MultiPlate MP200 structures are approved by most of EUROPEAN ROAD AND RAILWAYS ADMINISTRATIONS AND NATIONAL STANDARDS.
They are manufactured in accordance to european standards. This product has CE mark.
MultiPlate MP200 structures can be used as:
- under passed,
- ecological crossing,
- pedestrian tunnel,
- stores for ammunition ,
- belt conveyor protection,
- ventilating duct,
- and for reinforcement and reconstruction of existing structures as well.
MultiPlate structures can be used for every class of service load provided that appropriate backfilling procedure is performed.
Steel used for MultiPlate MP200 is produced in accordance with EN 10025:2000, PN-EN 10027-1:1997 and PN-EN 10113:1998.
Minimum yield strength 235 N/mm2.
Steel standard S235JR (S275JRG for special regrets).
Bolts and nuts conform to SS ISO 898-1 i SS ISO 898-6 and BSK 94.
Corrosion resistance of steel is the main factor deciding about the durability of steel structures. Long-term tests done in many countries of world have proven that, the proper corrosion protection of the steel structure let to prolong the life time of structures. Durability of structures built with use of MultiPlate 200 designed for the service conditions can be longer than one hundred years.Zinc coatings give the so-called cathode protection. Thanks to this they can protect the steel also in electrochemical way achieving the multi-elemental corrosion protection system.
When designing the MP200 structures durability one should consider the following:
- Zinc coatings,
- Paint coatings,
- Sacrificial thickness of steel as allowance for corrosion (increasing of the plate thickness),
- Other kinds of protections.
Method of proceeding when calculating the durability of multi-elements steel structure type MultiPlate MP200:
- Define function of structure,
- Define of the required durability of the structure,
- Define of conditions of the environmental aggressiveness (water, backfill, air) - choice the governing corrosion model,
- Specifying of the plate thickness with regards to static calculations (acc. to Sundquist - Petterson method),
- Specifying of corrosion protection (thickness of zinc coating, paint coating, paved bottoms, etc),
- Define of protection layers in upper and lower sphere of the structure with allowance the corrosion progress in surrounding environments with described aggressiveness,
- Calculation of durability period of the structure in upper and lower part,
- Comparison of the structure durability in the critical parts with the required value,
- Decision about acceptance of the structure or about rejection and change of parameters of corrosion protection
It is necessary to remark that the corrosion points appear most often in the bottom part, where the stress level in the steel structure is the lowest. It means that by designing the structure according the most stressed cross-section - the upper sphere, there’s an additional security reserve in scope of the structure durability.
MultiPlate MP200 structures can have additional elements depending of structure function e.g.:
- lighting boxes,
- shelves for animals,
- technological holes,
There is a possibility to make additional holes in structure. MultiPlate MP200 can be produced with bends.
The following algorithm should be used for design of MultiPlate structures:
- specify of function of a structure,
- selection of shape depending on function of the structure,
- selection of foundation system,
- specification of cover depth,
- determination of kind and value of dead and live loads,
- specification of backfill material,
- static calculations,
- checking of water flow,
- additional fittings (eg. reinforcing ribs),
- description of assembly method,
- assumption of required durability,
- selection of corrosion protection,
- estimation of labor and cost of assembly.
Before assembly, bottom shape under the culvert have to be proper with the same shape like a bottom plates of culvert - it’s mean with the same radius. As a foundation properly compacted aggregate about 30 cm thick should be used. Last layer inserted between the culvert and foundation have to be made with clean and not compacted sand to allow the corrugations to bed uniformly.
Assembling should be following instructions and assembly drawings supplied with each structure, which gives both the exact position of each plates and the progressive order of assembly.
A number of detailed drawings show the position of the pieces to be assembled in the case of culvert with cut ends.
The plates making up the structures are connected by high strength bolts of grade not lower than 8.8.
Their length varies with the thickness of the steel plates. Generally shorter bolts will be used to join two plates, longer bolts for three plate laps. Nuts should be situated from inside of culvert for bottom and corner plates, but in top plates the nuts should be situated from outside of culvert.
The plates should be positioned with the help of lifting equipment (e.g. crane). Then a small number of bolts is inserted to keep assembled plates in the correct position. The remaining bolts could be inserted after a few rings has been assembled.
To allow the plates a small setting tolerance, bolts must be left loose at this stage. Proceeding with assembly of the structure, the rings are closed to simplify assembly of the section.
The plates can be positioned exactly thanks to taper pins and handles, included in the supply.
When assembly is completed, the bolts are tightened up to the required torque.
Assembly of arch and box structures
Structures are placed on the special „channel” made in concrete footings. Flat steel is welded to the side plates of the structure.
Recommended dimensions of channel: width 20 cm, depth 15 cm and length 20 cm more than bottom length of the structure.
The fastest way for assembling arch or box structure is preassembling every rings in horizontal position and then placed it into final position using crane.
Torque of Bolts
For assembly one would used bolts with length 45 mm and 50 mm.
Tightened up to the required torque have to be done after assembled plates as a last step of assembling.
Required torque for structure with span until 7m: min. 240 Nm and max 360 Nm.
Required torque for structure with span more them 7m: min. 360 Nm and max 450 Nm.
Torque have to be checked for 5% of bolts. 95% of checked bolts must have required torque and remaining 5% must have min. 200 Nm.
Equipment which should be used for assembly:
- taper pins and handles, hammers
- mechanical wrenches
- scaffolding and ladders
- belts and ropes
- lifting slings,
- torque spanner for checking required torque etc.
As soon as the first full ring is assembled the preliminary control of shape of the structure should be performed.
After full structure is assembled control of shape have to be done as well.
Allowed tolerance for culvert dimension is 2% of design values.
During backfilling shape control (span and rise) have to be checked, too. Allowed tolerance of culvert dimension during backfilling is 2% of values from assembled culvert.
Algorithm for construction of flexible culverts:
- cut for foundation,
- preparation of bedding under structure,
- unloading of plates, bolts and nuts from truck with caution because of the corrosion protection,
- assembling of structure using assembly instruction,
- preparing suitable material for backfilling,
- fill of backfilling material with respect to right compaction and symmetrical layer placement
- protection of structure against technological load,
- shape control during backfilling,
- protection of structure against water leakage ( for tunnels and underpasses),
- suitable construction of additional elements (collars, paving, etc),
- suitable erosion protection.
Soil - structure interaction results in deformations of structure during backfilling. Backfill material (sand – gravel mix) should be of 0-45 mm aggregate. Proper preparation and compaction of soil (to 98% standard Proctor density) and assembly of a structure acc. to producer recommendations are the most important elements.
- tolerance of length and width ± 5mm,
- tolerance of length and high of wave ± 2mm,
- tolerance of distance between holes ± 2mm,
- tolerance of thickness of plates in accordance with EN 10051+A1,
- tolerance of radius ± 5mm.
Maximum deformation during backfilling 2% of nominal value.
Tolerance of rise, span, bottom and top length, x-inlet, x-out after assembly 2% of design value.
In case of any questions regarding MultiPlate 200 structures please contact our Export Department.