The invention relates to a tubbing lining according to the features in the preamble of claim 1.
The technical foundation for constructing modern subsurface structures is frequently based on insights gained from mining. In addition to the penetration of mountains with tunnel structures known from practical applications in regions with a demanding topology, there is an increased need especially in densely populated regions to construct infrastructure projects below the built-up surface. A sometimes feasible open construction method is frequently accompanied by serious interference with the above-ground use during the construction phase, so that the closed underground excavation is here also preferred. All these approaches require the obtained hollow space to be lined with at least one static load-bearing interior lining. In addition to the safe absorption of loading from the layers of earth above, in particular dynamic stress and convergence characteristics, for example caused by settling of the surrounding soil and rock, place high demands on the inner shell to be constructed for tunnels and shafts.
As already known since the mid-19th century, tubular annular segments successively arranged in the longitudinal direction, which are sometimes composed from individual segments, for example individual tubbing segments, can be used for the supporting inner shell. The required components can then advantageously be prefabricated with a reliable process and with high dimensional stability and introduced with a continuous excavation speed. The individual segments may be fabricated, for example, from cast iron or from concrete, where in the cast iron variant is also used as a lost shell for subsequent lining with concrete at the construction site. The single-shell construction method is typically preferred which simultaneously satisfies visual and static demands, while simultaneously providing a seal against hydraulic pressure.
Modern tubbing segments are nowadays used in form of prefabricated concrete segments as fixed support structure following closed shield driving. To obtain a closed static load-bearing tubbing construction, the individual tubbing sections are assembled inside the bored tube to a continuous tubbing ring. To obtain a static and water-impermeable total effect, the internally closed tubbing rings are then coupled with one another.
This produces a predetermined rigid circumference of the inner shell which does not permit adaption to deformations and other convergences of the rock formation. However, such movements begin mostly after the tunnel tube is driven in, causing compression of the rock formation surrounding the tube. This process may run at different speeds and may have a duration of several months. This noticeably increases loading of the supporting elements, which is already statically measured ahead of time and necessitates correspondingly larger dimensions of the individual components. Making the tubbing construction more economical requires this additional loading of the individual tubbing rings to be prevented by changing their respective cross-section for redistributing the surrounding forces.
EP 1 762 698 A1 discloses a flexible element for elongated subsurface spaces. In this embodiment, the flexible element is integrated between two mutually separated concrete shells arranged in the circumferential direction of the tunnel tube. The applied forces are distributed into circumferential ring forces and transferred to the flexible element, which yields under the pressure applied by the rock through compression. This embodiment has a substantially honeycomb-like structure with cavities which are reduced in size during the compression. This element satisfies its intended flexible behavior quite well.
EP 2 042 686 B1 describes an improvement of the flexible element known from EP 1 762 698 A1. This flexible element can be changed even after installation between the concrete shells by creating an increased resistance through reinforcement of the existing cavities by inserting of additional cavities. This allows in practice a better adaptation to local conditions.
The aforedescribed solutions are particularly suited for in-situ use with subsurface compound linings composed of channel profiles or lattice supports in combination with an in-situ concrete shell. The flexible element is hereby employed between two flexible in-situ concrete shells and cast in concrete into the concrete shells on both sides through a connecting reinforcement. Although the use in tubbing construction is mentioned, no practically application can be inferred, because the conventional tubbing segments are moved to the installation site as prefabricated elements, which makes subsequent integration in the hardened concrete body impossible. Moreover, tubbing segments are used in practical applications in a time-sequential method, where an in-situ incorporation of a flexible element between two tubbing segments facing each other in the circumferential direction would lead to inaccuracies, thus preventing loadbearing connections between the tubbing segments impossible. In addition, the flexible element does not have a compact structure that could be seamlessly integrated in the production of modern tubbing segments.
EP 0 631 034 B1 also discloses a controllably compressible compression bearing for tubbing segments in a tubbing ring from an elastically deformable material. This compression bearing is arranged in the butt joint between two tubbing segments that are successively combined to a tubbing ring with their end faces in a circumferential direction. The structure of the flexible element visually resembles the conventional structure of a horizontal coring brick and is predominantly composed of mutually parallel lands which intersect and thus form a plurality of continuous rectangular cavities. The cavities extend in the installed state between the opposite end faces of the tubbing segments. The elastic yleldability is controlled by filling the cavities with a plastically deformable fill mass, wherein the individual cavities may be connected with each other by passageways, thus allowing excess fill mass displaced by the compression to drain. The tubbing segments and compression bearing are connected with an adhesive. The actual pressure inside the compression bearing can be read out by integrating a pressure gauge and, if needed, reduced by draining the fill mass.
