EP1144762B1

EP1144762B1 - Safety barrier made of steel and/or plastics and earth

Info

Publication number: EP1144762B1
Application number: EP99929690A
Authority: EP
Inventors: Gabriele Camomilla; Stefano Bruschi
Original assignee: Autostrade SpA
Current assignee: Autostrade SpA
Priority date: 1998-12-29
Filing date: 1999-06-24
Publication date: 2005-03-30
Anticipated expiration: 2019-06-24
Also published as: DE69924525D1; EP1144762A1; WO2000039404A1; ITRM980813A1; IT1302955B1; AU4646499A; ITRM980813A0

Abstract

A barrier forming a two-row traffic divider or a lateral barrier for an artificial trench, comprising a continuous deformable structure (3, 3'; 13, 13'; 23, 23') including a plurality of modules which are mutually connected and are simply laid on the curbstone or pavement. The deformable structure allows the calibrated deceleration of the light vehicles. In case of a barrier formed by a two-row traffic divider, a central container (1) stops the movement of a heavy vehicle, while the same effect is obtained by means of the toe wall (16) in case of a lateral barrier.

Description

Technical Field

The present invention generally relates to road safety barriers, and in particular to those barriers which are capable of decelerating automobiles in a controlled manner, and of preventing from vaulting goods vehicles having a high center of gravity and a weight of more than 40 tons.
The barrier of the present invention may form -according to one of its embodiments- a two-row traffic divider comprising an amount of earth interposed between the two rows, and according to a further embodiment, a lateral barrier.

Background Art

It is well known that modern road safety barriers must satisfy the fundamental requirement of withstanding the impact caused by a goods vehicle, which may weigh more than 40 tons; therefore, a barrier which is capable of preventing vaulting of goods vehicles may represent a fatal obstacle for automobiles whose weight is within the interval 800-1500 kg.
Therefore, the problem arises of constructing a barrier which causes so-called "calibrated decelerations", that is, which allows to reduce progressively, in a gradual manner, the velocity of an automobile hitting the barrier at high velocity and/or with a great angle of impact.
US 4,681,302 relates to an "Energy absorbing barrier", which among the solutions proposed by the prior art, probably comes closest to the arrangement of the present invention. This safety barrier is made by a modular resilient structure, which extends continuously and in which each module is filled with water and forms a sealed container. Traction spoiler channels reduce the area of contact with the tire of the vehicle to reduce the risk of vaulting. The deformed part of the module(s) (during the impact) forms a region which "captures the wheel" and prevents vaulting, and the resiliency allows the module (s) which is (are) hit, to return to its (their) original shape.
However, this solution does not constitute a "bivalent barrier", that is a barrier which also stops heavy vehicles.

Disclosure of the Invention

An object of the present invention is to realize a road safety barrier of the kind of a two-row traffic divider with an interposed amount of earth, or of the kind of a lateral barrier, having all features required for preventing vaulting by goods vehicles, and at the same time for protecting the passengers of automobiles. This is solved by a traffic divider according to claim 1 or a lateral barrier according to claim 2.
The deformable structure arranged on one side (and on the opposite side) of the earth container, forms in fact itself a "barrier", and will be capable of reducing in a controlled manner the velocity of an automobile, by means of one or more of the following mechanisms:

the very configuration of the deformable structure or "barrier", which may be of the New Jersey kind, may contribute to reduce the velocity in a controlled manner;
the fact that the steel or plastic-made constitutive elements are deformable, may contribute to the same effect;
and finally the possible (backward) translation of the deformable elements, which are simply laid on the curbstone or pavement.

