Tunnel front door structure and construction method thereof

Abstract

The application belongs to the technical field of tunnel door hole, in particular to a tunnel front door hole structure and a construction method thereof, a pile body, the pile body is arranged on the slope surface of a mountain body, an arch shed, the arch shed comprises an arch frame and a pouring shed body, the arch frame is connected with the pile bodies on both sides, and the arch frame is provided with the pouring shed body, pipe sheds, the top of the arch shed is provided with a plurality of pipe sheds, and the ends of the plurality of pipe sheds away from the arch shed are all inserted into the inside of the mountain body in an inclined manner, the arch shed can be extended to the high position of the mountain foot through the piling mode, the pipe shed is arranged on the arch shed close to the high position of the mountain foot, the pipe shed can be directly inserted into the mountain body at a closer distance, the use length of the pipe shed is reduced, and in the construction process, the pipe shed is inserted into the mountain body in an inclined manner, even if a longer pipe shed is not used, the pipe shed can also be inserted into the inside of the mountain body deeper, and the support and connection effects on the position of the mountain body close to the door hole structure are improved.

Description

Technical Field

[0001] This invention belongs to the field of tunnel portal technology, specifically a tunnel front portal structure and its construction method. Background Technology

[0002] Traditional tunnel portals employ a "pre-positioned portal" method, emphasizing the protection of native vegetation on the tunnel slopes. This method involves a non-slope-cutting approach to tunnel entry. Without excavating the foothills outside the tunnel, I-beam steel arches are constructed sequentially through trenches on both sides. As the steel arches advance, they gradually "kiss" the mountainside. The arches are connected by longitudinal steel reinforcement to form a unified structure, and a temporary concrete lining is poured. This temporary lining forms the tunnel before entry, and after backfilling and counter-pressure, the tunnel excavation within the temporary lining proceeds. The pre-formed temporary lining serves as a protective measure for the slightly excavated slopes before tunnel construction.

[0003] In existing technologies, although the traditional pre-port portal can effectively reduce the damage to the original vegetation on the tunnel side slope and minimize the excavation of the soil at the foot of the mountain, for mountains with gentler slopes near the foot of the mountain, a small amount of excavation of the soil at the foot of the mountain is still required to meet the construction requirements of the traditional pre-port portal. Furthermore, when inserting the pipe roof into the mountain, for gentler slopes, the pipe roof is still far from the mountain after it enters the arch, so a longer pipe roof is required to meet the construction needs.

[0004] Therefore, the present invention provides a tunnel front portal structure and its construction method. Summary of the Invention

[0005] To overcome the shortcomings of existing technologies, the aim is to achieve a more stable portal structure by driving multiple piles into the mountainside at the foot of the mountain, so that the pipe roof can be driven closer to the mountainside and into the mountainside, and to reduce the excessive requirements for the length of the pipe roof.

[0006] The technical solution adopted by this invention to solve its technical problems and to achieve the objectives of overcoming the aforementioned technical problems is as follows: A tunnel pre-port structure according to this invention includes: piles, which are set on the slope of a mountain and driven into the interior of the mountain from the slope; multiple piles are provided, and the multiple piles are respectively located on both sides of the portal and are symmetrically distributed; an arched canopy, which includes an arch frame and a casting canopy; the arch frame connects the piles on both sides, the arch frame is a semi-circular arch structure, and the casting canopy is provided on the arch frame; and pipe canopies, which have multiple pipe canopies on the top of the arched canopy, with the ends of the multiple pipe canopies away from the arched canopy obliquely inserted into the interior of the mountain.

[0007] In some embodiments, a mounting base that can be integrally formed with the casting shed is provided on the top of the casting shed near the mountain. The top surface of the mounting base has a mounting groove, and a prefabricated top seat is installed inside the mounting groove. A pipe shed is installed on the prefabricated top seat. The prefabricated top seat and the mounting base are engaged. The prefabricated top seat has an inclined surface, and multiple inclined holes are pre-set on the inclined surface. The interior of the multiple inclined holes is used to insert the pipe shed, which is suitable for inserting the pipe shed into the mountain at a preset angle. The pipe shed is located at the top of the tunnel inside the mountain.

[0008] In some embodiments, the width of the mounting groove is greater than the size of the corresponding mating part of the precast top seat, which is suitable for situations where the precast top seat has been installed inside the mounting groove. In this case, a first gap is formed inside the mounting groove, and a limiting block is provided on the precast top seat inside the mounting groove. The first gap is suitable for being filled with concrete.

[0009] In some embodiments, the top of the precast top seat is provided with a placement groove communicating with the inclined hole. The interior of the placement groove is used to place a guide ring. The pipe shed is inserted into the interior of the inclined hole and passes through the guide ring and then into the mountain. The inner surface of the guide ring is provided with evenly arranged rollers. The middle part of the guide ring has a through hole. The guide ring has evenly arranged adjustment grooves on the inner side of the through hole. A slider is slidably connected inside the adjustment groove. A first spring is provided between the slider and the bottom of the adjustment groove. The rollers are provided on the side of the slider away from the bottom of the adjustment groove.

