AU2008229738A1

AU2008229738A1 - Yielding element

Info

Publication number: AU2008229738A1
Application number: AU2008229738A
Authority: AU
Inventors: Rudi Podjadtke
Original assignee: Bochumer Eisenhuette Heintzmann GmbH and Co KG
Current assignee: Bochumer Eisenhuette Heintzmann GmbH and Co KG
Priority date: 2007-09-27
Filing date: 2008-09-26
Publication date: 2009-04-23
Anticipated expiration: 2028-09-26
Also published as: ATE435965T1; AU2008229738B2; EP2042686B1; EP2042686A1; DE502007001042D1

Abstract

The element (8) has two supporting sheets (9, 10) and tubular bodies (16) arranged at a distance from each other, where the tubular bodies are provided between the supporting sheets. The supporting sheets fixable at gutter profiles (3) or at a lattice girder are provided with reinforcements (13) fastened to a concrete shell (6). Hollow sections (17) are inserted into the tubular bodies. The hollow sections comprise a split tube pressed into the tubular body in a form-fit manner. The hollow sections have a peripheral side closed tube provided in the tubular body by a fastening element.

Description

AUSTRALIA Patents Act COMPLETE SPECIFICATION (ORIGINAL) Class Int. Class Application Number: Lodged: Complete Specification Lodged: Accepted: Published: Priority Related Art: Name of Applicant: Bochumer Eisenhutte Heintzmann GmbH & Co. KG Actual Inventor(s): Rudi Podjadtke Address for Service and Correspondence: PHILLIPS ORMONDE & FITZPATRICK Patent and Trade Mark Attorneys 367 Collins Street Melbourne 3000 AUSTRALIA Invention Title: YIELDING ELEMENT Our Ref: 836595 POF Code: 1579/488930 The following statement is a full description of this invention, including the best method of performing it known to applicant(s): 000-q 2 Yielding element This application claims priority from European patent application No. EP 07 019 019.4 filed on 27 September 2007, the contents of which are to be taken 5 as incorporated herein by this reference. The invention concerns a yielding element to integrate in an underground compound support. 10 A reference herein to a patent document or other matter which is given as prior art is not to be taken as an admission that that document or matter was, in Australia, known or that the information it contains was part of the common general knowledge as at the priority date of any of the claims. 15 A yielding element is disclosed in EP 1 762 698 Al. It is used for the construction of long underground spaces, like for example spans and tunnels. The yielding element is so constructed that it can be compressed under the influence of the rock pressure. It has a honeycomb structure and has intermediate layers and spacer elements which form voids. The voids are 20 offset relative one another and are reduced when compressed. A development of the yielding element of EP 1 762 698 Al is disclosed from the scope of the pamphlet "Compression element" of the Bochumer Eisenhatte Heintzmann GmbH & Co. KG. This compression element comprises at least 25 two support plates provided at a distance from one another and a plurality of spaced tubular bodies provided between the support plates. Such a compression element is predominantly used between two arch supports from yielding channel sections or lattice girders. Furthermore, it may be provided behind such arch supports towards the rock shell. Each of the top and bottom 30 support plate have fastening elements, which serve the purpose of assembling the arch support. Moreover, the support plates have reinforcements engaging the concrete shell. W.Vule\AxnmwCompetes83595.doc 3 The channel sections or lattice girders are embedded by means of concrete cast in-situ or air-placed in a concrete shell circumferentially introduced into the tunnel or span. 5 It can be appreciated during the construction phase of a tunnel or a span as to what magnitude of force will act from the rock on the compound construction. In particular what sort of force will act on the yielding element. Consequently, a yielding element is predominantly used in fault zones or rock formations under pressure. The number of yielding elements to be integrated in each compound 10 support depends on the local conditions. Documents WO 99/28162 and DE 42 21 656 Al disclose further yielding elements. 15 It would be desirable to provide a yielding element to be integrated in an underground compound support that has an increased capacity to resist the force from the rock formation. According to the present invention there is provided a yielding element to 20 integrate in an underground compound support, the yielding element comprising channel sections lattice girders and a concrete shell, the yielding element having at least two support plates provided at a distance from one another and a plurality of tubular bodies provided at a distance from one another between the support plates, the support plates being fastenable to the 25 channel sections or to the lattice girders, the support plates being provided with reinforcements engaging the concrete shell, wherein at least one hollow section is inserted into at least one of the plurality of tubular bodies. Accordingly, at least one hollow section is inserted into at least one tubular 30 body of a yielding element. Whether in this connection a hollow section is inserted into each tubular body or hollow sections are provided only in selected tubular bodies or whether more than one hollow section is inserted into a tubular body, depends on the local conditions. In this connection it is WuMe\AMeAComp1etes\B36595.doc 4 conceivable that the expert inserts the hollow sections into the tubular bodies directly on the spot according to the requirements. If the local conditions are prior known, the yielding elements can be already prepared at the manufacturing plant and can be suitably prepared with hollow sections in the 5 tubular bodies. To secure the position of a hollow section in a tubular body the hollow section can be appropriately positionally fixed. In this manner it retains its intended position until the compound support is totally completed. 