A method for waterproofing tunnel linings formed by prefabricated cut stone, and prefabricated cut stone usable in this method.
The method uses prefabricated cut stones with grooves and injection pipes to fill interconnected hollow channels with sealant, addressing waterproofing gaps in tunnel linings, ensuring effective waterproofing and reducing repair costs.
Patent Information
- Authority / Receiving Office
- JP · JP
- Patent Type
- Applications
- Current Assignee / Owner
- MACCAFERRI TUNNELING SRL
- Filing Date
- 2024-05-23
- Publication Date
- 2026-06-30
AI Technical Summary
Existing methods for waterproofing tunnel linings formed by prefabricated cut stones fail to reliably prevent water intrusion due to gaps and incomplete contact between waterproof seals at the corners and joints, leading to costly and difficult repair work.
A method involving prefabricated cut stones with peripheral grooves and injection pipes is used to create interconnected hollow channels, which are filled with a watertight sealant to form a continuous sealing strand, ensuring waterproofing by forming a grid of hollow channels between the cut stones.
The method provides a reliable and efficient waterproofing solution that maintains tunnel integrity by preventing water intrusion, even in areas of incomplete contact between waterproof seals, and can be easily integrated into existing tunnel construction methodologies.
Smart Images
Figure 2026521341000001_ABST
Abstract
Description
Technical Field
[0001] The present invention generally relates to the technical field of ordinary tunnel construction. In particular, the present invention relates to a waterproof treatment method for a tunnel lining formed by precast cut stones and precast cut stones that can be used in such a method.
Background Art
[0002] As is known, one of the basic operations when constructing an ordinary tunnel by excavating underground is to generate one or more lining layers to stabilize and enclose the walls exposed by the excavation.
[0003] As a lining for a known type of ordinary tunnel, there is what is known as "cut stone" in which precast members made of concrete and formed into appropriate shapes are installed adjacent to each other. This type of lining is usually realized by sequentially forming a lining ring that extends over the entire circumference of the excavation section as the excavation progresses and each of which is formed from a plurality of cut stones.
[0004] This type of lining is generally used in ordinary tunnels constructed by so-called "mechanized" techniques, but is not limited thereto. In this case, basic operations such as underground excavation, removal of excavated soil and sand, and lining of the excavation wall surface are continuously and simultaneously performed by a large-sized automated machine called a TBM (Tunnel Boring Machine) that is appropriately designed. These machines perform excavation integrally and continuously, while removing excavated soil and sand from the excavation face and gradually arranging the tunnel lining as the excavation face progresses.
[0005] In the case of ordinary tunnels constructed using "mechanized" technology, a single lining layer precisely formed from prefabricated cut stone is typically installed, as described above. In this case, the tunnel lining must ensure the structural stability of the tunnel while simultaneously preventing water from entering the tunnel. Such intrusion must be avoided as much as possible, not only for the sake of ensuring the immediate safety of tunnel passage, but also because it causes premature deterioration of the lining. Repairing such intrusion requires extremely expensive work, both directly and indirectly, as it involves restrictions or even suspension of non-tunnel passage, making the construction difficult and often lacking in effectiveness and durability. In particular, with linings formed from prefabricated cut stone, water can penetrate into the areas of the joints between adjacent cut stones, and especially combined with repeated freezing and thawing, concrete cracks and damage occur in the areas at the edges of the cut stones over time.
[0006] To waterproof tunnel linings formed of prefabricated cut stones, it is known to use cut stones with waterproof seals along their entire perimeter. These are typically waterproof seals made of sufficiently large elastomer material that can withstand the high compressive forces subjected to them during use without damage, and usually have a planar outer waterproof surface. As the cut stones are assembled to form cut stone rings, and then the cut stone rings are placed side by side in the axial direction, the contact pressure between adjacent cut stones causes the opposing waterproof surfaces of the waterproof seals of adjacent cut stones to press against each other, typically causing partial deformation of the waterproof seals themselves, and as a result, a sealed joint line is formed between adjacent cut stones that is waterproof and prevents water from passing through the tunnel lining thus formed.
[0007] In practice, the above solution has been found to cause problems in the corner areas of the cut stones. In these areas, gaps can form between the waterproofing surfaces of the waterproofing seals of adjacent cut stones, allowing water to seep in, and in some cases, a large amount of water may seep in.
[0008] This drawback is related to the type of waterproof seal used in these applications and can occur even if the worker takes the utmost care in precisely positioning the cut stone. In fact, when these waterproof seals are applied continuously to the corner zone area of cut stone, their large dimensions and structure generally result in shape changes that prevent good contact with the opposing waterproof surface of the waterproof seal of adjacent cut stone. To overcome this drawback, waterproof seals for cut stone have been developed, in which the corner area consists of a suitable molded insert bonded or vulcanized to the corresponding straight portion of the waterproof seal. However, in this case, although control over maintaining the geometric shape of the corner area is enhanced, variations in the consistency of the waterproof seal may occur, potentially resulting in incomplete contact with the opposing sealing surface of the waterproof seal of adjacent cut stone.
[0009] Furthermore, although less frequent, if the joints are not perfectly aligned, the contact between the opposing waterproof surfaces of the waterproof seals of adjacent cut stones may be incomplete, resulting in gaps that allow water to penetrate the straight sections of the joints between the cut stones.