[0010] In some embodiments, a stop is installed inside the adjusting groove between the slider and the bottom of the adjusting groove. The tube shed includes a first shaft segment, a second shaft segment, and a third shaft segment, which are coaxially connected in sequence. The diameter of the first shaft segment is larger than that of the second shaft segment. The third shaft segment has a conical structure and is adapted to be inserted into the interior of the mountain. During the process of the tube shed passing through the inclined hole, when the second shaft segment passes the roller, the roller on the slider guides the second shaft segment, and the end of the first spring away from the slider abuts against the stop. When the first shaft segment is guided to the position of the roller, since the diameter of the first shaft segment is larger than that of the second shaft segment, the first shaft segment squeezes the roller and squeezes the stop through the first spring. The stop has a weakening area, which is adapted to break under pressure so that the roller stops squeezing the first shaft segment.

[0011] In some embodiments, the stop includes a stop ring portion, a stop core portion, and a stop connecting portion; the stop ring portion is fixedly connected to the interior of the adjustment groove, and the middle portion of the stop ring portion is connected to the stop core portion through the stop connecting portion, so that the weakening zone is formed between the stop ring portion and the stop core portion.

[0012] In some embodiments, the width of the placement groove is greater than the width of the guide ring, a second gap is formed between the placement groove and the guide ring, and a third gap is formed between the pipe roof and the inclined hole, which is suitable for injecting concrete by searching the second gap and allowing the concrete to seep into the interior of the third gap; the guide ring is provided with uniformly arranged connecting holes, which connect the interior of the adjustment groove with the exterior of the guide ring, which is suitable for introducing concrete into the interior of the adjustment groove through the connecting holes.

[0013] In some embodiments, the pipe roof is provided with multiple outlet holes, and the pipe roof is provided with an annular groove at the outlet hole position;

[0014] The annular groove is provided with uniformly arranged elastic sheets inside. One end of each elastic sheet is connected to the inner side of the annular groove, and the other end of each elastic sheet is a free end. Corrugated spring sheets are connected between the elastic sheets.

[0015] In some embodiments, the pipe shed is provided with an annular sensing groove, the sensing groove is provided with a sensing ring inside, the sensing ring is connected to the bottom of the sensing groove with a second spring, and the bottom of the sensing groove is provided with a sensor and / or an alarm; the sensing ring includes a first half ring and a second half ring, and the first half ring and the second half ring are detachably connected by bolts.

[0016] A construction method for a tunnel pre-port portal structure, used for constructing the aforementioned tunnel pre-port portal structure, includes the following construction steps:

[0017] First, multiple piles are driven into the mountain on both sides of the tunnel. The piles are symmetrically arranged on both sides of the tunnel. An I-shaped arch frame is erected between the piles on both sides, and the arch frame and the piles are cast as one piece.

[0018] Weld steel bars for the formwork onto the arch frame, then install the formwork, pour concrete into the interior of the formwork, and remove the formwork after the concrete has solidified to form an arched shed.

[0019] By setting a precast top seat on the arched canopy, with inclined holes on the precast top seat, the pipe roof is directly inserted into the inclined holes, so that the pipe roof is inserted obliquely into the interior of the mountain. Then, the pipe roof is grouted, and the installation gap around the precast top seat is filled with concrete to reinforce it, forming the basic structure of the pre-positioned portal.

[0020] Compared with the prior art, the tunnel pre-port structure and its construction method provided by the present invention have the following beneficial effects:

[0021] 1. This invention provides a tunnel pre-port structure and its construction method. Multiple piles are driven into the mountainside on both sides of the tunnel, symmetrically arranged. An I-beam arch is erected between the piles, and the arch and piles are cast as a single unit. This pile driving method allows the arch to extend towards a higher point at the foot of the mountain. A pipe roof is then installed on the arch near the foot of the mountain, allowing for closer insertion into the mountainside and reducing the required length. Furthermore, the oblique insertion of the pipe roof into the mountainside during construction allows for deeper insertion even without using longer pipe roofs, improving support and connection to the mountainside near the portal structure.

[0022] 2. This invention provides a tunnel pre-port structure and its construction method. By setting a prefabricated top seat, and since the prefabricated top seat is made using a prefabrication process, the inclined holes on the prefabricated top seat can also be directly formed. After the prefabricated top seat is installed, the pipe roof can be directly inserted into the inclined holes without the need for on-site drilling. On the one hand, this can improve construction efficiency. On the other hand, due to the relatively gentle foot of the mountain, the installation position of the pipe roof is farther from the plane position at the foot of the mountain, and it is difficult for machinery to directly lift it to a position close to the foot of the mountain. Therefore, mechanical drilling is inconvenient, and manual drilling is also difficult to implement. Therefore, the use of a prefabricated top seat with a prefabricated structure effectively solves the above problems. After the pipe roof passes through the inclined hole, it continues to be inserted towards the mountain, so that the pipe roof is finally inserted into the interior of the mountain, forming an effective support and connection for the mountain. Furthermore, by using the inclined insertion method into the mountain, the distance between the pipe roof and the mountain surface can be further reduced, so that the pipe roof is inserted into the mountain more deeply, improving the fixing effect of the pipe roof. Attached Figure Description

[0023] The present invention will be further described below with reference to the accompanying drawings:

[0024] Figure 1 This is a perspective view of the tunnel front portal structure in an embodiment of the present invention;

[0025] Figure 2 yes Figure 1 A magnified view of a portion of point A in the middle;

[0026] Figure 3 This is a top view of the tunnel front portal structure in an embodiment of the present invention;

[0027] Figure 4 yes Figure 3 Cross-sectional view of BB;

[0028] Figure 5This is a cross-sectional view of the prefabricated top seat and pipe roof in an embodiment of the present invention;

[0029] Figure 6 This is a perspective view of the guide ring in an embodiment of the present invention;

[0030] Figure 7 yes Figure 5 A magnified view of a portion of point C in the middle;

[0031] Figure 8 This is a cross-sectional view of the stop in an embodiment of the present invention;

[0032] Figure 9 This is a first perspective view of the pipe shed in an embodiment of the present invention;

[0033] Figure 10 This is an internal structural diagram of the pipe shed in an embodiment of the present invention;

[0034] Figure 11 This is a second perspective view of the pipe shed in an embodiment of the present invention;

[0035] Figure 12 This is a cross-sectional view of the pipe shed in an embodiment of the present invention;

[0036] Figure 13 This is a flowchart of the construction method in an embodiment of the present invention.

