A temporary blocking structure for tunnel phased construction and its construction method

Abstract

The application provides a temporary plugging structure for tunnel staged construction and a construction method thereof, comprising a tunnel section constructed in advance, a waterproof assembly and a plugging assembly. The plugging assembly comprises a main plugging wall and a surrounding plugging wall. The main plugging wall is matched with the opening of the tunnel section constructed in advance. The upper part of the main plugging wall is connected with the roof of the tunnel section constructed in advance. The lower part of the main plugging wall is connected with the floor of the tunnel section constructed in advance. The surrounding plugging wall is plugged on the side of the main plugging wall away from the tunnel section constructed in advance. The waterproof assembly comprises a water stop and a seepage prevention member. The water stop is plugged on the side of the surrounding plugging wall away from the tunnel section constructed in advance. The main plugging wall and the tunnel section constructed in advance are provided with a reserved interface unit for installing the seepage prevention member. The seepage prevention member is arranged in the reserved interface unit. In this way, the water flow of the tunnel section constructed later can be prevented from flowing into the tunnel section constructed in advance by the water stop. The waterproof effect of the joint is effectively improved by arranging the seepage prevention member.

Description

Technical Field

[0001] The present invention relates to the technical field of tunnel phased construction, in particular to a temporary blocking structure and a construction method for tunnel phased construction. Background Art

[0002] With the continuous development of tunnel engineering construction in my country, foundation pits are increasingly developing in the direction of "deeper and larger". At the same time, with the continuous development of urbanization, tunnel construction is also facing more complex surrounding construction conditions. Nowadays, the progress of tunnel construction is not only restricted by factors such as equipment conditions and funds, but also needs to consider how to ensure that tunnel construction minimizes the impact on surrounding buildings and reduces the impact on surrounding existing roads. In order to properly consider the above factors, phased tunnel construction is becoming more and more common in cities.

[0003] The phased construction of tunnels usually requires the use of temporary blocking structures such as pile rows. Common blocking structures only use the blocking structure as a temporary retaining measure, such as the attached Figure 1 As shown, in the prior art, steel structures are usually embedded in the top and bottom plates and side wall concrete of the early construction side, and the soil pressure of the unexcavated side is transferred to the main structure of the early construction side through the steel structure; then, after the support of the later construction side is erected, the foundation pit is excavated, and after the main structure of the later construction side is completed, the blocking wall and the force-transmitting steel structure are removed, and finally, the concrete at the joints is poured. In this way, when a buried steel-edged rubber waterstop is set at the construction joint and the deformation joint for the layout of waterproof facilities, the reserved force-transmitting steel structure will destroy the structural steel bar setting of the waterstop, resulting in the inability to install the waterstop, thereby causing water from the unconstructed side to seep into the constructed side and cause damage; and failure to backfill the foundation pit of the early construction side in time will further increase the risk of foundation pit collapse due to excessive exposure time, making it impossible to quickly restore traffic on the ground road of the constructed side.

[0004] This temporary blocking structure did not take into account the possibility of water seepage at the blocking point when the blocking time is too long. At the same time, no sufficient waterproofing device was reserved at the blocking point, causing the blocking point to become a long-term water seepage point. Furthermore, it did not consider the risk of failure of the retaining structure and support due to the long exposure time of the foundation pit constructed in the early stage. In addition, it did not consider the requirement of timely backfilling of the upper part of the tunnel constructed in the early stage to ensure traffic.

[0005] In view of this, it is necessary to propose a method to solve or at least alleviate the above defects. Summary of the Invention

[0006] The main purpose of the present invention is to provide a temporary blocking structure and construction method for tunnel phased construction, so as to solve the problem in the prior art that the temporary blocking structure for tunnel phased construction cannot be installed with a water stop, thereby causing water from the unconstructed side to seep to the constructed side and cause damage.

[0007] To achieve the above-mentioned object, the present invention provides a temporary blocking structure for phased tunnel construction, comprising an early-stage tunnel section, a waterproof component, and a blocking component for blocking an end of the early-stage tunnel section near a later-stage tunnel section; wherein,

[0008] The blocking assembly includes a main blocking wall and a surrounding blocking wall. The main blocking wall matches the opening of the previously constructed tunnel section. The upper portion of the main blocking wall is connected to the top plate of the previously constructed tunnel section, and the lower portion of the main blocking wall is connected to the bottom plate of the previously constructed tunnel section.