[0010] Therefore, it is clear that the above technical solutions for waterproof tunnel linings formed from prefabricated cut stone cannot reliably ensure waterproofing against water intrusion from the surrounding ground into the tunnel. As already mentioned, repair work after the lining is completed and the tunnel is put into service is not only costly but also difficult to carry out, in particular, due to the difficulty of access and the potential for intrusion, the very narrow gaps between adjacent cut stones (usually 5 to 10 mm), and the uncertainty of the results, as each waterproof seal is usually located near the outer surface of the lining, and therefore a considerable distance (usually 300 to 1000 mm) from the accessible inner wall of the lining. [Overview of the project]
[0011] In view of the above, the main object of the present invention is a method for waterproofing a tunnel lining formed by prefabricated cut stone, and a prefabricated cut stone that can be used in the method and reliably guarantees the waterproofness of the lining with respect to water intrusion into the joint area between the cut stones.
[0012] Another object of the present invention is to provide a method for waterproofing a tunnel lining formed by prefabricated cut stone, and prefabricated cut stone that can be used in the method and can be readily used within the scope of any known methodology for constructing an ordinary tunnel that provides a lining formed by prefabricated cut stone, particularly in the context of a methodology based on "mechanized" technology using TBM.
[0013] According to the present invention, these objectives are achieved by a method for waterproofing a tunnel lining formed by prefabricated cut stone, comprising the steps described in Appendix Claim 1, and by prefabricated cut stone for use in the method described in Appendix Claim 9.
[0014] In particular, the present invention relates in its first embodiment to a method for waterproofing tunnel linings formed by prefabricated cut stone, a) A step of preparing a plurality of prefabricated cut stones, each prefabricated cut stone comprising an inner surface, an outer surface opposite to the inner surface, a periphery connecting the inner surface and the outer surface, and a periphery groove extending continuously in the longitudinal direction along the periphery, and at least some of the prefabricated cut stones further comprising at least one injection pipe having a first end opening in the inner surface region and at least one second end opening in the periphery groove region, b) A step of forming a tunnel lining by arranging a plurality of prefabricated cut stones along the wall of a tunnel, wherein the tunnel lining comprises a grid of interconnected joint lines defined between two adjacent prefabricated cut stones, and in the region of each joint line, corresponding portions of the peripheral grooves of two adjacent prefabricated cut stones face each other to form their respective hollow channels, thereby forming a grid of interconnected hollow channels corresponding to the grid of interconnected joint lines within the tunnel lining, c) A step of filling a grid of interconnected hollow channels with a watertight, injectable sealant, wherein the sealant is injected into the grid of interconnected hollow channels through a first end opening of at least one injection pipe of one or more prefabricated cut stones, each of which is provided with at least one injection pipe. Includes.
[0015] According to this method, waterproofing of tunnel linings formed by prefabricated cut stones is advantageously achieved by providing appropriate interconnected hollow channels in the region of the joint lines between the cut stones to form a continuous grid corresponding to the interconnected grid of the joint lines, and injecting appropriate sealing material into these hollow channels until the grid formed by the channels is completely filled. Once solidified and the final usage conditions are met, the injected sealing material forms a monolithic continuous sealing strand extending along the entire grid of the joint lines between the cut stones within the tunnel lining. This sealing strand ensures the predetermined waterproofing of the tunnel lining against water intrusion into the region of the joint lines between the cut stones and avoids the occurrence of problems associated with poor contact between waterproof seals of prefabricated cut stones, as described above, particularly with reference to the prior art.
[0016] Furthermore, the waterproofing treatment method of the present invention can be easily implemented without altering each work step and / or its order in the context of any known methodology for constructing ordinary tunnels using linings formed by prefabricated cut stone, but not limited to methodologies based on “mechanized” techniques, particularly those using TBMs. In fact, on the one hand, a grid of interconnected hollow channels for accommodating the sealing material is automatically formed during the work of arranging the cut stone to construct the tunnel lining, and on the other hand, once the lining is fully constructed, the injection of the sealing material can be carried out in an easy and controlled manner via injection pipes that are appropriately positioned in the cut stone and directly accessible from the inside of the lining itself.
[0017] According to a preferred embodiment of this method, each prefabricated cut stone further comprises a periphery waterproof seal, the periphery waterproof seal extending along its respective periphery and having a waterproof surface, i.e., a side surface, which is intended to contact the corresponding waterproof surface, i.e., the side surface, of the periphery waterproof seal of an adjacent prefabricated cut stone in the tunnel lining, and a periphery groove is formed on the waterproof surface of the waterproof seal.
[0018] Thus, the sealing action of the cut stone waterproof seals, which is typical of conventional solutions, is advantageously combined with the sealing action of the sealant injected into the grid of interconnected hollow channels, which are formed within the tunnel lining in the region of the joint lines between the cut stones, as described above, and are separated in this case by the mutually opposing waterproof seals of adjacent cut stones. In particular, the sealant can ensure waterproofing even when the mutually opposing waterproof surfaces of the waterproof seals of adjacent cut stones are not in complete contact with each other, and therefore water infiltration may occur.
[0019] In embodiments of this method, step c) of injecting a sealant to fill the grid of interconnected hollow channels can be performed during tunnel construction, before the tunnel is put into service, for example, immediately after the lining is in place, or even after the tunnel is put into service if it becomes apparent that water is seeping in between the waterproof seals of the cut stones.
[0020] In a modified version of this embodiment, the peripheral groove comprises a diaphragm that partitions a sealed chamber, the sealed chamber comprising at least one second end opening of at least one injection pipe extending longitudinally inside the peripheral groove, and in step c) filling a grid of interconnected hollow channels with sealant, the injection of sealant causes the diaphragm to invert to the outside of the peripheral groove and to the inside of the peripheral groove opposite to that of the adjacent prefabricated cut stone.
[0021] Advantageously, after inversion, the diaphragm forms a containment bag for the injected sealant within corresponding channels formed by two opposing peripheral grooves, providing waterproofing against sealant loss in the interface area between the waterproof seals in contact with each other, which can occur in the case of improper alignment of the waterproof seals in the radial direction of the tunnel lining.
