TUNNEL LINING MADE OF PREFABRICATED REINFORCED CONCRETE ELEMENTS AND PROCESS FOR ITS MANUFACTURING AND INSTALLING
1. TECHNICAL FIELD TO WHICH THIS INVENTION IS RELATED
This invention is related to the system for manufacturing tunnel linings by prefabricated arc- formed self-supporting hydro-insulated concrete elements, serving at the same time as a formwork for concrete filling. This invention saves the working time in the tunnel, lowers the amount of jet-concrete needed for the base of hydro-insulated layer and the hydro-insulation itself, as the working phase in the tunnel is not necessary. So in the case of inclusion of a fire protection system, it shall be performed as two-layer element including outer fireproof layer. The application of prefabricated arc-formed self-supporting hydro-insulated concrete elements provides the possibility for decreasing tunnels burrow profiles.
According to the International Patent Classification, the invention is classified and assigned a classification symbol E21D 11/08, 11/18, 11/40.
2. TECHNICAL PROBLEM
(for which patent protection is applied for)
The technical problems to be solved by this invention of tunnel lining made of prefabricated arc-formed self-supporting hydro-insulated concrete elements, are: 1. Production of arc-formed elements in the factory,
2. Assembling of elements "under the roof,
3. Interconnection of elements,
4. Hydro-insulating layer of upper sheet and sealing of connections, including a fire protection of concrete, 5. Assembling of circular automotive working platform in the tunnel, and
6. Automation of working operations.
3. STATE OF THE ART
(presentation and analysis of well-known solutions of technical problems defined)
No system of prefabricated tunnel lining has been elaborated in our country thus far, so tunnel lining is performed monolithically by means of sliding linings. First of all, a layer of approx. 20-cm jet-concrete is made and then a hydro-insulation as sliding lining upon it. After that the monolithic tunnel lining is made, as sliding lining, whose progression is dependent on the length of the lining and the time needed for concrete solidification. To my knowledge there is a solution of prefabricated lining only for hydro-technical tunnels and completely circular profile tunnels, but it is completely different from the present invention.
4. DISCLOSURE OF THE ESSENCE OF THE INVENTION (in such a way that the technical problem and its solution may be understood as well as the indication of the technical novelty of the invention in relation to the state of the art)
4.1 Production of arc-formed concrete elements in the factory
The special technical problem is making of the lining, requiring the making of elements in the geometric form following the plan's curvature of the tunnel axes, since to turn a solid circular bottom between two cylinder's surfaces is impossible.
The solution is that the bottom's surface (13), in the part which closes the lining bellow, is to be made in segments (13.1) which are interconnected by rubber joint (13.2). It enables changing of curvature radius and transforming of circular segment into ellipsoid segment, or performing of lateral sides in two parts respectively, with the possibility of interjecting triangular element. Lowering of elements' dimensions due to concrete's congregation is solved by well-known technological production process of concrete mixture with additives for ranking of concrete.
4.2 Assembling of elements "under the roof
Assembling of 5-tons weight elements "under the roof of tunnel, provided that the free space between elements and the wall is only few millimetres, is very difficult technical problem,
which we solved by the system of automotive working platform for transversal and circular drawing of elements. The working platform (1.1, 1.2, 1.3 and 1.4) consists of the central part with the opening for the site vehicles passing tlirough, and the lateral parts (2.1, 2.2). Their purpose is receiving and mounting of the lower lining elements (A and E), and receiving and launching of upper lining elements (B, C and D) on the upper circular grille (IT) with cylinders (1.2 and 1.3) for reception, longitudinal and transversal transportation of prefabricated elements (B, C and D). The symmetric quality of the working platform enables reception, launching and assembling of elements on the left and right side, depending of the situation on the site, as well as assembling of tunnel lining, consisting of three elements in transversal cross-section, and all according to the same details and operations. The description of assembling, the way of attachment and the insurance of stability apply to both systems presented, and supported by the description of articulated drawings.
