EP0998610B1

EP0998610B1 - New jersey type barrier for the sides of a bridge

Info

Publication number: EP0998610B1
Application number: EP98929647A
Authority: EP
Inventors: Gabriele Camomilla; Stefano Bruschi
Original assignee: Autostrade Concessioni e Costruzioni Autostrade SpA
Current assignee: Autostrade Concessioni e Costruzioni Autostrade SpA
Priority date: 1997-07-22
Filing date: 1998-06-26
Publication date: 2002-09-11
Anticipated expiration: 2018-06-26
Also published as: WO1999005364A1; DE69807893D1; DE69807893T2; EP0998610A1; ITRM970452A1; ATE223989T1; ES2183382T3; ITRM970452A0; IT1294202B1; AU7932198A

Abstract

Steel-made New Jersey type barrier, comprising "monolithic" modular elements including uprights and handrails, obtained from adequately folded and welded sheet steel pieces (1, 2, 3, 4, 5, 6, 7). Every 1,5 meters there are provided vertical structural elements (3, 4) having a width of 15 cm and producing a "reticulated structure or lattice work", and a space (14) being provided for the insertion of ductile anchor means (32), which are used for fixing the barrier on its support (31). Every 3 meters said vertical structural element "extends upwards" forming the upright or post (13) for supporting the handrail tube (15). There are provided special connections between modular elements, to be used at the site of the expansion joints between the spans of a viaduct.

Description

Technical Field

The present invention relates to a motorway barrier to be used on the sides of bridges, and particularly to a monolithic barrier of this type, which can be homologated in the so-called B3 class of top resistance, which is particularly suited to be used on already existing bridges or motorway viaducts, due to its reduced weight, besides on newly erected structures of this kind.

Background Art

It is already known to utilize concrete-made monolithic New Jersey barrier blocks which form, after assembling, a protection of the B3-class kind, and whose costs are certainly inferior than those of a barrier obtained from sheet steel, but which, nevertheless, cannot be utilized on some already existing structures due to their weight per meter, which in certain cases is too high.
EP - 0 575 705 A1 discloses a metallic safety barrier with stiffening ribs which are at least two in number for each module and are L-shaped in cross section.
This type of barrier has no reticulated structure. Moreover, the way the different modules are hinged to each other is different from the present application.
WO 95/03453 relates to a light guardrail for bridges (same applicant as the applicant of the present application). This kind of barrier does not meet the requirements of the B3 class, whereas the barrier of the present invention has reinforcements in the form of reticulated structures for this purpose.
The hinges which connect the modules together are different from the present application, and the structure of the uprights is box-like, not reticulated.
A fundamental difference is that the barrier of the application WO 95/03453 can be assembled in situ, without the need of transporting monolithic blocks. In the present application, on the other hand, the modules are monolithic and can be connected directly to each other.

Disclosure of Invention

An object of the present invention is to realize a steel-made barrier for the sides of a bridge, which can be homologated in the class B3, with minimum production costs, employing a reduced amount of materials, and reducing the time for its erection.
Another object of the present invention, depending on the preceding one, is to realize the barrier in separate blocks or monolithic modules which can be directly connected to each other, which require a minimum assembling time and can be adapted to bridges of any span.
A further object of the present invention is to include in this new kind of barrier belonging to the B3 class, all features already advantageously used in this technical field; said features, which in part have been suitably modified, comprise among other things: the screw anchors with predetermined breaking threshold, the reinforcing ribs provided on the so-called "mantle" with the New Jersey profile, and the mutual connection systems among the barrier elements at the site of the expansion joints or their neighbourhood, that is, between the bays of the bridge, in order to allow displacements caused by thermal dilatation, eliminating the rise of dangerous mutual actions and stresses on the bridge top and barrier. The above objects are obtained by a steel made barrier with New Jersey profile, according to the features of claim 1. The dependent claims illustrate particular and/or preferred embodiments.