[0009] The enclosure blocking wall blocks the side of the main blocking wall away from the pre-constructed tunnel section;

[0010] The waterproof component is used to prevent water from the later construction tunnel section from seeping into the earlier construction tunnel section. The waterproof component includes a water stop and an anti-seepage component respectively arranged on both sides of the main sealing wall. The water stop is sealed on the side of the enclosing sealing wall away from the earlier construction tunnel section; a reserved interface unit for the installation of the anti-seepage component is provided between the main sealing wall and the earlier construction tunnel section, and the anti-seepage component is arranged in the reserved interface unit.

[0011] Preferably, the top end of the retaining sealing wall extends to the ground, and the bottom end of the retaining sealing wall extends downward and is arranged below the tunnel floor.

[0012] Preferably, the reserved interface unit includes a top plate tongue and groove, a side wall tongue and groove, and a bottom plate tongue and groove, wherein:

[0013] The top plate tongue and groove is arranged between the main body blocking wall and the top plate of the previously constructed tunnel section, the side wall tongue and groove is arranged between the main body blocking wall and the side wall of the previously constructed tunnel section, and the bottom plate tongue and groove is arranged between the main body blocking wall and the bottom plate of the previously constructed tunnel section.

[0014] Preferably, the anti-seepage component adopts a centrally embedded steel-edged rubber waterstop, and the centrally embedded steel-edged rubber waterstop is respectively arranged in the top plate tongue and groove, the side wall tongue and groove, and the bottom plate tongue and groove in a one-to-one correspondence.

[0015] Preferably, a reinforced hidden beam extending laterally along the tunnel is also constructed in the top of the early-construction tunnel section, and the reinforced hidden beam is arranged in the top plate of the early-construction tunnel section near one end of the main blocking wall.

[0016] Preferably, it also includes a cantilever retaining wall extending laterally along the tunnel, wherein the cantilever retaining wall is arranged on the top plate of the previously constructed tunnel section, and the cantilever retaining wall includes a fixed end and a free end, wherein the fixed end is fixedly connected to the reinforced hidden beam, and the free end extends upward from the fixed end.

[0017] Preferably, a backfill space for filling backfill soil is formed between the side of the cantilever retaining wall away from the main blocking wall and the top plate of the previously constructed tunnel section, and a sand filling space for filling sand is formed between the side of the cantilever retaining wall close to the main blocking wall and the top plate of the previously constructed tunnel section and the main blocking wall.

[0018] Preferably, the water-stopping member is a water-stopping curtain, and the water-stopping curtain is made of one of a rotary jet pile or a mixing pile.

[0019] The present invention also provides a construction method for a temporary blocking structure for tunnel construction in stages, which is applied to the temporary blocking structure for tunnel construction in stages as described above, comprising the steps of:

[0020] S1, applying the water stop at a first preset distance from the early-construction tunnel section, wherein the water stop extends vertically and is located at one end of the later-construction tunnel section; wherein the water stop is a water-stop curtain;

[0021] S2, constructing the enclosing and blocking wall;

[0022] S3, excavating the foundation pit and constructing internal supports for the pre-constructed tunnel section;

[0023] S4, constructing the bottom plate, side walls near the bottom, and main body blocking wall structures of the pre-constructed tunnel section, and reserving bottom plate tongue and groove and side wall tongue and groove; wherein the bottom plate tongue and groove are provided between the main body blocking wall and the bottom plate of the pre-constructed tunnel section, and the side wall tongue and groove are provided between the main body blocking wall and the side walls of the pre-constructed tunnel section;

[0024] S5, pre-embed an anti-seepage member to the tongue-and-groove of the bottom plate and the tongue-and-groove of the side wall; wherein the anti-seepage member is a centrally embedded steel-edged rubber waterstop;

[0025] S6, using a sequential method to remove the internal supports in sequence, and cast the side walls above the bottom of the previously constructed tunnel section and the main blocking wall structure in the middle;

[0026] S7, pre-embed reinforced hidden beam steel bars and reserve top plate tongue and groove; wherein the top plate tongue and groove is set between the main body blocking wall and the top plate of the pre-constructed tunnel section;

[0027] S8, embedding the middle-embedded steel edge rubber waterstop to the top plate and the side wall;

[0028] S9, pouring the top plate and the main body sealing wall structure above the middle part.

