US3601995A

US3601995A - Shoring construction

Info

Publication number: US3601995A
Application number: US784295A
Authority: US
Inventors: Rudolf Siez; Hans-Gunther Lichtenbaumer; Joachim Neefe; Wolfgang Scheer; Franz Gantke; Walter Zywietz
Original assignee: Hoesch AG; Bochumer Eisenhuette Heintzmann GmbH and Co KG
Current assignee: Hoesch AG; Bochumer Eisenhuette Heintzmann GmbH and Co KG
Priority date: 1967-12-12
Filing date: 1968-12-12
Publication date: 1971-08-31
Anticipated expiration: 1988-08-31
Also published as: CH521484A; AT300010B; FR1587181A; BE725129A; GB1250515A

Abstract

A shoring for underground passages includes a plurality of annular supporting frame members which are arranged axially of one another and whose adjacent axial end portions are provided with juxtaposed endfaces, each two juxtaposed endfaces defining with each other a circumferentially extending gap. An annular wedging frame closes the respective gaps in such a manner as to provide for substantially uniform transmission of tensile or compressive stresses between the adjacent supporting frame members at all circumferential locations, and provides for such closing regardless of the angular inclination of the juxtaposed endfaces with respect to one another as long as this inclination is within a predetermined range.

Description

United States Patent Inventors Dortmund-Kirehhorde, all 01, Germany Appl. No. 784,295 Filed Dec. 12, 1968 Patented Aug. 31, 197] Assignees Hoeseh AG Dortmund, Germany; Bochumer Eisenhutte Heintzamann 8: Co. Bochum, Germany Priority Dec. 12, 1967 Germany SHORING CONSTRUCTION 23 Claims, 14 Drawing Figs.

US. Cl 61/45, 61/42 Int. Cl E2ld 11/22 Field of Search 61/45, 42, 43, 84, 85; 52/584 Primary Examiner-Dennis L. Taylor Atlorney-Michael S. Striker ABSTRACT: A shoring for underground passages includes a plurality of annular supporting frame members which are arranged axially of one another and whose adjacent axial end portions are provided with juxtaposed endfaces, each two juxtaposed endt'aces defining with each other a circumferentially extending gap. An annular wedging frame closes the respec tive gaps in such a manner as to provide for substantially uniform transmission of tensile or compressive stresses between the adjacent supporting frame members at all circumferential locations, and provides for such closing regardless of the angular inclination of the juxtaposed endfaces with respect to one another as long as this inclination is within a predetermined range.

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TTORNEY snonnvo consrnucrron BACKGROUND OF THE INVENTION The present invention relates generally to shoring for underground passages, such as tunnels, shafts, and the like. More specifically, the invention relates to such a shoring which preferably prevents the intrusion of water into the interior of such tunnels, shafts or the like.

Underground passages, which term hereafter shall be considered to include any type of underground space of the general nature such as tunnels, shafts, bores or the like must be shored to prevent them from collapse. For this purpose it is known to provide supporting frame members of profile steel, of concrete or of steel-reinforced concrete which are arranged in abutment with one another as seen with respect to the axial extension of the underground passage with their abutment faces extending transversely to this axial extension. For facilitating the introduction of these frame members into the passage, and their advancement to the desired locations, it is preferred to construct these frame members in segments which are then connected together in situ. The manner in which the abutment faces are made to engage one another depends on prevailing circumstances and such engagement may be in pressure and/or tension-transmitting abutment. Particularly at locations where shoring is erected immediately subsequent to the formation of the underground passage, it is necessary to support the supporting frame members one against the other in pressure-transmitting relationship, because the leading frame members, that is those which are closely adjacent to the equipment forming the passage, act as the supporting abutment for the passage-forming equipment or, in loose strata, for the hydraulic advancing cylinders of the passage-forming devices. Additionally, it is frequently necessary, for instance where the underground passage has a downward inclination, to connect the supporting frame members for transmission of tensile stresses, the latter type of connection sometimes being the only type which is required.

Connection of the adjacent supporting members for trans mission of tensile and compressive stresses, as well as for transmission of either type of stresses, does not usually provide any problems where the underground passage is straight. Compressive stresses of course are 'transmittedby having the endfaces of adjacent supporting frame members abut against one another, whereas connection to withstand tensile stresses is effected by connecting the adjacent supporting frame members in the region of their abutment faces with hooks, fishplates, or analogous elements. In fact, the use of fishplates provides a connection which is resistant not only to tensile stresses but also to compressive stresses. If it is desired that the connection between adjacent supporting frame members be water tight, to prevent the intrusion of water into the interior of the passage from the surrounding strata, then it is simply necessary to introduce requisite types and quantities of sealing material between the abutment faces of adjacent supporting frame members. Insofar as the supporting frame members consist of individual segments which are connected together, sealing against the intrusion of water can be effected in similar manner at the joints between the respective segments.