[0022] According to another embodiment of the method of the present invention, the prefabricated cut stone does not have a peripheral waterproof seal, and the peripheral grooves can be formed directly, i.e., integrally, in the peripheral region of each cut stone itself. In this case, the waterproofing of the tunnel lining against water intrusion into the joint region between the cut stones is ensured only by the sealing material filled in the grid of the interconnected hollow channels, but in any case, the sealing material must be injected in advance during tunnel construction.
[0023] In a variation of this alternative embodiment, at least some of the prefabricated cut stone comprises peripheral tubular elements made of elastomer material and received in their respective peripheral grooves, and at least one second end opening of each at least one injection pipe opens into the tubular element. In step c) filling the grid of interconnected hollow channels with sealant, the sealant is injected into the tubular element, and the tubular element expands within the hollow channel formed by the peripheral groove of the cut stone and the corresponding peripheral groove opposite to that of the adjacent prefabricated cut stone.
[0024] In this case, the tubular element also forms a containment bag for the sealant injected into the associated hollow channel, providing waterproofing against sealant loss in the area of the joint line between adjacent prefabricated cut stones, which may occur in the case of radially adjacent prefabricated cut stones in the tunnel lining.
[0025] Preferably, step c) filling the grid of interconnected hollow channels with sealant, c1) Injecting the sealing material through one of the injection pipes of a precast cut stone with at least one injection pipe until the injection pressure reaches a predetermined maximum value; c2) Interrupting the injection; c3) Defining the spread area of the sealing material, which fills the corresponding parts of the grid of interconnected hollow channels, and checking which injection pipes, surrounding the previously used injection pipe, are at least partially filled with the injected sealing material; c4) Resuming the injection of the sealing material in the area of another injection pipe of a precast cut stone with at least one injection pipe, which is located outside the previously defined spread area of the sealing material; c5) Repeating steps c1) to c4) over the entire range of the tunnel lining; including.
[0026] In this way, the filling of the grid of interconnected hollow channels is carried out sequentially for each zone until the entire area of the tunnel lining is covered. Advantageously, this allows injection to be carried out at a relatively low pressure and better control the spread of the sealing material injected into the grid of interconnected hollow channels. The extent of the spread area of the sealing material introduced in each injection step can be easily evaluated by visually inspecting the injection pipes around the injection pipe used, and the injection pipes at least partially filled with the injected sealing material can be identified.
[0027] Preferably, step b) of arranging the precast blocks comprises arranging the precast blocks so as to form a plurality of rings of precast blocks adjacent to one another in the longitudinal direction of the tunnel, each ring of blocks being angularly offset in the circumferential direction of the tunnel with respect to the adjacent rings, so that the grid of interconnected joint lines and the grid of interconnected hollow channels comprise a plurality of continuous circumferential rings connected by a plurality of longitudinally straight portions angularly offset from one another in the circumferential direction of the tunnel, at least in adjacent rings of precast blocks.
[0028] Preferably, the water-blocking and injectable sealing material is a synthetic resin having a high modulus of elasticity after polymerization, preferably a polyurethane resin or a silicone resin.
[0029] A second aspect of the present invention relates to a precast block for tunnel lining that can be used in the above method, the block comprising an inner surface, an outer surface opposite the inner surface, a peripheral edge connecting the inner surface and the outer surface, a peripheral groove extending continuously in the longitudinal direction along the peripheral edge, and at least one injection pipe having a first end opening in the region of the inner surface and at least one second end opening in the region of the peripheral groove.
[0030] The precast block having the above features provides the same advantages as those described above with respect to the first aspect of the present invention. In particular, by juxtaposing these blocks during the construction of the tunnel lining, a grid of interconnected hollow channels corresponding to the grid of joint lines formed between adjacent blocks is automatically generated, and this grid can be filled with a water-blocking sealing material. By injecting the sealing material, the tunnel lining can be made waterproof or water-blocking against the ingress of water into the region of the joints between the blocks. The injection of the sealing material can be carried out in an easy and controlled manner through an injection pipe appropriately arranged within the block and directly accessible from the inside of the tunnel lining.
[0031] Preferably, the prefabricated cut stone is provided with at least one injection pipe on each side of its individual periphery. Advantageously, the number of injection pipes in the region of each side of the periphery can be proportional to the length of the side, thereby providing more injection pipes on longer sides than on shorter sides.
[0032] According to a preferred embodiment, the prefabricated cut stone further comprises a periphery waterproof seal extending along its periphery, the periphery waterproof seal having a waterproof surface or side intended to contact the corresponding waterproof surface or side of the periphery waterproof seal of an adjacent prefabricated cut stone in the tunnel lining, and a periphery groove is formed on the waterproof surface of the periphery waterproof seal.
[0033] In a modified version of this embodiment, the peripheral groove is provided with a diaphragm that demarcates a sealed chamber extending longitudinally within the groove itself, and the sealed chamber comprises at least one second end opening of at least one injection pipe of the prefabricated cut stone.
[0034] According to the alternative embodiment, the prefabricated cut stone does not have a peripheral waterproof seal, and the peripheral groove is formed directly, i.e., integrally, on the peripheral edge of the prefabricated cut stone.
[0035] In a modified version of this embodiment, the prefabricated cut stone further comprises a peripheral tubular element made of an elastomer material and received in a peripheral groove, wherein at least one second end opening of at least one injection pipe opens into the tubular element.
[0036] The peripheral groove generally has any suitable cross-sectional shape, including straight and / or curved portions.