The plastic-made deformable modular elements are filled with salt water or sand in order to obtain the required weight for resisting, in the required way, to the impact caused by the automobile.
In case of deformable steel-made elements, their very weight and the resistance provided by the latticework of their reinforcement elements, will withstand the impact of the automobile.
In the latter case, the deformable structure arranged on each side of the earth container will be formed by steel sheets with a New Jersey profile and a reduced thickness, which are simply laid on the support (curbstone or pavement).
A salt or generally an antifreeze (antifreezing substance) will be mixed to the water contained in the modular plastic elements, to avoid that the deformable structure behaves as a rigid structure upon impact by a vehicle, during the winter, and in order to avoid at the same time that the water which could escape from the barrier elements, forms ice on the pavement.
The modular elements of deformable plastics are not completely filled with salt water, instead they are only partially filled, so as to reach the necessary mass (weight) and the optimum capability of deforming themselves when they are hit by a light vehicle. It would also be possible to fill completely the plastic elements, but in this case the capability of the barrier of deforming itself would be reduced, because the liquid would be immediately "compressed".
The word "earth", which denotes the bulk (loose) material contained inside the central container of the traffic divider, must be interpreted widely and in a non-limitative way.
Thus, the central container - whose function is to limit or to prevent the backward movement of the barrier upon impact by a goods vehicle - may be filled with different materials of different densities, as will be explained in the detailed description of the invention. Thereby the weight of the container (central component of the barrier) may be varied, and in this way it is possible to modulate its resistance to an impact caused by a goods vehicle, according to the particular design needs. In a second possible embodiment, the present invention makes use of the aforementioned deformable structure (comprising plastic or steel-made modules) for realizing a lateral barrier.
In this lateral barrier, in presence of a classical slope, a raw of modular deformable elements will be provided in front of a rearwardly arranged earth container; obviously, the slope will begin behind the container.

Brief Description of Drawings

The present invention will now be described for illustrative and non-limitative purposes referring to particular embodiments thereof, which are shown in the drawings, wherein:
Fig. 1 is a cross-sectional view of a two-row traffic divider of the New Jersey type, made from plastic material and comprising two continuous (but modular) structures on the two sides of the earth container, wherein gaps are formed between the plastic-made components and the earth container;
Fig. 2 shows a barrier which is similar to the barrier of Fig. 1, except for using plastic-made structures with a profile different from the New Jersey (NJ) profile and having appropriate longitudinal reinforcement offsets;
Fig. 3 is a cross-sectional view of a two-row traffic divider, wherein the two deformable structures on both sides of the earth container are steel-made; also in this case a gap is present on both sides of the container;
Fig. 4 is a cross-sectional view analogous to Fig. 1, omitting however the gaps between the earth container and both modular deformable structures;
Fig. 5 is a cross-sectional view of a lateral plastic barrier in presence of a raised embankment providing excellent protection of the environment, not according to the present invention;
Fig. 6 is a cross-sectional view of a plastic-made lateral barrier, installed in the vicinity of an embankment slope.