[0037] In the diagram: Pile body 100,

[0038] Arched shed 200, arch frame 210, cast-in-place shed body 220

[0039] Pipe shed 300, first shaft section 310, second shaft section 320, third shaft section 330, outlet hole 340, annular groove 350, elastic sheet 360, corrugated spring sheet 370, sensing groove 380.

[0040] Mounting base 400, mounting slot 410, first gap 420

[0041] Precast top seat 500, inclined hole 510, placement groove 520, limiting block 530, second gap 540, third gap 550,

[0042] Guide ring 600, through hole 610, adjusting groove 620, slider 630, first spring 640, roller 650, stop 660, weakening zone 661, stop ring part 662, stop core part 663, stop connecting part 664, connecting hole 670.

[0043] Sensing ring 700, second spring 710, sensor 720, first half-ring 730, second half-ring 740, bolt 750.

[0044] The mountain is 800 meters high. Detailed Implementation

[0045] To more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the specific implementation methods of the present invention will be described below with reference to the accompanying drawings. Obviously, the drawings described below are merely some embodiments of the present invention. For those skilled in the art, other drawings and other implementation methods can be obtained based on these drawings without any creative effort.

[0046] To keep the drawings concise, each figure only schematically shows the parts relevant to the invention, and these do not represent the actual structure of the product. Furthermore, to facilitate understanding, in some figures, only one of components with the same structure or function is schematically depicted, or only one is labeled. In this document, "one" not only means "only one," but can also mean "more than one."

[0047] It should also be further understood that the term "and / or" as used in this specification and the appended claims refers to any combination of one or more of the associated listed items and all possible combinations, and includes such combinations.

[0048] In this document, it should be noted that, unless otherwise explicitly specified and limited, the terms "installation," "connection," and "linking" should be interpreted broadly. For example, they can refer to fixed connections, detachable connections, or integral connections; they can refer to mechanical connections or electrical connections; they can refer to direct connections or indirect connections through an intermediate medium; and they can refer to the internal communication between two components. Those skilled in the art can understand the specific meaning of the above terms in this invention based on the specific circumstances.

[0049] Furthermore, in the description of this invention, the terms "first," "second," etc., are used only for distinguishing descriptions and should not be construed as indicating or implying relative importance.

[0050] like Figures 1-13As shown, this embodiment provides a tunnel front portal structure, including piles 100, arches 200, and pipe sheds 300. Multiple piles 100 are driven directly into the slope of the mountain 800 near the foot of the mountain. The multiple piles 100 are connected to the arch frame 210 to form an arch frame 210 structure at the foot of the mountain. Then, template steel bars are welded on the arch frame 210 structure to form a three-dimensional reinforcement of the arch frame 210. Then, templates are added to the outside of the arch frame 210 to form a hollow cavity structure. Concrete is injected into the cavity to form a cast-in-place shed 220. After the concrete solidifies, the templates are removed, and the cast-in-place shed 220 and the arch frame 210 form an arch shed 200 structure as a whole. Then, multiple pipe sheds 300 are added to the arch shed 200. The pipe sheds 300 enter and exit the interior of the mountain 800 to reinforce the connection with the mountain 800 and to reinforce and support the mountain 800.

[0051] In existing technologies, traditional tunnel entrances employ a "pre-positioned portal" method, emphasizing the protection of native vegetation on the tunnel slopes. This method involves a non-slope-cutting approach to tunnel entry, where, without excavating the foothills outside the tunnel, I-beam steel arches 210 are constructed sequentially through trenches on both sides. As the steel arches 210 are advanced, they gradually "kiss" the mountainside at a depth of 800 degrees. The arches 210 are connected as a whole by longitudinal steel reinforcement, and a temporary concrete lining is poured. Before entering the tunnel, this temporary lining forms the tunnel, which is then backfilled and counter-pressurized before the internal excavation within the temporary lining. The pre-formed temporary lining serves as a protective measure for the micro-excavation slopes before tunnel construction.

[0052] Although using the traditional pre-positioned portal can effectively reduce damage to the original vegetation on the tunnel slope and minimize the excavation of the soil at the foot of the mountain, for the gentler slope of the mountain 800, a small amount of excavation of the soil at the foot of the mountain is still required to meet the construction requirements of the traditional pre-positioned portal. Furthermore, when inserting the pipe roof 300 into the mountain 800, for the gentler slope, the pipe roof 300 is still far from the mountain 800 after penetrating the arch 200. Therefore, a longer pipe roof 300 is required to meet the construction needs.

[0053] To solve the above-mentioned technical problems, this embodiment provides an implementation method, specifically: a tunnel front portal structure, which involves driving multiple pile bodies 100 into the foot of the mountain 800 so that the pipe roof 300 can be driven into the mountain 800 more closely, thereby achieving a more stable portal structure even at the foot of a gentler mountain and reducing the excessive requirements on the length of the pipe roof 300.

