A method and fixing device for pre-embedding type water stop in secondary lining of tunnel

Abstract

The present invention relates to the technical field of tunnel excavation support construction, in particular to a method for pre-embedding a buried waterstop in a secondary lining of a tunnel. The method comprises the following steps: firstly installing a second lining formwork of a current segment second lining, then bending the waterstop from the middle, and fixing the exposed section of the bent waterstop on the inner side of an end formwork in the second lining formwork, so that the pre-embedded section of the waterstop is perpendicular to the end formwork; then pouring concrete into the pouring space in the second lining formwork of the current segment, so that the pre-embedded section can be pre-embedded in the concrete of the second lining; after removing the second lining formwork, the connection between the fixing device and the end formwork is disconnected, and through simple treatment, the bent exposed section can be bent in the reverse direction, so that the waterstop can be straightened to complete the pre-embedding construction of the pre-embedded section, avoiding the need to process the end formwork in two halves due to the installation of the waterstop, and further avoiding the need to separately install the two halves of the end formwork when installing the end formwork, thereby reducing the construction process of the end formwork and making the construction method simpler.

Description

Technical Field

[0001] The invention relates to the technical field of tunnel excavation support construction, in particular to a method and a fixing device for pre-embedding a buried water stop belt in a secondary lining of a tunnel. Background Art

[0002] The excavation construction of highway tunnels in mountainous areas mostly adopts mining excavation, and different mining excavation methods are adopted according to different surrounding rock types. For example, the stability of grade I, II, and III surrounding rock is better, and full-section excavation is adopted; while the stability of grade IV and V surrounding rock is poor, and mechanical excavation or local blasting methods are mostly adopted, such as: upper and lower step method or three-step method.

[0003] In addition, during the tunnel construction process, different lining types are designed according to different surrounding rocks. To ensure the safety of tunnel excavation and support operations, the tunnel secondary lining construction must meet the safety step distance required by the specifications, and the secondary lining concrete must closely follow the face construction. The tunnel secondary lining construction is constructed in sections along the longitudinal direction of the tunnel. An embedded waterstop is required between two adjacent sections of the secondary lining, and the width of the embedded waterstop is consistent along the longitudinal direction of the tunnel, and occupies half the width of each of the two sections of the secondary lining. For example, if the width of the embedded rubber waterstop is 300mm, the width of the embedded section is 150mm, and the width of the exposed section is 150mm, the end template of the secondary lining of the current segment must be divided, installed and reinforced due to the exposed section. Figure 1 As shown: the end template 1 refers to the template for sealing the end of the current segment, which is arranged along the circumferential direction of the initial support surface 3, and the end template 1 is divided into a first end template 11 and a second end template 12, so that the water stop belt 2 can pass through the gap between the first end template 11 and the second end template 12, but the first end template 11 and the second end template 12 of this construction method need to be installed and reinforced separately, and the construction is very complicated and cumbersome. Summary of the invention

[0004] The purpose of the present invention is to address the problem in the prior art that during the secondary lining operation of a tunnel, the pre-embedded rubber waterstop needs to be pre-embedded with half the width at the end of the secondary lining of the current segment tunnel, which causes the end template of the secondary lining of the tunnel to be divided into two halves to accommodate the installation of the rubber waterstop, and thus causes the end template to be processed in half, and the split end templates need to be installed and reinforced separately, resulting in cumbersome construction. A method and a fixing device for pre-embedding the embedded waterstop in the secondary lining of a tunnel are provided. In order to achieve the above purpose, the technical solution adopted by the present invention is as follows:

[0005] A method for pre-embedding a buried waterstop in a secondary lining of a tunnel comprises the following steps:

[0006] A. Install the secondary lining template of the current segment secondary lining; wherein the secondary lining template includes an end template;

[0007] B. Bend the exposed section of the water stop to a preset position close to the inner side of the end template and temporarily fix it, then fix the embedded section of the water stop to the embedded position and fix the exposed section at the preset position by a fixing device;

[0008] C. Pour concrete into the current segment;

[0009] D. After reaching the predetermined strength, the second lining formwork is removed, and the exposed section is released to complete the pre-embedding of the water stop.

