EP4628701A1

EP4628701A1 - Mining crib and a method of assembling thereof

Info

Publication number: EP4628701A1
Application number: EP24219696.2A
Authority: EP
Inventors: Waclaw Andrusikiewicz
Original assignee: Akademia Gomiczo Hutnicza
Current assignee: Akademia Gomiczo Hutnicza
Priority date: 2024-04-05
Filing date: 2024-12-13
Publication date: 2025-10-08
Also published as: PL448202A1

Abstract

Mining crib for supporting of the roof, comprising, beams arranged one on top of another in layers, wherein the beams of consecutive layers at the place of contact have notches which length is at least equal to the width of the beam, characterized in that it is constructed from cribs (1, 3) which are separated by connectors (2).A method for manufacturing a mining crib, in which beams are laid in layers one on top of the other, with the beams of successive layers having notches at their contact points with a length at least equal to the width of the beams, characterized in that beams of different types are produced, all having the same length (1) and width (b) but differing in height, as well as in the placement and length of the notches. These beams are then used to construct cribs (1, 3) separated by connectors (2).

Description

A subject of the invention is a mining crib and a method for manufacturing a mining crib. The invention is applicable in the fields of underground mining, underground construction (e.g., tunnel construction), and specialized construction (e.g., bridge construction).
The cribs used to support the roof layers, particularly in the vicinity of excavations that require prolonged support, especially near collapse zones, are well-known.
The mining crib has been known for thousands of years. Its construction involves the layered arrangement of wooden beams in an alternating pattern, with beams positioned perpendicularly to each other, in a manner that provides support for the roof layers. Depending on the spacing between the beams in a single layer, a lattice crib (where the distance between beams > 0) or a solid crib (where the distance between beams = 0) can be formed. For example, from patent document US 5435670 , the method and device for providing support for the hanging wall above a mining passage are known. The support system is mounted between the hanging wall and the passage. This system includes a spacer element, a filling element, and an inflatable bag filled with mortar, which, after setting, exerts a vertical force. The spacer element is much stiffer when compressed than the filling element, which deforms under compressive load applied by the hanging wall. The stiff spacer element lifts the deforming filling element to the appropriate working height without exceeding the allowable slenderness ratio of the compressed filling element.
Cribs known from the state of the art were made, for example, from round wood, beams, used railway ties, rail tracks, steel profiles, etc.
These solutions have undergone various modifications. For example, from patent document no. P. 233119 , a mining crib is known, consisting of longitudinal round beams arranged on top of each other in horizontal layers, where the beams of adjacent layers cross each other and rest in concave notches, creating a structure in the shape of a rectangular prism or a series of rectangular prisms, with each layer containing at least two beams. The notches are located only in the upper parts of the beams in each layer, except for the roof beams, which do not have notches.
Known are also solutions that involve fastening the individual elements of the crib together to increase its stability..
The support capacity of the crib primarily depends on the type of material from which its elements are made, the shape, and the arrangement of the elements used. The decisive factor is the load-bearing surface, or more specifically, the contact surface between the individual elements of the crib. To increase this surface, in the case of lattice cribs, the internal space of the crib is sometimes filled with material, such as waste rock.
Additionally, from patent document Pat. 182388 , a mining crib is known, which contains a set of longitudinal beams arranged on top of each other in layers, with each layer having the beams spaced apart and arranged parallel to each other, and arranged transversely to the beams in adjacent layers, crossing them at points located at a certain distance from their ends. Notches are formed in the upper and lower surfaces of the beams at the crossing points. These notches are interlocked and have a depth such that the middle part of the beam, located between the notches, and the end parts of the beam, located at its ends outside the notches, contact the corresponding parts of the beams in the layers above and below them. Thus, the crib forms a kind of box, with sides made of wooden beams arranged in a manner similar to a lattice crib, but at the contact points between the layers, notches are made with a length equal to the thickness of the beam and a depth equal to one-quarter of the height of the beam. This design results in full contact between all the beams forming the crib's wall, and additionally, the notches stabilize the individual walls of the crib in relation to each other. The crib may take the shape of a square or rectangle in plan. In the case of a rectangular crib, an additional transverse beam (wall) may be used inside the crib, as disclosed in patent document P. 399207 , which reveals a mining crib for roof support, consisting of transverse beams arranged in layers, one above the other, with notches at the contact points between the beams, each notch having a length at least equal to the width of the beams. Besides the additional transverse wall, a longitudinal wall may be introduced, for example such wall, as disclosed in utility model RU.070918 , which relates to a mining crib for roof support, consisting of transverse beams arranged in layers, one above the other, where the crossing beams in adjacent layers at the contact points have notches with a length at least equal to the width of the beams.
