arches 

Installation of a superstructure with a floating crane. Hinged and semi-hinged installation of metal superstructures of bridges. Suspended installation in the construction of a railway bridge across the river. Dnipro in the city of Dnipro

Topic 8.4. Construction of reinforced concrete bridges.

The type of crane and the method of installation are selected depending on the mass and dimensions of the elements to be mounted, the width, depth and regime of the river, navigation conditions, terrain, season, specified construction time and the production capabilities of the construction organization.

Lower assembly by self-propelled jib cranes is convenient for the construction of overpasses, overpasses, small bridges on dry valleys. For this purpose, general construction cranes on caterpillar or pneumatic wheels, as well as trailer cranes, are usually used. The soil in the crane movement area is planned and compacted, for example, by running in wheels or tracks of an unloaded crane. The bearing capacity of the soil should be at least 0.5 MPa in the area of ​​operation of pneumatic wheel cranes, and 0.2 MPa for crawler cranes. With insufficient bearing capacity of the soil, for example, on swampy floodplains and in the riverbed, installation is much more difficult. It is necessary to arrange a working bridge for the movement of the assembly crane and Vehicle with elements of prefabricated superstructures, which slows down the pace of work.

When mounted from the ground, jib cranes usually install beams up to 21 m and weighing no more than 30-35 tons. a), and then lowered by a cargo pulley onto the supporting parts (Fig. 24.8, b) freeing the straps. In this case, the crane sequentially installs the beams, moving across the axis of the bridge. With a clear organization of work, it is possible to mount structures "from wheels" without preliminary unloading and storage.

If the lifting capacity of one crane is insufficient, then two twin cranes are used. At the same time, the beam is slinged along its ends, lifted with cargo chain hoists at the smallest reach of arrows and then, increasing their reach within the limits of the permissible load capacity of the cranes, they are introduced into the span.

When installing beams of superstructures on overpasses across the railway, railway cranes are used.

Riding assembly with a jib crane (Fig. 24.9) is advisable when installing superstructures on bridges across permanent watercourses. Such an assembly is convenient and most economical, but is limited by the relatively small lifting capacity of jib cranes. The SKG-63A crane, for example, can install beams of a road bridge 18 m long, weighing 14.3 tons in front of itself with an allowable crane outreach of 14 m. To ensure the stability of previously installed beams, before the crane and vehicles move along them, the longitudinal joints of the beam plates are preliminarily monolithic. According to the calculation, a flooring of wooden beds is laid, which ensures the distribution of pressure on several beams and protects the reinforced concrete slab from unacceptable loads.



With a sufficient width of the carriageway of the bridge, the beams are fed directly to the crane on vehicles with trailers or trailers. With narrow bridges, it is possible to feed beams on narrow-gauge trolleys along rail tracks with preliminary reloading of the beams on the approaches.

Gantry cranes moving on the ground or on temporary overpasses usually mount multi-span prefabricated reinforced concrete bridges, long and heavy beams of prefabricated spans. For this purpose, cranes are used that are assembled in the conditions of a construction site from UICM elements (Fig. 24.10) or manufactured by the industry.




When sliding the beams into the span along the scaffolds (Fig. 24.11), the overpass is arranged narrow, and the top is usually located at the level of the support crossbars. The beams of the superstructure are mounted on trolleys and moved along the bridge into the span using winches or other means. Then they are set to the design position by transverse shifting. In this case, the beams are moved on other trolleys or skids along rails laid on the crossbars of adjacent supports or along auxiliary scaffolds along the support. Hydraulic jacks are used to lift the beams when moving them from the carts to the supporting parts. According to the safety regulations, the jacks are tested for double pressure, and in the process of their operation, safety metal semi-rings are placed between the jack head and the cylinder body.