4.3 Interconnection of elements
Interconnection of elements is possible in two basic ways, namely by wet and dry process. Wet process implies injecting concrete mortar or connection mixture respectively into openings reserved for this purpose on the connection surfaces of these elements. After solidification of injected mass the element takes-over the loading. Dry process, applied in this technical solution, requires precise production of elements in the factory, in which process grooves have to be coated by rubber of a corresponding solidity to annul production deficiencies of reinforced concrete elements.
4.4 Prefabricated assembly element as hydro-insulating and fire protection tunnel lining element
After binding and solidification of concrete in the factory warehouse a hydro-insulation of the upper surface is made with polymer-cement coating or with any good quality hydro-insulation, or to use impregnability additives in the concrete mixture to prevent penetrating of moisture from dripping water. Rubber proportionally profiled to concrete form is glued on the lateral sides, whose purpose is to serve as fitting element, and especially as a hydro-insulating element. The rubber is fire protected by special permanently elastic lute, which is heat-
resistant up to 300°C or by fireproof seals up to 1350°C respectively, and concrete itself is fire protected by two-layers out of which the lower layer is fireproof up to 1350°C.
4.5 Prefabricated assembly element as a formwork for concrete filling between the tunnel calotte and lining
After longitudinal force is applied to the assembled arc and the arc is reclined on the adjustable screw supports, the next step is concreting of arc-bed and space between assembled arc and calotte tunnel, so that the concrete filling completely fulfil the space between tunnel calotte and assembled arc. Concrete filling may be reinforced or non-reinforced, depending on the terms contained in technical documents.
In the case of necessity, there is a possibility of separating the arc-structure and concrete filling from tunnel calotte by previously covering tunnel calotte by compressible material of the thickness predetermined by the project. Compressible material, beside the dilatation role, has the role of cover lost.
4.6 Assembling of circular automotive working platform in the tunnel
By help of car-crane, lower part of working platform (1.4) is assembled classically as a driving unit (1.4), and upper part of a circular working platform (1.1) has to be unloaded from the truck in one piece and mounted transversally to the tunnel axes alongside already mounted part. By means of hydro-motor, previously mounting assembly elements "E" and "D" on sliders, it is lifted through a console on the height of beds on the part (1.4). Thereafter it is temporary leaned on the tubular working platform, which is trailed under circular carrier, stabilised and already assembled lower part is trailed under the circular carrier by its own drive. Follows screw-joining, then temporary support of light tubular working platform is disassembled and automotive working platform is ready for use.
4.7 Automatic control of working operations
Automatic control of working operation is solved by means of remote control of all working operations relating to reception of assembly element, to its trailing to the axes of circular assembly prefabricated automotive grid, and to its mounting into final position. Thereafter the working platform is turned out and transferred on new working position. In new working
position on one launching element (2.1) it receives assembly element "E" and "lafef for receiving tube for concrete transportation on the other launching element. Then it performs concreting of interspace between calotte and mounted arc-crown made of prefabricated reinforced concrete elements and after concreting is finished "lafef is taken off. Mounting of the next arc with "E" element, which was used as ballast for smooth concreting until now, may start. Automatic quality of these working operations consists of impossibility of starting activities, which might jeopardise the security of user, and provides for secure and correct performance of activity, which is in process.
5. DESCRIPTION OF FIGURES
Figures la and lb show reception of assembly elements "E" and "D" on launching sliders (2J). From this position element "E" is lifted into vertical position and transferred to the axis of assembly grid.
Assembly element (E) is brought to final position by shifting and turning of launching slider (Figures 2a and 2b). Vertical position is secured by adjustable screwed supports (3). Then, concrete formwork is made. At the same time, the lining assembly element (D) is brought to the axes of circular prefabricated grid by the sliding element (2.2). By turning the receiving arm of the slider (2.1) and by horizontal shifts of slider foot (2.2) the element (D) is brought to the launching position. It is fastened by steel line to the winches driven by hydro-motors (18) and over cylinders (1.2 and 1.3) is drawn by steel line (16) into the position onto already mounted element (E). Shifting of the elements into tunnel axes direction is done by the cylinders (1.3).