[0054] The specific scheme is as follows: A pile body 100 is set on the slope surface of the mountain 800, and the pile body 100 is driven into the interior of the mountain 800 from the slope surface. Multiple pile bodies 100 are set, and the multiple pile bodies 100 are located on both sides of the doorway and are symmetrically distributed; an arched canopy 200 includes an arch frame 210 and a cast-in-place canopy 220. The arch frame 210 connects the pile bodies 100 on both sides and has a semi-circular arch structure. The cast-in-place canopy 220 is located on the arch frame 210; and a pipe canopy 300 includes multiple pipe canopies 300 on the top of the multiple arched canopies 200. The ends of the multiple pipe canopies 300 away from the arched canopies 200 are all obliquely inserted into the interior of the mountain 800.During construction, instead of the traditional method of simply and symmetrically setting two piles 100, this application provides a method of setting multiple piles 100 along the slope of the mountain 800 at the foot of the mountain. The piles 100 are distributed symmetrically on both sides of the tunnel. Therefore, for relatively gentle mountain slopes, it is possible to achieve the goal of directly driving piles at the foot of the mountain 800 without excavating the mountain 800. Then, the arched canopy 200 is built on the foundation of the piles 100. Due to the support of multiple piles 100, the stability of the arched canopy 200 is greatly improved. Since the tunnel needs to be excavated after the portal structure is completed, in order to ensure the portal structure... To ensure effective connection between the structure and the mountain 800, and to guarantee that the connection between the mountain 800 and the doorway is adequately supported, preventing collapse or settlement at the connection point, a pipe shed 300 is installed on the arch 200. Traditionally, the pipe shed 300 is inserted directly into holes in the arch 200, and its end is also inserted into the mountain 800, thus connecting the pipe shed 300 to the mountain 800. The pipe shed 300 is generally inserted horizontally into the mountain 800. However, for gentler slopes at the foot of the mountain, where the slope is gentler or the angle of inclination is smaller, the pipe shed 300 is inserted horizontally directly into the mountain 800. Because there is relatively little soil at the top of the pipe roof 300, a longer pipe roof 300 needs to be inserted deeper into the mountainside 800 to achieve a better reinforcement effect. Furthermore, the relatively gentle mountainside 800 requires continuous excavation in the initial stages to bring the pipe roof 300 into close contact with the mountainside 800, which would significantly damage the vegetation and affect the construction results. Therefore, by using piling, the arched roof 200 can be extended towards a higher position at the foot of the mountain, and then the pipe roof 300 can be installed on the arched roof 200 near the higher position at the foot of the mountain, allowing the pipe roof 300 to be inserted into the mountainside at a closer distance. The 800mm pipe roof reduces the length of the 300mm pipe roof. Furthermore, during construction, the 300mm pipe roof is inserted obliquely into the mountainside (800mm). Even without a longer 300mm pipe roof, it can be inserted deeper into the mountainside, improving support and connection near the tunnel entrance structure. It's important to note that the insertion depth of the 300mm pipe roof must be at the top of the tunnel to avoid interfering with normal excavation. This ensures the protection of the tunnel entrance slope and native vegetation, further reducing the amount of excavation and protection work on the entrance slope and guaranteeing greater slope stability.

[0055] In one embodiment, a mounting base 400, integrally formed with the casting shed 220, is provided at the top of the casting shed 220 near the mountain 800. The top surface of the mounting base 400 has a mounting groove 410, and a prefabricated top seat 500 is installed inside the mounting groove 410. A pipe shed 300 is mounted on the prefabricated top seat 500. The prefabricated top seat 500 and the mounting base 400 are engaged. The prefabricated top seat 500 has an inclined surface with multiple inclined holes 510 pre-set on the inclined surface. The interior of the multiple inclined holes 510 is used to insert the pipe shed 300, suitable for inserting the pipe shed 300 into the mountain 800 at a preset angle. The pipe shed 300 is located on the mountain. The top of the 800 internal tunnel; during operation, an installation seat 400 is provided on the top of the pouring shed 220. The installation seat 400 can be directly constructed into shape by the template during the pouring of the pouring shed 220. Therefore, after the concrete pouring process, the installation seat 400 and the pouring shed 220 are integrally formed. Of course, in some other embodiments, the installation seat 400 can be constructed after the pouring shed 220 is completed, so that the installation seat 400 and the pouring shed 220 are connected as a whole. It is not limited to this. The top surface of the installation seat 400 has an installation groove 410 for installing a precast top seat 500. The precast top seat 500 and the installation groove 410 are engaged. Together, these features make the precast top seat 500 more securely installed. Furthermore, the precast top seat 500 is manufactured using a prefabrication process, meaning it can be pre-formed in the factory. During construction, the pre-formed top seat 500 is directly transported to the construction site and hoisted onto the installation slot 410, allowing it to be installed inside. Notably, because the precast top seat 500 uses a prefabrication process, the inclined holes 510 on it can also be directly formed. After the precast top seat 500 is installed, the pipe roof 300 can be directly inserted into the inclined holes 510 without on-site drilling. This improves construction efficiency, and also facilitates the installation of the pipe roof 300 on the gentler slope. The installation location is far from the flat area at the foot of the mountain, making it difficult for machinery to be directly hoisted to a location closer to the foot of the mountain. Therefore, mechanical drilling is inconvenient, and manual drilling is also difficult to implement. Therefore, the use of a prefabricated top seat 500 with a prefabricated structure effectively solves the above problems and avoids the problem of excessive dust during on-site drilling. After the pipe roof 300 is inserted into the inclined hole 510, it continues to be inserted towards the mountain 800, so that the pipe roof 300 is finally inserted into the interior of the mountain 800, forming an effective support and connection for the mountain 800. Furthermore, the inclined insertion method into the mountain 800 can further reduce the distance between the pipe roof 300 and the surface of the mountain 800, allowing the pipe roof 300 to be inserted deeper into the mountain 800 and improving the fixing effect of the pipe roof 300.