The sluice crane GP-2KhZO (Fig. 24.12) ensures the installation of beams with a span of up to 33 m with a mass of not more than 60 tons, taking into account slinging devices. It consists of a longitudinal truss of a triangular section and three supports. The rear and middle supports of the crane are equipped with wheeled trolleys for longitudinal movement along the rail track. The gauge of the crane runway is 5.6 m. The front support of the crane is equipped with screw devices that ensure the elimination of possible deflection and distortion of the console and tight support on the under-truss platform. When moving longitudinally to the next span, the crane operates on a cantilever system, and when installing superstructures, it is a two-span continuous system. The carrying capacity of the medium support trolley when moving the crane itself is 48.5 tons, when locking a beam weighing 60 tons along the axis of the crane - 66 tons, when the beam is moved transversely to the extreme position - 90 tons. Therefore, in places where the wheels of the undercarriage are supported, instead of sleepers, they put metal distribution beams. To give the crane stability when moving from span to span, a counterweight of reinforced concrete beams is installed.

The installation of the superstructure begins with the installation of the crane in the working position. The crane, assembled on the way, moves under its own power along the rail tracks into the span. At the warehouse located on the approach, the beam is loaded onto trolleys by two jib or portal cranes and fed under the sluice crane. The end of the beam closest to the crane is fixed on the chain hoist of the first cargo trolley and removed from the trolley. The beam with the front end suspended and the rear end supported on the transport trolley is moved (locked) into the span until its rear end is under the second cargo trolley, to the chain hoist of which it is attached.



The KShM-35 coke-sluice mobile crane (Fig. 24.13) is designed for the installation of superstructures up to 22.16 m long and weighing up to 35 tons, taking into account slinging devices. The design of this crane, unlike other sluice cranes, allows it to be transported in highways without dismantling the main beam and chain hoists, which dramatically reduces the time and labor required to bring the crane into working or transport position. The crane consists of a KrAZ-258 tractor with a counterweight, a main beam, front and rear supports with trolleys for transverse movement, two pneumatic and two cargo trolleys with traverses, two traction and two cargo winches, ways for the transverse movement of the crane. The front support is articulated, the rear is rigid. Before sliding the crane into the span, the front trolley with the turnstile is shifted into the span. Then the crane is supported on the transverse rolling rails and it is ready to lock the beams.


At present, a similar crane KShM-40 has been created for the installation of beams 24 m long.

Reinforced concrete superstructures of large bridges can be mounted using the method of hinged assembly, longitudinal sliding or installation afloat. Installation methods are chosen by a technical and economic comparison of options for organizing work.

The most common in domestic bridge building is a hinged assembly of ready-made blocks, installed in series without scaffolding in the direction from the support in both directions at the same time so that the consoles balance each other. Connect the blocks on the adhesive seams. At the same time, make sure that the joined surfaces of the installed blocks fit well to each other. This is achieved, for example, by concreting blocks afloat through one, followed by concreting intermediate blocks, the formwork of which is the ends of the finished blocks. To prevent adhesion, the ends are lubricated with milk of lime. Before mounting and gluing the blocks, the lime film is cleaned or washed off with a weak solution. of hydrochloric acid. Mounting blocks have retainers in the form of ledges in the walls of the blocks or metal embedded parts. Clamps facilitate aiming and alignment of the unit during installation.

Within the floodplain, blocks can be mounted with gantry cranes moving along the ground or overpasses (Fig. 24.14, a), and within the channel, by floating or mounting units moving along the mounted part of the span. Of the crane units, the GP-2X50 sluice crane or the SPK-65 unit crane is most consistent with the hanging installation technology (Fig. 24.14, b).


Longitudinal sliding with a conveyor-rear assembly (Fig. 24.15) is used for beam-continuous prestressed superstructures that can withstand alternating forces. To do this, the span structure is stressed in two stages: for mounting forces in the process of sliding with special beams of reinforcement and for operational forces, rearranging these beams from the upper chord to the lower one in the middle of the spans and from the lower chord to the upper one in the overhead sections.