However, matters are not so simple where straight line passages are curved in horizontal and/or vertical direction. The problems which arise here are the more significant, the smaller the radius of curvature involved. In such sections of underground passages the adjacent supporting frame members must be arranged at an angle with respect to one another and it is then no longer possible to readily transmit stresses, particularly those exerted by the passage-forming devices, to a large number of supporting frame members in the sense of distributing the stresses evenly around their circumference. The remedy which seems to offer itself at first sight for such circumstances, namely to use inserts capable of bridging the variablewidth gap which under these conditions exists between the juxtaposed endfaces of any two adjacent supporting frame members, is economically impractical because it would require a large stock of differently configurated inserts to allow for all the different angular inclinations of adjacent supporting frame members relative to one: another, and therefore to bridge the differently configurated gaps between their juxtaposed endfaces, which may occur in dependence upon the radius of curvature required of the particular section of the underground passage.

Another possibility for solving this problem, which has also been suggested previously, is to so configurate the hook elements, fishplate connections or other connections used for securing adjacent supporting frame members to one another,

that adjacent supporting frame members may be inclined with respect to one another as needed and then be secured by the securing means provided. However, the extent to which such inclination is possible with the specially constructed securing means, is relatively narrowly defined and frequently inadequate, particularly if the radius of curvature of the passage section being short is relatively small. Additionally, economic considerations again play a role in this: solution. It will be appreciated that resort to this solution requires specially constructed and configurated supporting frame members and connecting means which must be used even where a tensionresisting connection between adjacent supporting frame members is not required and where it would be sufficient to provide compression-resistant abutment between adjacent ones of the supporting frame members. As mentioned earlier, the latter type of connection is usually all that is required, a connection which resist tensile stresses or both compressive and tensile stresses being required only occasionally. Therefore, the necessary use of the more elaborately constructed components in circumstances where such elaborate construction is not needed, results in unwarrantedly high economic expenditures which largely negate any advantages derived from this solution.

SUMMARY OF THE INVENTION It is, accordingly, a general object of the invention to provide shoring for underground passages which is not possessed of the aforementioned disadvantages and provides the features which have above been characterized as advantageous.

A further object of the invention is to provide such a shoring which makes it possible to connect adjacent supporting frame members against compressive and/or tensile stresses but yet to position them at such inclination relative to one another as may be required by' curved sections of the underground passage being shored.

4 A concomitant object of the present invention is to provide a shoring of the type in question which obviates the need for using expensive bridging members bridging the gaps between annular adjacent supporting frame members when the latter are inclined relative to one another because of the curvature of the underground passage, bridging members which must be specially manufactured and kept in stock for each of the many differently configurated gaps which may occur depending upon the extent of curvature of the underground passage.

In accordance with the above objects, and others which will become apparent hereafter, one feature of our invention resides in providing shoring for underground passages which includes at least two annular supporting frame members arranged axially of one another and having adjacent axial end portions provided with juxtaposed endfaces defining with each other a circumferentially extending gap. In accordance with the invention, we provide annular wedging frame means constructed and arranged for closing the radial gap in abutment with the adjacent axial end portions with a predetermined range of angular inclinations of the endfaces with reference to each other, and which wedging frame means serves to effect substantially uniform transmission of stresses between the supporting frame members at all circumferential locations.

The cross-sectional configuration of the annular wedging frame means according to the present invention is identical at all circumferential points thereof and we wish it to be understood that reference to annular" wedging frame means is intended to include constructions where the wedging frame.

means is annularly incomplete. In other words, the wedging frame means may not only be a circular outline, and of otherthan-circular but circumferentially complete annular outline, but it may also be arch-shaped or similarly configurated in a manner which we have chosen to designate as being at least substantially annular" in outline. Also, it should be understood that the annular wedging frame means according to the present invention is necessarily required only where an underground passage being shored is of other-than-straight configuration, but that it can be used anywhere, including in straight line sections of underground passages. By interposing our annular wedging frame means between the juxtaposed endfaces of the two axial adjacent supporting frame members, or by having it surround the end portions on which the juxtaposed endfaces are provided in the manner still to be discussed later, we can provide the desired effect of wedging any radial gap between adjacent and mutually inclined supporting frame members which develops as a result of curvature. of the underground passage. This bridging is accomplished by having available only a single type and size of supporting frame means for any given shoring installation, and the only requirement made of the configuration of the supporting frame means is that it be capable of bridging the largest gap which can develop in the given shoring installation. So configurated compensation for differently dimensioned gaps is simply effected by eccentrically offsetting the wedging frame means with respect to the juxtaposed endfaces of the supporting frame members between which the gap to be bridged exists.

