Classifications

• • E—FIXED CONSTRUCTIONS
  • E02—HYDRAULIC ENGINEERING; FOUNDATIONS; SOIL SHIFTING
  • E02D—FOUNDATIONS; EXCAVATIONS; EMBANKMENTS; UNDERGROUND OR UNDERWATER STRUCTURES
  • E02D29/00—Independent underground or underwater structures; Retaining walls
  • E02D29/02—Retaining or protecting walls
  • E02D29/0225—Retaining or protecting walls comprising retention means in the backfill
  • E02D29/0241—Retaining or protecting walls comprising retention means in the backfill the retention means being reinforced earth elements

Definitions

• the present invention relates to a clip-on connector to geogrid for segmental block reinforced soil retaining wall mechanical connection system.
• the invention relates to a clip-on connector that overcomes some of the outstanding problems in connecting dry laid segmental blocks to geogrids used for reinforced soil retaining structures, in particular achieving full pull out strength connection with the geogrids having high conjunction strength.
• the connector also provides for the ability to be used with blocks having a connection profile in one bed face only or shared between both top and bottom bed faces or with hollow blocks.
• Geogrids which have a high junction strength between the warp and weft elements of the grid are typically extruded HDPE or modified sheet HDPE materials. These are characterised by the large cross sectional differences between the thin strong tensile elements of the grid and the thicker junction areas of the grid. This type of grid needs careful attention to the connection with segmental blocks. The aim is to obtain a full strength connection between the two. That is to say the connection strength should be equal to the manufactured tensile strength of the geogrid usually taken over one metre width.
• each tensile element of the grid must be supported by or connected to the blocks. This assumes any frictional connection between the grid and blocks is ignored since this is unreliable and dependant on the pressure between the blocks.
• the grid has to be manually held in place on top of the blocks whilst further blocks are placed on top of the grid and means of connection.
• pins per block are used to connect the upper and lower blocks and theses pins are the sole method of mechanical connection between the grid and blocks and hence can not provide a full strength connection, any other connection being frictional.
• These pins are sometimes either a very good fit in the holes in the blocks or a very loose fit. In both cases they are disadvantageous because if they are a good fit, they restrict the freedom of the wall to take up uneven settlement and, when a bad fit, they do not provide a good location for the blocks or positive connection with the grid .
• the aim of the invention is to provide a connector that overcomes the drawbacks of the prior art, being able to be connected to a geogrid without the risk that the handling of the geogrid causes the connector to fall off the geogrid.
• an object of the present invention is to provide a connector that can be used with different blocks.
• Another object of the present invention is to provide a connector that is of easy manufacturing, highly reliable and at low cost.
• a clip-on connector adapted to be connected to a geogrid, characterized in that it comprises a base portion wherefrom at least one finger portion extends toward an opposite edge of the base portion, such finger portion defining, with the edge of the base portion, a clip, said clip having two arms respectively defined by said finger portion and by said base portion, the spacing between said two arms being smaller than the thickness of a portion of a geogrid whereon the connector has to be coupled, but such that said geogrid portion can be inserted between said two arms.
• Figure 1 is a plan bottom view of the clip-on connector according to the present invention
• Figure Ia is a perspective view of the connector according to the present invention
• Figure 2 is a side view of the clip-on connector
• Figure 3 is a plan top view of the clip-on connector;
• Figure 4 is a cross-sectional view along line IV-IV of figure 3;
• Figure 5 is a rear view of the clip-on connector
• Figure 6 is a front view of the clip-on connector
• Figure 7 is a perspective view of a geogrid to be used with the clip-on connector of the present invention
• Figure 8 illustrates the use of the clip-on connector of the invention
• Figure 9 illustrates a variation of the use of the clip-on connector of the invention.
• Figure 10 illustrates a further variation of the use of the clip-on connector of the invention
• Figure 11 illustrates a still further variation of the use of the clip-on connector of the invention
• Figures 12a-12d illustrate a particular type of block wherein the connector of the present invention can be used
• Figure 13 illustrates an overview of a wall made of blocks, with the interposition of geogrids and connectors according to the invention. Ways of carrying out of the invention
• the connector according to the present invention is a connector in the form of a clip.
• the connector comprises a base 3 from which at least one finger 4 develops towards an edge of the base and defines with such edge a clip with arms 5 and 6, the arm 6 being part of the base 3 and the arm 5 being part of the finger 4.
• the clip is adapted to passes over a thick transverse bar 7 of uni-axial HDPE/Polypropylene extruded or punched sheet geogrid 2 and provides fingers which occupy the ends of elliptical apertures 8 between high tensile ribs 9 which both extend at generally right angles between the transverse bars 7 of the geogrid 2.
• the radius in the throat of the connector clip centres the thick transverse bar 7 of the geogrid 2 on the finger part 4 of the connector under load.
• the cross section of the geogrid 2 varies with its tensile strength ans so the clip part of the connector has to accommodate this variation.
• the finger part 4 of the connector 1 is designed to provide a mechanical connection with the geogrid 2 against pullout forces trying to separate the geogrid 2 from blocks 10.
• the clip defined by the at least one finger portion and the edge of the base portion presents a spacing between the two arms that is smaller than the thickness of the portion of the geogrid whereon the connector has to be coupled, but such that said geogrid portion can be inserted between said two arms.
• the connector has to be coupled to the geogrid so that the geogrid comes to be inserted between the two arms of the connector.
• the connector 1 In applications where the connector 1 is in a housing 1 1 shared between top and bottom bed faces of the blocks 10 (figure 8), the connector also provides a shear key connection between these adjacent blocks 10 thus eliminating the need for any secondary block to block connection means.
• the connector 1 provides the pull out resistance for the geogrid 2 only and some other means have to be provided for the block to block shear connection. Since the pitch of the apertures 8 of the geogrid 2 can vary according to the manufacturer or strength or due to production tolerances, the clip-on connector 1 as a single piece would normally have a maximum of three fingers 4. However, different number of fingers could be provided.
• connector 1 Alternatively to make the connector 1 fully universal and to ease its application on site, single fingers connectors strung together in groups of perhaps 10 or 20 can be used.
• figure 11 shows single finger connectors strung together on two wires 15 that pass through holes 16 provided in the base 3 of the connectors.
• wires 15 can be made of plastic, pultrusions or stainless steel and in this case the fingers 4 are free to float since the individual connector fingers 4 are narrower than the pitch of the apertures 8 of the geogrid.
• Single finger connectors could also be used individually.
• One leg or arm of the clip part of the connector can be straight, for example the arm 6 that is part of the base 3. This allows the connector 1 to be housed in a matching block profile such that the shear forces applied to the connector 1 by the adjacent block 10 are transferred to that block 10.
• a further advantage of the present connector is that the path of the geogrid is undisturbed being in a straight line.
• the applications can be one or both of these or a combination of the two depending on the particular hollow block design.
• connection system is of benefit to the use with hollow blocks since they can be pitched along the geogrid 2.
• This clip- on feature of the blocks is of advantage generally on site since the connectors 1 can not be missed or dislodged once placed on the geogrid 2.
• the adjacent blocks 10 sit on the thin high tensile ribs 9 of the geogrid 2 across the full bed face of the blocks 10 so there is no tilting or rotation of the blocks 10 since the bed faces of the blocks 10 remain parallel.
• the connectors 1 can also be used with woven or knitted geogrids 2 usually made from polyester fibres coated in PVC. The strength of the pull out resistance of the connection will depend on the junction strength of the geogrids warp and weft fibres.
• Figures 12a-12d illustrate a solid segmental block 20 with the connection profile shared between the upper and lower bed faces of the blocks and also the rib topped block used in the system for courses where there is no geogrid requirement.
• Figure 13 shows a typical reinforced soil structure with the blocks and connectors shown in figures 12a-12d and 8.
• an injection moulded one or two or three finger clip is supplied which is inserted through the apertures of the geogrid and by its unique design clips over the thick transverse bar of the geogrid.
• the two are connected together and can only be separated by deliberate manual intervention.
• the connector can be accommodated inside recesses defined in the blocks between which the geogrid is placed.
• Another advantage of the connector of the invention over the prior art is that it can be used in blocks where a groove can be placed at the top of the block, only the bottom of the mating block being substantially flat. In this case a method of providing shear connection between the blocks must be arranged.
• the connector of the invention can be used with hollow blocks with a groove correctly placed in the top only.
• the present connector does not require a second groove in the top or bottom of the block to accommodate the thick transverse (warp ) bar of the grid since it is housed within the connector itself.
• the present clip-on connector can also act as an inter block shear connector by locating the top block to the bottom block.
• the present connector also keeps the grid in a horizontal plane so that the pull out forces are kept horizontal and hence the disturbing forces between the blocks are at a minimum.
• the connector is housed in grooves in the top and bottom of the blocks or in the top of the block only the thin tensile fingers of the grid can be carried forward to the front of the block as well as to the rear of the block so that the blocks remain parallel in both planes.