The imported structures are installed on the embankment on a special slipway with an end stop. Gantry cranes mount a beam with an advance back at the end. As the assembly progresses, the structure is torn into the span by the pressure of hydraulic jacks fixed in a horizontal position. The beams are pushed in steps of 1 m, temporarily using inserts until a gap is formed, equal to the length mounting block. A new block is inserted into the resulting gap and combined with the previous part. Then the process is repeated. Within the slipway, the span beams are moved on steel sleds along rails lubricated with a mixture of grease and graphite, and on the bridge supports - along a fluoroplastic or naphtle plate laid in a steel cage. A polished and polished chrome-plated steel sheet 12 mm thick is placed under the bottom of the span. Fluoroplast has a sliding friction coefficient from 0.01 to 0.05 and allows a pressure of 25-40 MPa.

As the span is being advanced, it is necessary to periodically jack it up by 1-2 cm, pull out and shift the sheet to its original position, lower the span and again push it to the length of the sheet.

The use of a continuous anti-friction tape made of naphtle fabric allows you to push the superstructure without jacking up and periodically moving the steel sheet.

The installation of span structures afloat is used in the construction of bridges across navigable rivers, lakes, and reservoirs. To do this, spans are assembled in large blocks or entirely on the shore. Moreover, work can be carried out in parallel with the construction of supports. With the help of floating supports, the beams are delivered to the span. Floating supports are pontoon pontoons KS-3. Above-deck fittings are usually mounted from the elements of U and KM.

Omonolichivan it of prefabricated superstructures combine the beams that make it up with each other. The joint work of beams under load depends on the quality of monolithic. Beams are usually combined with the help of embedded parts or reinforcement outlets, which are welded by electric welding with electrodes with high-quality coating. After welding, the joints and gaps in the joints are filled cement mortar or concrete.

The technology of combining beams by prestressing is similar to the technology of pre-assembly of elements with prestressing reinforcement.

When the crane is placed on the ground (Fig. 5, a), the beams to be mounted are stored next to the crane in such a way as to ensure installation by turning the crane boom by 180 °. It is possible to install beams "from wheels" without a storage device for beams at the construction site.

The beam intended for installation is slinged, lifted, by turning the crane boom is introduced into the span and smoothly lowered onto the supporting parts, then freeing from the slinging devices. The crane is moved to a new position and proceed to install the next beam. The position of the crane and the location of the beams prepared for installation are chosen in such a way as to ensure a minimum reach of the crane boom and eliminate the need to move it with a load.

Rice. 5 - Schemes of installation of beam reinforced concrete superstructures with jib cranes: 1 - crane; 2 - traverse; 3 - installed beam; 4 - installed blocks of superstructures; 5 - beams prepared for installation

If the lifting capacity of one crane is insufficient for installation, use two cranes lifting the beam from both ends at the same time. The mounted beam is located in front of the cranes. Raising it first at the minimum reach of the boom, the beam is inserted into the span and installed on the supports, increasing the reach of the cranes. If the lifting capacity of the cranes does not allow the beam to be installed at the required boom reach, the mounted block is first lowered at the maximum possible reach of the boom, then the cranes move forward, the beam is raised again, repeating the operations performed.

Flying structures with jib cranes can be installed from the side (from the field) and from the front (Fig. 6). Slinging of blocks is carried out using standard and special slings and traverses. At the same time, both slings and traverses must be calculated with a margin: slings - with 6 ... 8-fold, traverses - with 2-fold.

Rice. 6. Installation of superstructures with jib cranes:

a - with one crane from the parking lot along the axis of the bridge when turning through 180°; b - with rotation and movement; in - on the side with a turn; g - on the side with lifting and moving; d - two taps; 1 - starting position; 11 - the position of the cranes at the time of installation of the superstructure; 1 - span block; 2 - crane; 3 - supports; 4 - axis of the bridge

The installation of superstructures on supports by cranes in whole or in large blocks has recently been found wide application thanks to the appearance in construction organizations of cranes with a large carrying capacity, high productivity and relatively simple work technology. The cranes used for these purposes can be divided into three groups: boom and gantry self-propelled, cantilever railway, floating. Each group of cranes has its own characteristics that affect the technology and organization of work.