[0010] Secondary lining formwork refers to the formwork for constructing the secondary lining segment, which can form a pouring space in conjunction with existing structures, such as the initial support surface, etc. Secondary lining formwork includes end formwork, which is the formwork used to close the longitudinal end face of the secondary lining tunnel before pouring the secondary lining; because the secondary lining is constructed in sections along the longitudinal direction of the tunnel, the current segmental secondary lining refers to a section of the secondary lining constructed along the longitudinal direction of the tunnel. The embedded waterstop is a waterstop product used to be set inside concrete such as concrete deformation joints and expansion joints, and has the ability to adapt to the expansion and contraction deformation of concrete with the elasticity of rubber materials and structural forms. By bending the waterstop from the middle of the width and fixing it with a fixing device, the fixing device here can be an integral structure or a plurality of single structures. By bending and fixing, the fixing device can ensure the bending state of the bent waterstop, that is, the exposed section needs to be close to the inner side of the end template, so that the embedded section is fixed in the embedded position, such as: the fixing device can adopt bolts and gaskets to fix the waterstop. After fixing, the other side of the waterstop is perpendicular to the end template and is fixed on the end template, maintaining the bent state; the embedded position refers to the position where the embedded section is buried in the secondary lining of the tunnel, and the embedded section is arranged along the longitudinal direction of the tunnel; the exposed section is arranged along the transverse direction of the tunnel, and it will be after the secondary lining construction of the current segment is completed, and it will eventually need to be exposed at the end of the secondary lining of the current segment. Through the above-mentioned method, the entire waterstop can be set inside the second lining formwork of the current segment and fixed on the end formwork. After pouring concrete into the pouring space in the second lining formwork of the current segment, the embedded section can be embedded in the concrete of the second lining. After removing the second lining formwork, the connection between the fixing device and the end formwork is disconnected. By simple treatment, such as cleaning the concrete around the exposed section, the bent exposed section can be bent in reverse, and the waterstop can be straightened to complete the embedded construction of the embedded section. By adopting the above-mentioned embedding method, the waterstop is restored by bending the waterstop and fixing the bent exposed section on the inner side of the end formwork, and then bending the exposed section in reverse after pouring, thereby avoiding the end formwork being processed in two halves due to the installation of the waterstop, and thus avoiding the need to install and support the two halves of the end formwork separately when installing the end formwork, reducing the construction process of the end formwork and making the construction method simpler.

[0011] Preferably, the fixing device comprises a first limiting segment, a second limiting segment and two fixing parts, the first limiting segment is an open-loop structure, one end of the first limiting segment is connected to one end of the second limiting segment, the other end is connected to one of the fixing parts, and the other end of the second limiting segment is connected to the other of the fixing parts;

[0012] The step B comprises the following steps:

[0013] B1: The exposed section is pressed against a preset position on the inner side of the end template and temporarily fixed;

[0014] B2: The opening of the first limiting section is oriented toward the end template and is sleeved on the outside of the embedded section, and the second limiting section is installed corresponding to the exposed section, and then the two fixing parts are respectively connected to the end template.

[0015] The fixing device can be an integral structure, through which the entire waterstop is directly limited and fixed; or it can be a number of small components, through which the waterstop is limited and fixed at multiple points. The first limiting section is used to limit the embedded section of the waterstop, which is an open-loop structure. The notch of the open-loop structure is the opening of the open-loop structure. When the embedded section is limited by the open-loop structure, the opening of the open-loop structure faces the end template, and is sleeved on the outer surface of the embedded section. It can be sleeved on the outside of the embedded section and limited; the second limiting section is used to limit the exposed section, which can cooperate with the end template to be tightly attached to the exposed section of the end template for limiting. The first limiting section and the second limiting section can limit the bent waterstop to ensure the bending state of the bent waterstop, and then the connection between the fixing device and the end template is realized by the fixing parts respectively connected to the first limiting section and the second limiting section. Through the fixing device, the bent waterstop can be directly limited in position in cooperation with the end template, and the bent waterstop can be indirectly fixed to the end template, avoiding the occurrence of damage to the waterstop when the waterstop is directly fixed to the end template, such as: fixing it by passing bolts through the waterstop, etc., further ensuring the waterstop function of the waterstop.