[0029] Preferably, the step S9 further comprises the step of:

[0030] S10, constructing the cantilever retaining wall;

[0031] S11, backfilling the sand filling space with fine sand and artificially tamping the backfilling space.

[0032] Compared with the prior art, the temporary sealing structure for tunnel staged construction has the following beneficial effects:

[0033] The temporary sealing structure for tunnel staged construction provided by the application comprises a tunnel section constructed in advance, a waterproof assembly, and a sealing assembly. The sealing assembly comprises a main body sealing wall and a surrounding sealing wall. The main body sealing wall is matched with the opening of the tunnel section constructed in advance. The upper part of the main body sealing wall is connected with the top plate of the tunnel section constructed in advance. The lower part of the main body sealing wall is connected with the bottom plate of the tunnel section constructed in advance. The surrounding sealing wall is sealed to the side of the main body sealing wall away from the tunnel section constructed in advance. The waterproof assembly comprises a waterstop and a seepage prevention member arranged on the two sides of the main body sealing wall, respectively. The waterstop is sealed to the side of the surrounding sealing wall away from the tunnel section constructed in advance. The main body sealing wall is provided with a reserved interface unit for installing the seepage prevention member between the main body sealing wall and the tunnel section constructed in advance. The seepage prevention member is arranged in the reserved interface unit. In this way, the water of the tunnel section constructed later can be prevented from flowing into the tunnel section constructed in advance by the waterstop. The waterproof effect of the joint is effectively improved by arranging the seepage prevention member, so that the groundwater is prevented from seeping into the tunnel section constructed in advance to corrode the related stressed members, the safety performance of the structure is improved, and the construction quality and durability of the tunnel project are improved. BRIEF DESCRIPTION OF DRAWINGS

[0034] In order to more clearly illustrate the technical solutions in the embodiments of the application or the prior art, the following will briefly introduce the drawings needed to be used in the embodiments or the prior art description. Obviously, the drawings in the following description only show some embodiments of the application, and for those skilled in the art, other drawings can also be obtained from the structures shown in the drawings without creative labor.

[0035] Figure 1 It is a schematic diagram of the sealing structure of the prior art;

[0036] Figure 2 It is an application scenario diagram of the temporary sealing structure in an embodiment of the application;

[0037] Figure 3Schematic diagram of the structure of a cantilever retaining wall in one embodiment of the present invention;

[0038] Figure 4 Schematic diagram of the structure of a water-stop curtain in one embodiment of the present invention.

[0039] The purpose, features and advantages of the present invention will be further described with reference to the accompanying drawings and in conjunction with the embodiments.

[0040] Description of Figure Numbers:

[0041] 10. Sealing components; 110. Main sealing wall; 120. Enclosure sealing wall; 20. Waterproof components; 210. Waterstop; 220. Anti-seepage components; 30. Early construction tunnel section; 310. Top plate; 311. Reinforced hidden beam; 312. Cantilever retaining wall; 320. Bottom plate; 330. Backfill space; 340. Sand filling space; 40. Later construction tunnel section. DETAILED DESCRIPTION

[0042] It should be understood that the specific embodiments described herein are only used to explain the present invention and are not intended to limit the present invention.

[0043] The following will clearly and completely describe the technical solutions in the embodiments of the present invention in conjunction with the accompanying drawings. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. All other embodiments obtained by ordinary technicians in this field based on the embodiments of the present invention without making any creative efforts shall fall within the scope of protection of the present invention.

[0044] It should be noted that all directional indications in the embodiments of the present invention (such as up, down, left, right, front, back, etc.) are only used to explain the relative position relationship, movement status, etc. between the various components under a certain specific posture (as shown in the accompanying drawings). If the specific posture changes, the directional indication will also change accordingly.