For the installation of superstructures on bridge supports, they are used self-propelled jib cranes on automobile, pneumowheel, tracked and railway tracks.

When performing work, cranes can be located at the top - on the carriageway of the bridge or embankment, as well as at the bottom - on the ground or floating facilities.

In the first case, the crane sets the superstructure in front of it with a long reach of the boom and therefore does not have the opportunity to maximize its load capacity; in the second, a crane located to the side of the bridge axis, in close proximity, installs superstructures at a minimum boom reach, having the highest load capacity.

It is recommended to install superstructures with one crane from one parking lot and without changing the boom radius. In case of insufficient load capacity of the crane, installation by separate beams with their combination in the span of the bridge or installation by two cranes is possible. During the lifting and moving of the beams by two cranes, their chain hoists must always be in a vertical position.

The ground in the moving area must be well leveled and compacted. Permissible pressure on the ground during operation of cranes on pneumatic wheels is 0.4 ... 0.5 MPa, and on caterpillar tracks - 0.2 ... 0.3 MPa. If the bearing capacity of the soil is insufficient, a flooring of wooden beds or reinforced concrete slabs is laid under the crane.

Moving a crane with a load is not desirable due to safety conditions and is allowed only if the mass of the superstructure (block) does not exceed 50% of the crane's load capacity at a given, as a rule, minimum outreach. Moving with a load of automobile and railway cranes is not allowed.

Span structures are slinged according to pre-designed schemes with steel inventory slings, cables or traverses. The use of traverses reduces the height of the slinging and eliminates horizontal compressive forces in the elevated superstructure. When slinging with steel cables in a girth under the slings at the corners of the bend of the cable, wooden linings or metal hemispheres from pieces of pipes with a diameter of 10 ... 15 cm are installed and fixed, excluding damage to the span and cable.



The installation of superstructures by jib cranes is carried out according to approved projects for the production of works, which indicate the parking lots and ways of moving cranes, the design of slinging devices and other devices, the procedure for lifting, turning and lowering the superstructure, the composition of the calculation (team) and other data necessary for high-quality and safe work performance.

Cantilever railway cranes without intermediate supports, spans up to 45.8 m long can be installed (Figure 5.1).

a– installation of a superstructure with solid main beams by a GEPC-130 crane; b- the same, with lattice main trusses by crane GEPC-130-17.5; in- the same, with a GEPC-130U crane; 1 - weight; 2 - slinging beam; 3 - additional chain hoist. Dimensions in meters

Figure 5.1 - Schemes of installation of steel superstructures with cantilever rotary cranes

Cantilever railway cranes GEK-80 and GEPK-130 each have four working positions for installing and unloading blocks. Each working position is characterized by the height from the rail head to the bottom of the console at the beginning of the useful reach (for GEPC‑130 to the bottom of the sling beam), taking into account the spring settlement and boom deflection from the maximum load.

In the working position with a suspended counterweight on the subconsole platform, the GEPC-130 crane without load has a load on one axis of the supporting platform of 280 kN (28 tf). With full use of the crane capacity, the axle load reaches 420 kN (42 tf). The maximum load on the axis of the support platform of the GEK-80 crane when installing the largest block by weight is 345 kN (34.5 tf). Therefore, the way for the passage of the crane with the load must be strengthened and meet the requirements set out in table 5.1. In order to reduce the amount of work on the preparation of the crane runway, it is necessary, if possible, to reduce the length of the crane working area to 100 ... 150 m, delivering the superstructure to the bridge on special trolleys or railway platforms.

Table 5.1 - Characteristics of the superstructure of the track

The passage of a jib crane in the working position is allowed at a speed of: without load up to 10 km/h (up to 8 km/h in new buildings), with a load up to 5 km/h (up to 3 km/h in new buildings). The work of the jib crane on the railway tracks in operation can be carried out with the permission of the head of the distance of the track.