Landscapes

• Engineering & Computer Science (AREA)
• Civil Engineering (AREA)
• Structural Engineering (AREA)
• General Life Sciences & Earth Sciences (AREA)
• Mining & Mineral Resources (AREA)
• Paleontology (AREA)
• Environmental & Geological Engineering (AREA)
• General Engineering & Computer Science (AREA)
• Life Sciences & Earth Sciences (AREA)
• Clamps And Clips (AREA)
• Retaining Walls (AREA)
• Connection Of Plates (AREA)
• Housing For Livestock And Birds (AREA)
• Joining Of Building Structures In Genera (AREA)
• Bulkheads Adapted To Foundation Construction (AREA)

Priority Applications (8)

Applications Claiming Priority (2)

Publications (1)

Family

ID=36637192

Family Applications (1)

Country Status (12)

Cited By (1)

Families Citing this family (7)

Citations (3)

Family Cites Families (12)

• 2006
  • 2006-05-10 GB GBGB0609204.3A patent/GB0609204D0/en not_active Ceased
  • 2006-10-11 RU RU2006135860/03A patent/RU2353730C2/ru active
  • 2006-10-11 RU RU2006135861/22U patent/RU65515U1/ru not_active IP Right Cessation
• 2007
  • 2007-05-08 PL PL07724977T patent/PL2016229T3/pl unknown
  • 2007-05-08 EP EP07724977A patent/EP2016229B1/de active Active
  • 2007-05-08 WO PCT/EP2007/004053 patent/WO2007128566A1/en active Application Filing
  • 2007-05-08 AT AT07724977T patent/ATE505592T1/de not_active IP Right Cessation
  • 2007-05-08 US US12/300,030 patent/US20090142145A1/en not_active Abandoned
  • 2007-05-08 CN CN2007800167807A patent/CN101443519B/zh not_active Expired - Fee Related
  • 2007-05-08 ES ES07724977T patent/ES2365170T3/es active Active
  • 2007-05-08 MX MX2008014360A patent/MX2008014360A/es active IP Right Grant
  • 2007-05-08 CA CA002650620A patent/CA2650620A1/en not_active Abandoned
  • 2007-05-08 DE DE602007013888T patent/DE602007013888D1/de active Active

Patent Citations (3)

Also Published As

Similar Documents

Legal Events