Brief Description of Drawings

A preferred embodiment of the present invention will be described in what follows only for illustrative and non-limitative purposes, referring to the annexed drawings, wherein:
Fig. 1 is a cross-sectional view of a module of the New Jersey barrier used on the bridge sides, taken along the line A-A of Fig. 3, at the site of the post of the handrail;
Fig. 2 is a front view of a detail of the module, in the direction of the arrow F of Fig. 1, at the site of the pole of the handrail;
Fig. 3 is a front view of the whole module of the barrier according to the present invention, in the direction of the arrow F of Fig. 1;
Fig. 4 is a front view which shows the adopted solution by the barrier of the present invention, for the handrail tube at its two ends;
Fig. 5 is a sectional exploded view of the various parts made of sheet steel, which, when welded to each other, form the barrier of Fig. 1, taken at the site of the structural reinforcement element, which in what follows will be named "upright";
Fig. 6 is a sectional view of the connection system between two tubes of the handrail (sleeve), at the site of the joint between two modules of the barrier;
Fig. 7 is a view which is analog to Fig. 6, but illustrating a special sleeve to be employed at the site of the "expansion joints" of viaducts, allowing relative displacements between the connected tubes;
Fig. 8 is a plan view from the top of the particular connection hinge between two modules of the barrier, to be used at the site of the "expansion joints" of the viaduct, in order to allow relative displacements between the two connected barriers;
Fig. 9 is a vertical elevational view in the direction of the arrow P (Fig. 8) of the hinge of Fig. 8, showing both the already assembled device (central part) and its different constituent parts taken individually;
Fig. 10 shows by means of different partial views, and according to a plan view, the connections between two respective adjacent barrier elements, obtained by means of a plate and a counterplate bolted together, according to the "standard" case and to the case applicable to expansion joints of viaducts;
Figs. 11A-11E show, according to a plan view, the steel-made plates and counterplates used to connect the modules of Fig. 10.
In the different figures, always the same reference number is used for the same structural element of the barrier utilized on the sides of a bridge.