In practice, elastic materials experience aging, which may result in undesirable properties during the entire service life of the tubbing structure. The use of pressure-controlled fill masses at each of the compression bearings arranged inside the entire elongated structure requires substantial maintenance work. A decrease in the elastic properties may cause unnoticed perforation of the individual lands forming the hollow chambers, for example towards the outside of the tubbing ring which cannot be visually inspected. This would allow unimpeded draining of the fill material, which could cause an uncontrolled change in the entire geometry of the tubbing lining. However, the use of elastic materials carries certain risks even without the use of the fill material, because displacement of the elastic components under a compressive load is difficult to control. For example, “sliding” of two tubbing segments parallel to the butt joint in the lower ring half of the tubbing ring due to shear loads may endanger the ring static in the upper ring half, because the circumferential connection between the tubbing segments and the elastic compression bearings is solely based on an adhesive joint.
Based on the state-of-the-art, it is therefore the object of the invention to provide a tubbing lining as a tubular inner shell of a tunnel or shaft, which allows controlled and limited permanent load-bearing deformability in the circumferential direction, wherein the novel aspects can be seamlessly integrated in the prefabrication and the rapid installation of modern tubbing segments.
The object is attained according to the invention with a tubbing lining having the features of claim 1.
Advantageous embodiments are recited in the dependent claims 2 to 12.
The invention provides a tubbing lining as a tubular inner shell of a tunnel or shaft having tube segments successively arranged in the longitudinal direction. The tube segments are each formed from a tubbing ring and are sealed against each other at their annular end faces at an annular joint. Each individual tubbing ring hereby includes tubbing segments which are consecutively arranged in the circumferential direction with their respective end faces, with a respective butt joint being formed between each two of the end faces. A deformable flexible element is arranged in at least one butt joint between two tubbing segments. According to the invention, at least one of the tubbing segments together with the flexible element forms a combined prefabricated element which is formed of a reinforcement framework made of steel and encased in concrete, with which the flexible element is connected by force-locking. The outer cross-sectional contour of the flexible element parallel to the butt joint hereby matches the outer contours of the end faces, whereby the flexible element completely covers at least one of the tube end faces of the tubbing segments.
The particular advantage is the force-locked connection of the flexible element with the reinforcement of one of the tubbing segments due to static and/or structural requirements, which produces a basic form which can easily processed further and which can be integrated directly into the concrete shape of the prefabricated tubbing segment. Although the flexible element may be constructed from different materials, for example plastic, it is advantageously constructed from a fireproof, aging-resistant material, for example metal. In addition to various alloys, these may also have a surface protection, such as zinc.
Together with the identical contour shapes of the flexible element in combination with one of the tubbing segments, an individual compact prefabricated element is thus provided which can be moved directly to the installation site and integrated. For example, two tubbing segments, each having half a flexible element, may thus be successively arranged in the circumferential direction of the tubbing ring, such that the two flexible elements abut each other at the butt joint and are thus combined into a single composite flexible element. The two flexible elements may be coupled together, for example, by welding, clamping or via releasable connecting means, or a combination thereof.
According to a preferred embodiment of the invention, the flexible element forms substantially a box profile with continuous hollow chambers arranged perpendicular to the circumferential direction of the tubbing ring. This box shape produces a compact and easily integratable structure which forms an almost internally closed unit. The simple shape allows a simple integration of the flexible element in the tubbing lining, filling the space of the butt joint. In particular, the force-lock to adjacent tubbing ring minimizes the complexity of a watertight structure. The continuous hollow chambers “sacrifice” themselves during the plastic deformation of the flexible element caused by the pressure from the rock through a reduction of their volume in one direction due to controlled compression. The subsequent flexible characteristic can thus be designed ahead of time based on the size and the number of the hollow chambers. In addition to the possible course of the hollow chambers perpendicular to the circumferential direction in relation to the longitudinal direction of the tunnel, the hollow chambers are advantageously oriented radially, so that they can be viewed from the inside of the tubbing lining. This allows not only a rapid visual evaluation of the deformation, but advantageously also a later introduction of, for example, elastically or plastically deformable materials and components into the hollow chambers, as well as their reinforcement by filling with concrete to produce properties similar to those of the tubbing segments.
