300
tons was made to erect a 40 meter span Ballastless sleeper free
prestressed concrete beam. Some construction units often use
standing steel scaffold members, dismounted beams or military beams
to form a simple bridge erecting machine to complete the bridge
erecting task in time.
Technical parameters and performance table of Bridge Erector |
| 50m | 40m | 30m |
model | JQJ200/50 | JQJ180/50 | JQJ160/50 | JQJ140/40 | JQJ120/40 | JQJ100/30 | JQJ80/30 |
Lifting capacity | 200t | 180t | 160t | 140t | 120t | 100t | 80t |
Applicable bridge span | 30~50m | 20~40m | 20~30m |
Applicable maximum gradient | Longitudinal slope £ 5% cross slope £ 5% |
Trolley lifting speed | 0.40m/min | 0.45 m/min | 0.5 m/min | 0.56 m/min | 0.65 m/min | 0.75 m/min | 0.9 m/min |
Crown block longitudinal speed | 3 m/min |
Traverse speed of crown block | 3 m/min |
Speed of bridge crane through hole | 3 m/min |
Traverse speed of bridge crane | 3 m/min |
Adapt to the angle of skew bridge | 0~45° |
Suitable radius of curved bridge | 400m | 300m | 200m |