Formwork support structure of subsurface tunnel

Abstract

The utility model relates to the technical field of tunnel construction, in particular to a template support structure of a subsurface tunnel, which comprises a template arranged on an arch crown and a side wall along the circumferential direction of the tunnel and a support used for supporting the template, the support is a disc buckle type steel pipe scaffold, and the section of the tunnel is divided into an upper step and a lower step in the vertical direction. A temporary inverted arch is arranged between the upper step and the lower step, a vertically-extending supporting rod is arranged on the section of the tunnel, the supporting rod and the temporary inverted arch are matched to divide the section of the tunnel into a plurality of areas, each area is provided with a set of branch supports, and the multiple sets of branch supports jointly form a support. According to the utility model, the section of the tunnel is divided into a plurality of areas to ensure the rigidity of each group of sub-brackets, so that the bracket formed by the sub-brackets can adapt to the strength and rigidity requirements of the tunnel with a larger span, and the rigidity of the disc buckle type steel pipe scaffold is larger, so that the strength and rigidity of the bracket are further improved.

Description

Technical Field

[0001] The utility model relates to the technical field of tunnel construction, and particularly relates to a formwork support structure for a mined tunnel. Background Technique

[0002] During tunnel lining construction, it is usually necessary to pour a certain thickness of concrete on the inner wall of the tunnel to maintain the stability and safety during the tunnel construction process. For tunnels with a large span, the amount of concrete required for construction lining is large, and the stiffness requirements for the formwork and support are correspondingly increased. The existing lining formwork and support structure have limited stiffness and are difficult to meet the safety requirements of large-span tunnels. Summary of the Invention

[0003] The purpose of the utility model is to provide a formwork support structure for a mined tunnel to solve the problem of insufficient stiffness of the existing lining formwork support.

[0004] To achieve the above purpose, the technical solution of the utility model is: a formwork support structure for a mined tunnel, including formwork arranged along the circumferential direction of the tunnel at the crown and side walls and a support for supporting the formwork. The support is a disc buckle steel pipe scaffold. The tunnel section is divided into an upper bench and a lower bench vertically. A temporary invert is provided between the upper bench and the lower bench. A support rod extending vertically is provided on the tunnel section. The support rod and the temporary invert cooperate to divide the tunnel section into multiple regions. Each region is provided with a group of sub-supports, and multiple groups of sub-supports together constitute the support. The two ends of the support rod support on the formwork at the crown of the tunnel and the bottom of the tunnel arch. The support rod is provided with an adjusting mechanism, and the adjusting mechanism is used to adjust the height of the support rod to adapt to the settlement deformation of the formwork at the crown of the tunnel.

[0005] In one embodiment, the sub-support includes a group of vertical rods and a group of horizontal rods arranged crosswise. The group of vertical rods includes multiple vertical rods arranged transversely at intervals in the tunnel section. An adjustable jack is provided at the top end of the vertical rod, and a base is provided at the bottom end of the vertical rod.

[0006] In one embodiment, the group of horizontal rods includes multiple crossbars arranged in the tunnel section and longitudinal bars extending along the longitudinal direction of the tunnel. Thus, the vertical rods, the crossbars, and the longitudinal bars form a three-way cross support structure in the tunnel. The two ends of the crossbars and the longitudinal bars are respectively connected to the vertical rods.

[0007] In one embodiment, the adjustable support includes a screw rod with an external thread, an adjusting nut, and a support base located at the top of the screw rod. The vertical rod is a circular steel pipe. The screw rod of the adjustable support is inserted into the circular steel pipe, and the position of the support base extending out of the vertical rod is adjusted by the threaded engagement between the adjusting nut and the screw rod. The vertical rod contacts the formwork or the temporary inverted arch through the support base.

[0008] In one embodiment, the support further includes a plurality of inclined braces. The upper ends of the inclined braces located on the upper bench are arranged at the arc-shaped cross-sections on both sides of the crown, and they reach the temporary inverted arch. The upper ends of the inclined braces located on the lower bench are arranged at the side walls on both sides and reach the top surface of the inverted arch of the tunnel.

