Waterproofing construction method for 3D printing tunnel lining construction joint

Abstract

This application relates to the field of 3D printing tunnel construction technology, and in particular to a 3D printing method for waterproofing tunnel lining construction joints, comprising: Step S1: After tunnel excavation and initial support for a certain distance, a drainage system is constructed, wherein a circumferential drainage blind pipe is installed at the designed lining construction joint; Step S2: A T-shaped waterstop is circumferentially fastened onto the circumferential drainage blind pipe at the lining construction joint; a groove is reserved at the horizontal end of the T-shaped waterstop for connecting the circumferential drainage blind pipe; a clamping groove is reserved at the vertical end of the T-shaped waterstop; Step S3: A first lining structure is constructed using 3D printing equipment, and the side of the first lining structure closest to the lining construction joint is embedded in the corresponding clamping groove; Step S6: The above steps are repeated until the tunnel excavation is completed; Based on the above scheme, a shift from blocking to interception in waterproofing approach is achieved, which can effectively improve the seepage prevention effect at the lining construction joint.

Description

Technical Field

[0001] This application relates to the field of 3D printing tunnel construction technology, and in particular to a waterproofing construction method for 3D printed tunnel lining construction joints. Background Technology

[0002] 3D printing tunnel technology is a new type of digital, intelligent, and automated tunnel construction technology. Through layered additive manufacturing and segmented molding, it achieves automated construction of tunnel lining structures, offering advantages such as no templates, high efficiency, high precision, and high adaptability. It represents an important development direction for the intelligent construction of future tunnel engineering. However, due to the segmented and layered printing process of 3D printing tunnels, numerous circumferential construction joints are formed between longitudinal segments, becoming the weakest impermeable interface in the lining structure. Currently, there is no systematic waterproofing construction method specifically for these construction joints in 3D printed tunnels.

[0003] Therefore, there is a need to provide an improved technical solution that addresses the shortcomings of the existing technology. Summary of the Invention

[0004] The purpose of this application is to provide a 3D printing method for waterproofing construction joints in tunnel linings, in order to solve or alleviate the problems existing in the prior art.

[0005] To achieve the above objectives, this application provides the following technical solution: A method for waterproofing construction joints in 3D-printed tunnel lining, comprising: Step S1: After the tunnel is excavated and initially supported for a certain distance, the drainage system is constructed, including the installation of circumferential drainage blind pipes at the designed lining construction joints; Step S2: Fasten the T-shaped waterstop along the circumferential direction onto the circumferential drainage blind pipe at the lining construction joint; the horizontal end of the T-shaped waterstop has a pre-reserved groove for connecting the circumferential drainage blind pipe; the vertical end of the T-shaped waterstop has a pre-reserved clamping groove. Step S3: The first lining structure is constructed using 3D printing equipment, and the side of the first lining structure closest to the lining construction joint is embedded in the corresponding groove. Step S6: Repeat the above steps until the tunnel excavation is completed.

[0006] Preferably, the construction method further includes: Step S4: Apply a waterproof membrane spray at the construction joint of the previous lining.

[0007] Preferably, the construction method further includes: Step S5: Use 3D printing equipment to construct the second lining structure, which covers the construction joint of the previous lining.

[0008] Preferably, the first lining structure is made of water-repellent concrete, and the second lining structure is made of impermeable concrete.

[0009] Preferably, in step S3, the 3D printing construction of the first lining structure is carried out layer by layer, following the principles of bottom-up, symmetrical synchronization, segmented advancement, and closed-loop forming.

[0010] Preferably, in step S3, following the principles of bottom-up, symmetrical synchronization, segmented advancement, and closed-loop forming, the 3D printing construction of the first lining structure is carried out layer by layer according to the S-shaped trajectory.

[0011] Preferably, in step S3, the layered printing thickness of the first lining structure at the tunnel arch foot is greater than the layered printing thickness at the sidewalls and the arch top.

[0012] Preferably, in step S2, the horizontal end portion outside the slot is inclined and abuts against the tunnel surrounding rock side.

[0013] Preferably, in step S2, the length of the horizontal end portion outside the slot located on the side of the first construction section is less than the length located on the side of the second construction section.

[0014] Preferably, in step S2, the T-shaped waterstop is provided with a waterstop ridge on the side away from the tunnel surrounding rock.