[0037] The present invention further relates to a tunnel including a lining constructed of prefabricated cut stone, wherein the lining is made waterproof by the method described above. [Brief explanation of the drawing]
[0038] Further features and advantages of the present invention will be better understood from the detailed description of the following preferred embodiments, as examples not limited to them, with reference to the accompanying drawings. [Figure 1] This is a schematic longitudinal cross-sectional view showing a portion of a tunnel including a lining formed by prefabricated cut stone according to the present invention and made waterproof by the method according to the present invention. [Figure 2] This is a schematic perspective view showing one embodiment of prefabricated cut stone according to the present invention. [Figure 2a] This is a detailed enlarged view of section D1 in Figure 2. [Figure 2b] This is a cross-sectional view of the prefabricated cut stone in Figure 2, along line II-II in Figure 2. [Figure 2c] This is a detailed enlarged view of section D2 in Figure 2b. [Figure 3] This is a schematic perspective view showing another embodiment of the prefabricated cut stone according to the present invention. [Figure 3a] This is a cross-sectional view of the prefabricated cut stone along line III-III in Figure 3. [Figure 3b] This is a detailed enlarged view of section D3 in Figure 3a. [Figure 4] Figure 1 is a schematic perspective view of the two prefabricated cut stone rings of the tunnel lining. [Figure 5] Figure 2 shows a schematic perspective view of two adjacent prefabricated cut stones in partial cross-section according to the embodiment. [Figure 6] Figure 3 is a schematic perspective view of four adjacent prefabricated cut stone sections according to the embodiment shown in Figure 3. [Figure 7] Figure 1 is a projection view of a portion of the tunnel lining, seen from the inside, onto a plan view. [Figure 8] This is a schematic cross-sectional view of the tunnel lining in Figure 1 within the region of line VIII-VIII shown in Figure 7. [Figure 9] This is a schematic cross-sectional view of the tunnel lining in Figure 1 within the region of the IX-IX line in Figure 7. [Figure 10] This is a schematic perspective view of a portion of the interconnected hollow channel grid formed within the tunnel lining shown in Figure 1, after the prefabricated cut stones shown in Figure 2 have been placed side by side. [Figure 11a] This is a schematic cross-sectional view similar to Figure 9, showing the step of filling a hollow channel formed in the joint area between two adjacent prefabricated cut stones in the tunnel lining of Figure 1 with an injectable sealant. [Figure 11b] Same as above. [Figure 11c] Same as above. [Figure 12] This is a schematic cross-sectional view similar to Figure 9, and the prefabricated cut stone on the left constitutes an alternative embodiment to the prefabricated cut stone in Figure 2. [Figure 13] Figure 7 is a schematic cross-sectional view of the tunnel lining in the IX-IX area shown in Figure 1. The cut stone on the right corresponds to the prefabricated cut stone embodiment shown in Figure 3, and the cut stone on the left constitutes a modified example of the same prefabricated cut stone. [Modes for carrying out the invention]
[0039] Figure 1 shows a portion of a tunnel 100 having a lining 110 formed by a plurality of prefabricated cut stones 1 according to the present invention. In a method known to itself, the cut stones 1 are configured as ring segments and are installed within the lining 110 to form a plurality of adjacent circular closed rings 111 in the longitudinal direction of the tunnel 100. Figure 4 shows two of these rings 111 formed by the cut stones 1 individually.
[0040] A preferred embodiment of the cut stone 1 forming the lining 110 of the tunnel 100 is shown in more detail in Figures 2 and 2a-c.
[0041] Each cut stone 1 is made of reinforced concrete and consists of a prefabricated (assembled) element having a rectangular or trapezoidal peripheral shape (in the case of the so-called "key cut stone" and the two cut stones adjacent to it within each ring 111) and a curvature corresponding to the curvature of the ring 111 in one of two spreading directions, particularly in the direction of maximum spreading. Thus, each cut stone 1 has an inner surface facing into the tunnel 100 when the cut stone 1 is installed, an outer surface 12 (shown in Figure 4) opposite the inner surface 11, and a peripheral edge 13 that connects the inner surface 11 and the outer surface 12 and is formed by a pair of parallel long sides or surfaces 131 and a pair of parallel or oblique short sides or surfaces 132.
[0042] Each cut stone 1 is further provided with a peripheral waterproof seal 2 that extends along the entire periphery 13, preferably close to the outer surface 12.
[0043] As clearly shown in Figure 2c, the waterproof seal 2 has an outward-facing waterproof surface or side surface 21 and, when installed in the lining 110 of the tunnel 100, is designed to contact the corresponding waterproof surface or side surface 21 of a similar waterproof seal 2 on an adjacent cut stone 1. Similar to the waterproof seal 2, the waterproof surface 21 has a groove 3 formed longitudinally that extends continuously along the entire periphery 13 of the cut stone 1. The presence of the groove 3 defines two separate longitudinal waterproof portions 211 on the waterproof surface 21 that are opposite to the groove 3, and these waterproof portions 211 extend continuously along the entire periphery 13 of the cut stone 1, providing particular waterproofing of the adjacent cut stone 1 against the waterproof seal 2 in that region.
[0044] In the preferred embodiment shown herein, the groove 3 has a cross-section including a first portion 31 distal to the waterproof surface 21 and forming the bottom of a circular groove 3, and a second portion 32 proximal to the waterproof surface 21, opening in that region, facing each other and parallel, and formed by two straight segments connected to the ends of the first portion 31 (see also Figure 8).
[0045] The groove 3 can generally have any suitable shape having a cross-section that includes straight and / or curved portions, which can be technically formed in the waterproof seal 2.
[0046] As particularly shown in Figures 2c, 8, 9, and 11a-c, the waterproof seal 2 preferably includes a pair of protruding fixing portions 22 extending longitudinally along the entire length of the waterproof seal 2 for fixing to the cut stone 1 on the back surface region opposite the waterproof surface 21. The cross-sectional shape of the fixing portions 22 can be, for example, substantially L-shaped. During the manufacturing process of the cut stone 1, the rear region of the waterproof seal 2 is surrounded when concrete is poured, and the fixing portions 22 provided in this region ensure a stable and secure connection between the waterproof seal 2 and the cut stone 1 body.
