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Title:
BOLLARD ASSEMBLY
Document Type and Number:
WIPO Patent Application WO/2020/082132
Kind Code:
A1
Abstract:
A bollard assembly (3) comprises a foundation (5) and a bollard post (7) extending upwardly from the foundation. The foundation and the bollard post are formed in the context of being contacted by a vehicle having a selected maximum design mass travelling at a speed up to a selected maximum speed for a nominated use of the bollard assembly. The foundation is configured to be immovable and to fix the bollard post to the ground, and the bollard post is configured to absorb all of the impact energy that is absorbed by the bollard assembly when contacted by a vehicle having a mass up to the selected mass travelling at a speed up to the selected maximum speed and thereby prevent the vehicle moving over the deformed bollard post into a protected space.

Inventors:
HOTCHKIN DARREN (AU)
Application Number:
PCT/AU2019/051170
Publication Date:
April 30, 2020
Filing Date:
October 24, 2019
Export Citation:
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Assignee:
SAFEROADS PTY LTD (AU)
International Classes:
E01F13/02; E01F9/631; E01F9/685; E01F15/00; E02D27/42
Domestic Patent References:
WO2015015218A12015-02-05
WO2012059766A12012-05-10
WO2011121324A12011-10-06
Foreign References:
US20090028638A12009-01-29
US20150016883A12015-01-15
GB2282623A1995-04-12
US20060133895A12006-06-22
Other References:
IQBAL, M.: "A Rational Method to Design Vehicular Barriers", STRUCTURE MAGAZINE, September 2010 (2010-09-01), pages 22 - 24, XP055711118, Retrieved from the Internet [retrieved on 20191205]
TRAN, P. ET AL.: "Design of a hybrid composite anti-ram bollard against impact", MECHANICS OF STRUCTURES AND MATERIALS: ADVANCEMENTS AND CHALLENGES - PROCEEDINGS OF THE 24TH AUSTRALASIAN CONFERENCE ON THE MECHANICS OF STRUCTURES AND MATERIALS, vol. 1, 6 December 2016 (2016-12-06), Perth, Australia, pages 599 - 604, Retrieved from the Internet [retrieved on 20161209]
MARSHALLS RHINOGUARD BOLLARDS CRASH TEST FOOTAGE, 1 April 2016 (2016-04-01), XP054980653, Retrieved from the Internet [retrieved on 20191209]
Attorney, Agent or Firm:
GRIFFITH HACK (AU)
Download PDF:
Claims:
CLAIMS

1. A bollard assembly comprises a foundation in the ground and a bollard post extending from the foundation, with the foundation being formed so that it does not move when a vehicle having a mass up to a selected maximum design mass relevant to a nominated use of the bollard assembly contacts the bollard post at a speed up to a selected maximum speed relevant to the nominated use of the bollard assembly, and with the bollard post being formed to deform in response to contact by the vehicle at a speed up to the selected speed and absorb all of the impact energy that is not absorbed by deformation of the vehicle on impact before the vehicle can move over the deformed bollard post into a protected space and thereby prevents the vehicle moving over the deformed bollard post into the protected space .

2. The bollard assembly defined in claim 1 wherein the protected space includes pedestrian areas such as

sidewalks, pedestrian crossings, and outdoor seating.

3. The bollard assembly defined in claim 1 or claim 2 wherein the bollard post is designed to deform by bending.

4. The bollard assembly defined in claim 3 wherein the bollard post is designed to deform by bending where the bollard post emerges from the foundation.

5. The bollard assembly defined in claim 1 or claim 2 wherein the bollard post is designed to deform by at least partially collapsing at the area of vehicle impact .

6. The bollard assembly defined in any one of the preceding claims wherein the bollard post is a hollow tube .

7. The bollard assembly defined in claim 6 wherein the hollow tube is a cylindrical tube that is made from steel plate that is folded into the tubular shape and welded or otherwise connected at adjoining side edges.

8. The bollard assembly defined in any one of the preceding claims wherein the foundation is a concrete foundation .

9. A bollard system that includes a line of a plurality of the bollard assembly defined in any one of the preceding claims spaced apart along the length of the line .

Description:
BOLLARD ASSEMBLY

FIELD OF INVENTION

The invention relates to a bollard assembly.