[0016] Preferably, the first limiting section and the second limiting section have a plurality of depressions on one side for contacting the water stop strip, and the depressions are used to fit the protrusions on the water stop strip;

[0017] The step B comprises: firstly fitting the embedded section to the first limiting section, then bending the exposed section until the protrusion of the exposed section is fitted to the depression of the second limiting section, and then fixing the two fixing parts to the end template.

[0018] The first limiting section and the second limiting section are processed according to the state of the waterstop after bending. By first installing the embedded section on the first limiting section and then bending the exposed section, the first limiting section can limit the embedded section, which is convenient for bending the exposed section. In addition, it can judge whether the bending angle is appropriate according to whether the cooperation between the exposed section and the second limiting section after bending has reached the expected value. Therefore, the bending accuracy can be improved, the installation of the waterstop can be made more accurate, and the use of the waterstop can be facilitated.

[0019] Preferably, the end formwork comprises a plurality of wooden formworks distributed along the tunnel arch, with gaps between adjacent wooden formworks, and the fixing device is a steel bar component, and the steel bar component is used to fix the water stop strip at each of the gaps.

[0020] Preferably, the steps of fixing the water stop strip at each gap using the steel bar component are as follows:

[0021] B2a: The opening of the first limiting section of the reinforcement member is directed toward the end template and is sleeved on the embedded section, and the second limiting section of the reinforcement member is pressed on the side of the exposed section away from the end template, so that the two fixing parts of the reinforcement member pass through the same gap;

[0022] B2b: bend the two fixing parts so that they are close to the outer side of the end template;

[0023] B2c: Seal the gap.

[0024] When the end template is formed by connecting several wood templates, the wood templates are distributed along the annular direction of the tunnel arch. The number of wood templates is determined according to the actual construction situation. There is a gap between two adjacent wood templates, which can ensure the passage of steel bars. The size of the steel bars is also determined according to the size of the gap between the two adjacent wood templates. Each of the waterstops needs to be limited and fixed by a fixing device processed by multiple steel bars. By using steel bars to process the fixing device, it is easy to process and it is convenient to process a fixing device that is suitable for the bent waterstop. At the same time, the fixing part of the fixing device can pass from the inner side of the end template to the outer side of the end template by means of the gap between adjacent wood templates, and by bending the fixing part, the bent waterstop is pressed against the inner side of the end template, so as to limit or fix the bent waterstop and maintain the bent state of the bent waterstop. Through the above method, it is possible to avoid the fixing device from damaging the end template and the waterstop, so that the bent waterstop is fixed on the end template, and it is convenient to separate the end template and the waterstop when demolding. The waterstop must be bent and fixed with a fixing device at each gap, which can strengthen the connection strength between the waterstop and the end formwork, ensure the stability of the waterstop when pouring concrete, and improve the accuracy of the waterstop after installation. After the steel bar is passed through the gap between the wooden formworks, the gap will leak slurry. The gap between the two adjacent wooden formworks can be sealed. The sealing can be done by filling the gap, such as using sealing glue; or by external covering, sealing from the outside of the end formwork. By sealing the gap between the two adjacent wooden formworks on the end formwork, leakage can be avoided during the later pouring of concrete. At the same time, the connection between the fixed part and the end formwork can be increased, which can ensure the quality of the construction of the second lining segment.

[0025] Preferably, in step B, the waterstop is constructed by bending in sequence from both sides to the middle along the tunnel arch ring, and the bent position of the waterstop is promptly fixed by using the fixing device.

[0026] The construction of the waterstop is carried out at multiple fixed points. At each fixed point, the portion of the waterstop corresponding to the fixed point needs to be bent and fixed. By first bending and fixing the waterstop at the fixed points on both sides of the tunnel arch, the initial installation and fixation of the entire waterstop is achieved, which facilitates the construction of the portion of the waterstop corresponding to the fixed point in the middle of the tunnel arch. By gradually constructing from both sides of the tunnel arch to the middle, after the waterstop is fixed by fixing devices on both sides, a stable installation environment can be provided for the fixed point of the next waterstop, which can facilitate the installation of the portion of the waterstop corresponding to the next fixed point and greatly speed up the installation rate of the waterstop. At the same time, after the waterstop corresponding to each fixed point is bent into a specified state, the fixed point is immediately fixed, which can protect the initial state of the waterstop portion corresponding to the fixed point after bending, improve the installation accuracy of the waterstop portion corresponding to the fixed point, and thus improve the installation accuracy of the entire waterstop.

