Supporting structure for intersection section of small-section construction adit and main tunnel
By using the side wall steel arch, double -speaking steel arch, steel arch, and support structure connected to the steel bars through the intersection of the construction branch of the Changtun tunnel, solve the stability and stability of the construction branch hole and the main hole section. The problem of construction transportation needs has realized the stability of the structure and the construction of the construction of the construction.
Patent Information
- Application Number
- CN202420540999.8
- Authority / Receiving Office
- CN · China
- Patent Type
- Utility models(China)
- Current Assignee / Owner
- Filing Date
- 2024-03-20
- Publication Date
- 2025-01-28
- Estimated Expiration
- 2034-03-20
AI Technical Summary
In the construction of long tunnels, the connection stability of the steel arch frame at the intersection of the construction branch hole and the main hole is difficult to take into account both the construction traffic needs. Especially when the surrounding rock is poor, the support structure is unstable and prone to deformation and damage.
Adopt a supporting structure of the steel arch of the wall, the double -piece steel arch, the steel arch, and the supporting steel bars connecting the steel bars. Through the continuous connection of the construction branches and the main hole, the concrete bottom wall and the foundation are set, and the steel arch is arranged at the interval, and the steel arch is set up, and the steel arch is arranged at the interval. Arrow the longitudinal reinforcement and reinforced mesh on the steel arch, and set the system anchor and the foot -locking anchor to ensure structural stability.
The stability of the construction branch hole and the main hole in the main hole, the small convergence and the amount of convergence are not abnormal, it does not affect the passage of the main hole, and the traffic performance during the construction period is maintained.
Smart Images
Figure CN222414863U_ABST
Abstract
Description
Technical Field
[0001] The utility model belongs to the technical field of long tunnel construction, and specifically relates to a support structure for the intersection of a small-section construction branch tunnel and a main tunnel. Background Art
[0002] In order to meet the requirements of the construction period and improve the construction conditions, long tunnels usually need to set up construction branch tunnels and open up multiple working faces, which is also convenient for segmented construction of long tunnels. The intersection section of the construction branch tunnel and the main tunnel is subject to complex forces, with stress concentration at the intersection. In addition, there is a construction traffic need for the main tunnel at the intersection with the branch tunnel, so it is impossible to construct a complete steel arch frame. When the surrounding rock of the intersection section is poor, the support structure is unstable and it is easy to deform and damage. Regarding the construction of the steel arch frame at the intersection section of the construction branch tunnel and the main tunnel, it is necessary to consider both the stability of the intersection tunnel section and the need for traffic in the main tunnel during construction. For small-section tunnels, the connection between the main tunnel steel arch frame and the construction branch tunnel steel arch frame is a pipe fitting that solves the stability problem of the intersection tunnel section. This is a technical issue that needs to be studied. Summary of the invention
[0003] In order to solve the problems of stability and traffic demand of the steel arch connection at the intersection section of the main tunnel and the branch tunnel, the present invention provides a support structure for the intersection section of the branch tunnel and the main tunnel with a small section.
[0004] A supporting structure for the intersection of a small-section construction branch tunnel and a main tunnel, characterized in that it comprises a side wall steel arch frame, a double-jointed steel arch frame, a steel arch frame and connecting steel bars; the full-section type of the construction branch tunnel is continuously connected to the side wall on the other side of the main tunnel, a side wall steel arch frame is arranged at the side wall of the main tunnel where the construction branch tunnel intersects with the main tunnel along the axis direction of the construction branch tunnel, and a concrete bottom side wall is vertically arranged along the side wall steel arch frame, and both sides of the bottom side wall are respectively connected to the main tunnel side walls on both sides, concrete foundations are respectively arranged at the bottom of both ends of the main tunnel where the main tunnel and the construction branch tunnel intersect, and a double-jointed steel arch frame is respectively arranged at both ends of the main tunnel of the intersection section. The arch feet of the double-jointed steel arch frames are arranged on the concrete foundation. Starting from the bottom side wall, several steel arch frames are arranged at intervals along the axial direction of the construction branch tunnel. The steel arch frames located above the double-jointed steel arch frames only retain the part that is higher than the arch top of the double-jointed steel arch frames, and the arch feet of the steel arch frames are welded to the top arch of the double-jointed steel arch frames; longitudinal connecting steel bars are arranged on the steel arch frames along the axial direction of the construction branch tunnel, and steel mesh is hung on the arch top of the steel arch frames, system anchor rods are set, locking anchor rods are arranged at the arch feet of the steel arch frames, concrete capping is set on the arch tops of all steel arch frames, and concrete side walls are set on both sides of the steel arch frames at the construction branch tunnels to connect with the main tunnel.
[0005] Furthermore, the double-jointed steel arch frame and the steel arch frame are both I14 steel arch frames.
[0006] Furthermore, the steel mesh has a specification of 20cm×20cm and a mesh aperture of 6cm.
[0007] Furthermore, the specifications of the system anchor rod and the locking foot anchor rod are both Φ25mm.
[0008] The beneficial effects of the present invention are that the structure has strong stability. In actual use, when monitoring the deformation of the intersection section of the main tunnel and the construction branch tunnel, the convergence amount is small and the convergence change amount is abnormal. It does not affect the passage of the main tunnel and will not reduce the traffic performance of the main tunnel during construction. BRIEF DESCRIPTION OF THE DRAWINGS
[0009] Figure 1 This is a plan view of the support structure for the intersection of a small-section construction branch tunnel and the main tunnel.