It is immaterial for purposes of the invention whether the supporting frame members consist of concrete, steel-reinforced concrete, s'teel-clad concrete or profiled steel segments, or whether the supporting frame members are circumferentially complete and of circular, elliptical or other configuration, or whether they are of substantially arch-shaped configuration. The configuration of the annular wedging frame means, which latter may consist of any of the aforementioned materials including the particular material from which the annular supporting frame members are constituted, has a configuration corresponding to that of the annular supporting frame members and under these circumstances is always capable of providing the required results.

The configuration of the sidefaces, that is the axially directed faces of the annular wedging frame means, may be chosen in dependence upon the type of shoring construction. Thus, if the shoring construction utilizes circumferentially complete annular supporting frame members or arch-shaped supporting frame members, then the sidefaces of the annular wedging frame means may be flat and the endfaces on the axial end portions of the supporting frame members may be so configurated as to provide surface-to-surface abutment with the sidefaces. If the configuration of the supporting frame members is different, for instance elliptical, the sidefaces of the wedging frame means will advantageously be concave or convex, preferably of S-shaped curvature, which guarantees in each and every instance at least line contact with the endfaces of the supporting frame members and adequate transmission of forces acting in longitudinal direction of the passage being shored, as well as adequate sealing against the entry of water. To enhance the sealing effect it is, however, advantageous if at least the sidefaces of the wedging frame means are provided with a layer or coating of resiliently yieldable sealing material of known type.

As mentioned earlier, the most common requirement in shoring construction is that adjacent supporting frame members be connected only against compressive stresses acting in the direction of elongation of the underground passage. Under these circumstances the endfaces of adjacent supporting frame members are juxtaposed with the sidefaces of the annular wedging frame means which will have a cross section at least substantially corresponding to a trapezium with the sidefaces being inclined at an angle of between approximately 20 and 35. It is advantageous if the base of the trapeziumfaces inwardly of the shoring, that is if it faces away from the surrounding earth strata. This facilitates the necessary adjustment because it avoids interference with such adjustment by the surrounding material and makes it possible to effect the adjustment from the interior of the shoring as needed.

The novel features which are considered as characteristic for the invention are set forth in particular in the appended claims. The invention itself, however, both so to its construction and its method of operation, together with additional objects and advantages thereof, will be best understood from the following description of specificembodiments when read in connection with the accompany drawing.

BRIEF DESCRIPTION OF THE DRAWING FIG. I is a somewhat diagrammatic end view, partially sectioned, into a section of an underground passage shored with the shoring according to the present invention;

' FIG. 2 is a horizontal section through the embodiment illustrated in FIG. 1; I

FIG. 3 is a section taken on the line III-III of FIG. 2;

FIG. 4 is a fragmentary internal view on an enlarged scale of the embodiment illustrated in FIGS. 1-3;

FIG. 5 is a section taken on the line V-V of FIG. 4;

FIG. 6 is a fragmentary enlarged sectional showing of a portion of FIG. 5;

FIG. 7 is similar to FIG. 6 but illustrates a different fragmentary section portionof the embodiment in FIG. 5;

FIG. 8 is a section taken on the line VIII-VIII of FIG. 7;

F IG. 9 and each show a section through a radial gap I between two adjacent supporting frame members in a shoring utilizing a different type of wedging frame means than that illustrated in FIGS. 1-8;

FIG. 10 and each show a somewhat diagrammatic fragmentary section through the radial gap between the adjacent supporting frame members in a shoring utilizing still another of wedging frame means; and

FIGS. 11 and Ila of use similar to FIGS. 10 and 10a but illustrating an embodiment utilizing yet a further type of wedging frame means.

DESCRIPTION OF THE FREF ERRED EMBODIMENTS Discussing now the drawing in detail, and firstly the embodiment illustrated in FIG. 1-8, we wish to point out that this embodiment is the preferred embodiment according to the invention and is illustrated in FIGS. 1, 2 and 3 as employed by way of example in an underground tunnel such as are utilized for subways or the like. FIGS. 4-8 illustrate details of this embodiment.