[0009] In one embodiment, the adjusting mechanism is a servo jack.

[0010] In one embodiment, the formwork includes pine boards arranged on the crown and side walls of the tunnel. The main keels and secondary keels are provided on the side of the pine boards facing away from the tunnel soil body. The main keels are made of I12 steel I-beams with a spacing of 600 mm, and the secondary keels are made of 50×50×3 mm square steel with a spacing of 300 mm.

[0011] The beneficial effects of the present utility model are as follows:

[0012] 1. By dividing the tunnel cross-section into multiple regions, the present utility model ensures the stiffness of each group of sub-supports, enabling the support formed by the sub-supports to meet the strength and stiffness requirements of a tunnel with a relatively large span. Moreover, the stiffness of the disc-locked steel pipe scaffolding is relatively large, further increasing the strength and stiffness of the support. The adjusting mechanism on the support rod can adjust the two ends of the support rod according to the settlement deformation of the crown formwork, so that the two ends of the support rod can support on the formwork and the arch bottom, preventing cavities from appearing at the top of the formwork.

[0013] 2. Using the servo jack as the adjusting mechanism, the adjustment method is simple and reliable, and the supporting force is large enough to better adapt to the settlement deformation caused by the self-weight of the formwork, improve the stiffness of the formwork, and increase the deformation capacity of the formwork.

[0014] 3. The three-way cross support formed by the vertical rods, horizontal rods, and longitudinal rods has relatively large stiffness and strength, providing a large supporting force for the formwork, and being able to provide sufficient supporting strength during the construction of the secondary lining until the secondary lining reaches the design strength. BRIEF DESCRIPTION OF THE DRAWINGS

[0015] Figure 1 is a schematic structural diagram of the secondary lining of the embodiment of the present utility model in the tunnel cross-section.

[0016] Figure 2 is a schematic structural diagram of the formwork and support of the embodiment of the present utility model in the tunnel cross-section.

[0017] Figure 3 It is a schematic diagram of the structure of the template and the bracket in the longitudinal direction of the tunnel according to an embodiment of the utility model.

[0018] Figure 4 It is a schematic diagram of the connection between the adjustable top support and the vertical pole in an embodiment of the utility model.

[0019] Where: S 1 Go up the stairs, S 2 Down steps, 10 temporary inverts;

[0020] 1 template, 11 pine board, 12 secondary keel, 2 brackets, 20 sub-brackets, 21 vertical poles, 22 horizontal poles, 23 longitudinal poles, 24 adjustable top supports, 241 screw rods, 242 adjusting nuts, 243 brackets, 25 bases, 26 diagonal braces, 3 support rods, 31 adjusting mechanisms. DETAILED DESCRIPTION

[0021] To further illustrate the various embodiments, the present invention provides drawings. These drawings are part of the disclosure of the present invention, which are mainly used to illustrate the embodiments and can be used in conjunction with the relevant descriptions in the specification to explain the operating principles of the embodiments. With reference to these contents, a person of ordinary skill in the art should be able to understand other possible implementations and advantages of the present invention. The components in the figures are not drawn to scale, and similar component symbols are generally used to represent similar components.

[0022] See also Figure 1 As shown, the utility model discloses a template support structure for a dark excavated tunnel, wherein the tunnel section is vertically divided into an upper step S 1 and down the stairs S 2 A temporary invert 10 is set between the upper step and the lower step. The pouring of secondary lining concrete is divided into two times. The first construction is to pour the invert concrete + 100cm high side wall above the temporary invert, and the second construction is to pour the remaining side walls and arch top of the underpass.