Modes for carrying out the invention

Fig. 1 shows a central container (receptacle) 1 which contains an amount of "earth" 2 therein. The central container 1 is bordered by two respective plastic-made, New Jersey type modular structures 3, 3', on both of its sides facing the two carriageways. Each module of the structures 3, 3' is perfectly sealed and contains water which not necessarily fills it up completely, as shown in the drawing. The various modules are the deformable elements in case of an impact caused by an automobile, and they are longitudinally connected so as to form a chain, using appropriate means such as ropes, tubes, section bars, flat bars, etc. For instance, the connection may be carried out using tubes or ropes (cables) which pass through sheaths or guides 4; said guides are already realized during moulding of the modular plastic barriers.
These longitudinal reinforcement elements will be mutually fixed at the head portions, by means of pins or other systems of mutual connection (e.g. restrained joint).
At the junction or head portions of the modules of the barrier, a male-female connection will be done between each module and the contiguous one.
The weight of the water will provide a certain resistance against the impact caused by an automobile, and moreover, the capability of both structures 3,3' of deforming themselves, and their capability of moving towards the earth container 1, due to the presence of the gaps 5, makes possible to decelerate the automobile in a controlled way.
A goods vehicle causes instead the immediate backward displacement of the structures 3, 3' and their complete breakage at the impact region, but the goods vehicle will be stopped by the central container 1.
The water contained inside the structures 3, 3' will be mixed with an antifreeze or a salt.
The word "earth" means a wide group of materials, e. g. loam soil mixed with natural or artificial soils and materials, of variable densities in order to obtain the required mass.
Light materials in this group may be pumice, expanded clay, polystyrene, etc., whereas as heavy materials it is possible to use a heavy volcanic aggregate, slags of steel plants, etc.
The granulometry of this "earth" may be appropriately chosen so as to limit the voids and thereby obtain the required resistance (weight).
The modular structures 3, 3' are simply laid on the support 6, which may be formed by the curbstone or pavement.
The container (receptacle) 1 may form a continuous caisson or tank, or alternatively it may comprise a plurality of separate blocks (receptacles) which are either in mutual contact or separated by gaps.
The material used to manufacture the container 1 could be concrete, plastics, steel, etc.
The container 1 could also be formed by a frame supporting nonwoven fabric or a permeable material allowing the flow of rainwater therethrough. Incidentally, note that in Fig. 1 holes 7 are provided on the bottom of the container 1 in order to be able to drain the rainwater.
Fig. 2 shows an alternative of the embodiment of Fig. 1, with modular elements having a profile different from the New Jersey profile, and having offsets 8 and a different shape, even if the manufacturing material is again plastics. The offsets 8 are used for stiffening, and they do not necessarily extend along the whole wall 9 of the plastic structures 13, 13'.
Therefore, the offsets 8 are preferably limited longitudinally (localized).
Fig. 3 shows a third realization of the modular elements, in which these elements are made of steel and have a New Jersey profile. According to this solution, the steel-made deformable structures 23, 23' are formed by a "mantle" or covering 10 having a New Jersey profile, welded to a certain number of reinforcement lattice-like structures 12 which are also used as supports.
In this case, the mantle 10 extends along the whole length of each module of the structures 23, 23'. On the contrary, the latticework used as reinforcement, indicated by the number 12, extends only along limited distances (e.g. 10-20 cm) and each latticework is welded to the front NJ mantle 10. Therefore, also the vertical rear walls 11 (included in the lattice-like reinforcement structures 12) have the same extension. Consequently, the deformable steel-made structures 23, 23' are rearwardly "open" in this embodiment, apart from the regions formed by the standards (uprights) comprising the components 11, 12.