Before passing the jib crane, the tracks that are in temporary operation must be carefully run in until the residual deformations stop. The running-in is carried out by conventional rolling stock with an axle load of 220…250 kN (22…25 tf). The number of axles of platforms during running-in must be at least eight, and the number of races at least twenty. After the elimination of the detected defects, an act of readiness of the track is drawn up.

Installation of superstructures on supports with cantilever cranes includes slinging the superstructure (a separate beam), moving the crane with a load, lowering and installing the superstructure on the supporting parts, returning the crane behind the next superstructure (beam).

Wholly transportable superstructures with a length 18.0 ... 34.4 m, as a rule, are installed with a fully assembled bridge deck. When using the GEPK-130 crane, the superstructure for slinging can be placed on sleeper cages on the side of the track outside the gauge. For the GEK-80 crane, the span is prepared at the nearest station, at a specially arranged dead end or on the side of the track near the bridge, followed by a transverse movement under the crane boom.

Solid beams spans 45 m long come from the factory in separate flat blocks, segmented along the length into two parts. A site for storage and pre-assembly of span structures for the full length is chosen as close as possible to the bridge in a section with a low embankment height. To unload metal structures from platforms with jib railway cranes, as well as to bring the jib crane into working position, it is recommended to arrange a temporary dead end with a length of at least 60 m and a distance of 5 m.

The choice of places for slinging blocks and the weight of the counterweight is carried out taking into account the following conditions:

The load on the chain hoists should not exceed the allowable according to the crane passport;

The load moment in the support section of the crane console should not be more than the allowable one;

To ensure the stability of a block suspended from two points, its center of gravity must be between the points of suspension, and not closer than 0.02 of the length of the block from the extreme chain hoist. With a total length of the span equal to 45.8 m, this value must be at least 0.92 m. The scheme of slinging and installation of such a span is shown in Figure 5.1, a.

Solid-walled superstructures with a length of more than 45 m are installed by jib cranes into the span divided along the length into two enlarged blocks. For their support and subsequent unification, an intermediate temporary support is erected in the span of the bridge. The height of the temporary support is taken taking into account the provision of the construction lift of the superstructure.

According to the conditions for the perception of mounting loads, a short block is installed first. With one end it rests on permanent support parts, with the other end on a metal cage located on a temporary support. The second block on a temporary support is installed on wooden wedges, with the help of which the holes are aligned when the blocks are combined into a single structure.

Installation of superstructures with lattice main trusses. The lifting capacity of the GEPK-130 crane is sufficient for the installation of lattice superstructures with a bottom ride up to 44.8 m long. Superstructures 55 and 66 m long are installed in the span divided into two blocks.

Using a GEPC-130-17.5 crane with a chain hoist base on a 7 m boom, a span structure 44.8 m long is installed using two transverse beams and sling cables (Figure 5.1, b). The front chain hoist is placed at a distance of 1.4 m from the center of gravity of the span. To ensure the stability of the strapped structure, an additional load of 14 tons is placed on the first panel from the crane.

When installing a span structure with a GEPK-130U crane, it is suspended from the main chain hoist using a sling eye, a pickup beam and sling loops, and to an additional chain hoist - only with the help of sling loops (Figure 5.1, in). The main chain hoist slings the superstructure for the longitudinal beams of the roadway, and with the additional one - for the lower belts (Figure 5.2, a b).

a- main chain hoist; b- auxiliary chain hoist; 1 - crane console; 2 - main chain hoist; 3 - superstructure; 4 - transverse slinging beam; 5 - slinging cables; 6 - lining; 7 - additional chain hoist; eight - wooden bars; 9 - clamp; 10 - wooden spacer. Dimensions in meters

Figure 5.2 - Scheme of suspension of a metal superstructure with a ride down to the console of the GEPC-130U crane

Figure 5.3 shows a diagram of the installation of a span structure 66 m long, block-by-block crane GEPC-130U. To unite the blocks in the span of the bridge, a temporary support is constructed. The space between the temporary and permanent support from the side of the crane is blocked by a span structure, onto which the crane enters with the first block. The second block is fed into the span after the removal of the temporary span. The initial connection of the blocks is made using mounting plugs and bolts. The slinging of the second block is carried out only after connecting it with the first block with the estimated number of plugs and coupling bolts.

