A temporary support for the second lining slope change construction at the slope change point of the buffer platform of a large longitudinal slope inclined shaft

Abstract

The present invention relates to a temporary support for the construction of a second lining slope change at a slope change point of a buffer platform of a large longitudinal slope inclined shaft, the support comprising a tunnel steel mold second lining trolley and an inner end formwork arranged at the slope change position of the buffer platform of the inclined shaft body. The top of the tunnel steel mold second lining trolley is provided with a panel, one end is provided with a second lining trolley end, and one side is provided with a second lining slope change concrete; the panel is provided with a number of template positioning and fixing piles in the shape of triangular supports, and each template positioning and fixing pile is provided with a circumferential double tie bar along the circumferential direction; the inner side of the second lining slope change concrete is provided with a waterproof board, and the inner end formwork is embedded between the waterproof board and the panel. The present invention has a simple structure, is easy to operate, has good economy, high safety, and guaranteed construction quality, and can be widely used as a temporary support for the construction of second lining concrete slope change and connection at the slope change point when the tunnel body changes slope.

Description

Technical Field

[0001] The invention relates to the technical field of highway and railway extra-long tunnel construction, and in particular to a temporary support for secondary lining slope change construction at a slope change point of a large longitudinal slope inclined shaft buffer platform. Background Art

[0002] In recent years, with the rapid development of highway construction projects and the continuous innovation of engineering construction technology, the scale and number of highway tunnel projects, especially long and large tunnel projects on expressways, have increased year by year in the entire highway construction. In order to ensure the ventilation effect during construction and operation, long tunnels are mostly ventilated and smoke exhausted by setting up inclined shafts. The setting of tunnel inclined shafts often has a large longitudinal slope. For the safe, fast and high-quality construction of the second lining concrete of large longitudinal slope tunnels, it is a new starting point in construction technology and construction experience. As for the construction of continuous variable slope concrete, domestic projects have been studied and summarized a lot, and a very complete construction technology and guidelines have been formed. However, there are very few studies and summaries on the construction of closed arched cast-in-place second lining concrete in tunnels with continuous variable slope.

[0003] At present, in the design of ventilation inclined shafts of long and large longitudinal slope tunnels, a buffer platform is set in the middle section of the tunnel body. At the buffer platform, the longitudinal slope of the tunnel body changes continuously, and the tunnel secondary lining also changes slope. According to the traditional tunnel secondary lining construction process, at the slope change point of the buffer platform, due to the rigidity limitation of the secondary lining steel formwork trolley, a spacer section will be left in the secondary lining, and the secondary lining cannot be constructed continuously. If traditional construction processes and technologies are used, the secondary lining construction of the interval section needs to be completed by customizing the formwork, setting up support brackets and working surface platforms. In this way, the construction speed is slow, the reinforcement consumes a lot of auxiliary materials, and the labor consumption is high. In addition, improper reinforcement is prone to problems such as mold running, mold expansion, and slurry leakage; the construction quality is poor, the construction is dangerous, and the cost is high. Therefore, at the slope change point, it is particularly important to safely and quickly complete the construction of closed arch formwork concrete continuous slope change, and how to use fast, economical, and safe support brackets to complete the concrete slope change construction. Summary of the invention

[0004] The technical problem to be solved by the present invention is to provide a temporary support for the second lining slope change construction at the slope change point of the large longitudinal slope inclined shaft buffer platform with low cost, high efficiency, simple and easy operation and good safety.

[0005] In order to solve the above problems, the present invention discloses a temporary support for the construction of a second lining slope change at the slope change point of a buffer platform of a large longitudinal slope inclined shaft, which is characterized in that: the support comprises a tunnel steel mold second lining trolley and an inner end head template arranged at the slope change position of the buffer platform of the inclined shaft body; a panel is provided on the top of the tunnel steel mold second lining trolley, a second lining trolley end is provided at one end, and second lining slope change concrete is provided on one side; a plurality of template positioning and fixing piles in the shape of triangular supports are provided on the panel, and annular double tension bars are provided along the circumferential direction on each template positioning and fixing pile; a waterproof board is provided on the inner side of the second lining slope change concrete, and the inner end head template is embedded between the waterproof board and the panel.