Best Mode of Carrying out the Invention

As has been already mentioned, the barrier belongs to the B3 class. This means that it must possess optimum features for preventing the "jumping over", that is the surmounting, by the vehicle, in order to avoid very serious consequences both to the passengers of the vehicle and to railways, roads, buildings, etc. which might be present below the bridge.
At the same time, the barrier must deform itself and withdraw so as to absorb the impact energy in a controlled way, causing limited vehicle decelerations, thereby causing the least possible injuries to passengers.
Considering the fact that the present barrier is not a traffic divider, the transversal displacement of the barrier, even if desirable, must however be limited, since the space available on the curbstone of a bridge is approximately 0.5 meters.
According to Italian law, the impact energy which the barrier must be able to absorb, is equal to E ≥ 600 kJ or more.
Moreover, the barrier must prevent its surmounting by lorries having a centre of gravity located at a height up to about 1.60 m. The three measured acceleration components must be less than the respective threshold values, and, additionally, the total acceleration must satisfy the following relation X2 + Y2 + Z2 ≤ 23g (g = gravitational acceleration).
The barrier according to the present invention has some structural reinforcement elements which are individually shown in fig. 5 and are denoted by the numbers 1,2,3,4,5,6,7,8,9,10,11. These structural reinforcement elements are welded to each other in order to obtain a structure which we may call reticulated or "lattice-work", which is clearly visible in Fig. 1.
Part 1 forms the "mantle" of the barrier, it has a "New Jersey" profile and is obviously continuous, thereby covering all the front part of the barrier module of about 6 meters of length. Part 2, having the shape of a double wave, forms a reinforcement element welded to the back side of the "mantle". The double wave 2 also extends along the whole length of the module. Parts 3 and 4 are also welded and belong to the base 12 of the module, but they extend only for a limited length, for instance 15 cm, at the site - and on both sides - of the hole 14 for the screw anchors with predetermined breaking threshold.
The height of the base 12 may be equal, for instance, to a 1 m, more or less.
The parts 5,6 are also limited in their extension, to a zone around the hole 14, and are welded to the back side 7 of the upright and the tube piece 8 supporting the handrail tube 15 (shown in Fig. 4), the latter being inserted inside the sleeve 8; as can be seen, the structural reinforcement element comprises also the post or upright 13 of the handrail.
As can be seen in Fig. 3, there are preferably six holes 14 (which are elliptical when observed frontally), comprising two lateral holes, allowing to connect the barrier modules to each other by means of the bolt 81, and four central holes 14 provided for assembling the ductile screw anchors 32, spaced about D _ 1500 mm from each other.
Obviously these distances are only illustrative and are applicable only to the present embodiment.
The uprights 13,13 of the handrail of Fig. 3 are provided only in the number of 2, at the site of only two of the four central structural uprights of the module which comprise the hole 14.
Fig. 6 shows the connection between two handrail tubes 15,15 belonging to two adjacent barrier modules (of about 6 meters). The sleeve 21 is inserted inside both tubes 15, 15 and fixed by bolts 22.
Both tubes 15 have a length which is approximately equal to that of a module, which may have a nominal length from 6 to 3 meters.
Usually, the modules, which after welding have a monolithic structure, are transported with the tube 15 being already inserted in the guides 8, and the sleeve 21 and one of the bolts 22 being already assembled onto one end of a tube 15. It will be sufficient, then, to introduce the other tube 15 (of the other module), in the sleeve 21, and move the tubes only for a short distance, in order to obtain the connection.
In Fig. 7, the sleeve 21' is longer (for instance about 160 mm) and has slots 23 which are crossed by one of the two bolts 22. This system allows a sliding movement of the tube 15 at the site of an "expansion joint" between two adjacent spans of a bridge.
In Fig. 3, there is shown how the sleeve 21 or 21', could be provided also in an intermediate point of the barrier. In Fig. 1, the detail 30 shows the anchor system for obtaining the connection to the curbstone 31. The anchor system comprises conventional components, like the constituent parts 9, 10, 11 which form the anchor chamber (welded to the structural upright), and the screw anchor 32 having a predetermined breaking threshold.
In the following, the connection system between two modules will be illustrated for a "standard"joint and for an "expansion joint" of the viaduct.
As shown in Fig. 9, the two modules 40,40 to be connected to each other, comprise a plurality of rings with elliptical cross-section 41 at their mating ends, which have been welded in a staggered way, so as to be able to penetrate each other like a zipper, when the two modules are put close to each other. Then, a pin or bar 42 is introduced from above into the circular hole formed by the ellipses of the rings 41 belonging to the two modules 40 (Fig. 10).
In order to fasten the pin 42 from above, and in order to increase to resistance of the joint, a first plate 43 is mounted (Fig. 11B) onto the upper surface of the base 12 (no upright 13 in this position), while a counterplate 44 (with shorter width to be able to pass beyond the pin 42), is applied on the other (inner) side of the upper surface 45 of the base 12 of the barrier. Bolts are inserted in the duly aligned four holes of the plates 43, 44 and thereafter these bolts are fastened.
It is to be noted that the holes of the plates on one side of the joint have an elongated form, this being necessary in order to facilitate assembling and for allowing certain tolerances. The gap 46 (Fig. 10) will be about 2 cm.
In the case of the expansion joint, which is also shown in Fig. 10, the connection is a bit more complex. The connection system may be understood by considering, jointly, the three figures 8,9 and 10.
Both modules 40, 40 are put close together, interposing between them a hinge consisting of two half-parts 50, 50', which are freely rotatable around a pin 42'and form therewith a single body.
Each of said half-parts 50, 50' includes a plurality of sheet steel elements shaped like half-moons 52 and 52' respectively, which are welded to steel strips 51 and 51' in order to form a unique integral piece.
As may be seen in the plan view of Fig. 8, two pins 42 are simultaneously inserted into the rings with elliptical cross section 41 of respective modules 40, 40 and into the half-parts 50, 50' whereas a untral pin is introduced inside both half-parts 50, 50' at the same time (specifically into the half-moon elements 52, 52').
Fig. 9 also shows how the half-parts 50,50' of the hinge are obtained, welding the flat strips 51 and 51' to the separate parts 52 (four pieces) and 52' (four pieces). The gap 60 (Fig. 8) in the case of the expansion joint is about 60 mm, but it may be more or less than this value (for instance ± 40 mm), allowing thermal displacements of the viaduct spans; these values can be obtained by means of the above described hinge. It should be noted that the parts 41, 52, 52', 41 are arranged in staggered positions so as to allow mutual penetration (see assembled joint shown centrally in Fig. 9).
The plate 70 (Fig. 11E) is used for the connection in the case of the expansion joint; it covers from above the whole above described hinge, securing the three pins 42, 42; 42', preventing the pins from being removed.
Slack bolts are introduced in the slots 72 of the plate 70 and into the slots 73 of the counterplate 71 (Fig. 11D). The counterplate 71 is applied on the other (internal) side of the upper wall 45 of the barrier base 12, with respect to the upper plate 70, the latter lying on the surface 45. Since the holes 72, 73 have an elongated form, and the bolts inserted therein are loose, the movement of the modules is not hindered at the site of the expansion joint.
Fig. 11C shows a plate 74 which is also illustrated in Fig. 4 and serves for connecting to the barrier module, the bent end 90 of the handrail.
Moreover, the two modules of the barrier are connected to each other by a bolt comprising a nut and a lock nut, having for example a length of 160 mm and denoted by the number 80, the connection being done at the foot of the barrier and at the site of an expansion joint. This bolt, which will not be fastened, must have in fact a length which is sufficient so as to prevent the hindrance of movements performed by the modules, which are themselves due to small displacements of the span ends. The bolt 81 has instead a much smaller length, for instance about 80 mm, and will be screwed tight in order to rigidly connect two different adjacent barrier elements in the standard position.

Industrial Applicability

The barrier is primarily used on the sides of a bridge, according to the present invention, may also be utilized in all cases where a barrier meeting the conditions of the B3 class is required, wherein these prerequisites are obtained through the particular reticulated structure of the handrail upright, which has been designed specifically for this purpose.