[0045] In addition, the descriptions of "first", "second", etc. in the present invention are for descriptive purposes only and should not be understood as indicating or implying their relative importance or implicitly indicating the number of the indicated technical features. Therefore, the features defined as "first" or "second" may explicitly or implicitly include at least one of such features. In addition, the technical solutions between the various embodiments can be combined with each other, but this must be based on the fact that they can be implemented by ordinary technicians in this field. When the combination of technical solutions is contradictory or cannot be implemented, it should be deemed that such combination of technical solutions does not exist and is not within the scope of protection required by the present invention.

[0046] Please see the attached Figure 1-4In one embodiment of the present invention, a temporary blocking structure for phased tunnel construction is provided, comprising an early construction tunnel section 30, a waterproof component 20, and a blocking component 10 for blocking one end of the early construction tunnel section 30 near the later construction tunnel section 40. First of all, it should be noted that the early construction tunnel section 30 of this application refers to a section that has been constructed during the phased construction of the tunnel, and the later construction tunnel section 40 refers to a section where the foundation pit has not yet been excavated during the phased construction of the tunnel. This is different from the prior art, which usually embeds steel structures in the top and bottom plates and side wall concrete of the early construction side, and transmits the soil pressure of the unexcavated side to the main structure of the early construction side through the steel structure; and then excavates the foundation pit after the support of the later construction side is erected, and after the main structure of the later construction side is completed, the blocking wall and the force-transmitting steel structure are removed, and finally the concrete pouring at the joints is carried out. For details, please refer to the attached. Figure 1 . In this way, when a buried steel-edged rubber waterstop is set at the construction joint and deformation joint for laying out waterproof facilities, the reserved force-transmitting steel structure will destroy the structural reinforcement setting of the waterstop, resulting in the inability to install the waterstop, thereby causing water on the unconstructed side to seep into the constructed side and cause damage; and failure to backfill the foundation pit on the first construction side in time will cause the foundation pit to be exposed for too long and further increase the risk of collapse of the foundation pit, making it impossible to quickly restore traffic on the ground road on the constructed side. This application solves the above-mentioned defects in the prior art by setting up a temporary blocking structure for phased tunnel construction. The details are as follows:

[0047] The sealing assembly 10 includes a main sealing wall 110 and a protective sealing wall 120. The main sealing wall 110 matches the opening of the previously constructed tunnel section 30. The upper part of the main sealing wall 110 is connected to the top plate 310 of the previously constructed tunnel section, and the lower part of the main sealing wall 110 is connected to the bottom plate 320 of the previously constructed tunnel section; the protective sealing wall 120 blocks the side of the main sealing wall 110 away from the previously constructed tunnel section 30.

[0048] Specifically, the sealing assembly 10 is used as a temporary sealing structure for phased construction, which includes a main sealing wall 110 and a retaining sealing wall 120. The main sealing wall 110 is used to bear the soil pressure on one side of the later construction tunnel section 40, and by connecting the upper part of the main sealing wall 110 to the top plate 310 of the earlier construction tunnel section, and the lower part of the main sealing wall 110 to the bottom plate 320 of the earlier construction tunnel section, the soil pressure on one side of the later construction tunnel section 40 is transmitted to the main structure of the earlier construction tunnel section 30 through the main sealing wall 110. In addition, the main sealing wall 110 matches the opening of the earlier construction tunnel section 30, thereby avoiding the risk of gaps due to mismatched openings that increase water and soil seepage.

[0049] The retaining planking wall 120 is used to retain one side of the early construction tunnel section 30, so as to avoid the soil of the later construction tunnel section 40 from falling into the early construction tunnel section 30, and therefore, the retaining planking wall 120 is blocked on the side of the main blocking wall 110 away from the early construction tunnel section 30. It is worth noting that the retaining planking wall 120 can adopt the form of row piles, which has the advantages of flexible plane layout, simple construction process, low cost, and small vibration and extrusion to the soil body, and is a common form in retaining wall structures.

[0050] The waterproof assembly 20 is used to prevent the water of the later construction tunnel section 40 from seeping into the early construction tunnel section 30, and comprises water-stopping pieces 210 and anti-seepage pieces 220 arranged on both sides of the main blocking wall 110 respectively. The water-stopping pieces 210 are blocked on the side of the retaining planking wall 120 away from the early construction tunnel section 30. The main blocking wall 110 and the early construction tunnel section 30 are provided with a reserved interface unit for installing the anti-seepage pieces 220, and the anti-seepage pieces 220 are arranged in the reserved interface unit.