[0015] Compared with the closest prior art, the technical solution of this application has the following beneficial effects: To effectively block water seepage at the lining construction joint, a T-shaped waterstop with a snap-fit ​​design is pre-installed on the circumferential drainage blind pipe at the lining construction joint, realizing a shift in waterproofing approach from blocking to interception. On the other hand, a groove structure that simultaneously clamps the first lining structure on both sides of the lining construction joint is also designed. This not only strengthens the tightness of the connection between the first lining structures on both sides, but also optimizes the simple unidirectional seepage path into a complex multidirectional seepage path, extending the seepage path and increasing the seepage resistance, thereby further improving the seepage prevention effect. At the same time, by snapping the T-shaped waterstop onto the circumferential drainage blind pipe, the intrusion of 3D printed materials can be effectively blocked, preventing pipe blockage and affecting drainage performance, thus achieving effective protection for the circumferential drainage blind pipe. Attached Figure Description

[0016] The accompanying drawings, which form part of this application, are used to provide a further understanding of this application. The illustrative embodiments and descriptions of this application are used to explain this application and do not constitute an undue limitation of this application. Wherein: Figure 1 This is a schematic diagram showing the completion of the construction of a second lining structure according to some embodiments of this application; Figure 2 for Figure 1 Enlarged view of a portion of point A in the middle.

[0017] Explanation of reference numerals in the attached figures: 1. Tunnel surrounding rock; 2. First lining structure; 3. T-shaped waterstop; 4. Second lining structure; 5. Lining construction joint; 6. Wing plate; 7. Slot; 8. Gap; 9. Waterstop ridge; 10. Circumferential drainage blind pipe; 11. First construction section; 12. Last construction section; 13. Waterproof membrane. Detailed Implementation

[0018] The present application will now be described in detail with reference to the accompanying drawings and embodiments. Various examples are provided by way of explanation and not by way of limitation. In fact, those skilled in the art will recognize that modifications and variations can be made to the present application without departing from the scope or spirit thereof. For example, a feature shown or described as part of one embodiment may be used in another embodiment to produce yet another embodiment. Therefore, it is desirable that the present application encompass such modifications and variations that fall within the scope of the appended claims and their equivalents.

[0019] In the following description, the terms "first / second / third" are used merely to distinguish similar objects and do not represent a specific order of objects. It is understood that "first / second / third" may be interchanged in a specific order or sequence where permitted, so that the embodiments of this application described herein can be implemented in an order other than that illustrated or described herein.

[0020] Unless otherwise defined, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this disclosure belongs. The terminology used herein is for the purpose of describing embodiments of this disclosure only and is not intended to limit this disclosure.

[0021] In the description of this application, the terms "longitudinal," "lateral," "upper," "lower," "front," "rear," "left," "right," "vertical," "horizontal," "top," and "bottom," etc., indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings. They are used only for the convenience of describing this application and do not require that this application be constructed and operated in a specific orientation, and therefore should not be construed as limiting this application. The terms "connected," "linked," and "set up" used in this application should be interpreted broadly. For example, they can refer to fixed connections or detachable connections; direct connections or indirect connections through intermediate components; wired connections, radio connections, or wireless communication signal connections. Those skilled in the art can understand the specific meaning of the above terms according to the specific circumstances.

[0022] The following will be combined with the appendix Figure 1-2 The waterproofing construction method for the 3D printed tunnel lining construction joint 5 of this application is further described in detail.

[0023] Waterproofing construction methods for 3D printed tunnel lining construction joints include: Step S1: After the tunnel is excavated and initially supported for a certain distance, the drainage system is constructed, including the installation of circumferential drainage blind pipes 10 at the designed lining construction joint 5. Step S2: The T-shaped waterstop 3 is fastened circumferentially onto the circumferential drainage blind pipe 10 at the lining construction joint 5; the horizontal end of the T-shaped waterstop 3 is reserved with a groove 7 for connecting the circumferential drainage blind pipe 10; the vertical end of the T-shaped waterstop 3 is reserved with a clamping groove 8. Step S3: The first lining structure 2 is constructed using 3D printing equipment. The side of the first lining structure 2 closest to the lining construction joint 5 is embedded in the corresponding groove 8. Step S6: Repeat the above steps until the tunnel excavation is completed.