[0027] A device for fixing an embedded waterstop in a secondary lining of a tunnel comprises a first limiting segment, a second limiting segment and two fixing parts, wherein the first limiting segment is an open-loop structure, one end of the first limiting segment is connected to one end of the second limiting segment and the other end is connected to one of the fixing parts, the other end of the second limiting segment is connected to another of the fixing parts, the fixing parts are used to connect to an end formwork, the second limiting segment is used to limit the exposed section of the waterstop to be close to one side of the end formwork, and the first limiting segment is used to limit the embedded section of the waterstop and make the embedded section located in the embedded position.

[0028] The first limiting section is used to limit the embedded section, which is an open-loop structure, and can be sleeved on the outside of the embedded section and limit the two sides of the embedded section; the second limiting section is used to limit the exposed section after being bent, and can be pressed on the side of the exposed section away from the end template, and clamp the exposed section together with the end template, and cooperate with the inner side of the end template to limit the exposed section; the connection between the fixing device and the end template is achieved by connecting the first limiting section and the second limiting section respectively; after the two fixing parts are connected to the end template, the end template and the fixing device form an L-shaped closed loop, and then the bent waterstop is nested inside the closed loop to form a limit, ensuring the bending state of the bent waterstop. Through the fixing device, the bent waterstop can be directly limited in cooperation with the end template, and the waterstop can be indirectly fixed to the end template, avoiding the situation of damaging the waterstop when fixing the waterstop, and further ensuring the waterstop function of the waterstop.

[0029] Preferably, the first limiting segment and / or the second limiting segment has a plurality of depressions on one side for contacting the waterstop, and the depressions are used to adapt to the protrusions on the waterstop. The surface of the waterstop is a surface with protrusions, including the protrusions brought by the center hole and the protrusions located on both sides of the center hole. The center hole is a circular through hole in the middle of the waterstop. When installing the waterstop, the center hole is generally located at the settlement joint of the building. This solution refers to the connection between adjacent two lining segments. The center hole can play a role in regulating deformation of contraction and expansion, compression and tension. The center hole will cause a semi-cylindrical protrusion to form on the surface of the waterstop. The first limiting segment and the second limiting segment have the depressions, and the number of the depressions is determined according to the protrusions of the waterstop. By using the depressions to adapt to the corresponding protrusions on the waterstop, the waterstop can be protected by limiting.

[0030] Preferably, the fixing device is a steel bar member.

[0031] It is made by bending round steel bar scraps, which is easy to install.

[0032] Preferably, the diameter of the steel bar member is 6-10 mm, which can meet the strength requirements of the fixing device and greatly reduce damage to the wooden formwork.

[0033] Preferably, the length direction of the fixing portion is adapted to the setting direction of the embedded section, and the fixing portion can pass through the gap of the end head template and be bent to be closely attached to the outer side of the end head template.

[0034] The end template includes a plurality of wooden templates distributed along the tunnel arch, and there are gaps between adjacent wooden templates.

[0035] By adapting the length direction of the fixing part and the setting direction of the embedded section, the fixing part can pass through the gap between adjacent wooden formworks, and then the water stop is fixed by bending the fixing part to fit closely to the outer side of the wooden formwork. This fixing method is simple and quick, and is convenient for the later removal of the end formwork, which can reduce the difficulty of construction.

[0036] In summary, due to the adoption of the above technical solution, the beneficial effects of the present invention are:

[0037] 1. The method for pre-embedding buried waterstop in secondary lining of tunnel described in the present invention achieves the restoration of the waterstop by bending the waterstop and fixing the bent waterstop on the inner side of the end formwork, and then bending the waterstop in the reverse direction after pouring, thereby avoiding the need to process the end formwork in two halves due to the installation of the waterstop, and further avoiding the need to separately install and support the two halves of the end formwork when installing the end formwork, reducing the construction process of the end formwork and making the construction method simpler.