[0047] The waterproof seal 2 is made from a suitable elastomer material, for example, EPDM rubber (ethylene propylene diene monomer) or silicone rubber having a Shore A hardness of preferably 30 to 90, more preferably 40 to 60.
[0048] Each cut stone 1 further comprises one or more injection pipes 4 appropriately positioned to inject a sealing material into a hollow channel formed in the lining 110 in the region of the joint line between adjacent cut stones 1, which will be described in more detail below with reference to a preferred embodiment of the waterproofing treatment method according to the present invention.
[0049] Preferably, each cut stone 1 is provided with at least one injection pipe 4 on each of the sides 131 and 132 of the periphery 13, and it is advantageous to provide more injection pipes 4 on the long side 131 than on the short side 132. In particular, as shown in Figure 2, in the preferred embodiment shown herein, each cut stone 1 is provided with one injection pipe 4 for each short side 132 of the periphery 13 and two injection pipes 4 for each long side 131 of the periphery 13.
[0050] The injection pipes 4 preferably all have the same configuration. In particular, as shown in Figure 2c, each injection pipe 4 is preferably L-shaped and comprises a first straight section 41 extending substantially parallel to each side 131 or 132 of the periphery 13 inside the cut stone 1, and a second straight section 42 extending substantially perpendicular to the same side 131 or 132 of the periphery 13 inside the cut stone 1. The first straight section 41 opens to the area of the outer inner surface 11 of the cut stone 1 via a first end opening 410 of the injection pipe 4, and the second straight section 42 opens to the groove 3 of the waterproof seal 2 via a second end opening 420 of the injection pipe 4. Thus, the injection pipe 4 allows fluid communication between the groove 3 of the waterproof seal 2 and the location of the inner surface 11 of the cut stone 1, and is accessible even when the cut stone 1 is installed within the lining 110.
[0051] The injection pipes 4 preferably have a circular cross-section with an inner diameter of 4 mm to 10 mm, for example 6 mm, and may be formed by individual tubes made of, for example, plastic material, which are incorporated into the cut stone 1 during casting.
[0052] Figures 3 and 3a-b show another preferred embodiment of the cut stone according to the present invention, indicated by reference numeral 1'. Elements identical or functionally similar to the cut stone 1 described above are indicated by the same reference numeral followed by a dash.
[0053] Cut stone 1' differs from the aforementioned cut stone 1 in that it does not have a waterproof seal along its periphery 13'. Instead of a waterproof seal, cut stone 1' has a periphery groove 3' that extends along the entire periphery 13', which is formed directly on the body of cut stone 1' during the manufacturing process of the cut stone 1' itself (see Figure 3).
[0054] As particularly shown in Figure 3b, the groove 3' has a cross-section that is preferably separated by straight walls, in particular a rectangular or square cross-section.
[0055] The cut stone 1' also includes an injection pipe 4' configured and positioned within the cut stone 1', similar to the injection pipe 4 of the cut stone 1. In this case, each injection pipe 4' has a second end opening 420' in the region of the groove 3' formed on its periphery 13', and the groove 3' itself is in fluid communication with the inner surface 11' of the cut stone 1'.
[0056] Otherwise, cut stone 1' has the same characteristics as cut stone 1 described above.
[0057] Hereinafter, preferred embodiments of the method for making the tunnel lining 110 of the tunnel 100 waterproof according to the present invention will be described with particular reference to the lining 110 formed by cut stone 1 according to the embodiments shown in Figures 2 and 2a to 2c. Unless otherwise specified, the following description also applies to the lining 110 formed by cut stone 1' according to the embodiments shown in Figures 3 and 3a to 3b.
[0058] After preparing the cut stones 1, the method arranges the cut stones 1 to form the lining 110. This step can be carried out using any apparatus by any known method for producing a tunnel lining formed by prefabricated cut stones, for example by TBM in the context of ordinary tunnel construction by “mechanized” technology. As already mentioned above, and as is also evident from Figures 1 and 4, the lining 110 is constructed by arranging the cut stones 1 to form a plurality of adjacent circular closed rings 111 in the longitudinal direction of the tunnel 100. It is preferable that each ring 111 is made to rotate in the circumferential direction of the tunnel 100 relative to adjacent rings 111, and therefore offset in angle. Figure 5 shows a portion of the lining 110 including two cut stones 1 belonging to two different adjacent rings 111.
[0059] By arranging the cut stones 1 side by side in the circumferential and longitudinal directions of the tunnel 100, a grid RTG of interconnected joint lines 112 is formed within the lining 110, each defined between the opposing sides 131 or 132 of the periphery 13 of adjacent cut stones 1. As is partially evident in Figures 1 and 7, by arranging the cut stones 1 according to the pattern described above, the joint lines 112 constitute a plurality of continuous circumferential rings connected by a plurality of linear longitudinal portions that are angularly offset from each other in the circumferential direction of the tunnel 100, at least in adjacent rings 111 of the cut stones 1.
[0060] As shown in Figures 8 and 9, in the region of each joint line 112, corresponding portions of two waterproof seals 2 in each pair of adjacent cut stones 1 are in contact with each other. This contact is brought about by the waterproof surface 21, more specifically, the waterproof portion 211 as defined herein, and the portions of the two waterproof seals 2 involved form a hollow channel 113 that extends continuously in the longitudinal direction in the region of the joint line 112 between the pair of adjacent cut stones 1, with their respective longitudinal grooves 3 formed in these waterproof surfaces 21 facing each other. Thus, when cut stones 1 are placed side by side in the lining 110, a grid RTC of hollow interconnection channels 113 is generally generated within it, and its shape replicates the shape of the grid RTG of the interconnected joint line 112 described above.