[0051] In detail, the waterproof assembly 20 is used to prevent the water of the later construction tunnel section 40 from seeping into the early construction tunnel section 30, and comprises water-stopping pieces 210 and anti-seepage pieces 220 arranged on both sides of the main blocking wall 110 respectively. The water-stopping pieces 210 are used to isolate the underground water on one side of the later construction tunnel section 40, and are therefore blocked on the side of the retaining planking wall 120 away from the early construction tunnel section 30 and arranged between the later construction tunnel section 40 and the retaining planking wall 120. It is worth noting that the water-stopping pieces 210 adopt the form of water-stopping curtain, which can adopt φ850@600mm rotary jet piles or mixing piles according to the geological conditions. The rotary jet piles have the advantages of simple construction, high efficiency, low cost, high strength and good durability. When the mixing piles are used as water-stopping curtain, they have good water-stopping and anti-seepage ability, and are a common technical means in water-stopping curtain. The person skilled in the art can determine according to the specific circumstances.

[0052] The anti-seepage pieces 220 are used to ensure the waterproof effect of the joint and prevent water from penetrating into the main structure through the joint, and therefore, a reserved interface unit for installing the anti-seepage pieces 220 is arranged between the main blocking wall 110 and the early construction tunnel section 30, so that the anti-seepage pieces 220 are arranged in the reserved interface unit. Thus, unlike the prior art, the anti-seepage pieces 220 are not convenient to install, and therefore, the present application has good water-stopping and anti-seepage effect.

[0053] As a preferred embodiment of the present invention, the top of the retaining sealing wall 120 extends to the road surface, and the bottom of the retaining sealing wall 120 extends downward and is disposed below the tunnel floor 320. It should be understood that the top of the retaining sealing wall 120 extending to the ground allows the retaining sealing wall 120 to support the road surface while blocking the soil on one side of the later tunnel construction section, while the bottom of the retaining sealing wall 120 extending downward and being disposed below the tunnel floor 320 can transfer a portion of the pressure exerted on the support to the geology below the floor 320, thereby sharing the pressure.

[0054] As a preferred embodiment of the present invention, the reserved interface unit includes a top plate tongue and groove, a side wall tongue and groove, and a bottom plate tongue and groove, wherein the top plate tongue and groove is arranged between the main blocking wall 110 and the top plate 310 of the early construction tunnel section, the side wall tongue and groove is arranged between the main blocking wall 110 and the side wall of the early construction tunnel section 30, and the bottom plate tongue and groove is arranged between the main blocking wall 110 and the bottom plate 320 of the early construction tunnel section.

[0055] It should be noted that the reserved interface unit is used for the installation of the anti-seepage component 220, which adopts the method of reserving a tongue and groove at the joint. In this way, the tongue and groove are reserved in advance when constructing the preliminary construction tunnel section 30, so as to facilitate the installation of the anti-seepage component 220. When constructing the main blocking wall 110, the corresponding tongue and groove form is also used for installation. At this time, the anti-seepage component 220 is arranged between the preliminary construction tunnel section 30 and the main blocking wall 110 to achieve the anti-seepage effect.

[0056] Among them, tongue and groove are reserved between the main sealing wall 110 and the top plate 310, side wall and bottom plate 320 of the early construction tunnel section. The top plate tongue and groove are set between the main sealing wall 110 and the top plate 310 of the early construction tunnel section, the side wall tongue and groove are set between the main sealing wall 110 and the side wall of the early construction tunnel section 30, and the bottom plate tongue and groove are set between the main sealing wall 110 and the bottom plate 320 of the early construction tunnel section.

[0057] It should be noted that the height of the top plate tongue and groove is half the thickness of the top plate 310 of the previously constructed tunnel section, the width of the side wall tongue and groove is half the thickness of the side wall of the previously constructed tunnel section 30, and the height of the bottom plate tongue and groove is half the thickness of the bottom plate 320 of the previously constructed tunnel section. This is more conducive to the layout and installation of the anti-seepage component 220 and the docking installation of the main blocking wall 110.