[0038] 2. The fixing device in the present invention can limit the bent waterstop by cooperating with the end template through the first limiting segment and the second limiting segment to ensure the bending state of the bent waterstop, and then realize the connection between the fixing device and the end template through the fixing parts respectively connected to the first limiting segment and the second limiting segment. Through the fixing device, the bent waterstop can be directly limited in position in cooperation with the end template, and the bent waterstop can be indirectly fixed to the end template, avoiding the situation of damaging the waterstop when directly fixing the waterstop to the end template, and further ensuring the waterstop function of the waterstop.

[0039] 3. When the end formwork is formed by connecting a number of wooden formworks, the fixing device in the present invention uses a steel bar component. Each of the waterstops needs to be limited and fixed by a fixing device processed by a plurality of steel bars. By processing the fixing device with steel bars, it is easy to process and it is convenient to process a fixing device that is suitable for the bent waterstop. At the same time, the fixing part of the fixing device can pass from the inner side of the end formwork to the outer side of the end formwork by means of the gap between adjacent wooden formworks, and by bending the fixing part, the bent waterstop is pressed against the inner side of the end formwork, so as to limit or fix the bent waterstop and maintain the bent state of the bent waterstop. Through the above method, it is possible to avoid the fixing device from damaging the end formwork and the waterstop, so that the bent waterstop can be fixed on the end formwork, and it is also convenient to separate the end formwork and the waterstop when removing the mold. BRIEF DESCRIPTION OF THE DRAWINGS

[0040] Figure 1 It is a schematic diagram of water stop installation in the prior art;

[0041] Figure 1 Icon: 1-end formwork; 11-first end formwork; 12-second end formwork; 2-waterstop; 3-initial support surface.

[0042] Figure 2 This is a schematic diagram of the structure of the fixing device in Example 1. Figure 1 ;

[0043] Figure 3 This is a schematic diagram of the structure of the fixing device in Example 1. Figure 2 ;

[0044] Figure 4 is a schematic diagram showing one side of the water stop installed in the first limiting section of the fixing device;

[0045] Figure 5 This is a schematic diagram of the water stop after bending;

[0046] Figure 6 It is a schematic diagram after the water stop is limited by the fixing device;

[0047] Figure 7 It is a schematic diagram of a fixing device fixing the water stop.

[0048] Figure 2-7 Icons: 1-end formwork; 2-waterstop; 21-embedded section; 22-exposed section; 3-initial support surface; 4-depression; 51-first limiting section; 52-second limiting section; 53-fixed part. DETAILED DESCRIPTION

[0049] The present invention will be described in detail below in conjunction with the accompanying drawings.

[0050] In order to make the purpose, technical solution and advantages of the present invention more clearly understood, the present invention is further described in detail below in conjunction with the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are only used to explain the present invention and are not used to limit the present invention.

[0051] Example 1

[0052] See also Figure 2-7 ,in: Figure 6-7 It is a top view of the left side of the tunnel, the upper side of the end template 1 is the inner side of the second lining template, the lower side is the outer side of the second lining template, and the left side is the initial support surface 3; this embodiment provides a method for pre-embedding a buried water stop in a tunnel secondary lining, comprising the following steps:

[0053] A: Install the secondary lining template of the current segment secondary lining; wherein the secondary lining template includes the end template 1 of the current segment secondary lining;

[0054] The second lining formwork is a formwork for constructing the second lining segment. Installing the second lining formwork of the second lining of the current segment not only involves the installation of the second lining formwork itself, but also includes the installation of the steel bars and steel frames inside the second lining formwork. Among them, the end formwork 1 can be a steel formwork or a wooden formwork, because the wooden formwork has the advantages of being easier to temporarily process at the construction site and convenient to transport. This embodiment is described by taking the wooden formwork as an example. The end formwork 1 is a plurality of wooden formworks distributed along the annular direction of the tunnel arch. When the end formwork 1 is formed by connecting a plurality of wooden formworks, the wooden formworks are distributed along the annular direction of the tunnel arch. The number of wooden formworks is determined according to the actual construction situation, and there is a gap between two adjacent wooden formworks. In this embodiment, when installing the wooden formwork, it is not necessary to cut each wooden formwork into two halves in order to adapt to the arrangement of the water stop 2 along the longitudinal direction of the tunnel as in the prior art construction method, thereby avoiding the installation and support of the two separated wooden formwork halves. This embodiment installs and supports the entire wooden formwork, reducing the construction process and construction difficulty of installing and supporting the wooden formwork.

