Double-spliced box type arch frame for underground excavation of transverse channel in soft stratum and construction method of double-spliced box type arch frame
By adopting double-box arch structure and grouting reinforcement technology in the construction of subway stations in weak formations, the problems of ground sinking and surrounding rock instability during concealed cross passages are solved, and the stability and construction safety of cross passages are achieved.
Patent Information
- Application Number
- CN202411938524.5
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- Filing Date
- 2024-12-26
- Publication Date
- 2025-05-30
AI Technical Summary
During the construction of subway stations in weak formations, hidden cross passages are prone to problems such as ground sinking, soil erosion and surrounding rock instability, resulting in safety accidents and economic losses.
The double-Link box arch structure is adopted, including locking anchors, double-Link box arch seats and main body arch frames. By erecting a pipe curtain structure and main body arch frame on the side of the vertical shaft, and grouting and reinforcement in the upper weak formation, the stability of the transverse channel is ensured.
Through the installation of double-box arch frames and the support structure for layered construction, the stability of the cross passage is ensured, ground sinking and soil erosion are avoided, construction risks are reduced, and construction processes are saved.
Smart Images
Figure CN120061881A_ABST
Abstract
Description
Technical Field
[0001] The present invention relates to the field of subway stations, and specifically to a double-spliced box arch for a mined cross-passage in soft strata and its construction method. Background Art
[0002] When constructing a subway station, it is difficult to construct in soft strata. And due to urban traffic requirements, mined construction is needed, so it is necessary to construct by excavating a cross-passage. During the construction of the strata, ground subsidence is likely to occur. During the construction of the cross-passage, it is necessary to ensure the water-stop effect of the cross-passage structure to prevent safety accidents caused by soil erosion. In addition, during the excavation of the cross-passage, the core soil is reserved and excavated in layers and sections, and temporary cross braces are constructed in time to ensure that the deformation value of the foundation pit during the excavation stage is within the allowable range of the design and specifications to ensure the stability of the surrounding rock. If the cross-passage is constructed improperly or the support is not timely, it may cause instability inside the tunnel. If the excavation method inside the tunnel is improper, it may lead to the landslide or slip of the soil inside the passage, and then lead to instability, collapse, road surface cracking and ground settlement inside the passage, etc., which will cause significant economic losses and serious social impacts. Summary of the Invention
[0003] The purpose of the present invention is to provide a double-spliced box arch for a mined cross-passage in soft strata and its construction method to solve the existing problems mentioned in the above background art.
[0004] To solve the above technical problems, the present invention provides the following technical solution: A double-spliced box arch for a mined cross-passage in soft strata, the double-spliced box arch includes lock-foot bolts, a double-spliced box seat and a main arch. The double-spliced box arch is arranged below the main arch at the position of the shaft. First, a pipe curtain structure is constructed on the side of the shaft. After the pipe curtain structure is completed, the soft strata above the cross-passage are grouted and reinforced. The main arch is constructed below the pipe curtain structure. The lock-foot bolts are arranged on the lower side of the main arch. The double-spliced box seat includes a steel box body, a pipe shoe and a grouting device. The steel box body is a hollow box member formed by butt-welding the wing plates of two I-beams. Two sealing plates are welded in parallel on the two webs of the steel box body. The pipe shoe is arranged at the end of the steel box body. The pipe shoe is set with a pointed cone at one end and a rectangular cross-section at the other end and is welded integrally with the end of the steel box body and serves as the soil-entering end. The grouting device is arranged at the front end of the steel box body. The grouting device includes a cover plate, a grouting pipe, a grouting ball valve and a grouting pressure gauge. The cover plate is used to seal the front end of the steel box body. A grouting hole is arranged on the cover plate. The grouting pipe is connected to an external grouting pump through the grouting ball valve and the grouting pressure gauge. Among them, a slurry leakage hole is arranged on the web. An outlet hole is arranged on the sealing plate.
[0005] The outlet holes are arranged in 3 vertical rows and are arranged in a plum blossom shape with a longitudinal spacing of 1000mm×1000mm; the slurry leakage holes are arranged in 2 vertical rows and are arranged in a plum blossom shape with a longitudinal spacing of 1000mm×1000mm.