[0061] The contact between the waterproof seals 2 of adjacent cut stones 1 forms a first seal barrier in the region of the joint line 112 of the lining 110, preventing water from entering from the excavation wall of the tunnel 100. This barrier may be affected by the same drawbacks described in the introduction with respect to prior art tunnel linings, which are related to improper contact between the waterproof seals 2 of adjacent cut stones 1.
[0062] The present invention provides a waterproofing method for creating an additional waterproof barrier in the region of the joint lines 112 of the lining 110 by filling the grid RTC of the interconnected hollow channels 113 with a water-impermeable, injectable sealant 5. As shown in Figures 11a-c, the sealant 5 is injected into the grid RTC of the hollow channels 113 by injection through injection pipes 4 appropriately positioned in the cut stones 1, and its first end opening 410, located in the region of the inner surface 11 of the cut stones 1, is accessible even when installed in the lining 110. Once solidified and the final operating conditions are met, the injected sealant 5 forms a monolithic continuous sealing strand within the lining 110 of the tunnel 100, extending along the entire grid RTG of the joint lines 112 between the cut stones 1. This sealing strand constitutes a second waterproof barrier that works synergistically with the first waterproof barrier formed by the waterproof seal 2 of the cut stone 1, ensuring the predetermined waterproofness of the lining 110 against water intrusion into the area of the joint line 112 between the cut stones 1, even in places where contact between the waterproof seal 2 of adjacent cut stones 1 is insufficient.
[0063] The injection of the sealing material 5 can be carried out during the construction of the tunnel 100, and therefore before it is put into operation, for example, immediately after the lining 110 is in place. However, if water penetrates between the waterproof seals 2 of the cut stones 1, it can also be carried out after the tunnel 100 is put into operation.
[0064] If the lining 110 is formed of cut stones 1' without peripheral waterproof seals, then when cut stones 1' are used, their respective peripheries 13' will be in direct contact, and the grooves 3' formed thereon will face each other in the region of the joint line 112 between adjacent cut stones 3' (see Figure 6). Therefore, in this case, the lining 110 also forms a grid RTC of interconnected hollow channels 113 corresponding to the grid RTG of the joint line 112. In this case, filling the grid RTC of the hollow channels 113 with an injectable sealant 5 is performed before the operation of the tunnel 100, preferably immediately after the lining 110 is in place, because the sealant 5 here is the only waterproof barrier against water intrusion through the lining 110 in the region of the joint line 112.
[0065] Regardless of the type of cut stone 1 or 1' used in the construction of the lining 110, and therefore the time at which the injection of the sealant 5 into the grid RTC of the hollow interconnect channel 113 is performed, this step of the waterproofing treatment method of the present invention is advantageous to perform in zones.
[0066] In particular, as schematically shown in Figure 7, this step involves selecting an injection pipe 4I within the lining 110 that is not yet filled with sealant 5, and injecting the sealant 5 through each of the first end openings 410, which are freely accessible from the inside of the lining 110, until the injection pressure reaches a predetermined maximum value. The predetermined maximum value of the injection pressure can be selected based on the characteristics of the injectable sealant 5 used and / or the available injection means. For example, this maximum value is equal to approximately 10 bar. Once the predetermined maximum value of the injection pressure is reached, the injection of sealant 5 through the injection pipe 4I is stopped.
[0067] At this point, the lining 110 defines a spread area A of the sealant 5 injected from the injection pipe 4I, and the sealant injected therein fills the corresponding portion of the grid RTC of the interconnected hollow channels 113. The shape and extent of the spread area A, shown by the dashed line in Figure 7, are for reference purposes only for the purposes of this specification.
[0068] The extent of the spread area A is evaluated, for example, by visual inspection to confirm which injection pipes 4S surrounding the previously used injection pipe 4I are at least partially filled with the injected sealant. Next, the injection pipes 4S surrounding the previously used injection pipe 4I are advantageously used as "spy pipes" to verify which sections of the grid RTC of the interconnected hollow channels 113 have been reached and filled by the sealant 5 injected from injection pipe 4I.
[0069] Next, the injection of sealant 5 is resumed in the area of a new injection pipe 4 that is outside the previously defined area of sealant 5's spread.
[0070] The steps described above are repeated iteratively until the entire lining 110 is covered or the grid RTC of the interconnected hollow channels 113 is covered.
[0071] Preferably, the sealing material 5, which is impermeable to water injected into the grid RTC of the interconnected hollow channels 113, may be a one- or two-component synthetic resin, preferably one that can be polymerized at low temperatures and has a high modulus of elasticity after polymerization, particularly a polyurethane resin or a silicone resin.
[0072] Figure 12 shows schematic cross-sectional views of two adjacent prefabricated cut stones 1, 1'' similar to those in Figure 9, where the leftmost cut stone 1'' constitutes another embodiment of the cut stone 1 described with reference to Figure 2. Elements identical or functionally similar to the aforementioned cut stone 1 are given the same reference number but are denoted by two dashes.
[0073] Unlike the aforementioned cut stone 1, the cut stone 1" has a groove 3" formed in the waterproof surface 21" of the peripheral waterproof seal 2" that includes a diaphragm 33" that partitions the sealed chamber 34" and extends longitudinally within the groove 3" and includes a second end opening 420" of the injection pipe 4" of the cut stone 1". The diaphragm 33" can be formed integrally with the waterproof seal 2" or it can be fixed to it by any suitable method, such as adhesive or heat welding.
[0074] Otherwise, cut stone 1" has the same characteristics as cut stone 1 described above.
