FRAME FOR THE SUPPORT AND CONSOLIDATION OF A PARTIAL EXCAVATION, AND METHOD FOR INSTALLING SUCH A FRAME INSIDE A PARTIAL EXCAVATION

Description

DESCRIPTION of the industrial invention entitled: “Centina for the support gno and consolidation of a partial excavation, and method for the installation of such a centimeter within a partial excavation" by: Maccaferri Tunneling Srl, of Italian nationality, with headquarters in Bologna Designated Inventor: Cristiano BONOMI filed on: May 24, 2024 * * * Field of invention The present invention relates to a support and consol- management of a partial excavation and an automatic method for the installation installation of a support structure inside a partially excavated excavation. By partial excavation we mean an excavation carried out using a method of sequential tunneling (SEM) or NATM (New Austrian Tunneling Method). Technological background For the support of excavations, such as motorway tunnels or railways, it is known to use consolidation arches called centering. In in particular a rib usually comprises a plurality of elements shaped steel structures connected to each other according to a confi- vaulted ceiling. These elements are made up of open profiles with a cross-section transverse to H, HEB, HEM, IPE, INP, C or double T. In some cases the elements can be tubular. In most cases, the elements structural members of a rib are connected to each other at the excavation to be consolidated after being shaped in carpentry. After its assembly and installation, each frame is connected to the adjacent ones through connecting organs, in jargon called "chains" even if nor- PROVVISIONATO & CO They are usually made using rigid elements, the ends of which are joined hook to supports welded along the body of the profiles of the ribs. The space between two consecutive centres and the wall of the excavation is consolidated usually given through sprayed concrete (spritz-beton) which forms a structural covering that also includes the ribs. The excavations can be made in full section, or, more commonly- mind, partialized. The partialized excavations, which are the area to which it is addressed ge the present description, are performed, whatever their section, advancing progressively with different phases that follow one another and repeat themselves no. In more detail, it starts with the dome plane and the tunnel is attached catalyzed with that section of excavation. The tunnel then proceeds with the method- classic methods of excavation and placement of formwork and sprayed concrete excavation then continues, after a distance depending on the conformation geological excavation, with the so-called strozzo excavation, that is with the excavation of the underneath the dome. It involves excavating one of the two portions of the side wall of the excavation, also called lateral excavation, or widening excavation of choke, or even pier, which gradually advances as much as the excavation of the dome. The excavation of the other portion of the lateral wall follows. excavation, that is, the other widening of the stranglehold, or pier, which also advances, but hand that advances the excavation of the dome and the first lateral excavation. The excavation of a central access ramp to the excavation floor also proceeds, ad- progressing as the excavation of the dome progresses. The last phase which proceeds in sequence is the formation of the reverse arch. The structural elements that make up traditional ribs are joined together by flanged couplings. An evolution and perfection PROVVISIONATO & CO of this system are described in WO 2015 / 186029, which describes a articulated connection system with automatic locking of the ele- structural elements that make up a rib, which has a confi- vaulted figure which generally recalls that of the excavation portion de- intended to be consolidated through the formwork itself. The structural elements natural materials that make up the frame, made of metallic material such as for example construction steel, are connected to each other with a swivel coupling, for example by means of hinges incorporated into the structural joint, so as to move from a first position in which the structural elements are substantial initially folded over each other to a second position in which they are di- move to form at least one substantially continuous portion of the frame. Another such system is described in WO 2022 / 254325. The systems described in WO 2015 / 186029 and WO 2022 / 254325 have proven effective for use in full-section excavations, but have ca- characteristics that limit its use in partial excavations. The advance progressive and partial excavation does not allow the use of the si- known stems, especially since the ribs cannot support the shell without being opened completely, which is impossible until at least the excavation of the side walls or widenings of choke, or jambs. This carries the risk that the wall of the dome, if not sustained for a certain period of time, it may collapse, with obvious and significant risks to people and equipment in the vicinity of the blast front I want. There is therefore a need for a rib with improved characteristics. tive, which can be advantageously used in the construction of the PROVVISIONATO & CO tunnels created by partial excavation. Exposition of the invention The aim of the present invention is therefore to create a centering for the support and consolidation of a partial excavation, which allows for a quick and secure connection between its elements structural, such as to be particularly stable for the support of the walls of the cap even without having to wait for the excavation of the cor- overhanging side walls, or widenings of the narrows or piers, which in the continuation in this