To increase the load-bearing surface for the loads from the roof layers to the bottom layers, the interior of the crib (box) can be filled with various materials, such as waste rock or binding mixtures, as disclosed, for example, in patent document P. 224768 . This document concerns a mining support pillar containing longitudinal and transverse layers. Each layer contains a pair of outer parallel beams. The longitudinal layers define the two longitudinal walls of the pillar. The transverse layers are arranged alternately with the longitudinal layers, so the outer beams of the transverse layers cross with the adjacent outer beams of the longitudinal layers at four crossing points and are interlocked with them via notches formed in the upper and lower surfaces of the outer beams. The transverse layers also contain a pair of internal beams that define the two internal walls of the pillar. The space defined by the internal walls of the pillar and the longitudinal walls of the pillar is filled with a self-hardening mixture.
Mining cribs were also discussed in the following publications:

Rak Z., 2011: "Utrzymanie wyrobisk przyścianowych za frontem eksploatacji w trudnych warunkach geologiczno-górniczych na przykladzie Kopalni LW "Bogdanka" S.A. - cz ść I - przegl d technologii. Przegl d Górniczy, nr 1-2", pages 33-42.
Rak Z., 2011: "Utrzymanie chodnika za ścian w trudnych warunkach geologiczno- górniczych na przykladzie Kopalni LW "Bogdanka" S.A. - cz ść II - doświadczenia ruchowe. Przegl d Górniczy, nr 1-2", pages 43-50.
Rak Z., 2017: "Dobre praktyki w utrzymywaniu wyrobiska w jednostronnym otoczeniu zrobami zawalowymi. Zeszyty Naukowe Instytutu Gospodarki Surowcami Mineralnymi i Energi Polskiej Akademii Nauk, nr 101", pages 117-132.

In practice, mining cribs are set up either directly next to each other or at short distances between them in a protected excavation. As a result, each crib works independently of its neighbours. Despite having similar load-deformation characteristics, the cribs may not always fully fulfil their role, especially in the case of weak roof conditions.
The underlying problem of the invention was to propose a mining crib that could reliably provide continuous roof support along the protected excavation, much like, for example, a backfill protective strip, and to propose a method for producing such a mining crib.
This problem was solved using a mining crib and a method for producing such a mining crib according to the invention.
A mining crib according to the invention has features defined in claim 1, the preferred features of that mining crib being defined in claims 2 to 7.
Method of producing a mining crib has features defined in claim 8, the preferred features of that method being defined in claims 9 to 15.
The proposed solutions applied in the mining crib refer to similar structures known from previous practice.
The undeniable advantage of the solution is achieving a support in a continuous form in practically unlimited length. It is a solution that is competitive in relation to the previously used point-supported cribs.
In addition to the previously known elements, new components have been introduced, enabling the construction of a continuous mining crib. The construction of the crib using these new elements does not require the user to acquire new qualifications.
An undeniable advantage of this solution is the creation of continuous support, which offers greater chances of maintaining the continuity of supported elements compared to previously used point-supported crib.
The construction of the continuous crib involves forming separate spaces within the crib, allowing these spaces to be filled, if necessary, with waste rock, binding mineral mixtures, or similar materials. This, in turn, increases the contact surface between the base and the supported element, for example, between the floor and the roof of a mining excavation.
An advantage of the solution is also cost of the solution according to the invention. In comparison to the known point-supported crib solutions, the construction of the continuous crib may save even 40% of wood while having comparable support.
The subject of the invention in the embodiments is illustrated in the attached drawing, with Fig. 1 showing a schematic top view of the continuous mining crib in a straight line arrangement, Fig. 2a shows a schematic top view of the continuous mining crib in a two-armed bent arrangement, Fig. 2b shows a schematic top view of the continuous mining crib in a three-arm bent arrangement, Fig. 2c shows a schematic top view of the continuous mining crib in a cross arrangement, Fig. 3 shows in a perspective view selected sections of the front crib, the connector made from the A-type beams (beams with tenons at both ends), and the pass-through crib in a straight-line arrangement, Fig. 3a shows in a perspective view selected sections of the front crib, the connector made from the B-type beams (with a notch at one end of the beam and a tenon at the other end), and the pass-through crib in a straight-line arrangement, Fig. 4 shows in a perspective view selected sections of the front crib, the connector made from the A-type beams (beams with tenons at both ends), and the pass-through crib in a two-armed bent arrangement, Fig. 4a shows in a perspective view selected sections of the front crib, the connector made from the B-type beams (with a notch at one end of the beam and a tenon at the other end), and the pass-through crib in a two-armed bent arrangement, Fig. 5 shows the base beam, Fig. 6 shows the base half beam, Fig. 7 shows the pass-through beam, Fig. 8 shows the pass-through half beam, Fig. 9 shows the A-type beam of the connector, Fig. 10 shows the A-type half beam of the connector, Fig. 11 shows the B-type beam of the connector, Fig. 12 shows the B-type half beam of the connector, Fig. 13 shows the example dimensions in centimetres of the base beam 8, Fig. 14 shows the example dimensions in centimetres of the pass-through beam 10, Fig. 15 shows the example dimensions in centimetres of the A-type beam 12 of the connector, Fig. 16 shows the example dimensions in centimetres of the B-type beam 14 of the connector.