The end view shown in FIG. 1 in partial section illustrates that the shoring comprises a plurality of annular supporting frame members 1 which are arranged axially adjacent to one another and are arrayed in the direction of elongation of the underground passage. Adjacent ones of the supporting frame members 1 are separated by radial gaps 2 and are connected against compressive stresses by annular wedging frame means 3 interposed in the respective gaps 2. Reference numeral 4 in FIG. 1 illustrates the surrounding ground or earth in which the passage has been formed, and reference numeral 5 identifies the backfill of concrete or the like which is used to completely fill the space between the surrounding earth 4 and the outside of the shoring. Reference numeral 6, finally, identifies a mass of concrete filling the lowermost sector of the area encircled by the shoring. It constitutes the support for the railbed or the like which is later to be provided.

FIGS. 4 and 5 in particularshow clearly that in this embodiment the supporting frame members 1 each consist of several-here assumed to be four-profiled steel segments 10 which about. one another at the lines 7 and are there connected to one another against tensile and compressive stresses and against the intrusion of water by means of plates 8 configurated in correspondence with the cross-sectional configuration of the supporting frame members ll.

As seen in FIG. 5, the segments llc constituting the supporting frame members ll consist of channel-shaped profiles provided with flanges whose end portions are configurated as radially inwardly extending tapering portions 111.; and lb. In other words, each of the segments is has at one axial end one of the portions la and at the opposite axial end of the portions lb. Thus, a portion lla of one segment always is proximal to the portion lb of an axially adjacent segment. They thus define between themselves radial gaps 2 as shown in FIGS. 2;, 4, and 5.

In accordance with the present invention, there are interposed into these radial gaps 2 the wedging frame means which are here illustrated as wedging frame members 3. In this embodiment the wedging frame members 3 have the cross-sectional configuration (compare FIGS. 2 and 5) of a trapezium facing with its base towards the interior of the shoring and having axially directed sidefaces or edgefaces and defining with one another an angle of substantially between and 35 As particularly clearly shown in FIG. 5, the edgefaces of the wedging frame members 3 abut against the juxtaposed endfaces provided on the adjacent portions Ila and lib of adjacent ones of the segments 1c. The wedging frame members 3 in this case are of circular outline corresponding to that of the supporting frame members l but which, if the latter were of different outline, have the same outline as that selected for the supporting frame members 11. The cross-sectional configuration of the wedging frame members 3 is identical at all circumferential points thereof and it will be appreciated that while the wedging frame members 3 may be of one piece they are advantageously also provided in form of segments which facilitates their handling in underground passages. These segments are identified in FIG. 3 with reference numeral 3a and abut against one another in circumferential direction at the lines 312. Evidently, they must be suitably connected with one another, for instance by use of plates analogous to the plates 3 provided for the supporting frame members 11, by pin and socket connections or the like, so that necessary shifting of the wedging frame members 3 in the radial plane of the respective gap 2 can be accomplished in toto without detriment to the coherence of the sections 3a.

As shown in FIG. 2, the passage being shored has its direction of elongation indicated by the arrow X. FIG. 2 clearly illustrates, however, that the passage is slightly curved towards the right, or in FIG. 2 in downward direction as seen with respect to the drawing. It is clearly evident that in correspondence with the decreasing radius of curvature as seen in the direction towards the right-hand side of FIG. 2, the wedging frame members 3 received in the respective gaps 2 are arranged increasingly eccentrically with respect to their adjacent supporting frame members ll, that is towards the lefthand side of FIG. 3 in their own radial plane or that of the respective gaps 2. Because of the particular cross-sectional configuration of the supporting frame members 3, this shifting thereof in their own radial plane compensates for the increasing angle of inclination between the juxtaposed endfaces of the adjacent supporting frame members l at the side of the passage opposite that towards which the passage curves, that is at the left-hand side of FIG. 3 and at the top of FIG. 2. This radial shifting alone is sufficient to completely compensate and effect complete closure of the respective radial gaps 2 and to assure that forces acting in the direction of elongation of the passage will be distributed and transmitted between adjacent supporting frame members and transmitted between adjacent supporting frame members i evenly and distributed over the entire circumference thereof. Of course, such forces in this instance will only be compressive forces because there is no provision made to withstand tensile forces.