description they will always be called lateral excavations, respect- right and left. Another object of the invention is to make a frame for the support and consolidation of a partial excavation that can be easily used to support the walls of the excavation even when they are the lateral excavations of a partial excavation were completed, without the need to interrupt the support of the cap portion. Another aim is to make a relatively eco-friendly frame. nomic and simple to manufacture. Another aim is to create a frame that can be in- installed quickly, automatically, with the aid of mechanical means only, or at least mostly automatic and, above all, safe for the person- nal and the excavation workers. These and other purposes are achieved by means of a pre-assembled rib. comprising several structural elements connected to each other in so that the frame can move from an initial, compact configuration, before installing to an intermediate configuration, partially PROVVISIONATO & CO extended, supporting the dome of a partial excavation on a ca- plane struggle, until a definitive configuration of support and consolidation is reached of the entire profile of the excavation, in which the formwork is supported on a base plane if it has a lower level than the dome plane. The structural elements come are blocked with structural continuity with respect to each other in a posi- reciprocal action which overall defines an arched form, initially but to support only the cap and subsequently the overall support of the excavation walls. An advantage of the present invention is the fact that it allows the con- immediate and integrated solidification of the excavated portion of the dome, first of the completion of the right and left lateral excavations. Another advantage of the frame of the present invention is the fact that it can support the walls of excavation not only independently of the progress of the excavation under- given the excavation of the cap, but also independently of the progression of the right lateral excavation compared to the left one. According to a first aspect, a support frame is described and consolidation of an excavation. The framework may include several elements structural. Structural elements can be connected to each other. The structural elements can be movably connected to each other. The connection between the structural elements can be such that the formwork can move from a pre-assembled configuration before installation, to a intermediate support configuration partially extended, up to a con- final configuration of fully extended installation. The configura- pre-assembled unit can be at least partially folded. In the confi- intermediate configuration, some structural elements can be blocked PROVVISIONATO & CO with respect to each other. In the final configuration, all the structural elements The elements of the frame can be locked in relation to each other. The ele- structural minds can be blocked with structural continuity, i.e. re- resisting the forces exerted by the walls of the excavation as if they were an ele- single chin or as if they were blocked with fixed connecting organs such as bolts and the like. Structural elements can be locked, in the final configuration, in a reciprocal position that defines the overall mind a rib with an arched profile. According to a particular aspect, the structural elements can be articulated, articulated or oscillating with respect to each other. The ele- structural minds can be connected to each other by means of control organs joint that includes hinges. According to another aspect, a method for the installation is described of a rib inside an excavation. The method may include the fa- if you want to prepare more structural elements than a rib. The method can comp- take the step of connecting said structural elements to each other to obtain keep a pre-assembled frame. The connection can be a con- mobile chin. The method may include the step of folding the rib, preferably at least partially, before its installation. The method where the transport of the frame can be included, preferably at least partially folded, inside the excavation. The method may include the phase of installing the frame in an intermediate configuration, partially extended, which supports the excavation of the dome of a partial excavation. The method which may include a further stage of bringing the frame into a configuration intermediate support for the dome of a partially excavated excavation, with app- PROVVISIONATO & CO hill extended in a lateral excavation area, excavated subsequently to the excavation of the cap. The method may include the installation phase of the rib in a final configuration with extended support on both sides lateral excavation areas, excavated in sequence and following the excavation of cap. Preferably in these phases the structural elements can be gradually blocked sequentially with structural continuity with respect to each other to others. From another perspective, the method may provide that the elements structural elements are irreversibly locked together. Brief description of the drawings Further features and benefits will be detailed in the description. cut that follows a preferred form of embodiment, with reference to the di- attached signs, given as a non-limiting example, in which: - Figure 1 is a schematic cross-sectional view of an example of partial excavation to be consolidated by means of formwork incorporating aspects of the the present invention; - Figure 2 is a perspective view of a frame incorporating elements of the present invention, in a partially extended intermediate configuration; - figures 3 - 6 show some phases of the installation sequence of the center of figure 2, corresponding to the progressive advancement