[0006] The template positioning and fixing piles are made of small channel steels with a width of 50 mm, a height of 60 mm and a wall thickness of 4 mm.

[0007] The inner end template is formed by installing wooden boards of different lengths, a width of 200 mm and a thickness of 50 mm.

[0008] The circumferential spacing of the mapping points on the end of the second lining trolley is 200 mm.

[0009] The circumferential double reinforcement refers to two Φ25 threaded steel bars, and the circumferential double reinforcement is 150 mm away from both ends of the inner end template.

[0010] Compared with the prior art, the present invention has the following advantages:

[0011] 1. The present invention arranges an inner end formwork to quickly and safely complete the construction of the second lining concrete at the slope change point of the buffer platform in the tunnel when the slope changes, and can smoothly connect, thereby solving the technical problems of slow construction speed, poor construction quality and high construction risk of the second lining concrete at the slope change point when the longitudinal slope changes in a tunnel with a large longitudinal slope.

[0012] 2. The present invention adopts the inner end formwork on the integral steel formwork second lining trolley to complete the second lining concrete construction at the slope change point. It is installed once and reused, which reduces the loss of turnover materials such as wood, reduces labor input and resource waste, speeds up the construction progress, saves the overall construction period, improves the project quality, improves the safety during the construction process, and saves production costs.

[0013] 3. The present invention has the advantages of simple structure, easy operation, good economy, high safety and guaranteed construction quality, and can be widely used as a temporary support for the construction of the second lining concrete slope change and connection at the slope change point when the tunnel body has a slope change. BRIEF DESCRIPTION OF THE DRAWINGS

[0014] The specific implementation modes of the present invention are further described in detail below in conjunction with the accompanying drawings.

[0015] Figure 1 It is the overall structural diagram of the present invention.

[0016] Figure 2 It is a longitudinal sectional view of the present invention.

[0017] Figure 3 It is a cross-sectional view of the present invention.

[0018] Figure 4 It is a detailed diagram of the present invention.

[0019] In the figure: 1—slope change point; 2—buffer platform of inclined shaft body; 3—secondary lining slope change concrete; 4—tunnel steel formwork secondary lining trolley; 5—leveling layer; 6—secondary lining trolley end; 7—inner end formwork; 8—panel; 9—waterproof board; 10—mapping point; 11—formwork positioning fixing pile; 12—wooden board; 13—circumferential double reinforcement. DETAILED DESCRIPTION

[0020] like Figures 1 to 4 As shown, a temporary support for the second lining slope change construction at the slope change point of the inclined shaft buffer platform with a large longitudinal slope is provided. The support comprises a tunnel steel mold second lining trolley 4 and an inner end template 7 arranged at the slope change position of the inclined shaft body buffer platform 2.

[0021] A panel 8 is provided on the top of the tunnel steel formwork secondary lining trolley 4, a secondary lining trolley end 6 is provided at one end, and a secondary lining variable slope concrete 3 is provided on one side; a plurality of template positioning and fixing piles 11 in the shape of triangular supports are provided on the panel 8, and a circumferential double tie bar 13 is provided along the circumferential direction on each template positioning and fixing pile 11; a waterproof board 9 is provided on the inner side of the secondary lining variable slope concrete 3, and an inner end head template 7 is embedded between the waterproof board 9 and the panel 8.

[0022] Wherein: the template positioning and fixing pile 11 is made of a small channel steel with a width of 50mm, a height of 60mm and a wall thickness of 4mm.

[0023] The inner end template 7 is formed by installing wooden boards 12 of different lengths, a width of 200 mm and a thickness of 50 mm.

[0024] The circumferential spacing of the mapping points 10 on the end 6 of the secondary lining trolley is 200 mm.

[0025] The annular double reinforcement 13 refers to two Φ25 threaded steel bars, and the annular double reinforcement 13 is 150 mm away from both ends of the inner end template 7.

[0026] The specific applications are as follows:

[0027] like Figure 1 The height of the leveling layer 5 before and after the slope change point 1 is sloped and lowered to provide sufficient operating space for the setting of the inner end template 7. After the waterproof board 9 is hung, the calculated inner end template 7 is laid out on the waterproof board 9 and marked.