In fact, in this embodiment where only compressive forces are expected, for instance forces exerted by the passage-forming advancing machinery, angularly acting forces on this type which result in changed inclinations between adjacent supporting frame members ll, will have the effect of automatically causing the interposed wedging frame members 3 to shift radi ally to positions where they completely fill the gap 2. It is, however, as a matter of principle preferable to provide specific adjustment for the wedging frame members 3 to their requisite positions despite this inherent tendency to assume such positions.

Coming now to the more detailed illustrations, particularly those in FIGS. ti-o, it will be seen that these Figures illustrate means for providing this adjustment. Specifically, this means includes plates 9 distributed at predetermined locations circumferentially about the interior of the shoring and against which the wedging frame members 3 or, if they are provided in form of segments 3a, their segments abut and are supported with their respective basis. Bolts M) are provided which are suitably secured to the supporting frame members 1, for instance by being welded to the flanges thereof, and nuts la are associated with the bolts 10 so as to draw the plates 9 against the basis of the respective wedging frame members 3. In fact, the plates 9 may serve an auxiliary purpose, namely to stiffen the shoring and to connect it, for which purpose they may be provided with their sidefaces 9b abutting against portions of the adjacent supporting frame members ll, so inclined as to correspond with this inclination to the inclination of the portions of the supporting frame members 11 against which sidefaces 9b abut. This is shown in FIG. 6 where it will also be seen that by providing apertures 9a in the plates 9 which are somewhat elongated in the direction of elongation of the underground passage, that is in the direction between the adjacent supporting frame members l, the bolts it) may be extended through these apertures 9a so that, when the nuts li0a are tightened, the plates 9 will be drawn against the basis of the respective wedging frame members 3 with the effect of driving the latter deeper into the respective gaps 2 in the direction in which this pressure is exerted while still maintaining the stiffening function of the plates 9. Thus, the wedging frame members 3 may be driven into the respective gaps 2 to such an extent and to such locations :as is necessary to provide the required compensation so as to completely fill the gaps 2 at all circumferential locations thereof.

In the illustrated embodiment, the plates 9 have yet an additional function, namely to bridge the lines of abutment 3b of the individual segments 3a of which the wedging frame members 3 are composed. This avoids the need for specific connecting means between the segments 3a. Of course, the lines of abutment 3b could be provided at other locations and not be bridged by the plates 9, but in this case separate bridging and connecting means in form of several plates, pins or sockets or the like would be necessary.

The plates 8, which have been mentioned earlier, are illustrated in FIGS. 4 and 5. As further shown in FIGS. 7 and 8, these plates 8 not only serve to connect abutting segments 10 of the supporting frame members ll against compressive and tensile stresses, but also to provide a seal at the lines of abutment 7 against the introduction of water. For this purpose, the plates 3 are provided with recesses 13 which overlap the lines of abutment 7 and which are filled with an elastically yieldable sealing material 1130 which prior to the erection of the shoring projects beyond the plane of the face in which the recesses 13 are provided. Thus, when the nuts 11a are tightened on the bolts llll welded to the supporting frame members 1 and serving to hold the plates 3 in place, a part of the material 130 will enter into their respective fissures existing along the lines of abutment 7.

FIGS. 7 and 8 also illustrate that the plates 8 serve further to abut against the sidefaces of the wedging frame members 3 in the region of the radial gaps 2, and that a coating layer 12 of elastically yieldable sealing material which may be similar to the material 13a and advantageously is on a synthetic plastic basis, is provided on the wedging frame members 3. However, in place of this coating, or in addition thereto, the endfaces of the portions and lb of the supporting frame members ll may be provided with such a coating. When the plates 8 are drawn inwardly in a sense providing sealing along the lines of abutment 7, there will also be a sealing engagement with the coating 12 so that the intersection between the lines of abutment 7 which extend axial direction of the passage and the radially extending gaps 2, which is particularly endangered by the entry of water from outside, is reliably sealed.

Coming now to the embodiment illustrated in FIGS. 9 and 9a, it will be seen that here identical reference numerals identify identical elements. The wedging frame member is, however, here identified with reference numeral 14 and is of substantially U-shaped cross section with the bight facing the interior of the shoring. The endfaces of the portions la and 1b are juxtaposed as before, and tapered to one another in radially outward direction. Each of the portions la and 1b has an additional face which faces axially away from the associated endface and also tapers radially outwardly but in axially opposite direction, as clearly visible in FIGS. 9 and 9a. This taper is at an angle of substantially between 10 and to the radial plane of the gap 2 and the wedging frame member 14 embraces these additional faces with its correspondingly tapered inner surfaces to that the radial gap 2, which in dependence on the relative angular position of the adjacent supporting frame members 1 opens or closes in which-shaped configuration and in circumferential direction, can again be bridged and completely closed by simple eccentric shifting of the wedging frame members 14 with reference to supporting frame members 1. In this embodiment, however, the connection is provided against tensile stresses so that tensile stresses are transmitted between adjacent ones of the supporting frame members 1 via the intermediary of the wedging frame member 14.