of the partial excavation of figure 1; - figure 7 shows a larger scale detail of the adjustment of a support foot of the frame on the excavation surface of the dome; - Figures 8 and 9 show further stages of the installation sequence of the center of figure 2, corresponding to the progressive advancement further higher than the partial excavation of figure 1; and PROVVISIONATO & CO - figure 10 shows a larger scale detail of the support foot of the rib in correspondence with the lateral excavation. Detailed description In the following implementation examples, characteristics are described: features that allow the invention to be implemented. The features described can be combined in various ways with each other, and are not necessarily limited to the precise form of implementation to which the drawings and the related description. In other words, an expert technician in the sector who reads the de- The following text will provide you with useful information to understand how to achieve one or more of the characteristics described by combining it with one or more more than the other characteristics described, without the particular formulation of the description, paragraphs, sentences or drawings constitutes a limitation the possibility of isolating one or more of the characteristics described and illustrated in order to combine them with one or more of any of the other features described and illustrated. Referring now to figure 1, it is illustrated schematically the progress of the partial excavation of a tunnel to be consolidated me- diante ribs incorporating aspects of the present invention. An excavation of S-wall, for example a highway or railway tunnel, includes a cap C and a base B which in the example of the figures is flat, but which can also be made with a concave central portion, to form the co- so-called "inverted bow". The excavation S proceeds progressively, in sections. First the excavation of the T-cave, followed by excavation of the portion below the cave- ta, in which one advances - in the example of figure 1 - first with the excavation PROVVISIONATO & CO right lateral (or narrowing or pier) and then with the excavation left side SX. The central area of ​​ramp R also proceeds pro- progressively, ensuring access to the P-shell plane as it progresses excavation of the T dome is progressing. Figure 2 illustrates a 10-metre support and consolidation structure. the partial excavation S, incorporating aspects of the present invention. In- Figure 2 shows the rib 10 in an intermediate configuration, prece- to the final installation. The 10th rib includes a burning portion cuata 15 which ends at its two ends with two intermediate feet 12. Two additional sections of frame are mounted near the intermediate feet 12 and end with two respective end feet 14. In figure 2, one of the end side feet 14, in particular the right extremity foot 14a, is shown in a final configuration, already extended, so as to rest on a corresponding flat area right side of base B of excavation S, when the excavation has been carried out right side VO corresponding to the position of the rib 10 along the axis of the gallery. The other left end foot 14b of the the rib is instead illustrated in a still folded position. In this position tion, the left intermediate foot 12b is extended and supported, which is de- intended to rest on the dome plane P, when it is not yet the left lateral excavation has been completed. When the excavation is also completed left SX end is completed, left end foot 14a can be extended from the folded position shown in figure 2, up to reach a final configuration symmetrical to that of the end foot right side 14a, so as to rest on the corresponding flat area PROVVISIONATO & CO left side of base B of excavation S. In this way the 10th formwork reaches the final, fully extended, support configuration of the entire excavation section S, with both end feet 14 ap- they rest on base B. The 10th centimeter is made up of several structural elements, for example, but not limited to, three structural elements 15, 16, 17, in addition to the inter- medium 12 and at the end feet 14. The structural elements 15, 16, 17 are preferably made of metallic material, such as construction steel tion (Fe 430 or other). According to a preferred embodiment each structural element 15, 16, 17 is formed by a body made of a profile with open cross-section, for example H-shaped or C-shaped or double T-shaped, for example a European standardized profile such as HEA, HEB, HEM, IPE, etc. However, it is not excluded that one or more of the structural elements 15, 16, 17 be made with different profiles, for example tubular profiles with a circular section round, elliptical, square, rectangular, etc. The rib 10 has a substantially symmetrical vault configuration. trica with respect to a plane of vertical symmetry, defined by one or more elec- structural elements, for example the three structural elements 15, 16, 17, which form the sides and the top of the rib 10 in the area of ​​the T cap. The con- symmetrical vault figure of the 10th rib, in the extended configuration where the end feet 4 are both extended as the end foot right side 14a of figure 2, reproduces in general the section of the port excavation section S intended to be consolidated through the formwork itself. The 10th frame illustrated in the figures comprises a first element lateral structural element 15, a central structural element 16, connected to the first PROVVISIONATO & CO lateral structural element 15 and connected lateral structural element 17 to the central structural element 15. In one embodiment not illustrated ta, the 10th rib can include an additional structural element at the bottom, preferably connected or connectable to the second