10 The hollow section can be a slotted tube that is compressed in the tubular body in a frictionally and form-locking manner. The hollow section may also consist of a circumferentially closed tube with a 15 preferably circular cross-section that is clamped in the tubular body by means of fastening elements. However, other cross-sections of a hollow section are also conceivable. The fastening elements may consist of wires fixed in the hollow section. For 20 example, in each hollow section two wires, for example welding rods, lying opposite one another and touching in spots are provided with bent legs and with their ends protruding past the faces, while the legs lying at the front of the insertion device are bent at approx. 1600, so that during the insertion of a hollow section into a tubular body they are compressed and slide on the 25 internal wall of the tubular body. The legs situated at the rear of the insertion device are bent at approx. 90". When these legs contact the rear face of the tubular body, the legs situated at the front of the insertion device are free of the face of the tubular body and can spring back, so that the hollow section is positionally fixed by the legs in the longitudinal direction of the tubular body. 30 In a further embodiment, the fastening elements consist of spring steel strips that can be inserted between the tubular body and the hollow section. When inserting a hollow section into a tubular body in this case also two spring steel Wje\ArewACAmplees836595.doc 5 strips are bent in two layers preferably in an arrangement whereby they oppose one another and are inserted into the gap between the hollow section and the tubular body. When inserting the hollow section into the tubular body the spring steel strips slide in the tubular body and finally, due to their inherent 5 expansion force, they will brace the hollow section in the tubular body. In a particularly advantageous embodiment of the invention, between the support plates at least two layers with tubular bodies and hollow sections inserted therein are provided, while between each two layers a separating 10 plate is provided. As to how many layers of tubular bodies and separating plates are required depends on the prevailing local conditions. Conceivable are, for example, three or four layers. The number of the tubular bodies with hollow sections in the individual layers can also vary from one place of application to another one. 15 According to a further embodiment of the invention, the tubular bodies and/or the hollow sections in one layer have wall thicknesses and/or diameters that are different from those of the tubular bodies and/or hollow sections in another layer. Thus it is, for example, conceivable that in the case of a yielding element 20 with three layers the top layer does not have any hollow section in the tubular bodies, however, the middle and bottom layers have hollow sections in the tubular bodies, whereas the wall thicknesses of the hollow sections in the bottom layer are greater than those of the hollow sections in the tubular bodies of the middle layer. Within the scope of the invention the wall thickness can be 25 varied with various diameters of the hollow section. Moreover, the diameters of the tubular bodies and their wall thicknesses can be varied in combination with the diameters and/or wall thicknesses of the hollow profiles. The number of the hollow sections in the tubular bodies can also vary from one place of application to another one. 30 Consequently, within the measures according to the invention a controlled yielding behaviour can be achieved, while the supporting capacity of a yielding element can be exactly coordinated with the adjacent channel sections or W:UueAndreMCompletes3595.doC 6 lattice girders. When, therefore, in an arch support comprising channel sections the channel sections commence to slide relative one another or the lattice girders of a construction commence to buckle, the yielding element also commences to deform and absorb loads. 5 The invention is explained in the following in detail based on the embodiments illustrated in the drawings. they show in: Fig. 1 - a view on a section of a compound support with channel sections in a 10 tunnel, Fig. 2 - a view on a section of a compound support with lattice girders in a tunnel, 15 Fig. 3 - a front view of a yielding element for a compound support according to Figs.1 and 2, Fig. 4 - a view on the face of the yielding element of Fig.3, 20 Fig. 5 - a view on the face of a tubular body, Fig. 6 - a view on the face of a hollow section for the tubular body of Fig.5, Fig. 7 - a view on the face of the tubular body of Fig.5 with an inserted hollow 25 section according to Fig.6, Fig. 8 - a vertical longitudinal section during the assembly of a hollow section in a tubular body, 30 Fig. 9 - a hollow section completely inserted into a tubular body, Fig.10 - a vertical longitudinal section during the assembly of a hollow section and of a tubular body according to a further embodiment, and w:uuewnarevcompletestsaosas.doc 7 Fig. 11 - a vertical longitudinal section of a hollow section completely inserted into a tubular body. 5 The reference numeral 1 in Fig.1 designates a compound support for a tunnel. The illustration shows the compound support 1 viewed from the longitudinal axis of the tunnel in the direction of the rock. The compound support 1 comprises an arch support 2 from channel sections 3 positioned end-to-end into one another, said channel sections being so braced together in the 10 overlap regions 4 with clamping means 5 (not illustrated in detail) that in the case of a correspondingly high rock pressure the channel sections 3 can slide relative one another. The compound support 1 further comprises a concrete shell applied to the rock 15 by means of concrete cast in-situ or air-placed, into which the channel sections 3 are embedded. In a hollowed out region 7 of the concrete shell 6 apart from the channel sections 3 there are yielding elements 8. As it can be seen from Figs.3 and 4 20 in this connection, each yielding element 8 has a bottom support plate 9 and a top support plate 10. To the underside 12 of a bottom support plate 9 and the upper side 11 of the top support plate 10 reinforcing elements 13 are welded in the form of wires bent to a U-shape, which, as it can be seen from Fig.1, protrude into the concrete shell 6. 