[0024] In a specific embodiment of this application, the drainage system includes a circumferential drainage blind pipe 10, a longitudinal drainage blind pipe, a transverse drainage hole, and an inner tunnel ditch. Multiple circumferential drainage blind pipes 10 and transverse drainage holes are arranged at intervals along the tunnel direction, while the longitudinal drainage blind pipes and inner tunnel ditch are arranged near the tunnel arch foot along the tunnel direction. Water accumulated behind the tunnel lining is collected through the circumferential drainage blind pipes 10 and the longitudinal drainage blind pipes and then discharged into the inner tunnel ditch through the transverse drainage hole.

[0025] The circumferential drainage blind pipe 10 is made of HDPE material, which has advantages such as corrosion resistance, aging resistance, high compressive strength, light weight, and easy processing, making it suitable for the long-term service requirements of tunnels and the characteristics of 3D printing construction. Considering that the lining construction joint 5 is a weak area of ​​the impermeable interface of the lining structure, the size of the circumferential drainage blind pipe 10 at the lining construction joint 5 is larger than that of the circumferential drainage blind pipe 10 outside the lining construction joint 5, so as to enhance the drainage capacity of the weak area. In a specific embodiment of this application, the inner diameter of the circumferential drainage blind pipe 10 at the lining construction joint 5 is 50mm and the wall thickness is 5mm; the inner diameter of the circumferential drainage blind pipe 10 outside the lining construction joint 5 is 40mm and the wall thickness is 3mm.

[0026] To effectively block water seepage at the lining construction joint 5, a T-shaped waterstop 3 with a snap-fit ​​design is pre-installed on the circumferential drainage blind pipe 10 at the lining construction joint 5, realizing a shift in waterproofing approach from blocking to interception. On the other hand, a clamping groove structure 8 is also designed to simultaneously clamp the first lining structures 2 on both sides of the lining construction joint 5. This not only strengthens the tightness of the connection between the first lining structures 2 on both sides, but also optimizes the simple unidirectional seepage path into a complex multidirectional seepage path, thereby extending the seepage path and increasing the seepage resistance, further improving the seepage prevention effect. At the same time, by snapping the T-shaped waterstop 3 onto the circumferential drainage blind pipe 10, the intrusion of 3D printed materials can be effectively blocked, preventing pipe blockage and affecting the drainage effect, thus achieving effective protection for the circumferential drainage blind pipe 10.

[0027] In a specific embodiment of this application, the slot 7 is specifically a C-shaped slot 7 that matches the shape of the circumferential drainage blind pipe 10; the opening size of the slot 7 is slightly smaller than the diameter of the circumferential drainage blind pipe 10, and the inner side is provided with anti-slip texture. It is made of rigid PVC or HDPE material to have a certain rigidity, forming an effective connection and protection for the circumferential drainage blind pipe 10; the vertical end of the T-shaped waterstop 3 is made of water-swellable rubber.

[0028] Construction methods also include: Step S4: Apply waterproofing spray at the construction joint 5 of the previous lining.

[0029] After the first lining structure 2 on both sides of the lining construction joint 5 is completed and the lining construction joint 5 is formed, a waterproof membrane is sprayed on the surface and a certain range on both sides of the lining construction joint 5 to form a waterproof membrane 13 to seal the tiny gaps on the surface of the lining construction joint 5. Together with the T-shaped waterstop 3 on the side of the tunnel surrounding rock 1, a double barrier against water is formed from the inside and outside. In the specific embodiment of this application, an acrylic waterproof coating is used for the spray waterproof membrane construction. The spray thickness is 3mm and the spray width is 300mm (150mm on each side of the lining construction joint 5).

[0030] To further improve the seepage prevention effect at the five construction joints of the lining, the construction method also includes: Step S5: Use 3D printing equipment to construct the second lining structure 4, which covers the construction joint 5 of the previous lining.

[0031] In a specific embodiment of this application, the second lining structure 4 and the first lining structure 2 adopt a staggered joint design, that is, the lining construction joint 5 of the first lining structure 2 is located in the middle of the segmented construction of the second lining structure 4, to ensure that the lining construction joint 5 does not penetrate the tunnel cross section.

[0032] The first lining structure 2 is made of water-repellent concrete, and the second lining structure 4 is made of impermeable concrete.

[0033] To prevent surface water and groundwater from seeping into the interlayer, the first lining structure 2 is constructed using hydrophobic concrete. Relying on the hydrophobic properties of the concrete itself, the driving force for water to seep into the inner layer is reduced. At the same time, the second lining structure 4 is constructed using impermeable concrete as the last line of defense to resist the seepage of remaining water. In the specific embodiment of this application, the first lining structure 2 is specifically made of C40 hydrophobic concrete, and the second lining structure 4 is specifically made of C40 impermeable concrete.