As in the preceding embodiment, the wedging frame member 14 may be configurated as a single entity. However, it is preferably also constituted of individual segments as is assumed to be the case in FIGS. 9 and 9a. Here the individual segments are provided at their ends with elongated apertures 140 through which bolts 15 extend which are welded to the respective adjacent supporting frame members 1 and onto which the nuts 15a are threaded so as to shift the segments which together constitute the wedging frame member 14 radi-- ally as necessary.

According to a further embodiment of the invention, we may provide a second or inner wedging frame member 3 corresponding to the one illustrated in the FIGS. 1-8. This is shown in dashed lines in FIGS. 9 and 9a which illustrates two different positions of the wedging frame member 3 in correspondence with differently configurated gaps 2. If the inner or additional wedging frame member 3 is provided, as shown in FIGS. 9 and 9a, the adjacent supporting frame member 1 will also be connected for transmission of compressive stresses. It goes without saying that the sealing layer or coating 12 may be provided in this embodiment also, and that FIG. 9 shows the position of the various components in the region of the narrowest portion of the radial gap 2 whereas FIG. 9a shows the corresponding position in the region of the widest gap of the widest portion of the gap 2.

FIGS. 10 and 10a are much more diagrammatic in their illustrations than FIGS. 9 and 9a. However, they illustrate the same conditions as shown in FIGS. 9 and 9a with nonessential portions having been omitted. In FIGS. 10 an 10a, however, the configuration of the annular supporting frame members 1 is assumed to be elliptical rather than circular. The wedging frame member 16 inserted into the gap 2 is provided, in this embodiment, with sidefaces which are curved in somewhat S- shaped manner so as to have a concave portion and a convex portion joining the concave portion. In this embodiment, compensation for differences in the width of the gap 2 by radially shifting the wedging frame 16 result only in a line contact with the edges of the portions la and lb of the members 1, as is illustrated. Because of this. the portions la and 1b illustrated earlier in such a manner that the line contact between them and the sidefaces of the wedging frame member 16 takes place only at those ends of the portions la and lb which face the interior of the shoring. This is not to say that a reversed arrangement would not be possible, but the illustrated arrangement is preferable because it facilitates necessary adjustment in the radial position of the wedging frame member 16 from the interior of the shoring and with the means which have bee described to with respect to the preceding embodiments.

FIGS. 11 and 1 la, finally, illustrate yet another embodiment wherein the wedging frame member 17a which closes and bridges the respective radial gap 2 is identical in its cross-sectional configuration with the annular supporting frame members 17 except for the fact that its profile is radially reversed. In other words, the members 17 have a somewhat trapeziumshaped cross section identical with the cross section of the wedging frame means 17a but, as shown, with the open side facing in the opposite radial direction from the open side of the cross section of the wedging frame member 17a. It goes without saying that this could be-reversed and that the open sides of the cross sections of the two members 17 could face in the direction in which the open side of the cross section of the wedging frame member 17a faces in the drawing, in which case the open side of the wedging frame member would then face in the opposite direction corresponding to what is now shown for the members 17. In FIG. 1 l we have illustrated the relationship of the

members

17 and 17a if the shoring is used in a straight line portion of an underground passage, whereas FIG. 11a shows the changed position of the adjacent supporting frame members 17 with reference to one another and to the wedging frame member 17a if the axial length of the radial gap 2 decreases as a result of use of the shoring in a curved portion of the underground passage, that is where the supporting frame members 17 are inclined angularly with reference to one another in the manner discussed with respect to the supporting frame members 1 earlier. Again, simple radial shifting of the supporting frame member 17a in the radial plane of the gap 2 provides the desired results. Again it goes without saying that the sealing layer 12 can be provided in this embodiment.

The embodiment of FIGS. 11 and 11a is usable for archtype shorings as well as for shorings of the circumferentially complete type and in this embodiment, as in all others, it is immaterial whether the supporting frame members or their segments consists of profile steel, concrete or steel-clad concrete. In the event that the steel profiles illustrated in FIGS. 11 and 1 1a are not strong enough to resist the static requirements of a given situation, they can be reinforced, for instance by filling them with concrete. I

Wherever the supporting frame members or the annular wedging frame members are composed of individual segments which are releasably connected once they have been installed in the shoring, it is advantageouswhere the outline of the members differs from a circular outline-that the segments either be substantially straight or have a longitudinal curvature which is at least substantially identical for all of them.