lateral structural element rale 17, for the possible reinforcement of the inverted arch of the excavation S, when expected. As illustrated, the first lateral structural element 15 and the se- second lateral structural element 17 are arranged according to a position substantially specular with respect to the vertical symmetry plane of the cen- tina 10. In other words, in this example configuration of the 10 rib the first lateral structural element 15 and the second structural element lateral 17 are lateral structural elements of the rib 10. The element central structural 16 preferably develops symmetrically between the first lateral structural element 15 and the second structural element la- terale 17 with respect to the same vertical symmetry plane. In the example of the rib 10, the central structural element 16 is a superstructural element upper, also called a ridge or summit structural element intended to support the upper area of ​​the T-cap. The ends of the various structural elements 15, 16, 17 are operable among themselves effectively connected, for example through articulated joint members. The intermediate feet 12 are also operationally connected to the ends of the the respective lateral structural elements 15, 17 in an articulated manner. The feet of ends 14 are in turn operationally connected to the intermediate feet 12. The connection of the end feet 14 to the intermediate feet can be done selectively, with a hookup that can occur after the 10th rib it was placed to support the excavation of the T dome only. PROVVISIONATO & CO The connecting organs between the various elements that make up the centi- na, feet included, are advantageously articulated joint members, swinging and / or swiveling, for example hinges. The structural elements and feet coupled through such connecting organs they can then pass from posi- positions folded back on each other, to intermediate positions in which at least part some of them are extended. In an intermediate position supporting only the ca- T-frame of excavation S, the formwork 10 can be without the end feet 14, which are connected and extended only when it is necessary to support late- generally the 10th centimeter following the advancement of the lateral excavations. Result- so particularly easy and advantageous to transport inside the excavation S the 10 rib folded on itself in the installation configuration tion, in which the structural elements 15, 16, 17, together with the intermediate feet 12 and, in some embodiments, also by the end feet 14 already assembled on the 10th rib, they are joined to each other continuously. Feet 12, 14 are preferably extendable and can be extended of an adjustable quantity to be placed respectively on the work surface fight P and on base B. Figure 7 shows an example of a larger scale implementation. tion of one of the intermediate feet 12, which includes a support element 20. The support element 20 comprises a movable or telescopic portion ca mounted in an extendable way with respect to the fixed structure of the intermediate foot god 12, which is fixed to a corresponding lateral structural element 15 or 17, preferably near its end. The fixed structure of the foot 12 can be fixed to the lateral structural element 15 or 17 by means of any known type of system, for example by welding or with PROVVISIONATO & CO bolts or rivets or other connecting parts of the same kind, although it is preferable bile that is mounted movably, for example by means of a joint or zipper 22. The mobile structure 20 can preferably be made with a tubular body, for example with a square or rectangular section, and in any case configured and sized to slide linearly with respect to the fixed body of the foot 12, preferably telescopically, without pos- rotation capability. Foot 12 is equipped with a locking mechanism and non-return, for example with a ratchet mechanism, which allows the structure to be fixed mobile 20 at a desired height with respect to the dome plane P. At the extremity lower part of the mobile structure 20, intended to rest on the work surface cap P, a support plate 24 is fixed. The support plate 24 has larger dimensions of the section of the mobile structure 20, to form a support base large enough to distribute the weight over a surface relatively large surface of the P-shaped dome. Once the operation is completed, extension of the mobile structure 20, the telescopic tubular section pica can be filled with concrete to create a 12 mo- foot nolitic that no longer moves in any direction. A connecting member is provided on the fixed structure of the foot 12. to 26 to which a corresponding connecting element 27 is connected of the end foot 14, shown on an enlarged scale in figure 10, when where it is necessary to support the frame following the lateral excavation that removes the cap plane. The end foot 14 also comprises a structure mobile 28, having functional characteristics similar to those of the structure mobile 20 of the intermediate foot 12, which ends with a support plate PROVVISIONATO & CO 30, functionally similar to the support plate 24, intended to form a support base large enough to distribute the weight over a relatively large surface of the base B of the excavation S. The end foot foot 14 is preferably connected to the intermediate foot 12 in an articulated manner. to, to move from a raised position, shown partially with line dashed in figure 10, to the final extended position in which it supports the cen- tina 10 resting on the base B of the excavation S. The connection formed by- the connecting organs 26, 27 respectively of the intermediate foot 12 and of the end foot 14 is preferably shaped so as to be able to be be irreversibly blocked when the end foot 14 is extended to reach the final support