As it is shown in Fig. 1, continuous mining crib in a rectilinear arrangement has at both ends front crib 1. Both front cribs 1 at the side opposite from the end of the continuous mining crib are connected with connectors 2, which at the opposite side to the front crib 1 are connected with the rectilinear pass-through cribs 3 such that on the entire length of the continuous rectilinear mining crib between the pass-through linear cribs 3 connectors 2 are located.
In the shortest variant, the continuous rectilinear mining crib consists of two front cribs 1 and one connector 2. In contrast, the length of the continuous rectilinear mining crib is practically unlimited, as it depends only on the number of installed connectors 2 and linear pass-through cribs 3, with the requirement that there must be a front crib 1 at both ends of the continuous rectilinear mining crib, and the number of connectors 2 must always be one greater than the number of installed rectilinear pass-through cribs 3.
In Fig. 2a, a two-armed bent continuous mining crib is shown, consisting of two mutually perpendicular continuous rectilinear cribs with a common connection in the form of an angular pass-through crib 4. The two-armed bent continuous mining crib has a front crib 1 at the ends of each arm. The front cribs 1 on the side opposite to the end of the two-armed bent continuous mining crib are connected to connectors 2, which in turn are connected to linear pass-through cribs 3 on the side opposite to the front crib 1, such that along the entire length of the two-armed bent continuous mining crib, connectors 2 are placed between the pass-through cribs 3. At the point of the crib's bend, i.e. the connection of the arms of the continuous mining crib, there is an angular pass-through crib 4 constructed of two mutually perpendicular solid walls 5 and two mutually perpendicular pass-through walls 6.
In the shortest variant, the two-armed bent continuous mining crib consists of two front cribs 1, two connectors 2, and the angular pass-through crib 4. In contrast the length of each arm of the two-armed bent continuous mining crib is practically unlimited, as it depends only on the number of installed connectors 2 and the rectilinear pass-through cribs 3, with the requirement that there must be a front crib 1 at each end of the arms of the two-armed bent continuous mining crib, and in each arm, the number of connectors 2 must always be one greater than the number of installed rectilinear pass-through cribs 3.
In Fig. 2b, a three-armed bent continuous mining crib is shown, consisting of two mutually perpendicular continuous rectilinear cribs with a common connection in the form of an angular pass-through crib 4. The three-armed bent continuous mining crib has a front crib 1 at the ends of each arm. All the front cribs 1 on the side opposite to the end of each arm of the continuous bent mining crib are connected to connectors 2, which in turn are connected to rectilinear pass-through cribs 3 on the side opposite to the front crib 1, such that along the entire length of the three-armed bent continuous mining crib, connectors 2 are placed between the rectilinear pass-through cribs 3. At the point where the arms of the crib meet, there is an angular pass-through crib 4 consisting of one solid wall 5 and three pass-through walls 6.
In the shortest variant, the three-armed bent continuous mining crib consists of three front cribs 1, three connectors 2, and an angular pass-through crib 4. In contrast, the length of the arms of the three-armed bent continuous mining crib is practically unlimited, as it depends only on the number of installed connectors 2 and the rectilinear pass-through cribs 3, with the requirement that at each end of the arms of the three-armed bent continuous mining crib, a front crib 1 must be installed, and the number of connectors 2 must always be one greater than the number of installed rectilinear pass-through cribs 3.
In Fig. 2c, a cross-shaped continuous mining crib is shown, which consists of two mutually perpendicular continuous rectilinear cribs with a common connection in the form of an angular pass-through crib 4. The cross-shaped continuous mining crib has a front crib 1 at the ends of each arm. All the front cribs 1 on the side opposite to the end of each arm of the continuous mining crib are connected to connectors 2, which in turn are connected to rectilinear pass-through cribs 3 on the side opposite to the front crib 1, such that along the entire length of the cross-shaped continuous mining crib, connectors 2 are placed between the rectilinear pass-through cribs 3. At the point of the arms' connection, there is an angular pass-through crib 4 constructed of four pass-through walls 6.