It is obvious that the location of the reinforcement lattice structures (latticework) 12, may vary according to the realization; two latticeworks are arranged at the headportions, and an additional number of such spaced apart "uprights", e.g. two or three, is also provided for each module of the deformable structures 23, 23'. Alternatively, if no reinforcement is provided in the form of the latticeworks 12, the modules may be constructed so as to comprise only one sheet shaped in such a way as to include the NJ profile, the upper wall 15, and the rear wall 11.
The thickness of the sheets will in each case be chosen so as to allow the deformation of the structure, also in case of a collision caused by an automobile.
Therefore, the function of the barrier shown in Fig. 3 is again the same as that of the plastic barriers shown in Figs. 1 and 2, even if no contribution provided by the water mass exists in this realization.
Obviously, the exact form of the latticework is not limited; the latter could in fact have different configurations, thereby varying its resistance. A further possible embodiment of a steel-made barrier uses only the mantles or coverings 10 (of Fig. 3), fixed at their upper end to the container 1 (which may be continuous or discontinuous), and laid on the curbstone or pavement at their lower end (this embodiment is not illustrated in the drawings).
This solution may be applied also to the barrier shown in Fig. 5, including a raised embankment, and in the case of this barrier the mantle or covering 10 would be fixed to the toe wall 16.
Fig. 5 is included only for illustration purposes, but does not make part of this invention. Even the last mentioned variant, with the mantle 10 attached to the toe wall 16 is not claimed in this document.
Instead, the various modules of the steel-made barriers of Fig. 3 are connected in a different way.
In this case the connection is realized by means of steel plates bolted at the upper ends 15 of each pair of adjacent modules.
Moreover, the connection may also be performed by means of horizontal bolts, at the foot of the modules (not shown).
Fig. 4 shows a realization with no gaps 5, which is otherwise identical to the realization of Fig. 1.
The gaps 5 could also be omitted from the embodiments of Figs. 2 and 3.
In this case the decelerations are absorbed only by the front profile of the modules, mainly by their deformation.
Fig. 6 shows a cross-section of a plastic-made lateral barrier, which is located near an embankment slope. Naturally, the deformable barrier may also in this case be realized using structures such as those denoted by 13 and 23 and their possible variants, which have been explained above.
The present invention can be modified in different ways and it is to be understood that the same is not limited to the embodiments shown.
Moreover, even if offsets are shown in Fig. 2, these stiffening offsets 8 could also be omitted and/or realized in different shapes and/or in a different number. They could also be arranged in the vertical direction instead of longitudinally, as in Fig. 2.
With regard to the materials employed, plastics has been mentioned above as a possible one, but this word (plastics) must be interpreted widely, even if it is preferred that the same have the following properties. The plastics used to manufacture the barrier must be of a non toxic kind - during manufacturing -, it must also be obtainable from recycling processes, it must be treated to resist to UV rays and have a suitable structure to reach the required resistance, such as e.g. super-linear polyethylene.
This plastics may have the abovementioned properties because of its intrinsic structure, or it may obtain these properties after combination with other materials or as a consequence of its manufacturing process (use of rotation moulds, pultrusion, etc.).