[0056] In one embodiment, the width of the mounting groove 410 is greater than the size of the corresponding mating part of the precast top seat 500. This is suitable when the precast top seat 500 is already installed inside the mounting groove 410. A first gap 420 is formed inside the mounting groove 410, and a limiting block 530 is provided on the precast top seat 500 inside the mounting groove 410. The first gap 420 is suitable for filling with concrete. During operation, by designing the width of the mounting groove 410 to be greater than the width of the precast top seat 500, since the precast top seat 500 and the mounting seat 400 are engaged together, the fixing effect between the precast top seat 500 and the mounting seat 400 will not be affected. Of course, to further ensure... The installation is made more secure by setting a limiting block 530 on one side of the precast top seat 500. The limiting block 530 makes the precast top seat 500 fit into the mounting groove 410, improving the limiting effect. At the same time, it also forms a first gap 420 between the precast top seat 500 and the mounting seat 400. After the complete precast top seat 500 is installed, since the precast top seat 500 is a post-installed structure, its stability will be slightly worse than that of an integrally formed structure. Therefore, concrete is injected into the first gap 420 to fill the first gap 420 and achieve a complete connection between the precast top seat 500 and the mounting seat 400. This ensures that there will be no loosening of the precast top seat 500, the mounting seat 400, and the pipe roof 300 during long-term use.

[0057] In one embodiment, the top of the precast top seat 500 is provided with a placement groove 520 communicating with the inclined hole 510. The interior of the placement groove 520 is used to place the guide ring 600. The pipe shed 300 is inserted into the interior of the inclined hole 510 and passes through the guide ring 600 and then into the mountain body 800. The inner surface of the guide ring 600 is provided with evenly arranged rollers 650. The middle part of the guide ring 600 has a through hole 610. The guide ring 600 has evenly arranged adjustment grooves 620 on the inner side of the through hole 610. A slider 630 is slidably connected inside the adjustment groove 620. A first spring 640 is provided between the slider 630 and the bottom of the adjustment groove 620. The rollers 650 are provided on the side of the slider 630 away from the bottom of the adjustment groove 620.During operation, because the inclined hole 510 serves a fixing and guiding function, the friction between the pipe roof 300 and the inclined hole 510 is relatively large when the pipe roof 300 is inserted into the inclined hole 510. It is difficult for workers to push it in manually, or it requires considerable force. However, if the pipe roof 300 is initially inserted into the inclined hole 510, there is not enough guiding area between them. Directly pushing it with a machine can easily cause the pipe roof 300 and the inclined hole 510 to tilt and jam, resulting in damage to the pipe roof 300 or the inclined hole 510. Therefore, during the fabrication of the precast top seat 500, the friction is directly applied to the top of the precast top seat 500. The precast top seat 500 has a placement groove 520. Before installing the pipe roof 300, the guide ring 600 is placed into the precast top seat 500 through the placement groove 520. At this time, the through hole 610 in the middle of the guide ring 600 corresponds to the inclined hole 510. During the process of inserting the pipe roof 300 into the inclined hole 510, the pipe roof 300 will also be inserted into the through hole 610 of the guide ring 600. Since a roller 650 is provided in the through hole 610 of the guide ring 600, the roller 650 can support and guide the pipe roof 300, and the roller 650 and the pipe roof 300 can be rolled together. The process of the pipe roof 300 being pushed inside the inclined hole 510... In this design, the roller 650 significantly reduces the frictional resistance of the pipe roof 300, making operation easier for workers. Furthermore, an adjustment groove 620 is provided inside the through hole 610 of the guide ring 600. A slider 630 is slidably connected inside the adjustment groove 620, and a roller 650 is mounted on the slider 630. A first spring 640 is positioned between the slider 630 and the bottom of the adjustment groove 620. Therefore, when a portion of the roller 650 is compressed by the pipe roof 300, the roller 650 compresses the first spring 640 via the slider 630, thereby allowing the roller 650 to move and adjust in the opening direction of the adjustment groove 620, preventing the pipe roof 300 from being squeezed. 0. When the pipe roof 300 is installed at an angle inside the inclined hole 510, a jamming problem occurs. When the pipe roof 300 is inserted close to the surface of the mountain 800, the pipe roof 300 is then pressed down by the machine to insert it into the mountain 800. After completing the above work, concrete can be directly injected into the placement groove 520 to further fix the guide ring 600, the pipe roof 300, and the precast top seat 500. This also prevents rainwater from seeping into the space between the pipe roof 300 and the precast top seat 500 through the placement groove 520 during long-term use, thus avoiding a decrease in the fixing effect of the pipe roof 300.