In the shortest variant, the cross-shaped continuous mining crib consists of four front cribs 1, four connectors 2, and an angular pass-through crib 4. In contrast the length of the arms of the cross-shaped continuous mining crib is practically unlimited, as it depends only on the number of installed connectors 2 and rectilinear pass-through cribs 3, with the requirement that at each end of the arms of the continuous mining crib, a front crib 1 must be installed, and the number of connectors 2 must always be one greater than the number of installed rectilinear pass-through cribs 3.
In Fig. 3, a fragment of a continuous rectilinear crib is shown. Front crib 1, connector 2, and rectilinear pass-through crib 3 are shown here in more detail. It can be seen that front crib 1 and rectilinear pass-through crib 3 are box-shaped. Front crib 1 is constructed from three solid walls 5 and one pass-through wall 6. The solid wall 5, perpendicular to the connector 2, is built in the first layer from one base half beam 9, and in the subsequent layers from stacked one on top of the other base beams 8, with notches at the point of contact at least as long as the width of the beams, allowing base beams 8 forming a solid wall 5 parallel to connector 2 to be fitted into these notches. The pass-through wall 6 of the front crib 1, facing the connector 2, is built in the first layer from one pass-through half beam 11, and in the following layers from stacked one on top of the other pass-through beams 10 with notches at the point of contact of such length that in the mortise formed by the notch, a base beam 8, forming a solid wall 5 perpendicular to the pass-through wall 6, and the end of the A-type beams 12 of the connector, forming the pass-through wall 7, can be inserted. The rectilinear pass-through crib 3 consists of two parallel solid walls 5 and two parallel pass-through walls 6. The pass-through walls 6, perpendicular to the connector 2, are built in the first layer from one pass-through half beam 11, and in the subsequent layers from stacked one on top of the other pass-through beams 10, with notches at the point of contact of such length that in the mortise formed by the notch, a base beam 8 forming a solid wall 5 perpendicular to the pass-through wall 6 and the end of the A-type beams 12 of the connector, forming the pass-through wall 7, can be inserted.
In Fig. 3a, a fragment of a continuous rectilinear crib is shown. This crib differs from the crib shown in Fig. 3 in that instead of A-type beams 12 of the connector, B-type beams 14 of the connector are used, such that the end of the B-type beam 14 of the connector, in the form of a notch similar to the notches in the base beam 8, is fitted into the mortise formed by the notch in the pass-through beams 10 and the pass-through half beam 11, in which the base beam 8, forming the solid wall 5 perpendicular to the pass-through wall 6, and the end of B-type beams 14 of the connector, forming the pass-through wall 7 of the connector, are also placed. As a result, a stiffer connection between the pass-through wall 6 and the wall 7 of the connector is obtained.
In Fig. 4, a fragment of the continuous bend crib is shown. Front crib 1, connector 2, and angular pass-through crib 4 are shown here in more detail. It can be seen that the front crib 1 and the angular pass-through crib 4 are box-shaped. The front crib 1 is built from three solid walls 5 and one pass-through wall 6. The solid wall 5, perpendicular to the connector 2, is built in the first layer from one base half beam 9, and in the following layers from stacked one on top of the other base beams 8, with notches at the point of contact at least as long as the width of the beams, allowing the base beams 8 forming a solid wall 5 parallel to the connector 2 to be fitted into these notches. The pass-through wall 6 of the front crib 1 and the pass-through crib 3, facing the connector 2, is built in the first layer from one pass-through half beam 11, and in the following layers from stacked one on top of the other pass-through beams 10 with notches at the point of contact of such length that in the mortise formed by the notch, a base beam 8, forming a solid wall 5 perpendicular to the pass-through wall 6 and an end of the A-type beams 12 of the connector, forming the pass-through wall 7, can be inserted. The angular pass-through crib 4 consists of two mutually perpendicular solid walls 5 and two mutually perpendicular pass-through walls 6. The pass-through walls 6 allow the insertion of beams forming the walls 7 of the connector 2. From the point where the direction of the crib's path bends, the wall 7 of the connector is built in the first layer from one A-type half beam 13 of the connector, and in the following layers from stacked one on top of the other A-type beams 12 of the connector. The subsequent pass-through cribs 3 or front crib 1 are built such that the solid walls 5 parallel to walls of the connector 2 are constructed from base half beams 9 in the first layer, and from base beams 8 in the subsequent layers. In the rectilinear pass-through cribs 3, the pass-through walls 6 perpendicular to the connector 2 are constructed from pass-through beams 10, while the solid wall 5 in the front crib 1 perpendicular to the connector 2 is constructed from the base beams 8
In Fig. 4a, a fragment of the continuous bend crib is shown. This crib differs from the crib shown in Fig. 4 in that instead of A-type beams 12 of the connector and A-type half beams 13 of the connector, B-type beams 14 of the connector and B-type half beams 15 of the connector are used. As a result, a stiffer connection between the pass-through wall 6 and the wall 7 of the connector is achieved.
