The present invention relates to an assembly of a pivoting ground anchor and a tension member.

US 2008/0282625 Al discloses in general a pivoting ground anchor, also referred to as earth anchor.

EP 863 262 relates to an anchor drive system in general.

Summary of the invention

The invention aims to provide an improved ground anchor assembly which is less prone to corrosion.

To this purpose the invention provides an assembly of a pivoting ground anchor and a tension member, the anchor comprising;

- a first coupling member for temporary coupling the anchor with a driving rod to drive the anchor to the considerable depth; and,

- a second coupling member which fixedly couples the anchor to the tension member such that the anchor pivots when the tension member is taken in, wherein the tension member is suitable for coupling the anchor to the object to be anchored, and comprises fibre reinforced material.

Tension members per se made of fibre reinforces plastic are well known and marketed by for example "Pultron Composites" or "FiReP". These tension members are often referred to as "FRP bars" or "GRP bars". Another example of a tension member comprising a fibre reinforced plastic can be a basalt fibre composite reinforcing bar or rod. For example, RockBar as marketed by MagmaTech, UK.

This type of tension member can be coupled with the ground with a grout system or something similar that hardens or sets. This grout system based coupling of the tension member with the ground essentially differs with that of a ground anchor which requires a pretensioning phase to build up a cone of ground above the ground anchor. The tension member is in particular made of fibre reinforced material, more particular fibre reinforced plastic.

In an embodiment, the tension member is a hollow or solid bar.

In an embodiment of the assembly according to the invention, the tension member is coupled with the second coupling member by a treaded connection. The FRP or basalt fiber reinforcing composite bar is provided with an outside thread for engaging the hardened grout, which couples with a female thread provided in the second coupling member which female thread is configured to mate with the outside thread of the FRP or basalt fiber reinforcing composite bar.

In an embodiment of the assembly according to the invention, the threaded connection is configured such that the coupled tension member has a play of about 1 mm to several millimeters along the thread axis. This provides an equal load and/or load distribution on all the windings of the threaded connection.

In an embodiment of the assembly, the second coupling member comprises a second coupling member body having a body recess provided with a female thread wherein a threaded end of the tension member is accommodated with a loose fit. The diameter D of the body recess may exceed 15 mm.

In an embodiment of the assembly, wherein the second coupling member body overlaps with the tension member along its longitudinal axis at least with an overlap Lo of at least 50 mm, preferably at least 60.

In an embodiment of the assembly, the ratio of the overlap Lo and the diameter D of the body recess exceeds 1, preferably 1,5.

The invention further relates to the use of a tension member, made of fibre reinforced plastic, in a pivoting ground anchor assembly. The invention further relates to a device comprising one or more of the characterising features described in the description and/or shown in the attached drawings.

The invention further relates to a method comprising one or more of the characterising features described in the description and/or shown in the attached drawings.

The various aspects discussed in this patent can be combined in order to provide additional advantageous advantages.

Description of the drawings

The invention will be further elucidated referring to an preferred embodiment shown in the drawing wherein shown in:

Fig. 1 in side view an assembly according to the invention; and

Fig 2 a detail view of fig. 1.

Detailed description of embodiments

The invention will be further described in detail referring to an preferred embodiment shown in the figures 1 - 2. In the figure 1 an assembly 15 of a tension member 3 and an anchor 1 is shown. The shown tension member 3 is known per se and is made of fibre reinforced plastic (FRP). Another example of tension member can be a basalt fibre composite reinforcing bar or rod, e.g. RockBar as marketed by

MagmaTech, UK. The tension member 3 is coupled with the second coupling member 4, specifically the second coupling member body 6, by a treaded connection 18.

Therefore, the tension member is 3 is provided with an outside thread 16 for engaging hardened grout. The shape of the thread 16 is uncommon for a threaded connection 18. The outside thread 16 couples with a female thread 17 provided in the second coupling member body 6 which female thread 17 is configured to mate with the outside thread 16 of the tension member 3 to constitute the threaded connection 18. The threaded connection 18 is configured such that the coupled tension member 3 has a play of about 1 mm to several millimeters along the thread axis 19. Therefore the second coupling member body 6 has a body recess 7 provided with a female thread 17 wherein a threaded end of the tension member 3 is accommodated with a loose fit. This loose fit facilitates screwing of the tension member 3 into the body recess 7 over a considerable overlap Lo. The second coupling member body 6 overlaps with the tension member 3 along its longitudinal axis with an overlap Lo of at least 50 mm.

Here, the diameter D of the body recess 7 is about 15 mm, however other diameters are conceivable. The pitch p of the threaded connection 18 is about 10 mm. The ratio of the overlap Lo and the diameter D of the body recess 7 exceeds 1, preferably 1,5.

The anchor 1 is shown in its set position wherein the longitudinal axis 12 of the anchor 1 is substantially transverse with respect to the longitudinal axis 8 of the tension member 3.

The anchor 1 comprises a first coupling member 2 for temporary coupling the anchor with an elongate driving member, like a rod, to drive the anchor to a desired depth. The first coupling member 2 comprises a first coupling member cavity 11 for accommodating an end of the elongate driving member. The first coupling member cavity 11 is here defined by a cavity wall 16. The first coupling member cavity 11 extends along the longitudinal axis 12 of the anchor 1. The first coupling member cavity 11 and the end of the elongate driving member have a loose fit for temporarily coupling the driving device with the anchor 1 and release the end of the elongate driving member from the first coupling member cavity 11 once the desired depth for the anchor 1 has been reached.

It will also be obvious after the above description and drawings are included to illustrate some embodiments of the invention, and not to limit the scope of protection. Starting from this disclosure, many more embodiments will be evident to a skilled person which are within the scope of protection and the essence of this invention and which are obvious combinations of prior art techniques and the disclosure of this patent.