[0055] After the end template 1 is installed, perform step B: bend the water stop 2 from the middle of the width to the exposed section 22 to be close to the preset position inside the end template 1 and temporarily fix it, and then fix the embedded section 21 of the water stop 2 to the embedded position and fix the exposed section 22 to the preset position by a fixing device;

[0056] Among them, the embedded section 21 refers to half of the width of the waterstop 2 embedded in the second lining segment, and its setting direction is the longitudinal direction of the tunnel; the embedded position refers to the position where the embedded section 21 is buried in the second lining segment; the exposed section 22 refers to the half of the waterstop 2 that needs to be exposed at the end of the second lining segment after the construction of the second lining segment is completed; the preset position refers to: when the embedded section 21 is located at the embedded position, the exposed section 22 is bent so that the exposed section 22 is attached to the position on the inner side of the end template 1.

[0057] And the implementation method of step B is determined according to the actual construction situation. In this embodiment, the waterstop 2 is bent and constructed in sequence from both sides to the middle along the tunnel arch, and the position of the waterstop 2 after bending is promptly fixed by the fixing device. The construction of the waterstop 2 is divided into multiple fixed points. At each fixed point, the part of the waterstop 2 corresponding to the fixed point needs to be bent and fixed. By first bending and fixing the waterstop 2 at the fixed points on both sides of the tunnel arch, the initial installation and fixation of the entire waterstop 2 is achieved, which facilitates the construction of the part of the waterstop 2 corresponding to the fixed point in the middle of the tunnel arch. By adopting a method of stepwise construction from both sides of the tunnel arch to the middle, after the waterstop 2 is fixed by the fixing device on both sides, a stable installation environment can be provided for the next fixed point of the waterstop 2, which can facilitate the installation of the part of the waterstop 2 corresponding to the next fixed point, and greatly speed up the installation rate of the waterstop 2. At the same time, after the waterstop 2 corresponding to each fixed point is bent into a specified state, the fixed point is immediately fixed, which can protect the initial state of the waterstop 2 corresponding to the fixed point after bending, improve the installation accuracy of the waterstop 2 corresponding to the fixed point, and then improve the installation accuracy of the entire waterstop 2.

[0058] This embodiment also provides a tunnel secondary lining embedded water stop fixing device, see Figure 2-5The fixing device is used to fix the bent water stop 2 on the end template 1. The fixing device can be an integral structure, through which the entire water stop 2 is directly limited and fixed; or it can be a number of small components, through which the water stop 2 is limited and fixed at multiple points. In this embodiment, the fixing device includes a first limiting segment 51, a second limiting segment 52 and two fixing parts 53. The first limiting segment 51 is an open-loop structure. One end of the first limiting segment 51 is connected to one end of the second limiting segment 52 and the other end is connected to one of the fixing parts 53. The other end of the second limiting segment 52 is connected to another of the fixing parts 53.

[0059] In this embodiment, the fixing device uses a small component to limit and fix the water stop 2 at multiple points. Specifically, the fixing device is a steel bar component, and the size of the steel bar is also determined according to the size of the gap between two adjacent wooden templates. In this embodiment, ordinary φ8 round steel bar scraps are bent to make the fixing device. Specifically, step B specifically includes the following steps:

[0060] B1: bend the water stop strip 2 from the middle of the width to the exposed section 22 close to the preset position inside the end template 1 and temporarily fix it;

[0061] B2: The opening of the first limiting section 51 is oriented toward the end head template 1 and is sleeved on the embedded section 21 , and the second limiting section 52 is installed corresponding to the exposed section 22 , and then the two fixing parts 53 are respectively connected to the end head template 1 .

[0062] In this embodiment, the steel bar component is used at each of the gaps to fix the water stop strip 2. And the method of using the steel bar component to fix the water stop strip 2 at each of the gaps is:

[0063] B2a: The opening of the first limiting section 51 of the reinforcement member is directed toward the end template 1 and is sleeved on the embedded section 21, and the second limiting section 52 of the reinforcement member is pressed on the side of the exposed section 22 away from the end template 1, so that the two fixing portions 53 of the reinforcement member pass through the same gap;

[0064] B2b: bend the two fixing portions 53 so that they are closely attached to the outer side of the end template 1;

[0065] B2c: Seal the gap.