Installation of steel superstructures using floating cranes significantly reduces the volume of auxiliary structures, labor costs and construction time. This method is widely used in the construction of bridges in the area of ​​large port cities, where it is possible to use serial floating cranes with a lifting capacity of 100, 200, 350 and 600 tf. These cranes are usually self-propelled and have the necessary maneuverability.

In the report card of some bridge parts of the railway troops there is a floating collapsible crane PRK-50 (PRK-80), and in a number of bridge-building organizations a floating crane PRK-100. These cranes can be delivered to construction sites disassembled by railway or on the ground by road.

1 - span blocks; 2 - temporary support; 3 - temporary superstructure. Dimensions in meters

Figure 5.3 - Scheme of installation of a steel superstructure with lattice main trusses by a cantilever crane GEPK-130U in large blocks

The assembly of superstructures (or their blocks) is usually performed on the shore in the area of ​​the floating crane. With a small distance from the assembly site to the bridge, enlarged blocks or the entire superstructure can be transported directly on the crane hook. In other cases, the block is loaded onto barges or pontoons, delivered to the bridge and installed on the supporting parts by a floating crane.

The crane is fixed in the river bed using inventory anchors, and at high water flow rates, weak or rocky soils of the river bottom - with cables for the bridge supports or special weight anchors (Figure 5.4). Moving the crane near the bridge for short distances is carried out by the work of anchor winches, for long distances the crane is moved by tugboats, pusher boats and other light vessels.

The installation of superstructures with floating cranes is carried out in accordance with the project for the production of works, which indicates the procedure for performing all operations, the obligations of the performers and the safe conditions for the production of work.

1 - crane PRK-80; 2 - pusher boat; 3 - self-propelled anchor winch; 4 - pier; 5 - span structure; 6 - the place of the span in the bridge scheme

Figure 5.4 - Installation of a superstructure with a floating crane

For the installation of beams with a length of 12–42 m and a mass of up to 90 tons of road and city bridges, overpasses and overpasses, special sluice cranes are used. various types, in our case, based on a technical and economic comparison, the installation of beams with a cantilever-sluice assembly crane, KShM-35, was chosen.

KShM-35 is a mobile crane transported as a whole without disassembling into elements or with minimal separation into blocks and providing a significant increase in technical performance. m and weighing up to 35 tons, taking into account slinging arrangements. The design of the sluice crane, unlike other sluice cranes, allows it to be transported along roads without dismantling the main beam and chain hoists. This allows you to spend a minimum of time and labor on bringing the crane into working and transport position. The crane consists of the following main units: a KrAZ-258 tractor with a counterweight, a main beam, front and rear supports with transverse movement trolleys, two pneumatic and two cargo trolleys with traverses, two traction and two cargo winches, crane transverse movement tracks. The main beam of the crane in the working position rests on two supports, of which the back is rigid, and the front is articulated. At the KShM-35 crane designed in 1975, the front part of the main beam rotates around the horizontal hinge and rests on the back, which makes it possible to reduce the length of the main beam in the transport position.

The main beam of the crane in the working position rests on two supports, of which the rear is rigid, and the front is articulated. In the KShM-35 crane, the main beam is designed from three blocks with a length of about 19 m (rear), 10 m (middle) and 12 m (front). Two cargo trolleys move along the lower chord of the main beam, designed to receive, use and lower the superstructures onto the bridge supports.

On the rear cantilever part of the main beam, cargo and traction winches are mounted for lifting superstructures and moving cargo carts. The transverse movement of the crane is used to install the superstructure in the design position across the bridge. The front track is installed on the bridge support, the rear track - at the ends of the blocks of the previously installed span.