The invention relates particularly, although by no means exclusively, to a bollard assembly that can prevent a vehicle from penetrating a protected space, for example pedestrian areas .

BACKGROUND OF THE INVENTION

There are different types of bollard assemblies that are designed to meet a range of objectives, by way of example, to protect pedestrian areas such as sidewalks, pedestrian crossings, outdoor seating etc., from vehicle impacts .

One bollard type comprises bollard assemblies that have rigid bollard posts that are mounted in solid

foundations and form inflexible barriers to vehicles contacting the bollards . These bollard assemblies are constructed to cause vehicles rather than the bollard posts to collapse on contact with the bollards and thereby decelerate the vehicles via absorption of energy as the vehicles collapse, and in this way prevent vehicles passing beyond the bollard assemblies and penetrating a protected space. The primary objective of this type of bollard assembly is to prevent vehicle access to a

protected space. Minimising impact injuries to occupants of vehicles is a secondary objective.

Another type of bollard assembly comprises flexible bollard posts that bend and deform elastically from a vertical, i.e. upright, orientation when contacted by vehicles and absorb vehicle energy via deformation of the bollard posts. These flexible bollard posts return to their original orientation and shape after vehicle impact . The design of these bollard assemblies, by virtue of the flexibility of the bollard posts, is focussed on two considerations of minimising impact injuries to occupants of vehicles and preventing vehicles penetrating a

protected space .

Another type of bollard assembly is formed to

selectively collapse when contacted by vehicles, with the bollard posts and/or the foundations absorbing vehicle energy due to the collapse of the bollard assemblies . By way of example, the bollard posts may include crumple zones or other areas that can selectively collapse and absorb energy by this mechanism. Alternatively, the foundations may be designed to be collapsible and absorb impact energy in this way. These bollard assemblies balance two considerations of preventing access of vehicles to a protected space and minimising impact injuries to occupants of vehicles .

The applicant has realised that there is a need for an alternative bollard assembly to the bollard assemblies known to the applicant, with a particular although by no means exclusive focus as a defence against vehicle

terrorist attacks on members of the public at public events .

The above description is not to be taken as an admission of the common general knowledge in Australia and elsewhere.

SUMMARY OF THE INVENTION

In broad terms the invention provides a bollard assembly that comprises a foundation in the ground and a bollard post extending from the foundation, with the foundation being formed so that it does not move when a vehicle having a mass up to a selected maximum design mass relevant to a nominated use of the bollard assembly contacts the bollard post at a speed up to a selected maximum speed relevant to the nominated use of the bollard assembly, and with the bollard post being formed to deform in response to contact by the vehicle at a speed up to the selected maximum speed and absorb all of the impact energy that is not absorbed by deformation of the vehicle on impact before the vehicle can move over the deformed bollard post into a protected space and thereby prevents the vehicle moving over the deformed bollard post into the protected space .

In other words, the foundation of the bollard

assembly is immovable and fixes the bollard post to the ground and the bollard post absorbs all of the impact energy that is absorbed by the bollard assembly when contacted by a vehicle up the selected maximum design mass travelling at a speed up to the selected maximum speed for the nominated use of the bollard assembly and thereby prevents the vehicle moving over the deformed bollard post into a protected space .

Typically, the bollard assembly is formed so that there is above-ground deformation of the bollard post only, with no deformation of the post underground. With this arrangement, it is a straightforward exercise to remove a deformed post and insert a replacement post into the foundation.

The protected space may be any space, such as

pedestrian areas such as sidewalks, pedestrian crossings, and outdoor seating.

The selected maximum design mass may be any suitable mass that is relevant to the nominated use of the bollard assembly .

Similarly, the selected maximum speed may be any suitable speed that is relevant to the nominated use of the bollard assembly.

The invention is based on a recognition that the bollard assembly of the invention, with a deformable bollard post and a foundation that does not move on vehicle impact, typically with deformation of the post above-ground only, is a straightforward construction that is adapted to prevent vehicle penetration into a protected space across a range of different vehicle masses and different impact speeds.