Claims

Steel-made New Jersey type barrier to be used preferably on the sides of a bridge, belonging to the B3 class, comprising monolithic modules 12,13 extending, in use, along the barrier formed by parts (1,2,3,4,5,6,7,8,9,10,11) welded together and anchored to a support (31) by means of ductile anchor means having a predetermined breaking threshold (32), and comprising also a handrail tube (15) extending, in use, along the barrier and being inserted into sleeve guides (8) of said modules, wherein there are provided structural reinforcement uprights, some of which extending upwards forming an upright or post (13) for the handrail (15), and said uprights have a structure formed by internal welded parts (3,4,5,6) whose extension, in use, along the longitudinal barrier is limited to the region of holes (14) for said ductile anchor means (32), wherein each of said modules has a front mantle (1) extending along the whole length of the module and having a New Jersey profile, which is provided with a reinforcement (2) also extending along the whole length of the module and thus connecting the various structural uprights with or without an upper extension for the post (13) of the handrail (15) and said tube (15) of the handrail of a module being connected to the tubes (15) of the adjacent modules by means of a sleeve (21;21') and bolts (22), preferably at the position of the joint between a module and its adjacent modules, in order to ensure an assembling in a minimum period of time, characterized in that said internal welded parts (3,4,5,6) form, in cross section perpendicular to the longitudinal extension of the barrier, a reticulated structure.
Steel-made New Jersey type barrier according to claim 1, to be used preferably on the sides of a bridge, characterized in that the extension (13) for the post of the handrail tube, associated to a structural reinforcement upright, has approximately a trapezoidal form, with a lager size base, and a smaller size base at the site of the welding line to the sleeve (8) of the handrail tube (15).
Steel-made New Jersey type barrier according to claim 1 and 2, to be used preferably on the sides of a bridge, characterized in that at the site of an expansion joint, that is near the gap existing between two bridge spans, the two adjacent modules have their two tubes (15) of the handrail connected by means of a sleeve (21) with a larger length, wherein said sleeve has slots (23) for allowing the sliding of the connection bolts (22), which are loose bolts in this case of an expansion joint.
Steel-made New Jersey type barrier according to claims 1-3, to be used preferably on the sides of a bridge, characterized in that the connection between two modules in a zone which is distant from a span end, is obtained by means of a first row of rings (41) of substantially elliptical cross-section and integral with the back side of the first module, a second row of rings (41) of the same kind as those belonging to the first row and integral with the back side of the second module, but fixed in a staggered position with respect to the rings (41) of the first row, and a vertical pin (42) which is inserted with a small play inside the guide hole of approximately circular form, which is defined by the mutual penetration of said rows of rings (41) arranged in staggered positions; said connection being completed by means of two steel plates (43,44), wherein the upper (43) of said plates is applied onto the upper plane surface (45) of the barrier, on both ends of the modules at the same time, whereas the lower plate (44) having a smaller width, is applied on the lower surface of said upper surface, by letting it pass through a slot; the said two plates (43, 44) being fixed to each other and to the modules, by means of bolts passing through the duly aligned holes of the plates (43, 44).
Steel-made New Jersey type barrier according to claim 4, to be used preferably on the sides of a bridge, characterized in that at the foot of the barrier two adjacent modules are connected together by means of a bolt (81), washers, and a nut which presses the washers against the lateral cover walls of said two modules.
Steel-made New Jersey type barrier according to claims 1 to 5, to be used preferably on the sides of a bridge, characterized in that at the site of an expansion joint the two adjacent modules are connected by means of a double hinge (50, 50') with a central pin (42'), and the ends of said double hinge (50, 50') are hinged to said ring rows (41) of each module through other two pins (42).
Steel-made New Jersey type barrier according to claim 4, to be used preferably on the sides of a bridge, characterized in that an upper plate (70) which covers from above the double hinge (50, 50'), is connected to a lower counterplate (71) having a smaller width, which is introduced in two slots provided for this purpose on the lateral cover walls of the adjacent modules, so as to be in contact with the lower side of the upper surface (45) of the barrier; wherein the connection between both plates (70;71) is made by means of slack bolts which pass through elongated holes (72, 73) of the two plates (70, 71).
Steel-made New Jersey type barrier according to claim 7, to be used preferably on the sides of a bridge, characterized in that the connection to the foot of the barrier, between the two adjacent modules, at the site of an expansion joint, is obtained by means of a bolt (80) which allows longitudinal displacemants promoted by said double hinge (50, 50'); said bolt (80) having therefore a length such that these displacements are not prevented and being preferably provided with tightened nuts so as to allow relative displacements of the modules.
Steel-made New Jersey type barrier according to claims 1 to 8, to be used preferably on the sides of a bridge, characterized in that the distance between two modules, for a normal joint, is about 2 cm, and the distance after the erection of the barrier, for an expansion joint, is about 6 cm; the aforesaid expansion joint allowing for relative movements of about ± 4 cm.
Steel-made New Jersey type barrier according to claim 1, to be used preferably on the sides of a bridge, characterized in that said reinforcement (2) has the shape of a "double wave".