According to one possible variant of the design of the flexible element, the hollow chambers are formed by two lands running in parallel, with each land extending between two opposing longitudinal walls extending parallel to the end faces as well as between corresponding transverse walls extending in a common plane with the annular surfaces. The individual lands hereby cross each other at right angles, forming a lattice structure. Advantageously increases the resistance at the beginning of pressure loading, because the individual lands are initially loaded in their longitudinal direction, causing them to “buckle” to produce plastic deformation.
According to another modified embodiment of the invention which incorporates the aforedescribed lattice structure, the longitudinal walls of the flexible element have an inwardly-facing curvature parallel to the longitudinal axis of the tubbing ring. The longitudinal walls make here full-area contact with the abutting end faces of the tubbing segment having matching shapes. Because the longitudinal walls of the tubbing sections extend biconcave with respect to one another and their end faces have a matching plano-convex shape, only one side of the flexible element has a fixed connection with one of the end faces of the tubbing segment, whereas the opposite side only makes shape-adapted contact with the end face of the other tubbing segment. This produces an articulated effect between the adjacent tubbing segments in the circumferential direction, allowing an angular adjustment with respect to each other. Notwithstanding the deformation-free mobility, which occurs for example with an uneven change in the cross-section of the tubbing lining, the position of the two tubbing segments with respect to each other is clearly defined, enabling shear forces to be reliably transmitted between the semi-circularly shaped longitudinal walls as well as the end faces. This effect is particularly advantageous also for transferring shear forces when both end faces of the tubbing segments are connected with the interposed flexible element.
Referring to the biconcave embodiment of the longitudinal walls, in another advantageous embodiment the two longitudinal walls of the flexible element are each formed of a side panel embodied as a hollow profile having a cross-section shaped as a segment of an arc. Each arc of the circle of the segment of an arc is located in the corresponding shape-adapted end faces of the tubbing sections. The respective plano-convex shape of the longitudinal walls then also produces the aforedescribed advantages of an articulation with a one-sided connection of the flexible element with one of the tubbing segments, as well as an improved transfer of the shear forces. The embodiment of the longitudinal walls as a hollow profile also simplifies the manufacture of the lattice structure produced internally from lands, because each of the employed hollow profiles has on the side facing the arc of the circle a straight surface extending parallel to the lands, between which the transverse lands extend and are terminated in a straight fashion.
According to the invention, the flexible element in one variant to the lattice structure has two opposing planar opposing longitudinal walls extending parallel to the two end faces of the tubbing segments, and that the interposed hollow chambers are formed from individual tubular bodies. The tubular bodies are each arranged in a row parallel to the longitudinal walls and make contact with each other along the circumference. At least one intermediate land, at which the individual tubular bodies are secured in the respective orientation, is disposed between two adjacent rows. At the beginning, the ground cross-sectional shape of the tubular bodies slightly reduces the resistance with respect to the lattice structure, because the outside surfaces of the tubular bodies are directly subjected to bending stress. In general, the tubular bodies in a row may also have a mutual distance between their respective outside surfaces commensurate with the radius, so that the yieldability of the tubular cross-section up to its planar deformation takes place without contact. By successively arranging the tubular bodies, the outside surfaces support each other, so that the respective deformation must take place towards the inside of the tubular cross-section, which increases the resistance. To adapt to specific requirements, the resistance of the flexible element may be deliberately “adjusted” via the thickness of the wall as well as the diameter, spacing and the number of tubular bodies and the number of rows of tubular bodies. The hollow spaces inside and between the tubular bodies can here also be filled similar to the lattice structure.
Advantageously, considering a subsurface lining cooperating as a total system, an adjusting element may advantageously be arranged in the butt joint between the end faces of the tubbing segments, allowing a distance between the end faces to be changed with the adjusting element. Even if the adjusting element may be arranged outside the butt joint disposed between the adjacent butt joints, for example in the tubbing segments or generally next to the annular plane and is coupled with the tubbing segments by way of a suitable connection, the arrangement according to the invention with the adjusting element disposed in the circumferential plane of the individual ring sections is preferred. This produces a compact closed system which advantageously can statically transfer the existing ring forces. In addition, the interior volume of the tubbing lining can be optimally used by integrating of the adjusting element inside the tubbing rings.