[0023] See also Figure 1 and Figure 2 As shown, before pouring, a template 1 and a bracket 2 for supporting the template should be set on the arch and side wall along the tunnel circumference. The bracket 2 is a disc-type steel pipe scaffolding. A vertically extending support rod 3 is provided on the cross section of the tunnel. The support rod 3 and the temporary inverted arch 10 cooperate to divide the cross section of the tunnel into multiple areas. In this embodiment, it is divided into six areas. Each area is provided with a group of brackets 20, and multiple brackets 20 together constitute the bracket 2. The two ends of the support rod 3 are supported on the template of the tunnel arch and the tunnel arch bottom. The support rod 3 is provided with an adjustment mechanism 31. The adjustment mechanism 31 is used to adjust the height of the support rod 3 to adapt to the settlement deformation of the template 1 of the tunnel arch.

[0024] The utility model ensures the stiffness of each component support 20 by dividing the tunnel section into multiple regions, enabling the support 2 composed of the component supports 20 to meet the strength and stiffness requirements of tunnels with a relatively large span. Moreover, the stiffness of the disc-locked steel pipe scaffold is relatively large, further increasing the strength and stiffness of the support 2. The adjusting mechanism 31 on the support rod 3 can adjust the two ends of the support rod 3 according to the settlement deformation of the arch top formwork, so that the two ends of the support rod 3 can support on the formwork 1 and the arch bottom, preventing cavities from appearing at the top of the formwork 1.

[0025] The adjusting mechanism 31 in this embodiment is a servo jack. Specifically, a servo jack refers to a jack with a servo drive motor, and the lifting height thereof is controlled by a servo motor. Therefore, its adjustment method is simple and reliable, and the supporting force of the jack is large enough to well adapt to the settlement deformation caused by the self-weight of the formwork, improve the stiffness of the formwork 1, and increase the deformation capacity of the formwork.

[0026] Refer to Figure 2 and Figure 3 As shown in

[0027] The three-way cross vertical rods 21, horizontal rods 22, and longitudinal rods 23 make the support have greater strength and stiffness to meet the relatively large strength and stiffness requirements of large-span tunnels.

[0028] The longitudinal rod 23 is arranged inside the vertical rod 21, and its length is not less than 3 spans. Each step of the horizontal rod 22 and the longitudinal rod 23 must be connected and pulled through by a disc-locked node. The horizontal rod 22 is arranged at the intersection of the vertical rod 21 and the longitudinal rod 23, and both ends of the horizontal rod 22 are fixed on the vertical rod to form an overall force-bearing space structure.

[0029] Refer to Figure 2 and Figure 4As shown in the figure, the adjustable head support 24 includes a screw rod 241 with external threads and an adjusting nut 242. The vertical rod 21 is a circular steel pipe. The adjustable head support 24 is inserted into the circular steel pipe. The adjustable head support 24 further has a socket 243 located at the top of the screw rod 241. The position where the socket 243 extends out of the top of the vertical rod 21 is adjusted by the threaded engagement between the adjusting nut 242 and the screw rod 241. The vertical rod 21 contacts the formwork 1 or the temporary inverted arch 10 through the socket 243. The presence of the adjustable head support 24 facilitates the installation and fastening of the vertical rod 21, reduces the installation difficulty of the vertical rod 21 and ensures the supporting strength of the vertical rod 21.

[0030] Referring to Figure 2 As shown in the figure, in order to further support the formwork 1, the support 2 further includes a plurality of inclined braces 26. The upper ends of the inclined braces 26 located on the upper bench are arranged at the arc-shaped cross-sections on both sides of the vault crown and reach the temporary inverted arch 10. The upper ends of the inclined braces 26 located on the lower bench are arranged at both side walls and reach the top surface of the inverted arch of the tunnel. The support of each sub-support 20 for the arc-shaped cross-sections on both sides of the upper bench and both side walls of the lower bench is weak. Therefore, in order to prevent the formwork of the arc-shaped cross-sections on both sides of the upper bench and both side walls of the lower bench from deforming or shifting due to the concrete pressure, inclined braces are arranged at these places to strengthen the stability of the formwork.