25 The support plates 9, 10 are joined with the channel sections 3 in a manner not illustrated in detail. At the height between the two support plates 9, 10 there are two separating 30 plates 14, 15. Between the support plates 9, 10 and the separating plates 14, 15 tubular bodies 16, having a circular cross-sections, are welded. Consequently three layers L, Li and L2 are constructed with the tubular bodies 16. In the embodiment shown all tubular bodies 16 have the same diameter D Wilute\AnrwiCompletes\836595.doc 8 and the same wall thickness WD. It is, however, conceivable to vary the diameter D and/or the wall thickness WD of the tubular bodies 16 from layer L, Li to layer L1, L2. 5 In the bottom layer L and in the middle layer LI of the hollow bodies 16 circular hollow sections 17 with a relatively smaller diameter D1 are inserted. In addition, it can be recognised that the hollow sections 17 in the bottom layer L have a wall thickness WD1 that is greater than the wall thickness WD2 of the hollow section 17 in the middle layer LI. 10 The yielding element 8, explained on the basis of Figs.3 and 4, is used also in the case of the compound support 1a of Fig.2. This differs from the compound support 1 of Fig.1 merely by that instead of the channel section 3 lattice girders 18 are used as arch support 2a. Consequently a further description of Fig.2 is 15 omitted. To fix the position of a hollow section 17 in a tubular body 16, according to Figs.6 and 7 the hollow section 17a can be a slotted tube. As this can be seen in Fig.6, the slotted hollow section 17a is so expanded, that for the purpose of 20 insertion into the tubular body 16 according to Fig.7, it has to be compressed. In the compressed state it can then be inserted into the tubular body 16 according to Fig.7, so that, corresponding to the illustration of Fig.7, under the tension it will abut against the internal wall 19 of the tubular body 16 and subsequently it is braced trouble-free in the tubular body 16. 25 In the case of the embodiment of Figs.8 and 9 for the positional fixing of a circumferentially closed hollow section 17 in a tubular body 16 spring wires 20 are used. In this case two spring wires 20 are attached in an arrangement opposing one another touching in spots the inside surface 21 of a hollow 30 section 17. The ends 22 of the spring wires 20 lying at the front of the inserting device ER of the hollow section 17 protrude past the face 23 of the hollow section 17 and according to Fig.9 are bent to form a V-shape. The ends 24 of W.lue\And reComplete\36595.doc 9 the spring wires 20 lying at the rear of the insertion device ER of the hollow section 17 are bent outward at approx. 90*. As it can be seen from Fig.8, when the hollow section 17 is inserted into the 5 tubular body 16, the ends 22 of the spring wires 20 lying in front of the inserting device ER are compressed to form a U-shape, while the end sections 30 of the ends 22 slide on the internal wall 19 of the hollow body 16. When the free end sections 30 of the spring wires 20 reach the face 25 of the tubular body 16, they can spread outwards, so that according to Fig.9 they will abut 10 against the face 25. The rear ends 24 of the spring wires 20 abut against that face 26 of the tubular body 16 which is at the rear of the insertion device ER. The hollow section 17 is now positionally fixed in the longitudinal direction of the tubular body 16 with the aid of the bent ends 22, 24. 15 However, to fix a circumferentially closed hollow section 17 in a tubular body 16 according to Figs.10 and 11 spring steel strips 27 can be used. These spring steel strips 27, lying opposite one another, are first bent to form two layers and during the introduction of a hollow section 17 into a tubular body 16 are co-inserted into the gap 28 between the hollow section 17 and the tubular 20 body 16. When, according to Fig.11, the hollow section 17 reaches its final position in the tubular body 16, due to their inherent tension the spring steel strips 27 will brace the hollow section 17 in the tubular body 16. Prior to the insertion of the hollow section 17 into the tubular body 16 the spring steel strips 27 can be fixed touching in spots on the outside surface 29 of the hollow 25 section 17. Throughout the description of this specification the word "comprise" and variations of that word, such as "comprises" and "comprising", are not intended to exclude other additives or components or integers. 30 W:\ju e\AndrewiCopletes\836595.doc 10 List of reference numerals 1 - Compound support 1a - Compound support 2 - Arch support 2a - Arch support 3 - Channel section 4 - Overlap region 5 - Clamping means 6 - Concrete shell 7 - Free region of 6 8 - Yielding elements 9 - Bottom support plate 10 - Top support plate 11 - Upper side of 9 12 - Underside of 10 13 - Reinforcements 14 - Lower separating plate 15 - Upper separating plate 16 - Tubular body 17 - Hollow section 17a - Hollow section 18 - Lattice girder 19 - Internal wall of 16 20 - Spring wires 21 - Inside surface of 17 22 - Ends of 20 23 - Face of 1729 24 - Ends of 20 25 - Face of16 26 - Face of16 27 - Spring steel strips 28 - Gap between 16 and 17 W:\Jue\AndrewACompees\836595.doc 11 29 - Outside surface of 17 30 - Free end sections of 22 D - Diameter of 16 D1 -Diameter of 17 ER - Inserting device of 17 L -Bottom layer LI - Middle layer L2 -Top layer WD - Wall thickness of 16 WD1 - Wall thickness of 17 in L WD2 - Wall thickness of 17 in Li W:UudewrdrewACompletes\836595.doc