In Fig. 5, the base beam 8 is shown. This beam has length l, width b, and height h. At its both ends, at a distance a equal to the width b of the beam from each of its ends, on both its upper and lower surfaces, recesses forming notches are located with a length equal to at least the width b of the beam and a depth equal to at least one-quarter of the height h of the beam.
In Fig. 6, the base half beam 9 is shown. This beam has length l, width b, and height equal to half the height h of the base beam 8. At both ends, at a distance a equal to the width b of the beam from each of its ends, on its upper surface, recesses forming notches are located with a length equal to at least the width b of the beam and a depth equal to at least one-quarter of the height h of the base beam 8.
In Fig. 7, the pass-through beam 10 is shown. This beam has length l, width b, and height h. At its both ends, at a distance a equal to the width b of the beam from each of its ends, on both its upper and lower surfaces, recesses forming notches are located with a length equal to at least double the width b of the beam and a depth equal to at least one-quarter of the height h of the beam.
In Fig. 8, the pass-through half beam 11 is shown. This beam has length l, width b, and height approximately equal to half the height h of the pass-through beam 10. At its both ends, at a distance a equal to the width b of the beam from each of its ends, on its upper surface, recesses forming notches are located with a length equal to at least double the width b of the beam and a depth equal to at least one-quarter of the height h of the pass-through beam 10.
In Fig. 9, the A-type beam 12 of the connector is shown. This beam has length l, width b, and height h. At its both ends, on both its upper and lower surfaces, the beam has recesses with a depth equal to at least one-quarter of the height h of the beam, extending from the very end of the beam over a length equal to at least the width b of the beam. As a result, at both ends, the height of the beam is reduced to at most half of its essential height h over a length equal to at least the width b of the beam.
In Fig. 10, the A-type half beam 13 of the connector is shown. This beam has length l, width b, and height approximately equal to half the height h of the A-type beam 12 of the connector. At its both ends, on its upper surface, the beam has recesses with a depth equal to at least one-quarter of the height h of the A-type beam 12 of the connector, extending from the very end of the beam over a length equal to at least the width b of the beam. As a result, at both ends, the height of this beam is reduced to at most one-quarter of the height h of the A-type beam 12 of the connector over a length equal to at least the width b of the beam.
In Fig. 11, the B-type beam 14 of the connector is shown. This beam has length l, width b, and height h. At its one end, on both its upper and lower surfaces, the beam has recesses with a depth equal to at least one-quarter of the height h of the beam, extending from the very end of the beam over a length equal to at least the width b of the beam. As a result, at this end, the height of the beam is reduced to at most half of its essential height h over a length equal to at least the width b of the beam. At the other end, at a distance a equal to the width b of the beam from its end, on both its upper and lower surfaces, recesses forming notches are located with a length equal to at least the width b of the beam and a depth equal to at least one-quarter of the height h of the beam.
In Fig. 12, the B-type half beam 15 of the connector is shown. This beam has length l, width b, and height approximately equal to half the height h of the B-type beam 14 of the connector. At its one end, on its upper surface, the beam has recesses with a depth equal to at least one-quarter of the height h of the B-type beam 14 of the connector, extending from the very end of the beam over a length equal to at least the width b of the beam. As a result, at this end, the height of the beam is reduced to at most one-quarter of the height h of the B-type beam 14 of the connector over a length equal to at least the width b of the beam. At the other end, at a distance a equal to the width b of the beam from its end, on the upper surface, recesses forming notches are located with a length equal to at least the width b of the beam and a depth equal to at least one-quarter of the height h of the B-type beam 14 of the connector.
The method of manufacturing of rectilinear continuous mining crib consists of performing the following sequence of steps:
First, the front crib 1 is constructed. For the construction of the solid wall 5 of the front crib 1, perpendicular to the length of the crib, in the first layer a base half beam 9 should be used, while in subsequent layers base beams 8 should be used. For the construction of the solid walls 5 of the front crib 1 parallel to the length of the crib, base beams 8 should be used. For the construction of the pass-through wall 6 of the front crib 1, in the first layer a pass-through half beam 11 should be used, and in subsequent layers pass-through beams 10 should be used. The beams for the solid walls 5 and the pass-through wall 6 are arranged alternately in layers according to the scheme in Fig. 3.
Care should be taken to ensure that the pass-through wall 6 made of pass-through beams 11 and 10 are positioned on the side of the front crib 1 towards the direction of further construction. The construction of the front crib 1 should continue until it becomes impossible to insert the next base beam 8 or pass-through beam 10 due to the small distance from the ceiling. The crib should be finished with a half-beam 9 or 11 of the appropriate type.