[0058] As a preferred embodiment of the present invention, the anti-seepage component 220 adopts a buried steel-edge rubber waterstop, which is respectively arranged in the top plate tongue and groove, the side wall tongue and groove, and the bottom plate tongue and groove in a one-to-one correspondence. It is worth noting that the anti-seepage component 220 adopts a buried steel-edge rubber waterstop. Since the middle rubber body of the buried steel-edge waterstop is compressed, stretched, and deformed when the structure is deformed, it plays a role of sealing and water stopping. The galvanized steel edge strip has good adhesion to the concrete and is not easy to fall off or loosen, so that the waterstop can withstand greater tension and torsion. Since no new leakage seams will be generated between the steel strip and the concrete, or between the steel strip and the rubber, the steel edge rubber waterstop enhances the anti-seepage performance of the structural deformation and has good self-determination after installation. It is a better choice among the anti-seepage components 220. Those skilled in the art can also choose other anti-seepage components 220 according to actual conditions.

[0059] As a preferred embodiment of the present invention, a reinforced hidden beam 311 is constructed within the top of the pre-constructed tunnel section 30, extending transversely along the tunnel. The reinforced hidden beam 311 is disposed within the roof 310 of the pre-constructed tunnel section 30, near one end of the main blocking wall 110. It is worth noting that the reinforced hidden beam 311 is used to enhance the bending resistance of the roof 310 of the pre-constructed tunnel section 30 and to facilitate the subsequent installation of the cantilever retaining wall 312. Therefore, when pre-embedding the reinforcement of the reinforced hidden beam 311, the grade of the reinforcement of the reinforced hidden beam 311 should be at least one grade higher than the main reinforcement of the roof 310 of the pre-constructed tunnel section to enhance strength.

[0060] As a preferred embodiment of the present invention, it also includes a cantilever retaining wall 312 extending laterally along the tunnel, and the cantilever retaining wall 312 is set on the top plate 310 of the pre-constructed tunnel section. The cantilever retaining wall 312 includes a fixed end and a free end, the fixed end is fixedly connected to the reinforced hidden beam 311, and the free end extends upward from the fixed end.

[0061] It is worth noting that in order to ensure that the road above the early construction tunnel section 30 can be used normally, backfill construction must be carried out between the top plate 310 of the early construction tunnel section and the road surface. Therefore, the cantilever retaining wall 312 needs to be added to bear the pressure of the backfill soil to meet the upper traffic flow while ensuring that the foundation pit of the later construction tunnel section 40 can be excavated smoothly.

[0062] Among them, the cantilever retaining wall 312 is arranged on the top plate 310 of the pre-constructed tunnel section, and includes a fixed end and a free end. The fixed end is fixedly connected to the reinforced hidden beam 311, and the width of the fixed end should be consistent with the width of the reinforced hidden beam 311. The free end extends upward from the fixed end to form a cantilever retaining wall 312.

[0063] Furthermore, a backfill space 330 for filling backfill soil is formed between the side of the cantilever retaining wall 312 away from the main sealing wall 110 and the top plate 310 of the previously constructed tunnel section, and a sand filling space 340 for filling sand is formed between the side of the cantilever retaining wall 312 close to the main sealing wall 110 and the top plate 310 of the previously constructed tunnel section and the main sealing wall 110. It should be noted that a backfill space 330 for filling backfill soil is formed between the side of the cantilever retaining wall 312 away from the main sealing wall 110 and the top plate 310 of the previously constructed tunnel section, and the backfill space 330 is filled with artificially compacted soil; a sand filling space 340 for filling sand is formed between the side of the cantilever retaining wall 312 close to the main sealing wall 110 and the top plate 310 of the previously constructed tunnel section and the main sealing wall 110, and the sand filling space 340 is backfilled with fine sand. This has two effects. One is to minimize the load of backfill water and soil pressure on the cantilever retaining wall 312 as much as possible, so that the water and soil pressure on both sides of the cantilever retaining wall 312 is as balanced as possible. The other is to facilitate cleaning during later construction and reduce the impact on the pre-buried steel-edge rubber waterstop. When the backfill soil reaches the structural strength requirements, the road surface above can be restored to traffic, alleviating the traffic pressure on the road near the construction site.