Claims

1. A yielding element to integrate in an underground compound support, the yielding element comprising channel sections or lattice girders and a 5 concrete shell, the yielding element having at least two support plates provided at a distance from one another and a plurality of tubular bodies provided at a distance from one another between the support plates, the support plates being fastenable to the channel sections or to the lattice girders, the support plates being provided with reinforcements engaging the 10 concrete shell, wherein at least one hollow section is inserted into at least one of the plurality of tubular bodies.

2. A yielding element according to claim 1, wherein the at least one hollow section is positionally fixed in the at least one tubular body. 15

3. A yielding element according to claim 1 or 2, wherein the at least one hollow section is a slotted tube that is compressed in the at least one tubular body in a frictionally and form-locking manner. 20

4. A yielding element according to claim 1 or 2, wherein the at least one hollow section consists of a circumferentially closed tube that is clamped in the at least one tubular body by means of fastening elements.

5. A yielding element according to claim 4, wherein the fastening elements 25 consist of wires fixed in the at least one hollow section.

6. A yielding element according to claim 4, wherein the fastening elements consist of spring steel strips inserted between the at least one tubular body and the at least one hollow section. 30

7. A yielding element according to any one of claims 1 to 6, wherein at least two layers with tubular bodies and hollow sections inserted therein are W:\uie\AndrewACompletes\838595.doc 13 provided between the support plates, a separating plate being is provided between the at least two layers.

8. A yielding element according to claim 7, wherein the tubular bodies and/or 5 the hollow sections in one layer have wall thicknesses and/or diameters that are different from wall thicknesses of the tubular bodies and/or hollow sections in another layer.

9. A yielding element according to any one of the embodiments substantially 10 as herein described with reference to the accompanying drawings. W:uL ie\Ande Completes\30595.doc