[0058] In one embodiment, a stop 660 is installed inside the adjusting groove 620 between the slider 630 and the bottom of the adjusting groove 620. The pipe shed 300 includes a first shaft segment 310, a second shaft segment 320, and a third shaft segment 330, which are coaxially connected in sequence. The diameter of the first shaft segment 310 is larger than that of the second shaft segment 320. The third shaft segment 330 has a conical structure and is adapted to be inserted into the interior of the mountain 800. During the process of the pipe shed 300 passing through the inclined hole 510, the second shaft segment 320 passes the roller... When the roller 650 is in position, the roller 650 on the slider 630 is used to guide the second shaft segment 320, and the end of the first spring 640 away from the slider 630 abuts against the stop member 660. When the first shaft segment 310 is guided into the position of the roller 650, since the diameter of the first shaft segment 310 is larger than the diameter of the second shaft segment 320, the first shaft segment 310 squeezes the roller 650 and squeezes the stop member 660 through the first spring 640. The stop member 660 has a weakening area 661, which is suitable for the weakening area 661 to break under pressure so that the roller 650 stops squeezing the first shaft segment 310.During operation, after the pipe roof 300 is installed, it is constantly subjected to pressure from the first spring 640 via the roller 650. Due to the good mobility of the roller 650, this is very unfavorable for fixing the pipe roof 300. Furthermore, the continuous preload of the first spring 640 causes continuous internal stress between the precast top seat 500 and the pipe roof 300. Therefore, to solve these problems after the pipe roof 300 is installed, it is designed with a first shaft segment 310, a second shaft segment 320, and a third shaft segment 330, coaxially connected in sequence. The third shaft segment 330 is a pointed tip, facilitating the insertion of the pipe roof 300 into the mountain body 800. The diameter of the first shaft segment 310 is larger than that of the second shaft segment 320. During the initial installation of the pipe roof 300, the second shaft segment 320 directly presses against the roller 650, guiding the pipe roof 300. As the installation of the shed 300 nears completion, the first shaft section 310 moves to the position of the roller 650. The first shaft section 310 further compresses the roller 650, causing the roller 650 to compress the first spring 640 via the slider 630. The first spring 640 then compresses the stop member 660. The surface of the stop member 660 has a weakened area 661. When the compressive pressure from the first spring 640 on the stop member 660 exceeds the preset bearing capacity of the weakened area 661, the weakened area 661 breaks. The first spring 640 stops being pressed by the stop member 660. Since the stop member 660 is a certain distance from the bottom of the adjusting groove 620, the first spring 640 stops being compressed. The roller 650 stops compressing the first shaft section 310 of the shed 300, thus releasing the compressive pressure. Concrete is then poured into the corresponding gaps to ensure the long-term fixation of the shed 300.

[0059] In one embodiment, the stop 660 includes a stop ring portion 662, a stop core portion 663, and a stop connecting portion 664. The stop ring portion 662 is fixedly connected to the interior of the adjusting groove 620, and the middle part of the stop ring portion 662 is connected to the stop core portion 663 through the stop connecting portion 664, forming the weakened area 661 between the stop ring portion 662 and the stop core portion 663. During operation, the stop 660 is designed to include a stop ring portion 662, a stop core portion 663, and a stop connecting portion 664. The stop ring portion 662 is connected to the inner side of the adjusting groove 620, the stop core portion 663 directly abuts against the first spring 640, and the stop core portion 663 and the stop... The ring portions 662 are connected by a retaining portion 664. The thickness of the retaining portion 664 is smaller than that of the retaining ring portion 662 and the retaining core portion 663. Therefore, the strength of the retaining portion 664 is limited, which forms a weakened area 661 around the outer periphery of the retaining core portion 663. When the compression pressure of the first spring 640 on the retaining core portion 663 is too great, the retaining portion 664 in the weakened area 661 breaks, causing the retaining core portion 663 to separate from the retaining ring portion 662 as a whole. It then moves towards the bottom of the adjusting groove 620 along with the first spring 640, ensuring the initial installation and fixing effect of the first spring 640, and also obtaining a more complete fracture structure with more controllable fracture pressure.

[0060] In one embodiment, the width of the placement groove 520 is greater than the width of the guide ring 600, forming a second gap 540 between the placement groove 520 and the guide ring 600. A third gap 550 exists between the pipe roof 300 and the inclined hole 510, suitable for injecting concrete through the second gap 540 and allowing the concrete to penetrate into the interior of the third gap 550. The guide ring 600 has evenly arranged connecting holes 670, which connect the interior of the adjusting groove 620 to the exterior of the guide ring 600, suitable for introducing concrete into the interior of the adjusting groove 620 through the connecting holes 670. During operation, the width of the placement groove 520 is designed to be greater than the width of the guide ring 600, thus forming a second gap 540 between the placement groove 520 and the guide ring 600. The purpose of connecting the placement groove 520 and the inclined hole 510 is to allow the concrete to be poured into the third gap 550 between the inclined hole 510 and the pipe roof 300 more effectively and quickly after the pipe roof 300 is installed. This fills the third gap 550 inside the inclined hole 510. Furthermore, by setting a connecting hole 670 on the guide ring 600, the adjusting groove 620 and the placement groove 520 can be connected. Therefore, after the placement groove 520 is filled with concrete, the concrete can be quickly introduced into the adjusting groove 620 through the connecting hole 670, filling the adjusting groove 620. Ultimately, this completely fills the interior of the precast top seat 500, improving the strength of the precast top seat 500 and the connection effect between the precast top seat 500 and the pipe roof 300.