[0066] Among them, each of the waterstop strips 2 needs to be limited and fixed by a fixing device processed by multiple steel bars. By processing the fixing device with steel bars, it is easy to process and it is convenient to process a fixing device suitable for the waterstop strip 2 after bending. At the same time, the fixing part 53 of the fixing device can pass from the inner side of the end mold to the outer side of the end mold with the help of a gap between two adjacent wooden molds, and by bending the fixing part 53, the bent waterstop strip 2 is pressed against the inner side of the end template 1, so as to limit or fix the waterstop strip 2 after bending and maintain the bent state of the waterstop strip 2 after bending. Through the above method, it is possible to avoid the fixing device from damaging the end template 1 and the waterstop strip 2, so that the bent waterstop strip 2 is convenient to be fixed on the end template 1, and it is convenient to separate the end template 1 and the waterstop strip 2 when demolding.

[0067] Furthermore, the waterstop 2 must be bent and fixed with a fixing device at each gap, which can strengthen the connection strength between the waterstop 2 and the end formwork 1, ensure the stability of the state of the waterstop 2 when pouring concrete, and thus improve the accuracy of the waterstop 2 after installation. After the steel bars are passed through the gaps between the wooden formworks, the gaps will leak slurry. The gaps between the two adjacent wooden formworks can be sealed by filling the gaps, such as using sealing glue; or external covering can be used to seal from the outside of the end formwork 1. By sealing the gaps between the two adjacent wooden formworks on the end formwork 1, leakage can be avoided during the later pouring of concrete, and at the same time, the connection between the fixing portion 53 and the end formwork 1 can be increased, which can ensure the quality of the construction of the second lining segment.

[0068] In this embodiment, the first limiting section 51 and / or the second limiting section 52 has a plurality of depressions 4 on one side for contacting the water stop strip 2, and the depressions 4 are used to fit the protrusions on the water stop strip 2; Figure 2 As shown, the first limiting section 51 and the second limiting section 52 are both provided with a recess 4; Figure 3 As shown, the first limiting section 51 is provided with a recess 4. The step B may be performed by first bending and then fixing, or by the following steps: firstly, one side of the water stop 2 is adapted and installed on the first limiting section 51, such as Figure 4 Then bend the other side of the water stop 2 until the convexity on the other side of the water stop 2 is adapted to the concave portion 4 of the second limiting segment 52, as shown. Figure 5 Then the two fixing portions 53 are fixed to the end template 1, as shown Figure 6-7As shown. Since the first limiting section 51 and the second limiting section 52 are processed according to the state of the waterstop 2 after bending, when the second limiting section 52 is provided with the recess 4, by first installing the embedded section 21 of the waterstop 2 on the first limiting section 51 and then bending the exposed section 22 of the waterstop 2, the first limiting section 51 can limit the embedded section 21 of the waterstop 2, which is convenient for bending the exposed section 22 of the waterstop 2, and can judge whether the bending angle is appropriate according to whether the cooperation between the exposed section 22 after bending and the second limiting section 52 has reached the expected value, so the bending accuracy can be improved, the installation of the waterstop 2 is more accurate, and it is beneficial to the use of the waterstop 2.

[0069] After the entire water stop 2 is limited and fixed on the end formwork 1 according to the construction of step B, and the gap between the two adjacent wooden formworks is sealed, step C is implemented: pouring concrete for the current segment; then step D is implemented: after reaching the predetermined strength, the second lining formwork is removed, and the exposed section 22 is released to complete the pre-embedding of the water stop 2. When removing the second lining formwork, the end formwork 1 is also removed, and it is necessary not only to remove the support of the end formwork 1 itself, but also to bend the fixing part 53 of the fixing device back to the original state so that the end formwork 1 can be removed.

[0070] After the end formwork 1 is disassembled, the exposed section 22 is released and the water stop 2 is straightened to complete the pre-embedding of the water stop 2. When releasing the exposed section 22, because the exposed section 22 is inside the end formwork 1, the poured concrete will solidify around the exposed section 22, so it is necessary to simply clean and process the exposed section 22 around it before the exposed section 22 can be released and bent to be straightened, so that the width direction of the exposed section 22 returns to the longitudinal direction of the tunnel.