Alternatively, the flexible element is a compressible part of the aforementioned adjusting element or is combined with the adjusting element inside the individual tubbing rings. Through the combination within a component, the scope of the prefabrication is enhanced and a uniform production process is enabled.
According to a preferred embodiment of the tubbing lining, by varying the tubbing rings along the circumference, the tubbing rings may be connected with each other via a coupling unit to provide three-dimensional flexibility. The coupling unit is hereby a releasable connection. The tubbing rings can then “breathe” differently through respective relative changes in the circumference of the tubbing rings without significant stress, because adjacent tubbing rings can thus assume different diameters, without being hindered by a rigid connection with the adjacent tubbing rings. Overall, the individual segments are hereby securely and exactly positioned relative to each other, simultaneously providing considerable freedom for three-dimensional movement.
According to a preferred embodiment, a leak-tight contact between the flexible element and an adjacent tubbing ring in the longitudinal direction of the tubbing lining or with a differently shaped tube segment inside the annular joint can be produced with a flexible element having a corresponding recess for a seal oriented toward the annular surfaces of the tubbing ring. This recess extends along the sides of the flexible element between the two end faces of the tubbing segments and forms in cross-section a substantially semi-circular area. This embodiment can generally also be used with the adjusting element. In addition to the attained sealing action, in particular the shape of the recess ensures secure and accurate positioning of a rope seal inside the annular joint which is also maintained during possible movements of the tubbing rings with respect to each other coplanar with the annular surfaces. The end faces of the tubbing segments themselves have corresponding seals, with the end faces then sealing directly against each other or against components disposed in the butt joint. The employed adjusting element and the flexible element can be combined directly with seals overlapping with the respective element from the outside circumference. In other embodiments, the elements may already represent an integral seal.
Advantageously, a seal which extends continuously around the annular surface may be incorporated in the annular joint between the tubbing rings and additional tube sections in combination with the recess on the flexible element. The closed shape form by an O-ring securely seals the annular surfaces against each other to prevent a possible intrusion of surrounding water. In addition to potentially present groundwater, this approach should basically also to be included in all structures below the water surface. Even when the seal is composed of individual sections and is able to provide an effective seal, a one-piece circular solid rubber seal is advantageously used. The force caused by the pressure inside the annular joint due to coupling of the tubbing rings with each other is sufficient to attain the required degree of sealing. By forming a continuous annular groove inside the annular surfaces, in analogy to the recess of the flexible element and of the adjusting element, the respective movements of the tubular sections relative to one another are safely absorbed by deformations and highly accurate positioning of the seal.
According to another embodiment of the invention, in particular under extreme conditions, the seal may be formed of a solid material or of a radially flexible hose that can be filled with different media. Introduction of a medium into the interior of the hose causes an elastic change in the cross-section of the hose seal, which produces its sealing effect even when no pressing force or only a small pressing force is present inside the annular joint, by generating the necessary pressing force on its own through a volume increase. The seal can also be filled and compressed later through a valve reachable from the inside of the tubbing lining, which creates a connection to the interior of the seal in form of a stub. In addition to gaseous media, for example also permanently elastic or hardenable materials may be introduced into the seal. Advantageously, the hose seal is hereby provided with a second stub allowing a medium residing inside the seal and displaced during subsequent pressing to be discharged.
The tubbing lining according to the invention thus meets the stringent demands of a modern single-shell interior lining which can be flexibly handled. In addition to providing a coupling between two adjacent rings segments which yields in three dimensions, the coupling unit or components thereof can be easily accessed and exchanged at a later date. In combination with an adjusting element or a flexible element or with a combination of the two, the three-dimensionally yielding coupling allows different “breathing” in form of changes in the circumference of the individual ring segments without introducing significant stress. The adjacent rings segments can thus assume different diameters without being hindered by a rigid connection with adjacent rings segments. Overall, the individual segments are hereby securely and exactly positioned with respect to one another, while simultaneously allowing movement in three dimensions.