[0006] The cover plate is arranged as a stepped plug body, the cross-section of which matches that of the double-spliced box-shaped seat. One end of the stepped plug body is inserted into the inner cavity of the profiled steel box body. An extension plate is arranged on the outer side of the stepped plug body and is tightened with the angle steel arranged outside the double-spliced box-shaped seat by bolts. A rubber ring is arranged inside the stepped plug body.
[0007] Spaces for installing the stepped plug body are reserved on the two webs at the front end of the profiled steel box body. The webs are cut to ensure that the rubber ring is in close contact with the inner wall of the sealing plate when the stepped plug body is inserted, so as to meet the airtight requirements for grouting.
[0008] The present invention also provides a construction method for a double-spliced box arch of a mined cross-passage in soft strata. The cross-passage is used as a construction passage connecting a temporary shaft and a subway station and is constructed by means of layered excavation and layered support; Specifically as follows: Step 1: After measurement and positioning, a pipe curtain structure and a main arch are erected. The cross-passage is constructed in the shaft that has been completed. The shaft is used as a soil discharge passage for the excavation of the subway station. The cross-passage is used to connect the shaft and the subway station. First, the pipe curtain structure is constructed on the side of the shaft. After the pipe curtain structure is completed, the soft strata above the cross-passage are grouted and reinforced. The main arch is constructed under the pipe curtain structure; Step 2: Excavate the first layer of the cross-passage. First, construct the double-spliced box arch. First, use a pile press to press the double-spliced box-shaped seats on both sides into the strata under the arch feet, install a grouting device at its end, and perform grouting operations at the same time. The slurry penetrates into the strata through the slurry channeling holes and slurry outlet holes to form reinforcement for the strata on both sides; then excavate the soil layer of the first layer of the cross-passage, and sequentially construct and install the lattice arch. The lattice arch is installed along the excavation depth direction and is bolted to the double-spliced box-shaped seat; Step 3: Excavate the second to fifth layers of the cross-passage. The excavation and support processes are the same as those in Step 2. After the excavation and support of the third layer of the cross-passage are completed, construct the middle slab and the side wall of the first basement floor of the subway station; after the excavation and support of the fourth layer of the cross-passage are completed, excavate the fifth layer of the cross-passage, and finally construct the station floor slab and side wall; backfill with graded crushed stone, and backfill the last layer with a height of 2.8 m with C15 plain concrete; Step 4: After the construction of the station main body is completed, backfill the cross-passage. The lower part of the cross-passage is backfilled with graded crushed stone, and the last layer with a height of 2.8 m is backfilled with C15 plain concrete.
[0009] Compared with the prior art, the beneficial effects achieved by the present invention are as follows: (1) By arranging the double-spliced box arch and constructing the support structure of the cross-passage in layers, the double-spliced box arch is arranged under the arch feet of each layer of the cross-passage, ensuring the stability of the cross-passage and saving construction procedures.
[0010] (2) The double - joint box - shaped seat of the present invention not only prevents the settlement of the upper structure, but also processes the soil layers on both sides by grouting to meet the requirements of combined construction support and ensure the stability of its structure. BRIEF DESCRIPTION OF THE DRAWINGS
[0011] The drawings are used to provide a further understanding of the present invention, and constitute a part of the specification. They are used together with the embodiments of the present invention to explain the present invention, but do not constitute a limitation to the present invention. In the drawings: Figure 1 is a schematic diagram of the first - layer cross - passage of the present invention; Figure 2 is a sectional view of the double - joint box - shaped arch of the present invention; Figure 3 is a side view of the double - joint box - shaped arch of the present invention; Figure 4 is a schematic diagram of the relative positions of the cross - passage and the temporary shaft of the present invention.
[0012] In the drawings: 1, locking foot bolt; 2, double - joint box - shaped seat; 3, main arch; 4, pipe curtain structure; 21, section steel box; 22, pipe shoe; 23, grouting device; 210, web; 211, sealing plate; 230, cover plate; 231, grouting pipe; 232, grouting ball valve; 233, grouting pressure gauge; 212, slurry - channeling hole; 213, slurry - discharging hole; 214, rubber ring. DETAILED DESCRIPTION OF THE EMBODIMENTS
[0013] Hereinafter, the technical solutions in the embodiments of the present invention will be clearly and completely described in conjunction with the drawings in the embodiments of the present invention. Obviously, the described embodiments are only a part of the embodiments of the present invention, rather than all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those of ordinary skill in the art without creative efforts shall fall within the protection scope of the present invention.