At the same time, the element (C) is mounted to the launching slider, and by horizontal shift translation of slider (2.2) and by turning the arm (2.1) it is brought to the launching position. Then fastened by steel line (16) onto winches (18) driven by hydro-motors and over cylinders (1.2 and 1.3) it is drawn by steel line (16) into the position next to already mounted element (D) (Figures 3a and 3b). It is fastened provisionally to the element (D), and that only when mounting the first arc, the receiving element (9) is released, and lowered to the launching ramp (2.1) to receive the element (B). The same operation is repeated for the assembly element (B). At the same time, the element (A) (Figures 4a and 4b) is mounted to the launching slider, and by horizontal shift of slider (2.2) and by turning the arm (2.1) it is brought to the final position (figure 5a and 5b).
It comes up to securing of vertical position by adjustable screw supports (3), importing 120 to 150 kN stress force, by necessary protection against radial movements of connecting points of assembly elements by screw anchors (4) only for the first arc. Lateral wedging in the already mounted arc retains the next arcs, and formwork for concrete as lining support is built in. After that the working platform serves as the carrier of the formwork (only for the first arc) for concreting the interspace between the prefabricated lining and tunnel calotte (Figures 6a and 6b). After making the first arc, the working platform remains in this position approximately twenty hours, until the outer concrete formwork is removed. After removing the outer concrete formwork and releasing of all supports, the working platform is lowered 90 mm and is put over the four wheels (1.5 and 1.6), two of them being driving wheels (1.5), onto the longitudinal beam (5), which is supported by vertically and horizontally adjustable beds (6). By starting the driving wheels, the working platform is shifted into the new position for assembling of the new arc, which is assembled in the same way as it is described for the first arc. Thereby the new arc is fixed by assembling - disassembling linkage (10) onto the already finished arc by means of the grooves (7) and the protrusions (8) (Figures 7a and 7b, and Figures 8a and 8b).
The cross-section (Figures 9a, 9b, 9c and 9d) show the system of connecting assembly elements in the tunnel axes direction by means of cone groove (7) and cone protrusion (8) and assembling - disassembling linkage laths (10) ensuring nestling of arcs during concreting of intersections between assembly elements and tunnel calotte. The same cross-section shows the method of supporting and shifting of the working platform from one working position to another.
Figures 10a, 10b and 10c show the receiving element (9) with element (11) for receiving steel line and holding system (12) for receiving element onto launching slider (2.1).
Figures 11a and lib show three-dimensional assembly element "A" characterised by its lower part being formed for receiving hydraulic cranes and adjustable screw supports (3 and 4) for protection against vertical and horizontal shiftings. The upper part is provided with the characteristic cylindrical rib for wedging the assembly element "B". The lateral regions are provided with the conical grooves (7) on one side and conical protrusions (8) on the other.
There are two plastic inserts fixed from the inside, with inner thread for fixing the receiving element (9) for manipulation and assembling. Also there are two plastic inserts with inner thread on every lateral reinforcement of assembly element, for fixing assembling - disassembling linkages (10) made for securing mutual nestling of old and new arc during concreting of interspace between the arc and tunnel calotte. After the assembling is finished, the plastic inserts serve for the suspension of the illumination, signalization, ventilation and the like, to the tunnel lining.
Figures 12a and 12b show three-dimensional assembly elements "B", "C" and "D", which are equal mutually, and which are characterised by the fact that the lower part has a cylindrical groove for connecting to assembly element "A". The upper part is provided with characteristic cylindrical rib for wedging assembly element "C". The lateral sides are designed with conical grooves (7) on one side, and conical protrusions (8) on the other. There are two plastic inserts fixed from the inside, with inner thread for fixing the receiving element (9) for manipulation and assembling. Also there are two plastic inserts with inner thread on every lateral reinforcement of assembly element, for fixing assembling — disassembling linkages (10) provided for securing mutual nestling of old and new arc during concreting of interspace between the arc and tunnel calotte. After the assembling is finished, the plastic inserts serve for suspension of the illumination, signalization, ventilation and the like, to the tunnel lining.