[0034] In step S3, following the principles of bottom-up, symmetrical synchronization, segmented advancement, and closed-loop forming, the 3D printing construction of the first lining structure 2 is carried out layer by layer.

[0035] In a specific embodiment of this application, based on the consideration of concrete anti-sag performance, the 3D printing construction of the first lining structure 2 is carried out in sections and layers from bottom to top, following the order of arch foot, side wall, and arch crown. Before construction, the base surface is inspected, and floating slag and debris are cleaned to ensure that the drainage system and T-shaped waterstop 3 are installed in place. Then, the arch feet on both sides are sprayed upwards layer by layer, with the spray gun kept perpendicular to the sprayed surface and the spraying distance controlled at 0.8-1.2m. After the arch foot construction is completed, the spraying is paused until the concrete at the arch frame has cured to 50% of the design strength before continuing the construction of the side wall and arch crown upwards to avoid the upper concrete from slipping due to the lower concrete not being solidified. After each section is sprayed, the surface is checked for voids and cracks in a timely manner. If there are defects, they are treated by re-spraying to ensure that the lining is dense and there is no risk of water seepage.

[0036] In step S3, following the principles of bottom-up, symmetrical synchronization, segmented advancement, and closed-loop forming, the 3D printing construction of the first lining structure 2 is carried out layer by layer according to the S-shaped trajectory.

[0037] In a specific embodiment of this application, an S-shaped printing trajectory with one circle overlapping half a circle is adopted, which can significantly improve the interlayer density and reduce interlayer voids and weak linear joints that are prone to occur in traditional straight-line printing. The S-shaped printing trajectory can also make the concrete bundle more stable, with less impact and a lower rebound rate. The 3D printing equipment does not have frequent start-stop, reversal, or breakpoints, and the robotic arm moves more smoothly, resulting in higher printing efficiency. At the same time, the first lining structure 2 constructed using the S-shaped printing trajectory can form an interlocking lining construction joint 5 structure in the groove 8 at the vertical end of the T-shaped waterstop 3, thereby further improving the tightness of the connection of the first lining structure 2 at the lining construction joint 5 and the seepage prevention effect.

[0038] In step S3, the layered printing thickness of the first lining structure 2 at the tunnel arch foot is greater than that of the layered printing thickness at the sidewalls and the arch top.

[0039] The tunnel arch foot is the main load-bearing support point and seepage collection area of ​​the lining structure. It is subject to complex stress, has high waterproofing requirements, and the concrete has good stacking stability. Therefore, a larger layer printing thickness is adopted to improve the structural density, early strength and impermeability. However, the side walls and arch are prone to concrete slippage and detachment, so a smaller layer thickness is required to ensure molding quality and dimensional accuracy. In the specific embodiment of this application, the layer printing thickness at the arch foot of the first lining structure 2 is 100mm, and the layer printing thickness at the side walls and arch is 50mm.

[0040] In step S5, the same principles of bottom-up, symmetrical synchronization, segmented advancement, and closed-loop forming are followed. The 3D printing construction of the second lining structure 4 is carried out layer by layer according to the S-shaped trajectory. The layer printing thickness of the second lining structure 4 at the tunnel arch foot is greater than that at the side wall and the arch top.

[0041] In step S2, the horizontal end portion outside the slot 7 is inclined and abuts against the side of the tunnel surrounding rock 1.

[0042] In a specific embodiment of this application, the T-shaped waterstop 3 includes a wing plate 6, a groove 7, and a vertical end. The wing plate 6 is connected to both sides of the opening of the groove 7, and together with the groove 7, forms the horizontal end of the T-shaped waterstop 3. One end of the vertical end is connected to the bottom of the outer side of the groove 7, and the other end of the vertical end has a rectangular clamping groove 8. The wing plates 6 on both sides of the opening of the groove 7 are inclined away from the vertical end. By abutting against the side of the tunnel surrounding rock 1, they form a protective space for the circumferential drainage blind pipe 10, which further improves the protective effect of the T-shaped waterstop 3 on the circumferential drainage blind pipe 10. At the same time, it also expands the flow range of the circumferential drainage blind pipe 10 at the lining construction joint 5, further improving the drainage effect of the circumferential drainage blind pipe 10 at the lining construction joint 5.