[0061] In one embodiment, the pipe roof 300 is provided with multiple outlet holes 340, and an annular groove 350 is provided at the position of the outlet holes 340. The annular groove 350 is provided with uniformly arranged elastic plates 360 inside, one end of each elastic plate 360 ​​is connected to the inner side of the annular groove 350, and the other end of each elastic plate 360 ​​is a free end. Corrugated spring plates 370 are connected between the elastic plates 360. During operation, the pipe roof 300 has outlet holes 340. After the installation of the pipe roof 300 is completed, concrete needs to be injected into the pipe roof 300. Some of the concrete will be discharged through the outlet holes 340 on the surface of the pipe roof 300, allowing... The concrete penetrates into the interior of the mountain 800, causing the pipe roof 300 to harden around a portion of the structure within the mountain 800. Due to the pressure of the concrete grouting, the density of the mountain 800 near the pipe roof 300 is increased, improving the connection between the pipe roof 300 and the mountain 800 and reducing the risk of settlement. Furthermore, by setting an annular groove 350 at the outlet 340 of the pipe roof 300, more space is provided between the pipe roof 300 and the outlet 340. Therefore, more concrete delivered through the outlet 340 can be poured into the annular groove 350, improving the concrete density around the exterior of the pipe roof 300. The amount of soil further improves the fixing effect of the pipe roof 300 and also increases the contact area between the concrete and the soil around the pipe roof 300, resulting in a stronger compression effect on the soil of the hill 800. This leads to a higher density of the soil inside the hill 800 and around the pipe roof 300. When the pipe roof 300 is inserted into the hill 800, the open annular groove 350 increases the frictional resistance between the pipe roof 300 and the hill 800. Furthermore, a large amount of soil will enter the interior of the annular groove 350, and even the interior of the outlet 340, posing a risk of clogging the outlet 340. Therefore, by setting a... The elastic sheet 360 and the corrugated sheet 370 act as a shield when the pipe roof 300 is introduced into the mountain 800, reducing the amount of soil entering the annular groove 350. After the installation of the pipe roof 300 is completed, with the pressure of the injected concrete, the free end of the elastic sheet 360, which is fixed at one end, will expand away from the pipe roof 300, thereby squeezing and fixing the surrounding soil. This allows the concrete to flow further away from the pipe roof 300 and the elastic sheet 360 to expand and penetrate into the surrounding soil, further improving the fixing effect between the pipe roof 300 and the mountain 800.

[0062] In one embodiment, the pipe shed 300 is provided with an annular sensing groove 380, and the sensing groove 380 is provided with a sensing ring 700 inside. A second spring 710 is connected between the sensing ring 700 and the bottom of the sensing groove 380. A sensor 720 and / or an alarm is provided at the bottom of the sensing groove 380. The sensing ring 700 includes a first half-ring 730 and a second half-ring 740, which are detachably connected by bolts 750. During operation, due to the complex environment of the mountain 800, there is a risk of loose rocks rolling down or landslides during the rainy season. Although the precast top seat 500 can provide some protection, it is limited. If the risk points are not detected in time, it can easily lead to traffic accidents. Therefore, by setting the sensing groove 380 on the pipe shed 300, the sensing ring 700 on the pipe shed 300 can provide some protection. The sensing groove 380 is located outside the mountain body 800 and also outside the precast top seat 500. A sensing ring 700 is set inside the sensing groove 380. When the sensing ring 700 is squeezed by mud or rocks, it will squeeze the second spring 710. When the squeezing pressure exceeds the preset value, the sensing ring 700 squeezes the sensor 720, which may trigger an alarm or trigger both simultaneously to output a danger signal or directly trigger an alarm. To facilitate installation and prevent the sensing ring 700 from being accidentally touched when the pipe roof 300 is inserted into the inclined hole 510, the sensing ring 700 is designed as a half-structure. The first half ring 730 and the second half ring 740 are fixed by bolts 750, which makes the installation of the sensing ring 700 more convenient. The installation of the sensing ring 700 can be started only after the complete pipe roof 300 is installed inside the inclined hole 510, making the installation more convenient.

[0063] A construction method for a tunnel pre-port portal structure, used for constructing the aforementioned tunnel pre-port portal structure, characterized in that the construction method includes the following construction steps:

[0064] S1: First, multiple piles 100 are driven into the mountain 800 on both sides of the tunnel. The multiple piles 100 are symmetrically arranged on both sides of the tunnel. An I-shaped arch frame 210 is set between the piles 100 on both sides, and the arch frame 210 and the piles 100 are cast together as one piece.

[0065] S2: Weld formwork reinforcement bars onto the arch frame 210, then install the formwork, pour concrete into the interior of the formwork, and remove the formwork after the concrete has solidified to form an arch shed 200.

[0066] S3: By setting a precast top seat 500 on the arch 200, the precast top seat 500 has an inclined hole 510, and the pipe roof 300 is directly introduced into the inclined hole 510, so that the pipe roof 300 is inserted obliquely into the interior of the mountain 800. Then, the pipe roof 300 is grouted, and the installation gap around the precast top seat 500 is filled with concrete to reinforce it, forming the basic structure of the pre-positioned doorway.

[0067] The foregoing has shown and described the basic principles, main features, and advantages of the present invention. Those skilled in the art should understand that the present invention is not limited to the above embodiments. The embodiments and descriptions in the specification are merely illustrative of the principles of the invention. Various changes and modifications can be made to the invention without departing from its spirit and scope, and all such changes and modifications fall within the scope of the present invention as claimed. The scope of protection of the present invention is defined by the appended claims and their equivalents.