More particularly, the invention is based on a recognition that designing a bollard post of a bollard assembly to deform to a predetermined extent, typically above-ground only, and to absorb a part of vehicle impact energy (with the remainder of the vehicle impact energy being absorbed by the vehicle, such as by selective collapse) and to remain as a physical barrier to the vehicle moving over the bollard post is an effective barrier solution for a protected space.

It is relevant to note here that the design process includes selecting the requirements for a bollard assembly - specifically, the maximum mass of vehicle and maximum speed of vehicle that the bollard assembly has to prevent from entering a protected space . The next step of the design process is to make selections of (a) the foundation to remain an immovable fixed foundation, which typically prevents deformation of the bollard post below ground, and (b) the bollard post to absorb the vehicle impact energy that is not absorbed by the vehicle so that all of the vehicle impact energy is absorbed and the vehicle is stopped before passing over the bollard post into a protected space .

One example of the use of the bollard assembly of the invention is where a Council or other authority decides that a bollard assembly should be able to prevent

penetration into a pedestrian area of vehicles having a mass up to a selected maximum mass travelling at a speed up to a selected maximum speed. In this situation, the bollard post of the bollard assembly of the invention can be designed, for example by selection of steel grade and/or steel plate gauge in the case of a hollow bollard post made from steel plate, to absorb all of the impact energy that is not absorbed by the vehicle on impact, for example by selective crumpling of vehicle panels,

typically with no deformation of the bollard post below ground, before the vehicle can move over the deformed bollard post into the pedestrian area.

In addition, the bollard post can be designed

differently, for example by different selections of steel grade and/or steel plate gauge, or by forming the bollard post as a solid post, if the Council or other authority selects a different maximum vehicle mass and/or a

different maximum impact speed.

The invention was made by the applicant as part of a series of tests to understand the performance of different types of bollard assemblies, including:

(a) rigid bollard assemblies with rigid bollard posts mounted in solid foundations that form inflexible barriers; and

(b) energy absorbing bollards that have rigid bollard posts that are mounted in selectively

collapsible sections of foundations, with the selectively collapsible sections absorbing impact energy .

In one of the series of tests, discussed further below, the applicant found surprisingly that a bollard assembly that the applicant expected would function as a rigid bollard assembly and not deform, in fact, functioned as an energy absorbing bollard, with the bollard post deforming in a controlled way by bending where the bollard post emerged from the foundation and absorbed impact energy, with no deformation of the bollard post

underground, while the foundation remained in its

original position and did not move in response to vehicle impact. Moreover, the impact did not lead to the bollard post being bent to a point where the vehicle moved over the post. In other words, the bollard post continued to act as a physical barrier to the vehicle moving beyond the bollard post .

Analysis of this test result lead the applicant to conclude that selective deformation of a bollard post above ground that still retains the physical barrier function of the bollard post, in combination with an immovable foundation, is a viable bollard assembly.

In practice, the invention can be implemented by:

(a) considering the impact requirements for a bollard assembly, i.e. the maximum vehicle mass and vehicle speed that the bollard assembly will have to prevent moving over the barrier assembly from an impact side to a protected area side of the bollard assembly;

(b) selecting the requirements for the bollard post and the foundation in the context of the bollard post deforming above ground, typically with no deformation underground, and the foundation remaining fixed when impacted under the impact requirements in (a) above across a range of vehicles, noting that the configurations of vehicles, i.e. the shape, size and structure, will have a bearing on impact behaviour for vehicles of the same mass .

There is a number of factors that are relevant to bollard post selection - the extent of deformation

required, solid post, hollow post, material for the outer shell of the post, post diameter, post length, etc. There is a number of factors that are relevant to foundation selection, such as materials and size. There are other factors such as how the post is embedded or otherwise secured in the foundation. Nevertheless, once (a) and (b) are determined, the factors can be considered, and

selections made for the bollard post and the foundation.

The bollard post may be designed to deform by

bending, for example where the bollard post emerges from the foundation.

The bollard post may be designed to deform by at least partially collapsing at the area of vehicle impact .

The bollard post may be made a hollow tube, such as a cylindrical tube, that is made from steel plate, such as high carbon steel plate or low alloy steel plate, that is folded into the tubular shape and welded or otherwise connected at adjoining side edges. In this instance, the design options include steel grade, plate gauge, and tube profile .