Claims

Road safety barrier forming a traffic divider, comprising a central container (1) and two modular deformable structures (3, 3'; 13, 13'; 23, 23') which include several modules pavement laid on the curbstone (6) or on the without being fixed thereto and to the container, and each of said deformable structures is made of plastics or steel sheets of reduced thickness, wherein the deceleration of a colliding automobile of 800 to 1500 kg is calibrated and adjusted by the movement of the modules and/or their capability of deforming themselves, while a goods vehicle of more than 40000 kg causes their immediate backward displacement and their complete breakage at the impact region and wherein said modules are filled with sand or a liquid, if they are manufactured from plastics, and said liquid is preferably water mixed with salt or an antifreeze, the rear wall of each module abutting the central container (1), in such a way that the impact energy of an automobile is mainly absorbed by the module deformation, or being spaced apart by a gap (5) from the central container (1), in such a way that the energy of an automobile is absorbed in a controlled way also through the translation of the modular structures (3, 3';13, 13'; 23, 23') characterized in that said central container (1) contains bulky loose solid material (2) so that it has a weight such as to stop the movement of goods vehicles and to resist to high energy impacts, wherein said container is made of a continuous U-shaped caisson having a plurality of drain holes at its base, or is made of separate blocks, having a plurality of drain holes at their base which are in mutual abutment or are spaced apart so as to leave a gap between their respective head walls, or else is made of a frame of rigid material, supporting non-woven fabric or a permeable material, thus allowing the flow of rainwater therethrough, the modules being laid on the curbstone (6) or on the without being fixed thereto and to the container.
Road safety barrier, forming a lateral barrier, comprising a container (1) and a modular deformable structure (3; 13; 23) formed of several modules the curbstone (6) or on the pavement laid on without being fixed thereto and to the container, this modular deformable structure (3; 13; 23) being continuous, facing the pavement, and being formed of plastics or steel sheets with a reduced thickness; wherein the deceleration of a colliding automobile of 800 to 1500 kg is calibrated during the impact by the displacement of the modules and/or by the capability of the modules of deforming themselves, while a goods vehicle of more than 40000 kg causes their immediate backward displacement and their complete breakage at the impact region and wherein said modules are filled, in case they are made of plastics, with sand or a liquid, preferably water mixed with salt or an antifreeze the rear wall of each module abutting the container (1), in such a way that the impact energy of an automobile is mainly absorbed by the module deformation, or being spaced apart by a gap (5) from the container (1), in such a way that the energy of an automobile is absorbed in a controlled way also through the translation of the modular structure (3; 13; 23), characterized in that said container (1) contains bulky loose solid material (2) so that it has a weight such as to stop the movement of goods vehicles and to resist to high energy impacts, wherein said container (1) is made of a continuous U-shaped caisson having a plurality of drain holes at its base, or is made of separate blooks having a plurality of drain holes at their base, which are in mutual abutment or are spaced apart so as to leave a gap between their respective head walls, or else is made of, a frame of rigid material, supporting non-woven fabric or a permeable material, thus allowing the flow of rainwater therethrough the modules being laid on without being fixed thereto and to the container.
Barrier according to claim 1 or 2, wherein, in case the modules are made of plastics, they are perfectly sealed and are connected longitudinally by means of resistant elements, like ropes, tubes, flat bar irons, or channels, passing through inner sheaths or guides (4); said resistant elements being mutually connected at the joints or headportions, so as to form a resistant chain-like structure comprising the various modules.
Barrier according to claim 1 or 2, wherein, if said modules are made of plastics, they are also connected by a male-female restrained joint at their headportions.
Barrier according to claim 1 or 2, wherein said plastic-made modules have a New Jersey profile on the side facing the pavement.
Barrier according to claim 1 or 2, wherein said plastic-made modules have stiffening offsets (8) and may have a profile which differs from the New Jersey profile; and said offsets (8) are preferably localized and serve to stiffen the deformable structure (3, 3'; 13, 13'), and said offsets (8) are also preferably arranged longitudinally or vertically.
Barrier according to claim 1 or 2, wherein said steel-made modules formed of sheets of reduced thickness, are formed by a single moulded sheet, and in the case of a New Jersey profile, by a front covering or mantle (10) with a New Jersey profile, a rear continuous wall, and two terminal vertical sheets.
Barrier according to claim 1 or 2, wherein said modules made of steel sheets of reduced thickness, comprise sheets welded together, and include a front mantle or covering (10) which can be of the New Jersey type, and a reinforcement structure (12) in the form of a latticework, which is located at the headportions and at intermediate regions.
Barrier according to claim 1 or 2, wherein said modules formed of steel sheets of reduced thickness, comprise only one steel sheet (10) which preferably has a New Jersey profile, and which on its lower end is laid on the curbstone or the pavement, ant at its upper end is fixed to said container (1); said steel sheet or mantle (10) being reinforced by vertical plates or septa which extend towards, and are in abutment with, the container (1).
Barrier according to claims 1 or 2, wherein the container (1) includes prefabricated components formed by a rigid material, like concrete, plastics or steel, or by a synthetic or non synthetic material.
Barrier according to claim 1 or 2, wherein the loose material comprises a suitable mixture of light and heavy materials, in amounts varying between 0% and 100% by weight, said mixture being formed for instance by loam soil combined with aggregates and natural or artificial materials; the light materials comprising pumice and/or expanded clay and/or polystyrene, and the heavy materials including heavy volcanic aggregates, steel-plant slags, or the like.
Barrier according to claim 1 or 2, wherein the connection between contiguous modules made of steel sheets with reduced thickness, is performed by means of plates which are bolted at the upper end (15) of the modules themselves.
Barrier according to claim 12, wherein the connection between each module and an adjacent one, can further be made by means of bolts extending horizontally and connecting the two modules at their foot.
Barrier according to any of the preceding claims, wherein, if the deformable structure (3, 3'; 13, 13'; 23, 23') is made of plastics, this plastics will be non toxic during manufacturing, and/or can be obtained from recycling, and/or is treated so as to withstand UV rays and has the required structural resistance, said plastics being for instance superlinear polyethylene; said plastics having these features because of its combination with other materials or because of the fabrication process employing for instance rotational moulds, or pultrusion.