[0031] The formwork 1 includes pine boards 11 arranged on the tunnel vault crown and side walls. On the side of the pine boards 11 facing away from the tunnel soil mass, there are main keels (the main keels are not shown in the figure) and secondary keels 12. The main keels are made of I12 steel I-beams with a spacing of 600 mm, and the secondary keels 12 are made of 50×50×3 mm square steel with a spacing of 300 mm.

[0032] Concrete pouring holes should be reserved in the formwork of the vault crown and side walls. In addition, the formwork 1 of the side walls should also be reserved with vibrating ports to facilitate vibrating the concrete at the side walls tightly. The formwork of the vault crown should also be reserved with grouting holes and observation slurry discharge ports.

[0033] The parts not described above are the same as the prior art.

[0034] Although the present invention is specifically shown and introduced in combination with the preferred implementation embodiments, those skilled in the art should understand that the parts not described are the prior art, and various changes made to the present invention in form and details without departing from the spirit and scope of the present invention defined by the appended claims all fall within the protection scope of the present invention.

Claims

1. A formwork support structure for a dark excavated tunnel, characterized in that: It includes a template arranged on the arch and side wall along the tunnel circumference and a bracket for supporting the template, the bracket is a disc-type steel pipe scaffolding, the section of the tunnel is vertically divided into an upper step and a lower step, a temporary inverted arch is arranged between the upper step and the lower step, and a vertically extending support rod is arranged on the section of the tunnel. The support rod and the temporary inverted arch cooperate to divide the section of the tunnel into a plurality of areas, each of the areas is provided with a group of brackets, and a plurality of groups of the sub-brackets together constitute the bracket, the two ends of the support rod are supported on the template of the tunnel arch and the tunnel arch bottom, and the support rod is provided with an adjustment mechanism, and the adjustment mechanism is used to adjust the height of the support rod to adapt to the settlement deformation of the template of the tunnel arch.

2. The formwork support structure for a dark-excavated tunnel according to claim 1, characterized in that: The sub-bracket includes a cross-arranged vertical pole group and a horizontal pole group, the vertical pole group includes a plurality of vertical poles arranged at intervals in a transverse direction on the tunnel section, the top ends of the vertical poles are provided with adjustable top supports, and the bottom ends of the vertical poles are provided with bases.

3. The formwork support structure for a dark-excavated tunnel according to claim 2, characterized in that: The horizontal rod group includes a plurality of transverse rods arranged on the tunnel section and longitudinal rods extending in the longitudinal direction of the tunnel, so that the vertical rods, the transverse rods and the longitudinal rods form a three-way cross support structure in the tunnel; the two ends of the transverse rods and the longitudinal rods are respectively connected to the vertical rods.

4. The formwork support structure for a dark tunnel according to claim 2, characterized in that: The adjustable top support includes a screw rod with an external thread, an adjusting nut and a bracket located at the top of the screw rod. The vertical pole is a round tube steel. The screw rod of the adjustable top support is inserted into the round tube steel. The position of the bracket extending out of the vertical pole is adjusted by the cooperation between the adjusting nut and the thread of the screw rod. The vertical pole contacts the formwork or the temporary arch through the bracket.

5. The formwork support structure for a dark tunnel according to claim 1, characterized in that: The support also includes a plurality of diagonal braces, wherein the upper ends of the diagonal braces located on the upper step are arranged at the arc-shaped sections on both sides of the arch top and fall to the bottom of the temporary inverted arch, and the upper ends of the diagonal braces located on the lower step are arranged at the side walls on both sides and fall to the top surface of the inverted arch of the tunnel.

6. The formwork support structure for a dark-excavated tunnel according to claim 1, characterized in that: The adjustment mechanism is a servo jack.

7. The formwork support structure for a dark tunnel according to claim 1, characterized in that: The template includes pine boards arranged on the tunnel vault and side walls. The side of the pine boards facing away from the tunnel soil is provided with a main keel and a secondary keel. The main keel is made of I12 I-beam with a spacing of 600mm, and the secondary keel is made of 50×50×3mm double steel with a spacing of 300mm.

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