In the pass-through wall 6 of the front crib 1, mortises will be formed from the notches made in the pass-through beams 10 and 11. The tenons (ends) of the A-type beams 12 of the connector, which form the walls 7 of the connector 2, should be inserted into these mortises to their full depth. The construction should proceed sequentially from the lowest level of the mortises. The construction of the connector 2 should continue until it becomes impossible to insert the next A-type beam 12 of the connector due to the small distance from the ceiling. In this case, the wall 7 of the connector 2 should be finished with a A-type half beam 13 of the connector.
Alternatively, the walls 7 of the connector 2 may be constructed from B-type beams 14 of the connector. In this case, the walls 7 of the connector 2 should be built parallel to the pass-through wall 6 of the rising front crib 1 or the rectilinear pass-through crib 3, using the existing notches, in which the connector beams should be inserted with the full height end of the beam, in which the notches were made. When it becomes impossible to insert the next B-type beam 14 of the connector due to the small distance from the ceiling, the wall 7 of the connector 2 should be finished with a B-type half beam 15 of the connector.
After completing the construction of the connector 2, the construction of the rectilinear pass-through crib 3 can begin.
The rectilinear pass-through crib 3 from the side of the connector 2, i.e. its pass-through walls 6, is built in the first layer from pass-through half beams 11, and then from pass-through beams 10. The solid walls 5 of the pass-through crib 3 are constructed from base beams 8. The beams of the pass-through walls 6 should be arranged in layers alternately with the beams of the solid walls 5 according to the scheme in Fig. 3. Care should be taken to ensure that the tenons of A-type beams 12 of the connector or B-type beams 14 of the connector forming the walls 7 of the connector 2 are positioned along the entire length in the mortises formed from the notches made in the pass-through beams 10 and 11 forming the pass-through wall 5 of the pass-through crib 3.
The construction of the rectilinear pass-through crib 3 should continue until it becomes impossible to insert the next base beam 8 or pass-through beam 10 due to the small distance from the ceiling. In this case, the wall of the rectilinear pass-through crib 3 should be finished with the appropriate half beam 9 or 11.
In the opposite pass-through wall 6 of the pass-through crib 3, mortises will be formed from notches made in the pass-through beams 10 and 11. The operations leading to the construction of the wall 7 of the connector 2, involving the insertion of the tenons of A-type beams 12 of the connector to the mortises to their full depth, should be carried out sequentially from the lowest level of the mortises.
The construction of connectors 2 and pass-through cribs 3 is repeated until approaching the endpoint of the continuous rectilinear mining crib construction, which must be terminated with a front crib 1.
It is possible to create a bent continuous crib in plan, as schematically shown in Fig. 2a. To do this, the rectilinear pass-through crib 3, consisting of two parallel solid walls 5 and pass-through walls 6, should be modified. The construction of the angular pass-through crib 4 involves forming a crib from two mutually perpendicular solid walls 5 and pass-through walls 6, as shown in Fig. 4. The angular pass-through crib 4 enables the connection of two above described continuous rectilinear cribs at a right angle, thereby replacing the front crib for both continuous rectilinear cribs. Depending on the needs, the angular pass-through crib can be constructed from three pass-through walls 6 and one solid wall 5, as shown in Fig. 2b. In this case, for one continuous rectilinear crib, it will serve as the pass-through crib 3, while for the other continuous rectilinear crib, it will serve as the front crib.
In the extreme case, the angular pass-through crib 4 can be constructed from four pass-through walls, allowing the intersection of two continuous rectilinear cribs, thereby serving as a pass-through crib for both of these continuous rectilinear cribs. Such a crib is shown in Fig. 2c.
It is recommended that the crib elements (beams) be made of wood of at least class IV according to the Janka classification (e.g., beech, oak, ash, hornbeam). Using wood of a lower class will result in reduced load-bearing capacity of the crib.
In the exemplary embodiment of the invention, all beams are made of beech wood.
As it is shown in Fig. 13, the base beam 8 is 140 cm in length, 10 cm in width and 20 cm in height. The recess with minimum length of 10 cm and minimal depth of 5 cm is placed both at the bottom and top surface of beam 8 at its both ends, in distance of 10 cm from the given end of said beam.
As it is shown in Fig. 14, the pass-through beam 10 is 140 cm in length, 10 cm in width and 20 cm in height. The recess with minimum length of 20 cm and minimal depth of 5 cm is placed both at the bottom and top surface of beam 10 at its both ends, in distance of 10 cm from the given end of said beam.