It will be understood that each of the elements described above, or two or more together, may also find a useful application in other types of constructions differing from the types described above.

While the invention has been illustrated and described as embodied in a shoring for underground passages, it is not intended to be limited to the details shown, since various modifications and structural changes may be made without departing in any way from the spirit of the present invention.

What is claimed as new and desired to be protected by Letters Patent is set forth in the appended claims.

1. A shoring for underground passages, comprising at least two axially arrayed annular supporting frame members having adjacent axial end portions provided with juxtaposed end faces defining with each other a circumferentially extending radial gap, said frame members being capable of positioning in a plurality of relative positions in which their respective longitudinal axes are inclined to one another at different angles with concomitant variations in the width of said gap at different circumferential locations of the latter; and at least substantially annular wedging frame means of circumferentially constant but radially tapering cross section entering said radial gap at different circumferential locations of the latter to different extends depending upon variations of the width of said gap and sealingly closing said radial gap in abutment with said adjacent end portions, whereby to effect sealing of said gap within a predetermined range of angular inclinations of said axes by requisite displacement of said wedging frame means in the radial plane of said gap.

2. A shoring as defined in claim 1 wherein said supporting frame members and said wedging frame means are circumferentially complete.

3. A shoring as defined in claim ll, wherein said supporting frame members and said wedging frame means are circumferentially incomplete.

4. A shoring as defined in claim l, wherein at least said supporting frame members each consist of a plurality of connected discrete segments.

5. A shoring as defined in claim ll, wherein said wedging frame means comprise at least one annular wedging frame composed of a plurality of connected discrete wedging frame segments.

6. A shoring as defined in claim I, said wedging frame means encircling said radial gap in abutment with said adjacent axial end portions.

7. A shoring as defined in claim ll, said end portions being provided with radial flanges each having one of said juxtaposed endfaces and said endfaces diverging radially inwardly, and in axial direction of said annular supporting frame members; and wherein said wedging frame means is of radially outwardly converging wedge-shaped cross section with the axial faces of said wedging frame means abutting with surfaceto-surface contact against said endfaces.

Q. A shoring as defined in claim 1, said supporting frame members and said wedging frame means being of other-thancircular outline, and said wedging frame means being composed of a plurality of substantially straight segments.

9. A shoring as defined in claim ll, said supporting frame members and said wedging frame means being of other-thancircular outline, and said wedging frame means being composed of a plurality of segments of at least substantially identical arcuate curvature.

it A shoring as defined in claim ll, said end portions being in form of radially extending flanges; and further comprising a plurality of circumferentially distributed bolt-and-nut means provided on said frame members adjacent said flanges, said wedging frame being provided at opposite axial sides of said gap with openings elongated in axial direction of said wedging frame and in which said bolt-and-nut means are engageable for connecting said wedging frame means with said frame members.

llll. A shoring as defined in claim it, said wedging frame means having abutment faces abutting against said end portions; and further comprising elastically yieldable sealing material provided at least on said abutment faces for provided at least on said abutment faces for providing a fiuidtight seal between the same and said end portions.

12. A shoring as defined in claim 1, said annular wedging frame means being of at least substantially wedge-shaped radial cross-sectional configuration.

13. A shoring as defined in claim l2, said cross-sectional configuration resembling at least substantially a trapezium having side faces inclined to one another at angles of substantially between 20 and 35.

14. A shoring as defined in claim 13, wherein the base of the trapezium faces in radially inward direction of said annular wedging frame means.

15. A shoring as defined in claim 13, wherein said side faces are straight.

116. A shoring as defined in claim 113, wherein said side faces are arcuately curved.

ll7. A shoring as defined in claim 16, wherein said side faces have S-shaped arcuate curvatures.

18. A shoring as defined in claim 12, said wedging frame means of substantially wedge-shaped cross section having a base side facing radially inwardly; further comprising plate means overlying circumferentially distributed selected portions of said base side in abutment therewith and projecting axially therebeyond; and bolt-andmut means provided on said frame members and engaging said plate means for connecting the same and thereby said wedging frame means to said frame members.

19. A shoring as defined in claim 18 said endfaces of said frame members being inclined with reference to one another, and said plate means having edge faces tapered in correspondence with such inclination and abutting against the respective endfaces in surface-to-surface contact.