[0028] like Figures 2~4 On the end 6 of the secondary lining trolley, the mapping point 10 of the inner end template 7 is laid out and marked again, and one point is marked at an interval of 200 mm in the circumferential direction. According to the calculated data, each mapping point 10 of the end 6 of the secondary lining trolley is vertically mapped to the panel 8 according to the calculated length using a protractor and a steel tape measure. The points mapped on the panel 8 are measured by pulling the entire circle with a thin wire rope to verify the accuracy of the mapping point 10. After passing the inspection, a red ink fountain is used to pop out the inner end surface on the panel 8. In this way, the inner end section is completely mapped in the panel 8.

[0029] According to the mapped inner end point, a small channel steel of 50mm×60mm×4mm (width×height×wall thickness) is used to weld a row of template positioning and fixing piles 11 in a circular direction on the panel 8 according to the linear shape of the inner end section, and the spacing between each template positioning and fixing pile 11 is 500mm.

[0030] The welded template positioning and fixing pile 11 is welded to the template positioning and fixing pile 11 with two Φ25 threaded steel bars in the circumferential direction. The conventional second lining end steel formwork is cumbersome to operate in the use of the inner end template, has space limitations, and cannot be installed with the linear shape of the inner end section during installation, so a high-quality wooden board 12 of L (unequal) × 200mm × 50mm (length × width × height) is used as the inner end template 7. The distance between the marked point on the waterproof board 9 and the mapping point 10 of the panel 8 is measured, and wooden boards 12 of equal length are cut according to the measured distance. The wooden board 12 is wedged between the panel 8 and the waterproof board 9 (the width of the wooden board is 200mm, so the distance between all the marks is also 200mm, which can eliminate the board seam and prevent leakage), close to the two circumferential double tension bars 13, and after all the wooden boards are installed, the inner end template 7 is longitudinally reinforced and anchored, so that a temporary bracket for the construction of the second lining slope-changing concrete 3 at the slope-changing point 1 is formed.

Claims

1. A temporary support for the construction of a second lining slope change at a slope change point of a buffer platform of a large longitudinal slope inclined shaft, characterized in that: The support comprises a tunnel steel formwork secondary lining trolley (4) and an inner end template (7) arranged at a slope change position of a buffer platform (2) of an inclined shaft; a panel (8) is provided on the top of the tunnel steel formwork secondary lining trolley (4), a second lining trolley end (6) is provided at one end, and a second lining slope change concrete (3) is provided on one side; a plurality of template positioning and fixing piles (11) in a triangular support shape are provided on the panel (8), and a circumferential double tensioning bar (13) is provided on each template positioning and fixing pile (11) along a circumferential direction; a waterproof board (9) is provided on the inner side of the second lining slope change concrete (3), and the inner end template (7) is embedded between the waterproof board (9) and the panel (8); the inner end template (7) is embedded between the waterproof board (9) and the panel (8) and is obtained by the following method: the inner end template (7) is placed on the waterproof board (9), and then placed again. The sample is prepared, and the mapping points (10) of the inner end template (7) are marked. Each mapping point (10) of the second lining trolley end (6) is vertically mapped into the panel (8) according to the calculated length. Finally, the distance between the marked point on the waterproof board (9) and the mapping point (10) of the panel (8) is measured by pulling. According to the distance measured by pulling, wooden boards (12) of equal length are cut, and the wooden boards (12) are wedged between the panel (8) and the waterproof board (9) and closely attached to the two circumferential double tie bars (13). After all the wooden boards are installed, the inner end template (7) is longitudinally reinforced and anchored. The template positioning and fixing pile (11) is made of a small channel steel with a width of 50 mm, a height of 60 mm, and a wall thickness of 4 mm. The inner end template (7) is formed by installing wooden boards (12) of different lengths, a width of 200 mm, and a thickness of 50 mm.

2. A temporary support for the second lining slope change construction at the slope change point of the buffer platform of a large longitudinal slope inclined shaft as claimed in claim 1, characterized in that: The circumferential spacing of the mapping points (10) on the end (6) of the secondary lining trolley is 200 mm.

3. A temporary support for the second lining slope change construction at the slope change point of the buffer platform of a large longitudinal slope inclined shaft as claimed in claim 1, characterized in that: The annular double tie bars (13) are two Φ25 threaded steel bars, and the annular double tie bars (13) are 150 mm away from both ends of the inner end template (7).

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