The bollard post is not confined to hollow tubular posts made from steel plate as described in the preceding paragraph and extends to hollow posts made from any suitable materials and to solid posts, such as posts having an outer shell and concrete of other material filling the interior volume.

The foundation may be any suitable foundation.

By way of example, the foundation may be a concrete foundation .

The concrete may be any suitable mixture of

aggregate, sand, and cement.

The concrete foundation may include a cage of a reinforcement mesh .

The bollard post may be located in the foundation in any suitable way.

By way of example, the foundation may be formed with a shaft extending from an upper surface of the foundation that can receive a lower section of the bollard post .

The bollard post may simply sit in the shaft and be retained by virtue of the mass of the bollard post . With this arrangement, if the bollard assembly is impacted by a vehicle, and the foundation remains intact in accordance with the invention, the deformed post can be lifted clear of the foundation and a replacement bollard post inserted into the shaft .

The bollard post may be retained in the passage by means of a retaining element .

The invention also provides a bollard system that includes a line of a plurality of the above described bollard assemblies .

The spacing between adjacent bollard assemblies in the line may be any suitable spacing. DESCRIPTION OF FIGURES

The invention is described further by way of example only with reference to the drawings, of which:

Figure 1 is a perspective view of one, although not the only, embodiment of a bollard assembly in accordance with the invention,

Figure 2 is a series of photographs taken before a crash test on an embodiment of a bollard assembly in accordance with the invention;

Figure 3 is a series of photographs taken after the crash test on the bollard assembly; and

Figure 4 is a photograph of the bollard post of the bollard assembly after the crash test on the bollard assembly.

DETAILED DESCRIPTION

Figure 1 illustrates one of many possible embodiments of a bollard assembly 3 in accordance with the invention.

The bollard assembly 3 is suitable for use as one of a plurality of bollard assemblies that define a boundary of a protected space (not shown) , such as an outdoor seating area, and includes:

(a) a foundation 5 in the ground; and

(b) a bollard post 7 extending from the foundation. The foundation 5 is a block of concrete or any other suitable material that is formed so that it does not move when a vehicle of a mass up to a selected maximum mass contacts the bollard post at a speed up to a selected maximum speed.

The foundation is formed with a shaft (not shown) extending from an upper surface of the foundation that receives a lower section of the bollard post 7. The bollard post 7 simply sits in the shaft and is retained by virtue of the mass of the bollard post 7. With this arrangement, if the bollard assembly is impacted by a vehicle, and the foundation remains intact in accordance with the invention, the deformed bollard post 7 can be lifted clear of the foundation and a replacement bollard post 7 inserted into the shaft .

The bollard post 7 is formed to deform in response to vehicle contact by the vehicle at a speed up to the selected maximum speed and to absorb the impact energy that is not absorbed by deformation of the vehicle before the vehicle can move over the deformed bollard post into a protected space. Typically, the bollard post 7 is formed so that the deformation is above ground only and there is no deformation below ground.

The maximum mass and the maximum speed may be

selected as required.

Typically, the maximum mass may be 2270kg.

Typically, the maximum speed may be 60km/hr.

With further reference to Figure 1, the bollard post 7 is a hollow 1400 mm cylindrical tube having an external diameter of 168 mm that is made from 20.2 mm thick high carbon steel plate that is folded into the cylindrical shape and welded at adjoining side edges.

The bollard post 7 is designed to deform by bending, for example where the bollard post 7 emerges from the foundation 5.

The invention is not limited to this form of

deformation .

Another example, although not the only other example, is that the bollard post 7 is designed to deform by at least partially collapsing, such as by crumpling, at the area of vehicle impact .

As mentioned above, the invention was made when the applicant considered the surprising results of one of a series of vehicle impact tests carried out by the

applicant. The test is described below. INTRODUCTION - VEHICLE IMPACT TEST

A vehicle impact test was conducted at the Pakenham Factory of the applicant to assess impact response of an Omni Stop Ultra Security Bollard post of the applicant mounted in a concrete foundation with a 1600 ± 50kg vehicle travelling at 60km/h directly impacting the bollard post .

The bollard post was encased in a 125 x 125 x 125 mm block of concrete having a 800 mm high cylindrical cage of reinforcement mesh embedded in the concrete block, with the mesh made for 10 mm wire wrapped around 12 mm line wires .