By designing each one of the ring segments to actively adapt its circumference to the particular situations, the resulting simplified handling and the significantly expanded design space adds value in practical applications. Overall, installation is simplified and often accelerated, because each individual coupling unit of the ring segments can be easily accessed and the otherwise rigid shape of the inner shell can be readily adapted. With the combination with passive flexible elements and three-dimensionally yielding coupling units, a person of skill in the art now has at his disposal an efficient modular system that can be adapted on-site for the modern interior lining of subsurface structures, in particular of tunnels and shafts.
The invention will now be described in more detail with reference to exemplary embodiments schematically illustrated in the drawings, which show in:
As viewed in the longitudinal direction of the tunnel,
To better illustrate the individual components of the adjusting element 5a,
On a side of the box profile facing the connecting side 23a, the box profile is formed with two inclined planes, whereby the two side panels 20a have opposing inclined faces 24a with a common highest edge region located at the center of the side panels 20a and flattening out on both sides of the tubbing rings 2 linearly towards the annular surfaces 7, whereby the respective cross-section of the side panels 20a is tapered towards the two recesses 22a located at the edge.
The wedge-shape gaps between the two side panels 20a which open towards the front-side annular surfaces 7 are each at least partially filled by the wedge-shape spreading element 21a; the wedge-shape gaps oppose each other with their blunt wedge tip 25a, as already illustrated in
A side of the spreading element 21a facing the wedge tip 25a is formed as an anchor plate 26a. The two sides of the wedge-shaped spreading element 21a extending parallel to the inclined faces 24a each have corresponding pressure areas 27a which are in full-area contact with the inclined faces 24a of the side panels 20a. The spreading element 21a is coupled via releasable connecting means with the respective side panels 20a of the adjusting element 5a. The side panels 20a have each slots arranged in their inclined faces 24a to allow linear movement of the spreading element 21a between the two side panels 20a, with the slots extending in a longitudinal direction between the two front-side annular surfaces 7 and displaceably supporting the releasable connecting means and hence the respective spreading element 21a. The spreading element 21a is connected with the opposite spreading element 21a by two tension anchors 28a, which are arranged mutually parallel and extend from the anchor plate 26a to the anchor plate 26a by passing through the corresponding spreading element 21a and the respective anchor plate 26a. The tension anchors 28a are rotatably supported inside the spreading element 21a and have at one end a hex head which can be engaged by conventional tools for force transmission, wherein the opposite end of the tension anchor 28a has an exterior thread which is in engagement with a corresponding element fixedly connecting with the anchor plate 26a and having a corresponding interior thread. Each of the side panels 20a has a recess 22a at the corresponding ends of the adjusting element 5a facing the annular surfaces 7 of the tubbing rings 2, with the recess 22a extending from a connecting side 23a of the side panels 20a to the opposite connecting side 23a coplanar with the annular surfaces 7.
As shown in
In a second variant,
In a practical application, a shield driving device with an additional arrangement for installation of a tubbing lining is typically used for constructing an elongated subsurface tunnel section. A round rotating cutting tool is hereby driven into the rock formation. This cutter referred to as shield has openings through which the cutout material can be transported away with conveyor belts.
In the so-called trailer behind the shield, the freshly cut tunnel opening is directly lined with successively arranged tube segments. These tube segments represent a single-shell support structure which satisfies in addition to the static requirements also the requirement for water impermeability. Each of the ring segments is hereby formed of tubbing rings 2 with tubbing segments 4 consecutively arranged with their respective end faces 10 in the circumferential direction.
For optimal adaptation to local situations and requirements, differently prepared tubbing segments 4 are employed. These are of modular construction and equipped at their respective end faces 10 with an adjusting element 5a, 5b and/or a flexible element 6a, 6b, 6c, 6d. The inherently stiff and unyielding tubbing segments 4 made from reinforced concrete are hereby combined into an adaptable and customizable system in form of adjustable tubbing rings 2.
In areas where high dynamic pressures and a large convergence behavior can be expected, the tubbing rings 2 are designed to be flexible by using the flexible elements 6a, 6b, 6c, 6d in at least one butt joint 9 between the respective end faces 10 of the tubbing segments 4, thus allowing the tubbing rings 2 to withstand the rock pressure by compressing the flexible element 6a, 6b, 6c, 6d and thereby changing the circumference. The forces in the surrounding material are redistributed by increasing the diameter of the tubbing lining 1.