To bring the crane into working position, the tractor is connected to the rear end of the main beam, then the front end of the beam is raised, the transport trolley is rolled out, the front support is turned into a vertical position, a transverse path is suspended from it for rolling the crane along the support, a transverse path is laid to move the rear support. After that, the crane is slowly moved by a tractor into the span of the bridge, the front and rear supports are installed, the main beam is raised, the second transport trolley is rolled out and the tractor is removed.

Wooden supports are installed under the first mounted beam (B2) to prevent it from tipping over. The subsequent beams are fixed to the previous one by welding the outlets of the shelves reinforcement. After the installation is completed, the wooden supports are dismantled.

  • 1. Longitudinal reinforcement 8Sh18S500 is installed;
  • 2. Formwork is installed, supplied from the ground or from a boat, using manual winch. Formwork is fixed wooden board(pos. 2) and a wedge (pos. 1);
  • 3. Concrete for monolithing is supplied from a concrete mixer truck moving directly along the superstructure. Concrete is carefully compacted with a deep vibrator;
  • 4. The formwork is dismantled using a hand winch on the ground or boat.

Then a leveling layer 3 cm thick is arranged:

  • 1. We install the vibrating screed on wooden rails using a truck crane;
  • 2. Concrete is supplied from a mixer truck moving directly along the span;
  • 3. Dismantling the vibrating screed.

The installation of adhesive waterproofing "Mostoplast" of the roadway and sidewalks with a thickness of 1 cm.

  • - the lower layer of the coating with a thickness of 7 cm from hot asphalt concrete of porous coarse-grained mixtures, the density of stone materials is 2.5-2.9 t/m 3 ;
  • - the top layer of the coating with a thickness of 4 cm from hot asphalt concrete of dense fine-grained mixtures, the density of stone materials is 2.5-2.9 t/m 3 .

Applied technique when laying asphalt concrete pavement:

  • 1. Asphalt paver on wheels;
  • 2. Dump truck;
  • 3. Asphalt distributor;
  • 4. The roller is self-propelled.

Ladder descents are being built on both sides of the embankment at the beginning and end of the bridge. The final stage of construction is the liquidation of the construction site: dismantling and removal of all auxiliary structures and mechanisms, clearing the territory of construction debris, clearing the channel, dismantling the bypass road.

Do you know how many nuances are important to consider when designing bridge structures? For example, how the installation method of the span structure is selected. The accuracy of calculations directly depends on the experience of the organization. We have over 50 in our portfolio. We guarantee quality.

After the production of transport and preparatory work direct installation of structures begins . Depending on the project and existing technical conditions installation of span structures of bridges can be done in several ways.

Technologies for assembling span structures

Scaffold assembly. This option involves the use of superstructures with main trusses of a through type, the elements rest on the scaffolds at each node. Mounting scaffolds from universal structures and other inventory property are erected on temporary supports. Bridge inventory structures are made of rolled metal, in some cases it is allowed to use separate wooden elements. Depending on the technology, it can have several types:

Mounted or semi-mounted assembly. Works are carried out from the supports to the span between them, the structure works as a console. Elements in some places have an emphasis, while in other places they sag. Semi-mounted assembly is used in cases where it is considered impractical to install temporary supports for some reason. Sometimes a hinged assembly is performed by balancing - installation is simultaneously performed on both sides of the support.

Mounting with longitudinal sliding. It involves the sliding of spans assembled on the slipway with the help of rolling and pushing devices.

Crane Assembly. Installation of metal spans buildings performed using various crane equipment, allows you to minimize the time of construction and installation work.

Installation using floating facilities. It is used during the construction of multi-span bridges when it is impossible to install temporary supports in the riverbed.

The company "TRANSSTROYPROEKT" LLC provides qualified assistance in choosing best way holding construction works(), which makes it cheaper installation of beams of the span structure of the bridge and accelerate the commissioning of the facility. This takes into account existing rules and government recommendations. The pre-selected method is agreed with the customer and, after approval, the method is included in the design and working documentation, including SVSiU. Among our completed design work taking into account the choice of the method of installation of superstructures, objects such as, and many others.