[0064] The present invention also provides a construction method for a temporary blocking structure for tunnel construction in stages, which is applied to the temporary blocking structure for tunnel construction in stages as described above, comprising the steps of:

[0065] S1, the water stop member 210 is applied at a first preset distance from the early construction tunnel section 30, and the water stop member 210 extends vertically and is located at one end of the later construction tunnel section 40; wherein, the water stop member 210 is a water stop curtain; it is worth noting that when constructing the entire temporary blocking structure, the water stop curtain is first applied at a first preset distance from the early construction tunnel section 30, and the first preset distance should be the reserved space for the blocking component 10. The water stop curtain can adopt φ850@600mm rotary jet piles or mixing piles according to the geological conditions.

[0066] S2, constructing the enclosure sealing wall 120; it is worth noting that after the water-stop curtain reaches the designed strength, the enclosure sealing wall 120 can be constructed, and the enclosure sealing wall 120 can be in the form of pile rows.

[0067] S3, excavating a foundation pit and constructing internal supports for the pre-constructed tunnel section 30 in succession; it should be understood that excavating a foundation pit and constructing internal supports according to the construction process are well known to those skilled in the art, so they will not be described in detail here.

[0068] S4, construct the bottom plate 320, the side wall near the bottom and the main body blocking wall 110 structure of the pre-construction tunnel section, and reserve the bottom plate tongue and groove and the side wall tongue and groove; wherein, the bottom plate tongue and groove are set between the main body blocking wall 110 and the bottom plate 320 of the pre-construction tunnel section, and the side wall tongue and groove are set between the main body blocking wall 110 and the side wall of the pre-construction tunnel section 30; it should be noted that when constructing the bottom plate 320, the side wall near the bottom and the main body blocking wall structure of the pre-construction tunnel section, the tongue and groove are pre-buried for the next step of installing the embedded steel-edge rubber waterstop, wherein, the bottom The height of the plate tongue and groove is half of the height of the bottom plate 320 of the pre-constructed tunnel section, and the height of the side wall tongue and groove is half of the thickness of the side wall of the pre-constructed tunnel section 30; wherein, the side wall close to the bottom refers to the side wall constructed from the bottom up, and the main blocking wall structure close to the bottom refers to the main blocking wall structure constructed from the bottom up, and construction from the bottom up can make construction more convenient; it is worth mentioning that before constructing the main blocking wall 110, the enclosure blocking wall 120 needs to be roughened and leveled to increase the adhesion between the concrete of the post-cast main blocking wall 110 and the concrete of the enclosure blocking wall 120, eliminate joints, and ensure quality.

[0069] S5, pre-embed the anti-seepage member 220 to the tongue and groove of the bottom plate and the tongue and groove of the side wall; wherein the anti-seepage member 220 is a centrally embedded steel-edged rubber waterstop;

[0070] S6, adopt the forward method to remove the internal supports in sequence, and cast the side walls above the bottom of the early construction tunnel section 30 and the main body blocking wall 110 structure in the middle; wherein, the top plate tongue and groove are arranged between the main body blocking wall 110 and the top plate 310 of the early construction tunnel section; it should be noted that the forward method can be adopted to remove the internal supports and cast the side walls and top plate 310 of the early construction tunnel section 30 in sequence. The forward method has the advantages of simple, fast, economical and safe construction, and is a common tunnel construction technology; and the height of the top plate tongue and groove is half the height of the top plate 310 of the early construction tunnel section; wherein, the main body blocking wall 110 structure in the middle refers to the middle structure located above the constructed main body blocking wall 110 near the bottom but below the unconstructed main body blocking wall 110 near the top.

[0071] S7, pre-embedded reinforcement hidden beam steel bars 311 and reserved top plate tongue and groove; it is worth noting that the pre-embedded position of the reinforcement hidden beam 311 steel bars is set at the top of the pre-constructed tunnel section 30 close to one end of the main blocking wall 110, so as to facilitate the subsequent definition of the position of the cantilever retaining wall 312. Since it is necessary to add a cantilever retaining wall 312 to the reinforcement hidden beam 311, the reinforcement grade of the reinforcement hidden beam 311 should be at least one level higher than the main reinforcement grade of the top plate 310 to ensure strength.

[0072] S8, pre-bury the middle-burying steel edge rubber waterstop to the top plate and the side wall; it is worth mentioning that the protection of the middle-burying steel edge rubber waterstop should be paid attention to in the process of steel bar binding and concrete pouring.