[0071] The above description is only a preferred embodiment of the present invention and is not intended to limit the present invention. Any modifications, equivalent substitutions and improvements made within the spirit and principles of the present invention should be included in the protection scope of the present invention.

Claims

1. A method for pre-embedding a buried waterstop in a secondary lining of a tunnel, characterized in that: The following steps are involved: A. Installing the secondary lining template of the current segment; wherein the secondary lining template includes an end template (1); B. Bend the exposed section (22) of the water stop (2) to a preset position close to the inner side of the end template (1) and temporarily fix it, then fix the embedded section (21) of the water stop (2) to the embedded position and fix the exposed section (22) at the preset position by a fixing device; C. Pour concrete into the current segment; D. After reaching a predetermined strength, the second lining formwork is removed, and the exposed section (22) is released, thereby completing the pre-embedding of the water stop strip (2); the fixing device comprises a first limiting section (51), a second limiting section (52) and two fixing parts (53); the first limiting section (51) is an open-loop structure; one end of the first limiting section (51) is connected to one end of the second limiting section (52), and the other end is connected to one of the fixing parts (53); the other end of the second limiting section (52) is connected to another of the fixing parts (53); The step B comprises the following steps: B1: The exposed section (22) is pressed against a preset position on the inner side of the end template (1) and temporarily fixed; B2: The opening of the first limiting section (51) is oriented toward the end formwork (1) and is sleeved on the outside of the embedded section (21), and the second limiting section (52) is installed corresponding to the exposed section (22), and then the two fixing parts (53) are respectively connected to the end formwork (1); the end formwork (1) comprises a plurality of wooden formworks distributed along the tunnel arch, and there are gaps between adjacent wooden formworks, and the fixing device is a steel bar component, and the steel bar component is used to fix the water stop strip (2) at each of the gaps; the steps of fixing the water stop strip (2) at each of the gaps using the steel bar component are as follows: B2a: The opening of the first limiting section (51) of the reinforcement member is oriented toward the end template (1) and is sleeved on the embedded section (21), and the second limiting section (52) of the reinforcement member is pressed against the side of the exposed section (22) away from the end template, so that the two fixing portions (53) of the reinforcement member pass through the same gap; B2b: bending the two fixing portions (53) so as to make them close to the outer side of the end template (1); B2c: Seal the gap.

2. The method for pre-embedding a buried waterstop in a tunnel secondary lining according to claim 1 is characterized in that: In step B, the water stop strip (2) is bent in sequence from both sides to the middle along the tunnel arch ring direction, and the bent position of the water stop strip (2) is promptly fixed using the fixing device.

3. A fixing device for embedded waterstop in secondary tunnel lining, characterized in that: The invention comprises a first limiting section (51), a second limiting section (52) and two fixing parts (53), wherein the first limiting section (51) is an open-loop structure, one end of the first limiting section (51) is connected to one end of the second limiting section (52), and the other end is connected to one of the fixing parts (53), the other end of the second limiting section (52) is connected to another of the fixing parts (53), the fixing parts (53) are used to connect to the end template (1), the second limiting section (52) is used to limit the exposed section (22) of the water stop strip (2) to be close to one side of the end template (1), the first limiting section (51) is used to limit the embedded section (21) of the water stop strip (2) and make the embedded section (21) be located in the embedded position; A limiting section (51) and / or the second limiting section (52) has a plurality of recesses (4) on one side for contacting the water stop strip (2), and the recesses (4) are used to adapt to the protrusions on the water stop strip (2); the connection between the first limiting section (51) and the second limiting section (52) is an arc-shaped structure, and the connection between the second limiting section (52) and the fixing portion (53) is an arc-shaped structure; the connection between the first limiting section (51) and the fixing portion (53) is an arc-shaped structure; the length direction of the fixing portion (53) is adapted to the setting direction of the embedded section (21), and the fixing portion (53) can pass through the gap of the end head template (1) and bend to fit closely to the outer side of the end head template (1).

4. The embedded waterstop fixing device in the secondary lining of a tunnel according to claim 3 is characterized in that: The fixing device is a steel bar component.

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