[0043] To reduce the disturbance of the T-shaped waterstop 3 caused by the 3D printing construction of the first construction section 11, and to prevent the wing plate 6 on the side of the second construction section 12 from deviating from the surrounding rock 1 of the tunnel and failing to form effective protection for the circumferential drainage blind pipe 10, in step S2, the length of the horizontal end portion outside the slot 7 on the side of the first construction section 11 is less than the length on the side of the second construction section 12.

[0044] Furthermore, in a specific embodiment of this application, the contact area between the horizontal end portion outside the slot 7 on the side of the first construction section 11 and the tunnel surrounding rock 1 is smaller than the contact area between the horizontal end portion outside the slot 7 on the side of the second construction section 12 and the tunnel surrounding rock 1.

[0045] To further enhance the water-stopping effect of the T-shaped waterstop 3 and avoid affecting the flow of the circumferential drainage blind pipe 10, in step S2, a water-stopping ridge 9 is provided on the side of the T-shaped waterstop 3 away from the tunnel surrounding rock 1.

[0046] In a specific embodiment of this application, the side of the wing plate 6 away from the tunnel surrounding rock 1 is provided with a vertical water-stop ridge 9, and the outer side of the vertical end is provided with a horizontal water-stop ridge 9.

[0047] The above description is merely a preferred embodiment of this application and is not intended to limit this application. Various modifications and variations can be made to this application by those skilled in the art. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of this application should be included within the protection scope of this application.

Claims

1. A 3D-printed method for waterproofing construction joints in tunnel lining, characterized in that, The construction method includes: Step S1: After the tunnel is excavated and initially supported for a certain distance, the drainage system is constructed, including the installation of circumferential drainage blind pipes at the designed lining construction joints; Step S2: Fasten the T-shaped waterstop along the circumferential direction onto the circumferential drainage blind pipe at the lining construction joint; the horizontal end of the T-shaped waterstop has a pre-reserved groove for connecting the circumferential drainage blind pipe; the vertical end of the T-shaped waterstop has a pre-reserved clamping groove. Step S3: The first lining structure is constructed using 3D printing equipment, and the side of the first lining structure near the lining construction joint is embedded in the corresponding groove. Step S6: Repeat the above steps until the tunnel excavation is completed.

2. The 3D-printed tunnel lining construction joint waterproofing method as described in claim 1, characterized in that, The construction method also includes: Step S4: Apply a waterproof membrane spray at the construction joint of the previous lining.

3. The 3D-printed tunnel lining construction joint waterproofing method as described in claim 2, characterized in that, The construction method also includes: Step S5: Use 3D printing equipment to construct the second lining structure, which covers the construction joint of the previous lining.

4. The 3D-printed tunnel lining construction joint waterproofing method as described in claim 3, characterized in that, The first lining structure is made of water-repellent concrete, and the second lining structure is made of impermeable concrete.

5. The 3D-printed tunnel lining construction joint waterproofing method as described in claim 1, characterized in that, In step S3, following the principles of bottom-up, symmetrical synchronization, segmented advancement, and closed-loop forming, the 3D printing construction of the first lining structure is carried out layer by layer.

6. The 3D-printed tunnel lining construction joint waterproofing method as described in claim 5, characterized in that, In step S3, following the principles of bottom-up, symmetrical synchronization, segmented advancement, and closed-loop forming, the 3D printing construction of the first lining structure is carried out layer by layer according to the S-shaped trajectory.

7. The 3D-printed tunnel lining construction joint waterproofing method as described in claim 5, characterized in that, In step S3, the first lining structure at the tunnel arch foot has a layered printing thickness greater than that at the sidewalls and the arch top.

8. The 3D-printed tunnel lining construction joint waterproofing method as described in claim 1, characterized in that, In step S2, the horizontal end portion outside the slot is inclined and abuts against the tunnel surrounding rock side.

9. The 3D-printed tunnel lining construction joint waterproofing method as described in claim 8, characterized in that, In step S2, the length of the horizontal end portion outside the slot located on the side of the first construction section is less than the length located on the side of the second construction section.

10. The 3D-printed tunnel lining construction joint waterproofing method as described in claims 1-9, characterized in that, In step S2, a water-stop ridge is provided on the side of the T-shaped waterstop away from the surrounding rock of the tunnel.

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