[0075] According to the waterproofing treatment method of the present invention, when the sealing material 5 is injected into the groove 3" of the peripheral waterproof seal 2" of the cut stone 1" via one of the injection pipes 4" of the cut stone 1", the injection pressure causes the diaphragm 33" to invert to the outside of the groove 3" of the waterproof seal 2" of the cut stone 1" and to the inside of the opposing groove 3 of the adjacent waterproof seal 2 of the cut stone 1. By appropriately selecting the shape, wall thickness, and, if necessary, the material of the diaphragm 33"", as the amount of sealing material 5 injected into the sealed chamber 34" gradually increases, the diaphragm 33" can be made to stretch until it is in close contact with the inner wall of the opposing groove 3, or to inflate like a balloon. In this way, along at least a portion of the perimeter of the hollow channel 113, which is defined by two grooves 3 and 3” facing each other and has an interface between the waterproof seals 2 and 2”, the injected sealant 5 is surrounded by an additional layer to prevent its loss in the interface region, which could result from the radial misalignment of the tunnel lining 110 of the waterproof surfaces of the waterproof seals 2 and 2” that are in contact with each other.
[0076] Figure 13 is a schematic cross-sectional view of two adjacent prefabricated cut stone 1, 1', where the left cut stone 1' constitutes a modified embodiment of the cut stone 1' described above with reference to Figure 3. Elements identical or functionally similar to the cut stone 1' described above are given the same reference numerals.
[0077] In this modification, the cut stone 1' further comprises a peripheral tubular element 6' manufactured from an elastomer material and receiving into a peripheral groove 3' directly formed on the periphery 13' of the cut stone 1'. In this case, the second end opening 420' of the injection pipe 4' of the cut stone 1' is waterproofly connected to and opens into the tubular element 6'.
[0078] Otherwise, the cut stone 1' has the same properties as the cut stone 1' described above with reference to Figures 3, 3a-b. In this case, the sealant 5 injected from one of the injection pipes 4' of the cut stone 1' according to the waterproofing treatment method of the present invention reaches the interior of the tubular element 6' and gradually fills it, causing it to expand like an air chamber within the hollow channel 113 defined by the two opposing grooves 3' of the adjacent cut stone 1'. By appropriately selecting the wall thickness and elastomer material of the tubular element 6', it is possible to cause the volume of the sealant 5 injected therein to gradually increase and expand until it almost completely fills the hollow channel 113. Thus, in this case as well, the sealant 5 injected into the channel 113 is surrounded by an additional layer to prevent its loss in the region of the joint line between adjacent cut stones 1'.
[0079] Those skilled in the art may apply modifications and variations to the aforementioned embodiments of the method for waterproofing tunnel linings and prefabricated cut stone usable in this method to satisfy certain incidental application requirements, and these modifications and variations are also included within the scope of protection defined by the appended claims.
[0080] In particular, the lining 110 of the tunnel 100 may be formed by a single type of cut stone 1, 1', or 1'' from those described above, or by an appropriate combination of different types of cut stones 1, 1', and / or 1''.
[0081] The cut stones 1, 1' and / or 1" forming the lining 110 may all have the same number of injection pipes 4, 4' or 4", or they may have different numbers of injection pipes 4, 4' or 4". Some cut stones 1, 1' or 1" may not have any injection pipes 4, 4' or 4". Furthermore, the injection pipes 4, 4' or 4" may have a branching structure with one first end opening 410, 410' or 410" in the region of the inner surface 11, 11' or 11" of each cut stone 1, 1' or 1" and two or more second openings 420, 420', 420" in the region of the peripheral groove 3, 3' or 3".
[0082] Thick cut stone 1, 1', or 1” may have two or more peripheral grooves 3, 3', or 3” extending parallel to each other at different heights along their respective periphery 13, 13', or 13”. In this case, it is advantageous to provide at least one injection pipe 4, 4', or 4” for each existing peripheral groove 3, 3', or 3”.
Claims
1. A method for waterproofing a tunnel lining (110) formed by prefabricated cut stone (1;1';1"), a) A step of preparing multiple prefabricated cut stones (1;1';1"), wherein each prefabricated cut stone (1;1';1") has an inner surface (11;11';11"), an outer surface (12;12';12") opposite to the inner surface (11;11';11"), a periphery (13;13';13") connecting the inner surface (11;11';11") and the outer surface (12;12';12"), and a continuous periphery (13;13';13") A step comprising: a periphery groove (3; 3'; 3") extending in the longitudinal direction, and at least a portion of the prefabricated cut stone (1; 1'; 1") further comprising at least one injection pipe (4; 4'; 4") having a first end opening (410; 410'; 410") in the region of the inner surface (11; 11'; 11") and at least one second end opening (420; 420'; 420") in the region of the periphery groove (3; 3'; 3"), b) A step of forming a tunnel lining (110) by arranging a plurality of prefabricated cut stones (1;1';1") along the wall of a tunnel (100), wherein the tunnel lining (110) comprises a grid (RTG) of interconnected joint lines (112) defined between two adjacent prefabricated cut stones (1;1';1"), and in the region of each joint line (112), corresponding portions of the peripheral grooves (3;3';3") of two adjacent prefabricated cut stones (1;1';1") face each other to form their respective hollow channels (113), thereby forming a grid (RTC) of interconnected hollow channels (113) corresponding to the grid (RTG) of interconnected joint lines (112) within the tunnel lining (110), c) A step of filling the grid (RTC) of interconnected hollow channels (113) with a watertight, injectable sealant (5), wherein the sealant (5) is injected into the grid (RTC) of interconnected hollow channels (113) through a first end opening (410; 410; 410") of at least one injection pipe (4; 4'; 4") of one or more prefabricated cut stones (1; 1'; 1") provided with at least one injection pipe (4; 4'; 4"), and A method that includes this.