[0014] As Figures 1-4 shown, a double - joint box - shaped arch for a mined - out cross - passage in a soft stratum, the double - joint box - shaped arch includes a locking foot bolt 1, a double - joint box - shaped seat 2 and a main arch 3. The main arch 3 at the shaft position of the double - joint box - shaped arch is arranged at the lower part. First, a pipe curtain structure 4 is constructed on the side of the shaft. After the pipe curtain structure is completed, the upper soft stratum of the cross - passage is grouted and reinforced. The main arch 3 is constructed under the pipe curtain structure. The locking foot bolt 1 is arranged on the lower side of the main arch 3; The double-spliced box-shaped seat 2 includes a steel box body 21, a pipe shoe 22, and a grouting device 23. The steel box body 21 is a hollow box member formed by butt-welding the flanges of two I-beams. Two sealing plates 211 are welded in parallel to the two webs 210 of the steel box body 21; the pipe shoe 22 is arranged at the end of the steel box body 22. The pipe shoe is set with a pointed cone at one end and a rectangular cross-section at the other end, which is welded integrally with the end of the steel box body 22 and serves as the soil-entering end; the grouting device 23 is arranged at the front end of the steel box body 21. The grouting device 23 includes a cover plate 230, a grouting pipe 231, a grouting ball valve 232, and a grouting pressure gauge 233; the cover plate 230 is used to seal the front end of the steel box body. A grouting hole is arranged on the cover plate. The grouting pipe 231 is connected to an external grouting pump through the grouting ball valve 232 and the grouting pressure gauge 233. A slurry leakage hole 212 is arranged on the web 210; a slurry outlet hole 213 is arranged on the sealing plate.
[0015] The slurry outlet holes 213 are arranged in 3 vertical rows and are arranged in a plum blossom pattern with a longitudinal spacing of 1000mm×1000mm; the slurry leakage holes 212 are arranged in 2 vertical rows and are arranged in a plum blossom pattern with a longitudinal spacing of 1000mm×1000mm.
[0016] The cover plate 230 is set as a stepped plug body, the cross-section of which matches the cross-section of the double-spliced box-shaped seat. One end of the stepped plug body is inserted into the inner cavity of the steel box body 21. An extension plate is arranged on the outside of the stepped plug body and is tightened with an angle steel arranged outside the double-spliced box-shaped seat through bolts. A rubber ring 214 is arranged inside the stepped plug body.
[0017] A space for installing the stepped plug body is reserved on the two webs 210 at the front end of the steel box body 21. The webs 210 are cut to make the rubber ring in close contact with the inner wall of the sealing plate when the stepped plug body is inserted, so as to ensure the airtight requirement of grouting.
[0018] In addition, a construction method for a double-spliced box arch of a mined cross-passage in a soft stratum is provided. The cross-passage is used as a construction passage connecting a temporary shaft and a subway station and is carried out by means of layered excavation and layered support, specifically as follows: Step 1: After measurement and positioning, a pipe curtain structure 4 and a main arch 3 are erected. The cross-passage is constructed in the shaft that has been completed. The shaft is used as a soil discharge passage for the excavation of the subway station. The cross-passage is used to connect the shaft and the subway station. First, the pipe curtain structure 4 is constructed on the side of the shaft. After the pipe curtain structure is completed, the soft stratum above the cross-passage is grouted and reinforced, and the main arch 3 is constructed under the pipe curtain structure; Step 2: Excavate the first-layer transverse passage. First, construct the double-box arch frame. First, use a pile press to press the double-box seats 2 on both sides into the formation under the arch feet. Install a grouting device at its end, and at the same time perform grouting operations. Through the slurry channeling holes 212 and the slurry outlet holes 213, the slurry invades the formation to form reinforcement for the formations on both sides. Then, excavate the soil layer of the first-layer transverse passage, and successively construct and install the lattice arch frames. The lattice arch frames are installed along the excavation depth direction and are bolted to the double-box seats. Step 3: Excavate the second to fifth-layer transverse passages. The excavation and support processes are the same as those in Step 2. After the excavation and support of the third layer of the transverse passage are completed, construct the middle slab and the side walls of the first basement floor of the subway station. After the excavation and support of the fourth layer of the transverse passage are completed, excavate the fifth-layer transverse passage. Finally, construct the station floor slab and side walls. Backfill with graded gravel, and use C15 plain concrete for backfilling at the last layer with a height of 2.8 m. Step 4: After the construction of the station main body is completed, backfill the transverse passage. The lower part of the transverse passage is backfilled with graded gravel, and C15 plain concrete is used for backfilling at the last layer with a height of 2.8 m.