In areas where the diameter of the tunnel borehole must be cut larger when the tunnel tube is driven in, the tubbing rings 2 are designed to be adjustable with the adjusting element 5a, 5b inserted in the butt joint 9, so that the circumference and hence the diameter of the tubbing rings 2 can be enlarged and adapted to the true borehole diameter.
Tool allows a corresponding changes in the circumference and relative displacement of the individual tube segments, each individual of the tubbing rings 2 is connected with its adjacent tubbing segments by way of a corresponding three-dimensionally yielding coupling unit 36a, 36b, 36c, 36d, 36e, 36f arranged between two corresponding tubbing segments 4 in the region of the annular joint 3. The individual components are thus reliably coupled and positioned with the proper orientation in spite of the yielding connection.
To securely seal the individual tube segments against each other also in the annular joint 3, a continuous annular groove 16, into which a circular seal 8 is inserted, is arranged on each of the front annular surfaces of the tubbing rings 2. The opposing annular surfaces 7 are reliably sealed by the seal 8 with the pressing force in the annular joint 3 against hydraulic pressure. In extreme situations, the seal 8 is embodied as a hose filled with a medium and having an elastically changeable radial cross-section. When the annular joint 3 expands, the seal 8 can still be adapted to the enlarged cross-section by subsequently applying pressure.
1 tubbing lining
2 tubbing rings
3 annular joint
4 tubbing segment
5
a adjusting element in 9
5
b adjusting element in 9
6
a flexible element in 9
6
b flexible element in 9
6
c flexible element in 9
6
d flexible element in 9
7 annular surfaces of 2
8 seal in 3
9 butt joint between 4
10 end faces of 4
11 hollow chambers of 6a, 6b, 6c, 6d
12 lands of 6a, 6c, 6d
13
a Longitudinal walls of 6a
13
b Longitudinal walls of 6b
13
c Longitudinal walls of 6d
14
a Transverse walls of 6a
14
b Transverse walls of 6b
14
c Transverse walls of 6d
15
a Recess of 6a
15
b Recess of 6b
15
c Recess of 6c
15
d Recess of 6d
16 Annular groove in 7
17 Tubular body of 6b
18 Intermediate land of 6b
19 Longitudinal walls of 6c
20
a Side panels of 5a
20
b Side panels of 5b
21
a Spreading element of 5a
21
b Spreading element of 5b
22
a Recess of 5a
22
b Recess of 5b
23
a Connecting side of 20a
23
b Connecting side of 20b
24
a Inclined faces of 20a
24
b Inclined faces of 20b
25
a Wedge tip of 21a
25
b Wedge tip of 21b
26
a Anchor plate of 21a
26
b Anchor plate of 21b
27
a Pressure areas of 21a
27
b Pressure areas of 21a
28
a Tension anchor of 5a
28
b Tension anchor of 5b
29
a Service openings of 5a
29
b Service openings of 5b
30 Transverse straps of 5b
31 Connecting means of 5b
32 Transverse walls of 20b
33 Guide walls of 21b
34 Slots of 20b
35 Guide slots of 32
36
a Coupling unit in 3
36
b Coupling unit in 3
36
c Coupling unit in 3
36
d Coupling unit in 3
36
e Coupling unit in 3
36
f Coupling unit in 3
37 Anchor pin of 36a
38
a Annular component of 36a
38
b Annular component of 36b
39 Coupling plates of 36a
40 Clamping plates of 36b
41
a Anchor plate of 36c
41
b Anchor plate of 36e
41
c Anchor plate of 36e
41
d Anchor plate of 36f
42 Clearance opening
43
a Bolt of 36c
43
b Bolt of 36d
43
c Bolt of 36e
43
d Bolt of 36f
44
a Spring element of 36c and 36d
44
b Spring element of 36e
45
a shaping in 4
45
b shaping in 4
46 Pass-through opening
47 connection of 8
48 Closure element of 46
A Outer side of 2
B Inner side of 2
C Distance between 10
Number | Date | Country | Kind |
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102009057521.9 | Dec 2009 | DE | national |
Filing Document | Filing Date | Country | Kind | 371c Date |
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PCT/DE2010/001389 | 12/1/2010 | WO | 00 | 5/31/2012 |