EP2298999A2

EP2298999A2 - Crash barrier anchoring and method for anchoring of crash barriers

Info

Publication number: EP2298999A2
Application number: EP10175730A
Authority: EP
Inventors: Lars-Åke Gisslin
Original assignee: Birstaverken AB
Current assignee: Birstaverken AB
Priority date: 2009-09-08
Filing date: 2010-09-08
Publication date: 2011-03-23
Also published as: EP2298999A3; SE534052C2; SE0950642A1

Abstract

The invention relates to a barrier anchoring of the kind being used for anchoring of an end of a crash barrier (9) to allow transmitting of collision forces to the ground. The barrier anchoring comprises an anchoring unit (1), which comprises a bottom side, which is adapted to be facing the ground, a draw attachment in one end for connecting the crash barrier to the anchoring unit and at least one anchoring hole through the anchoring unit which is perpendicular in relation to the bottom side. Furthermore, the barrier anchoring comprises at least one anchoring tube (2), which in one end and along the main part of its longitudinal extension has a cross sectional dimension that is somewhat smaller than the cross sectional dimension of the anchoring hole, while it in an opposite end has an enlarged cross sectional portion (8) which prevents passage through the anchoring hole. The invention also relates to a method for anchoring of an end of a crash barrier to allow transmitting of collision forces to the ground.

Description

The present invention relates to a crash barrier anchoring of the kind being used for anchoring of en end of a crash barrier to allow transmitting of collision forces to the ground.
The invention also relates to a method for anchoring of a crash barrier into the ground.

Background of the invention

Roads and streets of today are provided with a number of road barriers or crash barriers of different kinds. It may for example concern crash barriers for separating different lanes, for separating motor traffic from pedestrians and cyclists or crash barriers for preventing driving off from the road downward slopes or other level differences. Furthermore, the crash barriers can be designed in many different ways, e.g. as wire barriers, barriers of profiled sheet metal or tube formed barriers having circular or rectangular cross section.
A common feature for all types of crash barriers is that they have to be anchored to the ground in one way or the other to be able to take up the collision forces that they are adapted to be designed for. Earlier, it was common that the ground anchoring for crash barriers consisted mainly solely by the posts that supported the barriers which were dug or driven into the ground. However, in recent years it has become more common that the entire or at least a great deal of the ground anchoring is carried out such that each end of a barrier is anchored into the ground and the barrier functions like a tightened cable that is fixated in both ends and absorbs the collision force.
Such end anchoring has earlier normally been carried out by means of concrete foundations which are excavated into the roadway and into which tie rods or barrier ends have been anchored. However, such anchoring of the barrier ends causes certain disadvantages. For example, excavating of the concrete foundations results in that the roadway is ruined by the excavation, which results in costs for repairing. Moreover, the excavation into the ground results in a disintegration of the ground material such that the anchoring force of the concrete foundation will be lower than it would have been in an intact ground. Furthermore, this method is time-consuming and causes unnecessary long disturbance for the traffic in the cases a barrier shall be mounted at an existing road.