The test was conducted with reference to AS/NZS

3845.2:2017 Section 8, part 8.3, test designation 1- 100.

The test was conducted with a test mass of 1600kg and 60km/h as defined by the applicant. A 1600C vehicle was chosen instead of standard 1,100C or 2,270P vehicles so the bollard post performance could be compared against other similar bollard posts tested in Australia.

The test was assessed in accordance with

Manual for Assessing Safety Hardware (MASH) 2 nd edition Clause 5.2.

TEST EQUIPMENT

• Accelerometers serial Nos. A063946 and A063944 -

Endevco (Registered TM) model 7264B.

• 1 Phantom high speed digital camera - HS Camera

Phantom Flex Serial No 11811 Resolution 1920x1080

1000 frames per second, frame exposure 200 micro seconds .

TEST OBJECT

An Omni Stop Ultra Security Bollard post of the applicant mounted in a concrete foundation. Basically, this bollard post is a bollard post of the type shown in Figure 1. TEST METHOD

A Ford Falcon was towed by a human-operated vehicle to a desired test velocity of 60km/h.

The vehicle was maintained in alignment with the bollard assembly when towed by means of a guide cable and was released by a cable release mechanism attached to its front right wheel prior to impact .

The bollard assembly was impacted at the centreline of the test vehicle.

Accelerometers (as described above) were placed at the centre of gravity and the B pillar of the test

vehicle .

Occupant Impact Velocity (OIV) was calculated using the COG pulse.

The observations and test results are detailed below.

Table 1: Test Conditions in accordanceto AS/NZS 3845.2:2817 Section 8.3

Table 2: Vehicle Mass

Figures 2 and 3 are photographs pre- and post- the crash test, respectively.

Figure 4 is a photograph of the bollard post post- the crash test .

Figures 3 and 4 are particularly instructive because they show the deformation of the bollard post with the foundation remaining intact .

SUMMARY OF RESULTS

The bollard post of the bollard assembly deformed by bending at the section of the post that emerged from the foundation and absorbed impact energy as a consequence of the deformation. The foundation did not move on impact. Significantly, the impact was not sufficient to deform the bollard post to a point where the vehicle was able to move over the post .

CONCLUSION BASED ON THE ABOVE TEST RESULTS

The bollard assembly performed well as an energy absorbing bollard assembly.

In particular, Figures 3 and 4 show that the impact energy of the vehicle was not sufficient to cause the bollard post 7 to deform to a point where the vehicle moved over the bollard post 7.

As a consequence, under the conditions of the tested vehicle mass and tested vehicle impact speed and vehicle configuration (size, shape and structure) , the bollard assembly prevented the vehicle from penetrating a notional protected space beyond the bollard post .

The positive test results evident from the above test results have been confirmed in other test results.

One such other test result is described below.

INTRODUCTION - ANOTHER VEHICLE IMPACT TEST A vehicle impact test was conducted at the Pakenham

Factory of the applicant to test whether an Omni Stop Ultra Security Bollard post mounted in a concrete

foundation could contain a 1600kg vehicle travelling at 50km/h when directly impacted by the vehicle. The test was designed to simulate an impact on a road side bollard struck by a medium-sized vehicle.

TEST EQUIPMENT

• Omni Stop Ultra Security Bollard post mounted in a concrete foundation of the applicant - as described above .

• Accelerometers serial Nos. B32158 and B27590 - as described above.

• 1 Phantom high speed digital camera - as described above . TEST METHOD

The test was conducted with respect to AS/NZS

3845.2:2017 (and MASH, Manual for Assessing Safety

Hardware, equivalent) . Test 1-100 with 1,600kg for 50kph +/-2kph impact .

The test speed was 50kph and the angle of vehicle to barrier was 0°. The test results were evaluated in accordance with the criteria set out in Table 5.1A of MASH with relevant sections B, C, D, F, H, and I.

As noted above, the vehicle weight was 1,600kg.