[0019] In another embodiment, construct the transverse passage in the already constructed shaft. The shaft is used as the soil discharge passage for the excavation of the subway station. The transverse passage is used to connect the shaft and the subway station. First, construct the pipe curtain structure 4 on the side of the shaft. After the pipe curtain structure is completed, grout and reinforce the soft formation above the transverse passage. Construct the main arch frame 3 under the pipe curtain structure, demolish the shaft retaining piles, and erect the arch frame steel grating. Excavate the first-layer transverse passage. After the main arch frame 3 is erected, construct the double-box arch frame. First, use a pile press to press the box-shaped steel 21 on both sides into the formation under the arch feet. Set a transfer plate 22 between the arch feet 33 and the box-shaped steel 21, and correspondingly install the clamping seat 221 and the arch feet 33, and construct the locking foot bolts 1 to ensure the stability of the bottom of the arch feet 33. Among them, the bearing plate 222 is used to increase the soil contact area and reduce soil settlement. During excavation, the excavation step distance of the transverse passage is 0.5 m. After initial spraying, construct mortar anchor pipes, wire meshes, and shotcrete on the inner wall of the transverse passage. When excavating in depth, the first layer of the transverse passage is subdivided into upper and lower steps I and II for excavation, and the reserved core soil excavation method is adopted. The longitudinal distance between the upper and lower steps is 3 - 5 m. After the excavation and support of the first layer of the transverse passage are completed, construct the advanced support of the small pilot holes and small ducts of the subway station, the large pipe shed and the advanced support of the small ducts at the arch top of the station. When excavating the second - layer cross - passage, the excavation step distance of the cross - passage is 0.5 m. After the initial spraying, mortar anchor pipes, wire meshes are installed on the inner wall of the cross - passage, and then shotcrete is applied; after the excavation and support of the second layer of the cross - passage are completed, the vault in the range of the small - adit horseshoe is reinforced in advance, the temporary replacement strut is constructed, and then the initial support of the cross - passage is partially removed to complete the force - bearing system conversion of the passage structure. Then, the small adit of the subway station, the side piles, middle columns and top longitudinal beams of the station are constructed; the vault of the horseshoe in the second - lining arch - closing part of the cross - passage is reinforced in advance, the temporary replacement strut is constructed, and then the initial support of the cross - passage is partially removed to complete the force - bearing system conversion of the passage structure. Then, the initial support of the arch - closing part is constructed, and finally the second - lining of the station vault is constructed; after the second - lining of the station vault in the cross - passage area is constructed, the gap between the second - lining and the cross - passage is backfilled with C15 concrete. It should be noted that in this article, relational terms such as first and second are only used to distinguish one entity or operation from another entity or operation, and do not necessarily require or imply any actual relationship or order between these entities or operations. Moreover, the term "comprising", "including" or any other variant thereof is intended to cover non - exclusive inclusion, so that a process, method, article or device comprising a series of elements not only includes those elements, but also includes other elements not expressly listed, or elements inherent to such process, method, article or device.
[0020] Finally, it should be noted that the above - mentioned are only the preferred embodiments of the present invention and are not used to limit the present invention. Although the present invention has been described in detail with reference to the foregoing embodiments, those skilled in the art can still modify the technical solutions recorded in the foregoing embodiments, or perform equivalent substitution on some of the technical features. Any modification, equivalent substitution, improvement, etc. made within the spirit and principle of the present invention shall be included within the protection scope of the present invention.