Summary of the invention

One object of the present invention is to eliminate problems and disadvantages with prior art anchoring for crash barrier ends. More precisely, the object of the invention is to provide a crash barrier anchoring, which can be more readily and easily mounted and which can be manufactured and mounted to a reduced overall cost. This object is achieved with a crash barrier anchoring according to claim 1.
The invention also relates to a crash barrier and a method for anchoring of crash barriers which present essentially the same object as above. At least this object is achieved with a crash barrier according to claim 5 and a method according to claim 6.
The basis of the invention is the insight that the above object may be achieved by an anchoring unit, which comprises a bottom side, which is adapted to be facing the ground at the anchoring location and in which is arranged at least one anchoring through hole through which an anchoring tube can be forced or driven down into the ground by means of some suitable device. One end of the anchoring tube and the main part of its longitudinal extension have a cross sectional dimension that is somewhat smaller than the cross sectional dimension of the anchoring hole such that the tube can be inserted into the hole. The opposite end of the tube, on the other hand, comprises an enlarged cross sectional portion, which accordingly will function as a head on the anchoring tube which prevents the anchoring tube from being entirely passed through the anchoring hole and ensures that the anchoring unit is held depressed towards the ground. Moreover, the anchoring unit comprises a draw attachment to which an end of the barrier is attachable.
This overall inventive idea can be modified and varied in many different ways within the scope of the following claims.
In accordance with the invention, tubes are utilized to anchor the crash barrier to the ground. Tubes are advantageous in that they have a high strength and a large area in relation to their material content and their weight. In the following exemplary embodiment, the tube has a circular cross section. However, also tubes having other cross sectional forms, for example square, could be conceivable. The enlarged cross sectional portion in the one end of the anchoring tube, which functions as a head, has the form of a flange which is extended along parts of the periphery of the tube. However, it should be understood that the enlarged cross sectional portion also could have many other embodiments and all embodiments which can prevent the tube from completely passing through the anchoring hole are possible.
In accordance with the invention it is intended that the anchoring tube is driven or forced down into the ground. The term "drive down" is to be extensively interpreted and comprises all methods where the tube is driven down without preceding drilling or digging, as with help of a large weight or by striking by means of a drop hammer or pile driver. There are principally two ways of forcing down the anchoring tube. On the one hand by forcing it down when a filling body is positioned in the tube, i.e. a body that essentially completely fills the inner bore of the tube. This method is used at difficult ground conditions, with e.g. a lot of stones, and the filling body will protect the tube from deformation during driving it down. After driving the tube down, the filling body is drawn up from the tube and the inner bore of the tube will thereby be empty and free from ground material but can be subsequently filled with e.g. soil or concrete. However, when forcing the anchoring tube down without any filling body in the tube, which can be performed when the ground conditions so permits, the ground material will be pressed into the anchoring tube and contributes thereby to the anchoring of the tube.
Also the anchoring unit can be formed in many different ways. In the illustrated and described embodiment, the anchoring unit has the form of a box having decreasing height in the direction from the crash barrier and the anchoring holes are arranged in the bottom of the box. In this way the enlarged cross sectional portions of the anchoring tubes can be hidden inside the box, which is provided with a cover when the anchoring has been performed. In the illustrated embodiment the anchoring unit is provided with two anchoring holes. However, it should be understood that anchoring units having different size and different numbers of anchoring holes can be provided in dependency of the anchoring forces that is desired to be achieved.
In the illustrated embodiment a crash barrier having a barrier beam with essentially a rectangular cross section is anchored. Accordingly, the anchoring unit is provided with a draw attachment which fits to this type of crash barrier. However, it should be understood that the design of the draw attachment can be adapted to many other types of crash barriers, such as crash barriers of profiled sheet metal or wire barriers. Furthermore, it should be understood that the barrier anchoring do not absolutely have to be located at an end of the barrier. Instead it would be conceivable that, with very long crash barriers, arrange barrier anchoring also at other locations along the longitudinal extension by making branchings or joints along the crash barrier.

Brief description of the drawings

An exemplary embodiment of the invention will be described hereinafter with reference to the drawings, in which:

Fig 1: is a perspective view of an anchoring unit and two anchoring tubes according to the invention;
Fig 2: illustrates a perspective view of an anchoring unit, according to fig 1, connected to a crash barrier and with the anchoring tubes partly inserted through the anchoring holes;
Fig 3: is a cut through side view of an anchoring according to the in- vention of an end of a crash barrier; and
Fig 4: is a schematic side view of a hammering device during hammer- ing down of an anchoring tube through an anchoring unit.

Detailed description of an embodiment of the invention

First, reference is made to fig 1, in which is illustrated an example of a crash barrier anchoring according to the invention comprising an anchoring unit 1 and two anchoring tubes 2. The anchoring unit is in the illustrated embodiment formed as an elongated box, which has two side portions 3, a bottom in form of two separated bottom plates 4 and a detachable cover 5. In one of its short sides the anchoring unit is provided with a draw attachment 6, which can be adapted for attachment to a crash barrier of some arbitrary type. In the illustrated embodiment the draw attachment has the form of a rectangular collar, which is adapted to be inserted into and be connected to a rectangular barrier beam of a crash barrier. In the same end as the draw attachment, the anchoring unit has its largest height but it decreases continuously towards the opposite end such that the anchoring unit will have an essentially pointed form.
The illustrated anchoring tubes 2 have circular cross sectional shape and may in a practical embodiment have e.g. a length of between 1-2 m and a diameter of between 15-20 cm. When anchoring of a crash barrier the anchoring tubes are intended to be inserted through anchoring holes 7 arranged in the bottom plates 4 of the anchoring unit and for this purpose, the one end of the anchoring tube and the main part of its longitudinal extension has a cross sectional diameter which is somewhat smaller than the diameter of the anchoring holes. However, in the upper end of the anchoring tubes these are provided with an enlarged cross sectional portion, in form of two flange portions 8, which will serve as a head which prevents that the anchoring tube can be completely passed through any of the anchoring holes 7.
Thereafter reference is made to fig 2 and 3, in which is illustrated the connection of a barrier anchoring according to the invention to a crash barrier. In the illustrated embodiment the barrier has the form of a barrier beam 9 having a rectangular cross section which is mounted on a distance above the ground on barrier posts 10, which are adapted to be partly buried into the ground. From the last barrier post a bent and downwards inclined terminating part 11 of the barrier beam is extended whose outer end is connected to the draw attachment of the anchoring unit, suitably by means of a not shown bolt connection. The anchoring unit 1 is in its turn adapted to be located with a bottom side facing the ground and the anchoring tubes 2 driven through the anchoring holes and down into the ground, i.e. normally down into the roadway. When the crash barrier is connected to the anchoring unit and it is anchored into the ground by driving down the anchoring tubes, as is illustrated in fig 3, a cover 5 is positioned over the anchoring unit. In this way the upper portions 8 of the respective anchoring tube, having the enlarged cross sectional portions, will be hidden inside the box shaped anchoring unit and the end of the crash barrier obtains in addition a smooth transition section having gradually decreasing height over the roadway which is of benefit from the point of traffic safety.
In fig 4 is illustrated a possible method for driving the anchoring tubes 2 through the anchoring holes 7 in the anchoring unit 1 and down into the ground. This can for example be performed by means of a schematically illustrated hammering device 12, which optionally can be supported on for example a truck, a loading machine or an excavator through a supporting arm 13. The hammering device comprises a supporting column 14, which is adapted to be supported against the ground with its lower end during the driving down and which supports a hammering assembly 15, which is displaceable upwards and downwards along the supporting column. A downward facing hammering mandrel 16 is supported in the lower part of the hammering assembly and can by means of a not shown hydraulic hammering mechanism be brought to hammer downwards with a large force. The lower part of the hammering mandrel 16 constitutes of a filling body 17 having a circular cross section which is insertable into the inner bore of the anchoring tube 2, while a hammering collar 18, which is provided immediately above the filling body, has a diameter that is larger than the anchoring tube such that it during operation of the hammering mechanism, will hammer against the upper end surface of the tube and drive the tube downwards into the ground, as is illustrated in the figure.
A huge advantage with the inventive method for anchoring of barrier ends is that no careful measurements of the anchoring have to be performed in advance. Instead, a downward inclined terminating part 11 of a barrier beam is mounted after the last barrier post, an anchoring unit 1 is connected to the outer end of the terminating barrier part and subsequently a sufficient number of anchoring tubes 2 are driven down through the anchoring holes of the anchoring unit and down into the ground until the enlarged cross sectional portions 8 of the anchoring tubes bears against the bottom parts of the anchoring unit. Furthermore, the barrier anchoring can easily be adapted to the anchoring force that is required by providing an anchoring unit which has the number of anchoring holes that is required for the design load.