A 1600kg vehicle was chosen instead of the standard

1,100C or 2,270P vehicles so the bollards performance could be compared against other similar bollards tested in Australia . TEST RESULTS

The performance of the bollard assembly - Omni Stop Ultra Security Bollard post mounted in a concrete

foundation - was evaluated, (using CofG accelerometer) , against the criteria specified in Table 8.1 of

AS3845.2 : 2017. Table 8.1 refers to Table 5.1A and 5. IB of

MASH 2016, Criteria B, C, D, F, H, I.

Two main criteria are required from the dynamic part of this test, OIV (Occupant Impact Velocity) , and

ride down Acceleration post OIV.

In the OIV it is assumed that the occupant's head continues to travel at 50kph relative to the ground whilst the vehicle is decelerated. This means that the OIV displacement of 600mm is the combined displacement of occupant and vehicle, (see page 161 of Appendix A of the MASH standard), resulting in an elapsed time of 107.7ms from vehicle impact on bollard until theoretical impact of occupant's head on interior of vehicle. The ride down acceleration was averaged from +/-5ms from 107.7ms,

(highest 10ms average acceleration - Appendix A, page 161 of MASH standard.

The bollard assembly captured and contained the vehicle with following detailed results .

Table 5.1A -

B: Bollard yielded predictably. PASS

C: Controlled stopping of the vehicle was achieved.

PASS

Table 5. IB —

D: No fragmentation occurred. PASS

F: Pitch and roll were below 75deg. PASS

H: Occupant impact velocity, OIV, was 13.26m/s at 107ms into impact. Maximum permitted is 12.2m/s. FAIL

I : The occupant ride down acceleration of the highest 10ms period average between 107ms and 118ms was 5.126 - Maximum permitted is 20.496. PASS

AS3845.2 Clause 8.4(c)

The structural element of the vehicle penetrated 440mm past the bollard centre line during impact measured at the vehicle bumper height (refer Fig.4) with

consideration for movement of the bollard during impact .

OBSERVATIONS AND CONCLUSIONS IN RELATION TO THE ABOVE TEST

The Omni Stop Ultra Security Bollard assembly passed the ride down acceleration criterion, (max 20.496), although the impact velocity figure was not achieved. It only marginally failed to meet this criterion - 13.26m/s actual against maximum permitted of 12.2m/s.

Current vehicle build technology, comprising driver and passenger airbags, knee bags, pre-tensioner seatbelts and stroking steering columns means that injury sustained in such collisions would be dramatically reduced from what would have been seen when the standard was written. From the crash pulse in this test, the 6 force experienced by the vehicle was comparable to what is seen in a typical ADR69 full width frontal test from the same speed (50kph) .

However, the duration of the deceleration was longer with the bollard, which would reduce injury sustained by occupants .

In summary, the bollard assembly performed well as an energy absorbing bollard assembly.

Based on the above test results, in practice, the invention can be implemented by:

(a) considering the impact requirements for a bollard assembly, i.e. the maximum vehicle mass and vehicle speed that the bollard assembly will have to prevent moving over the barrier assembly from an impact side to a protected area side of the bollard assembly;

(b) selecting the requirements for the bollard post and the foundation in the context of the bollard post deforming above ground, typically with no deformation underground, and the foundation remaining fixed when impacted under the impact requirements in (a) above across a range of vehicles, noting that the configurations of vehicles, i.e. the shape, size and structure, will have a bearing on impact behaviour for vehicles of the same mass .

There is a number of factors that are relevant to bollard post selection - the extent of deformation

required, solid post, hollow post, material for the outer shell of the post, post diameter, post length, etc. There is a number of factors that are relevant to foundation selection, such as materials and size. There are other factors such as how the post is embedded or otherwise secured in the foundation. Nevertheless, once (a) and (b) are determined, the factors can be considered, and

selections made for the bollard post and the foundation. Many modifications may be made to the embodiment of the invention shown in the drawings without departing from the spirit and scope of the invention.

By way of example, the invention is not confined to the Omni Stop Ultra Security Bollard post of the applicant described above. The bollard post may be any suitable post . Another specific example of a bollard post is the Omni Super Duty Bollard post of the applicant that has a 152 mm diameter and a 20.5 mm wall thickness.

Throughout this specification the word "comprise", or variations such as "comprises" or "comprising", will be understood to imply the inclusion of a stated element, integer or step, or group of elements, integers or steps, but not the exclusion of any other element, integer or step, or group of elements, integers or steps.