As it is shown in Fig. 15, the A-type beam 12 of the connector is 120 cm in length, 10 cm in width and 20 cm in height. At its both ends, both at its top and bottom surfaces the beam has recesses of minimal depth equal to 5 cm, that run from the very end of the beam through a minimal length of 10 cm, as a result, at the both ends the height of beam 12 is reduced to a maximum value of 10 cm over a minimum length of 10 cm
As it is shown in Fig. 16, the B-type beam 14 of the connector is 130 cm in length, 10 cm in width and 20 cm in height. At its one end both at its top and bottom surfaces the beam has notches of minimal depth equal to 5 cm, that run from the very end of the beam through a minimal length of 10 cm, as a result, at this end, the height of the beam is reduced to a maximum of 10 cm at the minimum length of 10 cm. At the other end, at a minimum distance of 10 cm from its end, both on its upper and lower surfaces, recesses forming notches are located with a minimum length of 10 cm and a minimum depth of 5 cm.

Figure indicators

1 -: Front crib
2 -: Connector
3 -: Linear pass-through crib
4 -: Angular pass-through crib
5 -: Solid wall
6 -: Pass-through wall
7 -: Connector wall
8 -: Base beam
9 -: Base half beam
10 -: Pass-through beam
11 -: Pass-through half beam
12 -: A-type beam of the connector
13 -: A-type half beam of the connector
14 -: B-type beam of the connector
15 -: B-type half beam of the connector

Claims

Mining crib to support a roof, comprising beams arranged in layers one on top of the other, wherein the beams of consecutive layers have at a points of contact notches of length at least equal to the width of the beams, characterised in that it is formed by cribs (1, 3) continuously arranged one after another, and which are separated from each other by connectors (2).
Crib according to claim 1 characterised in that at both ends of the mining crib there are front cribs 1, while between them, separated by connectors (2) there are rectilinear pass-through cribs (3) or angular pass-through cribs (4) placed, wherein the front crib (1) is made of base beams (8), a base half beam (9), and a pass-through half beam (11), arranged in the first layer, and in subsequent layers, alternately from the base beams (8) and the pass-through beams (10), wherein the base beam having a length (l), width (b), and height (h), at both ends at a distance (a) from each end, in both top and bottom surfaces, has recesses forming notches with a length equal to at least the width (b) of the beam and a depth equal to at least one-quarter of the height (h) of the beam, the pass-through beam (10) of length (l), width (b), and height (h), at both ends, at a distance (a) from each end, in both top and bottom surfaces, has recesses forming notches with a length equal to at least double the width (b) of the beam and a depth equal to at least one-quarter of the height (h) of the beam, the base half beam (9) of length (l) and width (b) has a height equal to half the height (h) of the base beam (8) and the pass-through beam (10), and at both ends, at a distance (a) from each end, in its top surface, has recesses forming notches with a length equal to at least the width (b) of the beam and a depth equal to at least one-quarter of the height (h) of the base beam (8) and the pass-through beam (10), the pass-through half beam (11) of length (l) and width (b) has a height equal to half the height (h) of the base beam (8) and the pass-through beam (10), and at both ends, at a distance (a) from each end, in its top surface, has recesses forming notches with a length equal to at least double the width (b) of the beam and a depth equal to at least one-quarter of the height (h) of the base beam (8) and the pass-through beam (10), and wherein the front crib (1) on the side of the connector (2) has a pass-through wall (6) made of pass-through beams (10) and pass-through half beams (11) and wherein the last, top layer of the front crib is formed from base half beams (9) and/or pass-through half beams (11).
Crib according to claim 2, characterised in that in the pass-through wall (6) of the front crib (1) there are recesses from notches made in the pass-through beams (10) and in pass-through half beams (11).
Crib according to claim 3, characterised in that in the assembled state of the crib, tenons of A-type beams (12) of the connector are located in mortises over the full depth of the mortises, wherein the A-type beam (12) of the connector having length (1), width (b), and height (h), at its both ends, both on the upper and lower surfaces, has recesses with a depth equal to at least one-quarter of the height (h) of the beam, extending from the very end of the beam for a length equal to at least the width (b) of the beam, so that at both ends, the height of the A-type beam (12) of connector is reduced to at most half its essential height (h) over a length equal to at least the width (b) of the beam.
Crib according to claim 3, characterised in that in the assembled state of the crib, tenons of B-type beams (14) of the connector are located in mortises over the full depth of the mortises, wherein the B-type beams (14) of the connector having length (/), width (b), and height (h), at its one end, both on its upper and lower surfaces, has recesses with a depth equal to at least one-quarter of the height (h) of the beam, extending from the very end of the beam for a length equal to at least the width (b) of the beam, so that at this end, the height of the beam is reduced to at most half its essential height (h) over a length equal to at least the width (b) of the beam, while at the other end, at a distance (a) equal to the width (b) of the beam from its end, both on its upper and lower surfaces there are recesses forming notches with a length equal to at least the width (b) of the beam and a depth equal to at least one-quarter of the height (h) of the beam.