[0010] Figure 2 This is the elevation section view of the AA surface.
[0011] Figure 3 This is the elevation section view of surface BB.
[0012] Among them, 1-side wall steel arch frame, 2-bottom side wall, 3-double steel arch frame, 4-steel arch frame, 5-connecting steel bars, 6-steel mesh, 7-system anchor rod, 8-locking anchor rod, 10-main hole, 11-construction branch hole. DETAILED DESCRIPTION
[0013] Example 1: A support structure for the intersection of a small-section construction branch tunnel and a main tunnel is arranged in a section of the Dianzhong Water Diversion Phase II supporting project in Yunnan Province. The main tunnel 10 is 2m×2m, and the construction branch tunnel 11 is 3.5m×4m. The structure includes a side wall steel arch frame 1, a double-piece steel arch frame 3, a steel arch frame 4 and connecting steel bars 5. During construction, starting from the intersection of the construction branch tunnel 11 and the main tunnel 10, the full-section type of the construction branch tunnel 11 at the intersection is continuously excavated to the side wall on the other side of the main tunnel 10, and a Ⅰ14 side wall steel arch frame 1 is set along the axial direction of the construction branch tunnel at the side wall of the main tunnel 10 where the construction branch tunnel 11 intersects with the main tunnel 10, and C20 concrete is sprayed along the side wall steel arch frame 1 to seal and form a bottom side wall 2. A 20 cm thick C25 concrete foundation is poured at the bottom of both ends of the main tunnel 10 where the main tunnel 10 and the construction branch tunnel 11 intersect, and a number of steel arch frames 4 are arranged at intervals from the bottom side wall 2 along the axial direction of the construction branch tunnel 11. The steel arch frame 4 located at the double-joined steel arch frame 3 only retains the part higher than the arch top of the double-joined steel arch frame 3, cuts off the part lower than the arch top of the double-joined steel arch frame 3, and the processed arch feet of the steel arch frame 4 are welded to the top arch of the double-joined steel arch frame 3. Longitudinal connecting steel bars 5 are arranged on the steel arch frames 3 along the axial direction of the construction branch tunnel. The connecting steel bars 5 are firmly welded to the steel arch frames 4. A φ6@20cm×20cm steel mesh 6 is hung on the top arch of the steel arch frames 4, and Φ25 system anchor rods 7 are arranged on the steel arch frames 4. Φ25 locking foot anchor rods 8 are arranged at the arch feet of the steel arch frames 4. Finally, C20 concrete is sprayed on the tops of all the steel arch frames 4 to form a cap, and concrete side walls are set on both sides of the steel arch frames 4 at the construction branch tunnel 11 to connect with the main tunnel 10.
[0014] The deformation of this section was monitored, and the average convergence of the intersection section was 0.02mm / d, with the maximum convergence being 0.3mm, the minimum convergence being 0mm, and the cumulative convergence being 3.5mm. There was no abnormality in the convergence change, and the convergence was stable.
Claims
1. A support structure for the intersection of a small-section branch tunnel and a main tunnel, characterized in that It includes side wall steel arch frames, double steel arch frames, steel arch frames and connecting steel bars; the full section of the construction branch hole is continuously connected to the side wall on the other side of the main hole; a side wall steel arch frame is set at the side wall of the main hole where the construction branch hole intersects with the main hole along the axis of the construction branch hole, and a concrete bottom side wall is vertically set along the side wall steel arch frame. The two sides of the bottom side wall are respectively connected to the main hole side walls on both sides. Concrete foundations are set at the bottom of both ends of the main hole where the main hole and the construction branch hole intersect, and a double steel arch frame is set at each end of the main hole at the intersection section. The arch feet of the double steel arch frame are arranged on the concrete On the foundation, several steel arch frames are arranged at intervals from the bottom side wall along the axial direction of the construction branch tunnel. The steel arch frame located above the double steel arch frame only retains the part higher than the arch top of the double steel arch frame, and the arch foot of the steel arch frame is welded to the top arch of the double steel arch frame; longitudinal connecting steel bars are arranged on the steel arch frame along the axial direction of the construction branch tunnel, and steel mesh is hung on the arch top of the steel arch frame, system anchor rods are set, locking anchor rods are arranged at the arch foot of the steel arch frame, concrete capping is set at the arch top of all steel arch frames, and concrete side walls are set on both sides of the steel arch frame at the construction branch tunnel to connect with the main tunnel.
2. A support structure for the intersection of a small-section construction branch tunnel and a main tunnel as claimed in claim 1, characterized in that The double-jointed steel arch frame and the steel arch frame are both I14 steel arch frames.
3. A support structure for the intersection of a small-section construction branch tunnel and a main tunnel as claimed in claim 1, characterized in that The steel mesh has a specification of 20cm×20cm and a mesh aperture of 6cm.
4. A supporting structure for the intersection of a small-section construction branch tunnel and a main tunnel as claimed in claim 1, characterized in that The specifications of the system anchor rod and the locking foot anchor rod are both Φ25mm.