position, illustrated with a line solid line in figure 10. The installation of the 10 ribs in the S excavation can be done in automatic or semi-automatic mode thanks to the use of known machines at- designed for this purpose, to follow the partial progression of the excavation S. The 10 ribs described above are transported to the site of the excavation S in the configuration in which the structural elements 15, 16, 17 and the intermediate feet 12 are folded, to assume a com- flap whose extension on the plane containing the structural elements and feet intermediate is less than the extension of the section of the T-shaped dome excavation. The support elements 20 of the intermediate feet 12 are preferably sol- raised or retracted so as to take up little space in the central storage tina 10 and during its first positioning in the gallery, as visible in the figure 3. Transport is therefore easy and the elements that co- they constitute the frame and are already prepared for correct positioning. PROVVISIONATO & CO namento in the final configuration. When the rib 10 is in the expected position inside the sca- vo S which progresses with the advancement of the excavation of the cap T, the element central structural 16 is raised so that the structural elements la- laterals 15, 17 rotate at the articulated joints to carry in progressively open configurations, as illustrated in figure 4. With the central structural element 16 arranged in correspondence with the wall upper part of the T-shaped dome excavation, the lateral structural elements 15, 17 ad the adjacent ones are placed next to the vault of the excavation, as illustrated in the figure 5. At the end of the relative rotation, the lateral structural elements 15, 17 are fixed in the installation position shown in figure 5 thanks to the snap-locking of the connecting parts between the structural elements natural. The creation of snap-fit ​​joint components allows for the securing rare that the structural elements remain firmly in position desired project upon completion of the installation, without the risk of it closing again. not one on top of the other. In the intermediate position where the rib 10 is installed in the sca- of the cap 10, the intermediate feet 12 are extended and positioned so such as to rest on the dome plane P, as visible in figure 6. In this position, the movable portions of the support elements 20 of the inter- 12 medium can be extended so as to support stably on the P-shell plane. In this intermediate configuration it is possible to carry out a first application of shotcrete on the portion of the frame that occupies for the excavation of the T. cap. PROVVISIONATO & CO As the excavation S progresses, in the area where it has been installed the 10th centimeter begins to make the lateral excavations, first (as in the non-limiting example of the figures) the right lateral excavation DX, se- followed by the left lateral excavation SX. As visible in figure 8, in pre- viewing the progress of these lateral excavations, the connection is provided of the 14 end feet to the 12 middle feet. The 14 end feet are initially in a bent position relative to the extension of the rib in the dome excavation, so as to rest on the dome plane P, co- me precisely illustrated in figure 8. When the right lateral excavation DX is completed, as shown in figure 9, the right foot 14 is extended and lengthened so as to rest on the base B of the excavation, co- me illustrated in figure 9. Similarly, when also the lateral excavation of left SX is completed, left end foot 14 is extended and extended to reach a similar support position on base B of the excavation. The support elements of the end feet 13 are per- arranged laterally and lower than the side walls of the excavation, and are extended or rotated until they touch the ground at the base B. In this condition the consolidation of the formwork can be completed with shotcrete in the lateral area of ​​the excavation freed from the lateral excavations. The installation of the frame is therefore quick and substantial. initially automatic. Each rib is then connected to an adjacent rib me- diante connecting organs called "chains" or equivalent organs of the no- type to. The connecting organs are made in such a way as to allow prefer- probably an automatic connection from one rib to another. PROVVISIONATO & CO The formwork used to support and consolidate an excavation they can have elastic joints of a known type that can be inserted between two sections of the structural elements of the formwork. The adoption of one or more elastic joints allow you to absorb, by reacting elastically, the thrusts that can be exerted by the walls of the excavation on the formwork. The main inventive concept of the invention is not dependent on the type of profile of the frame that is used to make the elements structural and / or intermediate feet and end feet. Although previously profiles with an open cross-section have been mentioned as preferable ta, the use of the invention with tubular profiles with which to realize to fully or partially control the overall profile of the frame and / or one or more of its structural elements. In general terms, it is still possible to use create different profiles for different portions of the frame, not being excluding the possibility of using different profiles even for parts of elements structural, with open and / or closed / tubular profiles, separated from each other example from the elastic joints described above. Naturally, without prejudice to the principle of the invention, the forms of at- The situation and the construction details may vary widely. with respect to what is described and illustrated, without thereby departing from the scope of the present invention. PROVVISIONATO & CO