Figures 13a and 13b show three-dimensional assembly element "E", which is characterised by the fact that its lower part is formed for receiving hydraulic cranes and adjustable screw supports (3 and 4) for protection against horizontal and vertical shifting. The upper part is provided with characteristic cylindrical groove for wedging assembly element "D". The lateral sides are provided with conical grooves (7) on one side, and conical protrusions (8) on the other. There are two plastic inserts fixed from the inside, with inner thread for fixing the receiving element (9) for manipulation and assembling.
Also there are two plastic inserts with inner thread on every lateral reinforcement of assembly element, for assembling - disassembling linkages (10) made for securing mutual nestling of old and new arc during concreting of interspace between the tunnel arc and tunnel calotte. After the assembling is finished, the plastic inserts serve for the suspension of the illumination, signalization, ventilation and the like, to the tunnel lining.
Figure 14 shows the system of receiving assembly element "C" and the conducting system for steel line (16), which is manually put on the receiving element (11). The complete assembly (9, 11, "C") is withdrawn by hydro-motor (18) over the cylinders 1.2 and 1.3 toward final position. By passing the lower receiving element (11) over the steel line (17), it is automatically hooked by special hook to the receiving element (11). In this way we have the possibility of moving the assembly element into both directions, which is important during the movement of the assembly element in the tunnel direction, for the wedging of the protrusions (8) to the grooves (7).
Figure 15a shows the side view of assembly element, Figure 15b shows the drawing of the lining, Figure 15c shows the plan of the lining, Figure 15d shows the detail of the bottom. All this is for the purpose of better presentation of the system of lower bottom (13) with the solid steel part (13.1), rubber joints (13.2), and adjustable supports (13.3). The lower bottom is brought out of the perpendicular position between the outer (13.4) and inner (13.5) lining by adjustable supports, as in details of the project, so that concrete assembly element, for the part of lining in the curve, has necessary trapezium form in the plan.
Figure 16 shows THE SYSTEM OF TUNNEL LINING MADE OF THREE
PREFABRICATED REINFORCED CONCRETE ELEMENTS shown in the cross-section.
6. DETAILED DESCRIPTION OF AT LEAST ONE WAY FOR CARRYING OUT THE INVENTION
6.1 Production of assembly elements
Production of assembly elements is advisable in closed area equipped by crane of min. 50 kN of loading force, and sufficient space for 50 moulds beneath the crane for production of prefabricated assembly elements, and space for products of three-day production also beneath the crane. Those elements are set up in such a way, that depending on the space available, it enables finishing of lateral sides for gluing rubber tape afterwards. Finishing the upper side by hydro-insulating lining is enabled in intermediate stage by transmission to the warehouse of the factory or on the platform in front of the tunnel. Trapezium formed elements in the plan
necessary for carrying out of tunnel lining in the curve, are made by means of adjustable bottom section (13) with rubber joints.