Claims

1. A tunnel front-entrance structure, characterized in that, include: The pile body is set on the slope of the mountain and is driven into the interior of the mountain from the slope. There are multiple pile bodies, which are located on both sides of the doorway and are symmetrically distributed. An arched shed, comprising an arch frame and a cast-in-place shed body, wherein the arch frame connects the piles on both sides, the arch frame is a semi-circular arched structure, and the cast-in-place shed body is mounted on the arch frame; The arched shed has multiple pipe sheds on its top, and the ends of the multiple pipe sheds that are away from the arched shed are obliquely inserted into the interior of the mountain. The top of the casting shed is provided with an installation base that can be integrally formed with the casting shed. The top surface of the installation base is provided with an installation groove, and a prefabricated top seat is installed inside the installation groove. A pipe shed is installed on the prefabricated top seat. The prefabricated top seat and the mounting seat are engaged. The prefabricated top seat has an inclined surface, and multiple inclined holes are pre-set on the inclined surface. The interior of the multiple inclined holes is used to insert the pipe roof, which is suitable for inserting the pipe roof into the mountain at a preset angle. The pipe shed is located at the top of the tunnel inside the mountain.

2. The tunnel front portal structure according to claim 1, characterized in that, The width of the mounting groove is greater than the size of the corresponding mating part of the precast top seat, which is suitable for the installation groove to form a first gap when the precast top seat is already installed inside the mounting groove. A limit block is provided on the precast top seat inside the mounting groove. The first gap is suitable for filling with concrete.

3. The tunnel front portal structure according to claim 2, characterized in that, The top of the precast top seat is provided with a placement groove that connects to the inclined hole. The inside of the placement groove is used to place a guide ring. The pipe roof is inserted into the inside of the inclined hole and passes through the guide ring and then into the mountain. The inner surface of the guide ring is provided with evenly arranged rollers. The guide ring has a through hole in the middle, and the guide ring has evenly arranged adjustment grooves on the inner side of the through hole; a slider is slidably connected inside the adjustment groove; a first spring is provided between the slider and the bottom of the adjustment groove, and a roller is provided on the side of the slider away from the bottom of the adjustment groove.

4. The tunnel pre-port structure according to claim 3, characterized in that, Inside the adjusting groove, a stop is installed between the slider and the bottom of the adjusting groove. The tube shed includes a first shaft segment, a second shaft segment, and a third shaft segment, which are coaxially connected in sequence. The diameter of the first shaft segment is larger than that of the second shaft segment. The third shaft segment has a conical structure and is suitable for insertion into the interior of the mountain. During the process of the tube shed passing through the inclined hole, when the second shaft segment passes the roller, the roller on the slider guides the second shaft segment, and the end of the first spring away from the slider abuts against the stop. When the first shaft segment is guided to the position of the roller, since the diameter of the first shaft segment is larger than that of the second shaft segment, the first shaft segment squeezes the roller and squeezes the stop through the first spring. The stop has a weakening area, which is suitable for the weakening area to break under pressure so that the roller stops squeezing the first shaft segment.

5. A tunnel pre-port structure according to claim 4, characterized in that, The stop includes a stop ring, a stop core, and a stop connecting part; the stop ring is fixedly connected to the interior of the adjustment groove, and the middle part of the stop ring is connected to the stop core through the stop connecting part, so that the weakening zone is formed between the stop ring and the stop core.

6. The tunnel pre-port structure according to claim 5, characterized in that, The width of the placement groove is greater than the width of the guide ring. A second gap is formed between the placement groove and the guide ring. A third gap is formed between the pipe roof and the inclined hole, which is suitable for injecting concrete through the second gap and allowing the concrete to seep into the interior of the third gap. The guide ring is provided with evenly arranged connecting holes, which connect the inside of the adjusting groove with the outside of the guide ring, so that concrete can be introduced into the inside of the adjusting groove through the connecting holes.

7. A tunnel pre-port structure according to any one of claims 1-6, characterized in that, The pipe shed is provided with multiple outlet holes, and the pipe shed is provided with an annular groove at the outlet hole position; The annular groove is provided with uniformly arranged elastic sheets inside. One end of each elastic sheet is connected to the inner side of the annular groove, and the other end of each elastic sheet is a free end. Corrugated spring sheets are connected between the elastic sheets.

8. A tunnel pre-port structure according to any one of claims 1-6, characterized in that, The pipe shed is provided with an annular sensing groove, the inside of the sensing groove is provided with a sensing ring, a second spring is connected between the sensing ring and the bottom of the sensing groove, and a sensor and / or alarm is provided at the bottom of the sensing groove. The sensing ring includes a first half-ring and a second half-ring, which are detachably connected by bolts.

9. A construction method for a tunnel pre-port portal structure, used for constructing the tunnel pre-port portal structure according to any one of claims 1-6, characterized in that, The construction method includes the following steps: First, multiple piles are driven into the mountain on both sides of the tunnel. The piles are symmetrically arranged on both sides of the tunnel. An I-shaped arch frame is erected between the piles on both sides, and the arch frame and the piles are cast as one piece. Weld steel bars for the formwork onto the arch frame, then install the formwork, pour concrete into the interior of the formwork, and remove the formwork after the concrete has solidified to form an arched shed. By setting a precast top seat on the arched canopy, with inclined holes on the precast top seat, the pipe roof is directly inserted into the inclined holes, so that the pipe roof is inserted obliquely into the interior of the mountain. Then, the pipe roof is grouted, and the installation gap around the precast top seat is filled with concrete to reinforce it, forming the basic structure of the pre-positioned portal.

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