Claims

1. Frame for the support and consolidation of an excavation, comprising several structural elements (15, 16, 17) connected in a mobile manner to each other so that the frame can move from a pre-assembled configuration at least partially folded before installation, to an intermediate, partially extended configuration supporting the dome (C) of a partial excavation on a dome plane (P), up to a definitive configuration supporting it on a base plane (B) placed at a lower level than the dome plane (P), in which the structural elements (15, 16, 17) are blocked with structural continuity with respect to each other in a reciprocal position which overall defines an arched frame.

2. Frame according to claim 1, wherein a pair of intermediate feet (12) are mounted in an articulated manner at the ends of the set of structural elements.

3. Frame according to claim 2, wherein the intermediate feet (12) are extendable.

4. A frame according to any of the preceding claims, comprising a pair of end feet (14) selectively connectable to the ends of the structural elements or to said intermediate feet (12).

5. Frame according to claim 4, wherein the end feet (14) are extendable. PROVVISIONATO & CO - 18 PI2951 6. A frame according to any of the preceding claims, comprising at least three structural elements (15, 16, 17) mounted in an articulated manner to each other, lockable in an intermediate configuration in which intermediate feet (12) can rest on a canopy plane (P).

7. Method for installing a frame inside an excavation according to any of the preceding claims, comprising the steps of: - arranging several structural elements (15, 16, 17) of a frame (10), - movably connecting said structural elements (15, 16, 17) to each other to obtain a pre-assembled frame, - at least partially folding the frame before its installation, - transporting the at least partially folded frame inside the excavation (S), - installing the frame (10) in an intermediate, partially extended configuration, to support the dome (C) of a partial excavation on a dome plane (P), - connecting end feet (14) to the frame, - configuring the frame in a definitive support configuration on a base plane (B) made at a lower level than the dome plane (P), in which the structural elements (15, 16, 17) are positioned at a lower level than the dome plane (P),17) are blocked with structural continuity with respect to each other in a reciprocal position which overall defines an arched form.

8. Method according to claim 7, wherein the frame comprises a pair of intermediate feet (12) mounted in an articulated manner at the ends of the set of structural elements, wherein the step of installing the frame in the intermediate configuration comprises extending and / or lengthening the intermediate feet (12) and positioning them to rest on the canopy plane (P).

9. Method according to claim 7 or claim 8, wherein the frame comprises a pair of end feet (14) selectively connectable to the ends of the structural elements (15, 16, 17) or to said intermediate feet (12), wherein the step of installing the frame in the final configuration comprises: - connecting the end feet (14) to the ends of the structural elements (15, 16, 17) or to the intermediate feet (12), - extending the end feet (14) and positioning them to rest on the base (B).

10. Method according to claim 9, wherein in connecting the end feet (14) to the ends of the structural elements (15, 16, 17) or to the intermediate feet (12) the end feet (14) assume a folded configuration, the end feet (14) being subsequently extended to form with the structural elements (15, 16, 17) an arched configuration which rests on the base (B).