6.2 Assembling of elements in roadway tunnel
Prefabricated assembly elements are transported and deposited beside the tunnel margin and the working platform. The crane is lifting them to carry them above the launching ramp (2.1), on which they are fixed through receiving element (9) by means of two screws. A launching ramp is pulled into the axis direction of circular working platform by endless transporting chain. Assembly element "E" is mounted by launching ramp to the final position, where it is fixed by adjustable screw supports (3 and 4), and by assembling - disassembling linkages next to the previously positioned element. Simultaneously, assembly element "D" is pulled into the axis direction of circular working platform by launching ramp and by means of built in hydraulic cylinders it is brought to the trajectory for drawing it to the site. In this position the upper line (16) is attached to the receiving element (9) and drawing of the element is starting. When the element passed approx. 4 m of trajectory, the lower line (17) is hooked automatically to the receiving element and concrete assembly element "D" is drawn to the final position. Here, by means of lines and cylinders (1.3), it is brought to the final position in transversal and longitudinal sense. Here, it is now attached to the previously assembled arc by assembling - disassembling linkages (10), which are fixed by screws provided with plastic anchors. After fixing the elements to the previously assembled arc, receiving element (9) is separated from assembly element "D", and by means of lines it is drawn back to the launching ramp (2.1). Disassembling of lower line from the receiving element is performed automatically, when the element "D" is passing through the position of element B". The upper line is now manually separated from the receiving element, which is then received automatically on the launching ramp, which then, with the receiving element and by means of endless chain is moved out from circular working platform to get element "C". Element "C" is brought to the place of assembling in the same way as the element "D", and is attached to already existing arc by means of assembling - disassembling linkages, and after that receiving element is released and drawn back to the launching ramp. Then, the element "B" is taken and assembled in the same way next to the element "C" and the existing arc, and it is attached to the existing arc but not with full force. It remains fixed to the upper line (16) until the launching ramp delivers the element "A", which
is drawn towards the element "B" and attached by means of assembling - disassembling linkages but not with full force, next to the existing arc. By means of hydraulic cranes set to the heel of the crown and directed to the element "A", the longitudinal force of approx.120 kN is directed to the assembled arc which is thereby undertaking the loading. The heel of the crown is secured in the vertical and horizontal direction by means of adjustable screw supports (3, 4), hydraulic working platforms are taken out and the lining of the heel of the crown is assembled. Then, receiving element is released from elements "A" and "B", circular automotive working platform is taken down to the wheels and driven by its own power out from mounted arc. Then it is fixed to new operating position and has now function of tube carrier for transporting concrete to the cavity between tunnel calotte and mounted arc, made of prefabricated assembly elements. This facilitates and accelerates the manipulation with usually heavy concreting tube, and achieves an ideal concreting of arc, gradually both on one and another side from the heel of the crown towards the top by approx.2/3 width of mounting element, to simply embedding the concrete by vibrating. Immediately after concreting is finished, tube carrier for concrete transport is taken down and the new arc assembling is going to start.
7. WAY OF USING THIS INVENTION
The solution of these technical problems, include the following technical-technological characteristics which are combined in tunnel construction process:
• Elements assembled in arc unit constitute final treatment of tunnel surface, • Waterproof layer is made by hydro-insulated layer on outer surface and rubber seals on lateral surfaces,
• Hydro-insulation on the jet-concrete layer is omitted,
• Jet-concrete layer thickness is depending on geo-mechanical characteristics of rock and is decreased from approx. 25 cm to approx. 5 cm, • Substitution of monolith part of tunnel lining,
• Serves as a formwork for concrete filling,
• In the case of needed of fire-protection, in double-layer it serves as fireproof element for concrete lining protection,
• Fixing points for manipulation and mounting of plates are used for ventilation fastening, runnel illumination and other tunnel signalling equipment.
It is important to notice that automotive working platform for circular mounting of prefabricated tunnel lining elements serves also for concreting cavity between tunnel arc and tunnel calotte. This is because it is provided to lead tubes for concrete transportation exactly over circular arc with the same equipment as for assembling reinforced concrete elements, i.e. concrete transporting tube is fixed onto sliding circular element "lafef with the possibility of moving the tube to the tunnel direction.
Apart from using the working platform in the manufacturing of tunnel lining made of prefabricated reinforced concrete elements, it can be used, with minor adaptations, for assembling of hall arc-constructions, bridges and inside covering assemblies and the like, in the construction of boats, aircrafts and other constructions with rounded inner surface. With minor structural changes, it can be used as a working platform for maintaining road tunnels and for reconstruction operations requiring constant traffic movement, which is very important for tunnel usage during general maintenance and reconstruction operations.