20. A shoring as defined in claim ll, said annular supporting frame members and said wedging frame means each having a radial cross-sectional configuration resembling a trapezium, and wherein the base line of said wedging frame means faces in an opposite radial direction than the base lines of said supporting frame members.

21. A shoring as defined in claim 20, each of said trapeziumshaped cross sections having two sides paralleling one another and one of which is the base line, and wherein one of said two sides is an open side.

22. A shoring as defined in claim ll, said end portions being in form of radially extending flanges; and further comprising a plurality of circumferentially distributed bolt-and-nut means provided on said frame members adjacent said flanges and engageable with said wedging frame means for connecting the same with said frame members.

23. A shoring as defined in claim .22, said bolt-and-nut means being operative for exerting radially inwardly directed wedging pressure ,on said wedging frame means.

Claims

3. A shoring as defined in claim 1, wherein said supporting frame members and said wedging frame means are circumferentially incomplete.

4. A shoring as defined in claim 1, wherein at least said supporting frame members each consist of a plurality of connected discrete segments.

5. A shoring as defined in claim 1, wherein said wedging frame means comprise at least one annular wedging frame composed of a plurality of connected discrete wedging frame segments.

6. A shoring as defined in claim 1, said wedging frame means encircling said radial gap in abutment with said adjacent axial end portions.

7. A shoring as defined in claim 1, said end portions being provided with radial flanges each having one of said juxtaposed endfaces and said endfaces diverging radially inwardly, and in axial direction of said annular supporting frame members; and wherein said wedging frame means is of radially outwardly converging wedge-shaped cross section with the axial faces of said wedging frame means abutting with surface-to-surface contact against said endfaces.

8. A shoring as defined in claim 1, said supporting frame members and said wedging frame means being of other-than-circular outline, and said wedging frame means being composed of a plurality of substantially straight segments.

9. A shoring as defined in claim 1, said supporting frame members and said wedging frame means being of other-than-circular outline, and said wedging frame means being composed of a plurality of segments of at least substantially identical arcuate curvature.

10. A shoring as defined in claim 1, said end portions being in form of radially extending flanges; and further comprising a plurality of circumferentially distributed bolt-and-nut means provided on said frame members adjacent said flanges, said wedging frame being provided at opposite axial sides of said gap with openings elongated in axial direction of said wedging frame and in which said bolt-and-nut means are engageable for connecting said wedging frame means with said frame members.

11. A shoring as defined in claim 1, said wedging frame means having abutment faces abutting against said end portions; and further comprising elastically yieldable sealing material provided at least on said abutment faces for provided at least on said abutment faces for providing a fluidtight seal between the same and said end portions.

13. A shoring as defined in claim 12, said cross-sectional configuration resembling at least substantially a trapezium having side faces inclined to one another at angles of substantially between 20 and 35*.

15. A shoring as defined in claim 13, wherein said side faces are straight.

16. A shoring as defined in claim 13, wherein said side faces are arcuately curved.

17. A shoring as defined in claim 16, wherein said side faces have S-shaped arcuate curvatures.

18. A shoring as defined in claim 12, said wedging frame means of substantially wedge-shapeD cross section having a base side facing radially inwardly; further comprising plate means overlying circumferentially distributed selected portions of said base side in abutment therewith and projecting axially therebeyond; and bolt-and-nut means provided on said frame members and engaging said plate means for connecting the same and thereby said wedging frame means to said frame members.

19. A shoring as defined in claim 18, said endfaces of said frame members being inclined with reference to one another, and said plate means having edge faces tapered in correspondence with such inclination and abutting against the respective endfaces in surface-to-surface contact.

20. A shoring as defined in claim 1, said annular supporting frame members and said wedging frame means each having a radial cross-sectional configuration resembling a trapezium, and wherein the base line of said wedging frame means faces in an opposite radial direction than the base lines of said supporting frame members.

21. A shoring as defined in claim 20, each of said trapezium-shaped cross sections having two sides paralleling one another and one of which is the base line, and wherein one of said two sides is an open side.

22. A shoring as defined in claim 1, said end portions being in form of radially extending flanges; and further comprising a plurality of circumferentially distributed bolt-and-nut means provided on said frame members adjacent said flanges and engageable with said wedging frame means for connecting the same with said frame members.

23. A shoring as defined in claim 22, said bolt-and-nut means being operative for exerting radially inwardly directed wedging pressure on said wedging frame means.