Claims

A barrier anchoring of the kind being used for anchoring of an end of a crash barrier to allow transmitting of collision forces to the ground, characterized in that it comprises an anchoring unit (1), which comprises a bottom side, which is adapted to be facing the ground at the anchoring location, a draw attachment (6) in one end for connetion of the crash barrier (9) to the anchoring unit, and at least one anchoring hole (7) through the anchoring unit which extends perpendicular to the bottom side, as well as at least one anchoring tube (2), which in one end and along the main part of its longitudinal extension has a cross sectional dimension that is somewhat smaller than the cross sectional dimension of the anchoring hole, while it in an opposite end has an enlarged cross sectional portion (8) which prevents passage through the anchoring hole.
A barrier anchoring according to claim 1, characterized in that the anchoring unit (1) has a longitudinal shape and decreasing height from one end, in which the draw attachment (6) is provided, to an opposite end.
A barrier anchoring according to claim 1 or 2, characterized in that the anchoring unit (1) is box shaped having a bottom (4), side walls (3) and a detachable cover (5), wherein the enlarged cross sectional portion (8) of the anchoring tube (2), after driving down of the tube, is accomodated and hidden inside the inner space of the box.
A barrier anchoring according to any of the preceding claims, characterized in that it comprises at least two anchoring tubes (2) and two anchoring holes (7) in the anchoring unit (1) through which the anchoring tubes, respectively, are insertable.
Crash barrier which in at least one end is provided with a barrier anchoring according to any of the preceding claims.
Method for anchoring of one end of a crash barrier to allow transmitting of collision forces to the ground, comprising the steps of:
providing an anchoring unit (1), which comprises a bottom side, a draw attachment (6) in one end for connection of the crash barrier (9) to the anchoring unit, as well as at least one anchoring hole (7) through the anchoring unit, which is extended perpendicular to the bottom side;

positioning the anchoring unit with its bottom side facing the ground at the anchoring location;

providing an anchoring tube (2), which in one end and along the main part of its longitudinal extension has a cross sectional dimension that is somewhat smaller than the cross sectional dimension of the anchoring hole, while in an opposite end it has an enlarged cross sectional portion (8), which prevents passage through the anchoring hole;

driving the anchoring tube, without preceding excavating or drilling, through the anchoring hole down into the ground as far such only the enlarged cross sectional portion is located above the anchoring hole; and

connecting the crash barrier to the draw attachment of the anchoring unit.
Method according to claim 6, comprising the further step of:
driving the anchoring tube (2) downwards by means of a hammering device.
Method according to claim 6 or 7, comprising the further step of :
driving the anchoring tube (2) downwards without any filling body in the anchoring tube such that after the driving into the ground the bore of the anchoring tube is filled with ground material.
Method according to claim 6 or 7, comprising the further step of :
driving the anchoring tube (2) downwards with a filling body (17) in the bore of the anchoring tube such that after the driving down there are no ground material in the bore of the anchoring tube.