Claims
1. A double-jointed box-shaped arch frame for a horizontal tunnel dug in a soft stratum, the double-jointed box-shaped arch frame comprising a locking foot anchor rod (1), a double-jointed box-shaped seat (2) and a main arch frame (3), the double-jointed box-shaped arch frame being arranged at the lower part of the main arch frame (3) at the position of a vertical shaft, a pipe curtain structure (4) being first constructed on the side of the vertical shaft, and after the pipe curtain structure is completed, grouting reinforcement is performed on the upper soft stratum of the horizontal tunnel, and the main arch frame (3) is constructed at the lower part of the pipe curtain structure, and the locking foot anchor rod (1) is arranged on the lower side of the main arch frame (3); 1. Its characteristics: The double-piece box seat (2) comprises a steel box body (21), a pipe shoe (22), and a grouting device (23); the steel box body (21) is a hollow box body component formed by butt-welding two I-beam wing plates, and two sealing plates (211) are welded in parallel to two webs (210) of the steel box body (21); the pipe shoe (22) is arranged at the end of the steel box body (21), one end of the pipe shoe is set to be a pointed cone, and the other end is set to be a rectangular cross-section and is welded to the end of the steel box body (22) as a whole, and serves as the end for entering the soil; the grouting device (23) is arranged at the front end of the steel box body (21), and the grouting device (23) comprises a cover plate (230), a grouting pipe (231), a grouting ball valve (232) and a grouting pressure gauge (233); the cover plate (230) is used to close the front end of the steel box body, a grouting hole is arranged on the cover plate, the grouting pipe (231) is connected to an external grouting pump through the grouting ball valve (232) and the grouting pressure gauge (233), wherein a grouting hole (212) is arranged on the web plate (210); and a grouting outlet hole (213) is arranged on the sealing plate.
2. The double-box arch frame for a dark excavation transverse passage in a soft stratum according to claim 1 is characterized by: The slurry outlet holes (213) are arranged in three vertical rows with a longitudinal spacing of 1000 mm×1000 mm in a plum blossom shape; the slurry channeling holes (212) are arranged in two vertical rows with a longitudinal spacing of 1000 mm×1000 mm in a plum blossom shape.
3. The double-box arch frame for a dark excavation transverse passage in a soft stratum according to claim 1 is characterized by: The cover plate (230) is configured as a stepped plug body, the cross section of which matches the cross section of the double-piece box-type seat. One end of the stepped plug body is inserted into the inner cavity of the steel box body (21). An extension plate is provided on the outside of the stepped plug body and is tightened to the angle steel provided on the outside of the double-piece box-type seat by bolts. A rubber ring (214) is provided in the stepped plug body.
4. The double-box arch frame for a dark excavation transverse passage in a soft stratum according to claim 2 is characterized by: The two webs (210) at the front end of the steel box (21) are reserved with space for installing the step-shaped plug body. The webs (210) are cut so that the rubber ring is in close contact with the inner wall of the sealing plate when the step-shaped plug body is inserted, thereby ensuring the airtightness requirement of grouting.
5. A construction method for a double-jointed box-type arch frame for a dark excavated horizontal passage in a soft stratum according to any one of claims 1 to 4, wherein the horizontal passage is used as a construction passage connecting a temporary shaft and a subway station, and is carried out by layered excavation and layered support, and is characterized in that: The details are as follows: Step 1: After measuring and positioning, the pipe curtain structure (4) and the main arch frame (3) are set up, and a transverse passage is constructed in the completed vertical shaft. The vertical shaft is used as a drainage passage for the subway station. The transverse passage is used to connect the vertical shaft and the subway station. The pipe curtain structure (4) is first constructed on the side of the vertical shaft. After the pipe curtain structure is completed, the soft stratum on the upper part of the transverse passage is reinforced by grouting, and the main arch frame (3) is constructed under the pipe curtain structure. Step 2: excavate the first layer of the transverse passage, first construct the double-jointed box-type arch frame, first use a pile driver to press the double-jointed box-type seats (2) on both sides into the stratum below the arch foot, install a grouting device at the end thereof, and simultaneously perform grouting operations, so that the slurry penetrates into the stratum through the slurry holes and the slurry outlet holes to form reinforcement for the stratum on both sides; then excavate the soil layer of the first layer of the transverse passage, and sequentially construct and install the grid arch frame, the grid arch frame being installed along the excavation depth direction and bolted to the double-jointed box-type seat; Step 3: Excavate the second to fifth layers of the transverse passages. The excavation and support process is the same as step 2. After the excavation and support of the third layer of the transverse passage is completed, the middle plate and the side wall of the underground first floor of the subway station are constructed; After the excavation and support of the fourth layer of the transverse passage is completed, the fifth layer of the transverse passage is excavated, and finally the station floor and side walls are constructed; graded crushed stone is backfilled, and the last layer with a height of 2.8m is backfilled with C15 plain concrete; Step 5: After the main construction of the station is completed, the cross passage will be backfilled. The lower part of the cross passage will be backfilled with graded crushed stone, and the last layer with a height of 2.8m will be backfilled with C15 plain concrete.