2. The method according to claim 1, wherein each prefabricated cut stone (1;1") further comprises a peripheral waterproof seal (2;2") extending along its periphery (13;13"), the peripheral waterproof seal (2;2") having a waterproof surface (21;21"), the waterproof surface (21;21") intended to contact the corresponding waterproof surface (21;21") of the peripheral waterproof seal (2;2") of an adjacent prefabricated cut stone (1;1") within the tunnel lining (110), and a peripheral groove (3;3") is formed in the waterproof surface (21;21") of the waterproof seal (2;2").
3. The method according to claim 2, wherein the peripheral groove (3") comprises a diaphragm (33') that demarcates a sealed chamber (34"), the sealed chamber (34") comprises at least one second end opening (420") of at least one injection pipe (4") that extends longitudinally within the peripheral groove (3"), and in step c) filling, the injection of sealing material (5) causes the diaphragm (33') to be inverted to the outside of the peripheral groove (3") and to the inside of the opposing peripheral grooves (3;3';3") of the adjacent prefabricated cut stone (1;1';1")
4. The method according to claim 1, wherein the peripheral groove (3') is formed integrally with the peripheral edge (13').
5. The method according to claim 4, wherein at least some of the prefabricated cut stone (1') further comprises a peripheral tubular element (6') made of an elastomer material and received in a peripheral groove (3'), and at least one second end opening (420') of at least one injection pipe (4') opens into the tubular element (6'), and in step c) filling, a sealing material (5) is injected into the tubular element (6') and the tubular element (6') is expanded in a hollow channel (113) formed by the peripheral groove (3') and the opposing corresponding peripheral grooves (3') of adjacent prefabricated cut stone (1').
6. Step c) filling the grid (RTC) of interconnected hollow channels (113) is, c1) A step of injecting a sealant (5) through one injection pipe (4I) of a prefabricated cut stone (1;1';1") equipped with at least one injection pipe (4;4';4") until the injection pressure reaches a predetermined maximum value, c2) The step of interrupting the injection, c3) A step of defining the spread area (A) of the sealant (5) where the injected sealant (5) fills the corresponding portion of the grid (RTC) of the interconnected hollow channels (113), and confirming which injection pipe (4S) surrounding the previously used injection pipe (4I) is at least partially filled with the injected sealant (5), c4) Resuming injection of sealant (5) in the region of another injection pipe (4;4';4") located outside the previously defined area (A) of sealant (5) in one of the prefabricated cut stone (1;1';1") pieces, which is equipped with at least one injection pipe (4;4';4"), c5) The step of repeating steps c1) to c4) over the entire area of the tunnel lining (110) The method according to any one of claims 1 to 5, including the method described above.
7. The method according to any one of claims 1 to 6, wherein step b) arranging prefabricated cut stones (1;1';1") comprises arranging the prefabricated cut stones (1;1';1") so as to form a plurality of rings (111) of prefabricated cut stones adjacent to each other in the longitudinal direction of the tunnel (100), each ring (111) being angularly offset relative to adjacent rings (111) in the circumferential direction of the tunnel (100), and as a result the grid of interconnected joint lines (112) (RTG) and the grid of interconnected hollow channels (113) (RTC) comprises a plurality of continuous circumferential rings connected by a plurality of longitudinal straight portions that are angularly offset relative to each other in the circumferential direction of the tunnel (100) in at least the adjacent rings (111) of the prefabricated cut stones.
8. The method according to any one of claims 1 to 7, wherein the water-impermeable and injectable seal ring material (5) is a synthetic resin having a high modulus of elasticity after polymerization, preferably a polyurethane resin or a silicone resin.
9. A prefabricated cut stone (1;1;1") for tunnel lining (110) comprising an inner surface (11;11';11"), an outer surface (12;12';12") opposite to the inner surface (11;11';11"), a periphery (13;13';13") connecting the inner surface (11;11';11") and the outer surface (12;12';12"), a periphery groove (3;3';3") extending continuously in the longitudinal direction along the periphery (13;13';13"), and at least one injection pipe (4;4';4") having a first end opening (410;410';410") in the region of the inner surface (11;11';11") and at least one second end opening (420;420';420") in the region of the periphery groove (3;3';3").
10. The prefabricated cut stone (1;1;1") according to claim 9, comprising at least one injection pipe (4;4';4") on each side forming the periphery (13;13';13").
11. The prefabricated cut stone (1;1") according to claim 9 or 10, further comprising a periphery waterproof seal (2;2") extending along the periphery (13;13"), the periphery waterproof seal (2;2") having a waterproof surface (21;21") intended to contact the corresponding waterproof surface (21;21") of the periphery waterproof seal (2;2") of an adjacent prefabricated cut stone (1;1") within the tunnel lining (110), and a periphery groove (3;3") formed in the waterproof surface (21;21") of the periphery waterproof seal (2;2").
12. The prefabricated cut stone (1") according to claim 11, wherein the peripheral groove (3") comprises a diaphragm (33") that demarcates a sealed chamber (34") extending longitudinally within the peripheral groove (3"), and the sealed chamber (34") comprises at least one second end opening (420") of at least one injection pipe (4").
13. The prefabricated cut stone (1') according to claim 9 or 10, wherein the peripheral groove (3') is formed integrally with the peripheral edge (13').
14. The prefabricated cut stone (1') according to claim 13, further comprising a peripheral tubular element (6') made of an elastomer material and received in a peripheral groove (3'), wherein at least one second end opening (420') of at least one injection pipe (4') opens into the tubular element (6').
15. A tunnel (100) comprising a lining (110) constructed of prefabricated cut stone (1;1';1"), wherein the lining (110) is made waterproof by the method described in any of claims 1 to 8.