Crib according to claim 1, characterised in that the pass-through walls (6) of the rectilinear pass-through crib (3) on the side of the connectors (2) are made of pass-through beams (10) and pass-through half beams (11), while the solid walls (5) are made of base beams (8) and base half beams (9), wherein these beams are arranged alternately in layers.
Crib according to claim 1, characterised in that in the pass-through wall (6) of the rectilinear pass-through crib (3), there are mortises formed from the notches made in the pass-through beams (10) and pass-through half beams (11)
Method of producing a mining crib in which beams are arranged in layers one on top of the other, wherein the beams of consecutive layers at the points of contact have notches with a length at least equal to the width of the beams, characterized in that beams of different types are produced with all beams having the same length (1) and width (b), but differing in height, as well as the placement and length of the notches, and then these beams are used to build cribs (1) and (3), arranged continuously one after the other and separated by connectors (2).
Method according to claim 8, characterised in that at both ends of the mining crib, front cribs (1) are arranged, and between them, separated by connectors (2), are arranged rectilinear pass-through cribs (3) or angular pass-through cribs (4), the front crib (1) being built first, wherein base half beams (9) and pass-through half beams (11) are arranged alternately in layers, wherein the base beam (8) with length (l), width (b), and height (h) has, at both ends, at a distance (a) from each of its ends, in both its top and bottom surfaces, has recesses forming notches with a length at least equal to the width (b) of the beam and a depth of at least one-quarter of the height (h) of the beam, the pass-through beam (10) with length (1), width (b), and height (h), at both ends, at a distance (a) from each of its ends, in both its top and bottom surfaces, has recesses forming notches with a length equal to at least double the width (b) of the beam and a depth of at least one-quarter of the height (h) of the beam, the base half beam (9) with a length (1) and width (b) has height equal to half the height (h) of the base beam (8) and the pass-through beam (10), and at both its ends, at a distance (a) from each of its ends, in its top surface, has recesses forming notches with a length equal to at least the width (b) of the beam and a depth equal to at least one-quarter of the height (h) of the base beam (8) and the pass-through beam (10), while the pass-through half beam (11) with a length (1) and width (b) has a height equal to half the height (h) of the base beam (8) and the pass-through beam (10) and at both its ends, at a distance (a) from each of its ends, in its top surface, has recesses forming notches with a length equal to at least double the width (b) of the beam and a depth equal to at least one-quarter of the height (h) of the base beam (8) and the pass-through beam (10), wherein the pass-through wall (6) of the front crib (1), facing the connector, is formed from the pass-through beams (10) and the pass-through half beams (11).
Method according to claim 8, characterised in that the mining crib is built until it becomes impossible to install another base beam (8) or pass-through beam (10) due to the small distance from the ceiling, at which point a base half beam (9) or a pass-through half beam (11) is placed at the end of the crib construction.
Method according to claim 8, characterised in that during the construction of the front crib (1), mortises are created in its pass-through wall (6) from notches made in the pass-through beams (10) and pass-through half beams (11), wherein tenons of A-type beams (12) of the connector or tenons of B-type beams (14) of the connector are inserted into the mortises throughout the entire depth of the mortises, wherein the construction is carried out sequentially from the lowest level of the mortises.
Method according to claim 8, characterised in that parallel to the construction of the connector (2), the rectilinear pass-through crib (3) is constructed.
Method according to claim 12, characterised in that the pass-through walls (6) of the rectilinear pass-through crib (3) on the side of the connectors (2) are constructed from pass-through beams (10) and pass-through half beams (11), while the solid walls (5) are constructed from base beams (8) and base half beams (9), wherein the beams are arranged alternately in layers.
Method according to claim 13, characterised in that in the pass-through wall (6) of the pass-through crib (3), mortises are created from notches made in the pass-through beams (10) and pass-through half beams (11).
Method according to claim 8, characterised in that the operations of introducing tenons of the A-type beams (12) of the connector into the mortises over the full depth of the mortises, carrying out the construction sequentially from the lowest level of the mortises, building the rectilinear pass-through crib (3) parallel to the construction of the connector (2), constructing the pass-through walls (6) of the rectilinear pass-through crib (3) on the side of the connectors (2) from pass-through beams (10) and pass-through half beams (11), and constructing the solid walls (5) from base beams (8) and base half beams (9), arranging the beams alternately in layers, and forming mortises from notches made in the pass-through beams (10) and pass-through half beams (11) in the pass-through wall of the rectilinear pass-through crib (3) are repeated until reaching the end of the continuous rectilinear mining crib construction, wherein the continuous rectilinear mining crib ends with a front crib (1).