[0073] S9, pour the top plate 310 and the main body blocking wall 110 structure above the middle part, wherein the main body blocking wall 110 structure above the middle part refers to the remaining main body blocking wall 110 structure close to the top which has not been constructed.

[0074] Further, the step S9 further comprises the step of:

[0075] S10, the cantilever retaining wall 312 is constructed; it is worth mentioning that the thickness of the fixed end of the cantilever retaining wall 312 should be consistent with the width of the reinforced hidden beam 311, the vertical steel bars of the cantilever retaining wall 312 should be anchored into the top plate 310, and the anchoring depth should meet the specification requirements, and a certain interval distance should be left between the height of the retaining wall and the road surface, so as to facilitate the later buried underground pipelines and other structures, and generally the height of the cantilever retaining wall should not exceed 8m, and this value is only used as an auxiliary understanding for the person skilled in the art, and the specific value can be set according to the actual situation.

[0076] S11, the sand filling space 340 is backfilled with fine sand, and the backfilling space 330 is artificially tamped and filled with soil; it can be understood that the backfilling work can be carried out after each concrete structure reaches the design strength, and the related backfilling technical indexes should meet the design requirements.

[0077] The above is only the preferred embodiment of the present application, and does not limit the patent scope of the present application, and any equivalent structure or equivalent process transformation using the content of the specification and drawings of the present application, or direct or indirect application in other related technical fields, are also included in the patent protection scope of the present application.

Claims

1. A temporary blocking structure for tunnel construction in stages, characterized in that: The invention comprises an early-construction tunnel section, a waterproof component, and a blocking component for blocking an end of the early-construction tunnel section close to the later-construction tunnel section; wherein: The blocking assembly includes a main blocking wall and a surrounding blocking wall. The main blocking wall matches the opening of the previously constructed tunnel section. The upper portion of the main blocking wall is connected to the top plate of the previously constructed tunnel section, and the lower portion of the main blocking wall is connected to the bottom plate of the previously constructed tunnel section. The enclosing blocking wall blocks the side of the main blocking wall away from the pre-constructed tunnel section; a reinforcing hidden beam is also constructed in the top of the pre-constructed tunnel section and extends in the transverse direction of the tunnel. The reinforcing hidden beam is arranged in the top plate of the pre-constructed tunnel section near one end of the main blocking wall; The waterproof assembly is used to prevent water from the later-construction tunnel section from seeping into the earlier-construction tunnel section. The waterproof assembly includes a waterstop and an anti-seepage member respectively arranged on both sides of the main blocking wall. The waterstop is sealed on the side of the enclosure blocking wall away from the earlier-construction tunnel section. A reserved interface unit for installing the anti-seepage member is provided between the main blocking wall and the earlier-construction tunnel section, and the anti-seepage member is arranged in the reserved interface unit. The tunnel also includes a cantilever retaining wall extending transversely along the tunnel, the cantilever retaining wall being arranged on the roof of the pre-constructed tunnel section, the cantilever retaining wall including a fixed end and a free end, the fixed end being fixedly connected to the reinforced concealed beam, and the free end extending upward from the fixed end; A backfill space for filling backfill soil is formed between the side of the cantilever retaining wall away from the main blocking wall and the top plate of the previously constructed tunnel section, and a sand filling space for filling sand is formed between the side of the cantilever retaining wall close to the main blocking wall and the top plate of the previously constructed tunnel section and the main blocking wall.

2. The temporary blocking structure for tunnel construction in stages according to claim 1, characterized in that: The top end of the enclosure sealing wall extends to the ground, and the bottom end of the enclosure sealing wall extends downward and is arranged below the tunnel floor.

3. The temporary blocking structure for tunnel construction in stages according to claim 1, characterized in that: The reserved interface unit includes a top plate tongue and groove, a side wall tongue and groove, and a bottom plate tongue and groove, wherein: The top plate tongue and groove is arranged between the main body blocking wall and the top plate of the previously constructed tunnel section, the side wall tongue and groove is arranged between the main body blocking wall and the side wall of the previously constructed tunnel section, and the bottom plate tongue and groove is arranged between the main body blocking wall and the bottom plate of the previously constructed tunnel section.

4. The temporary blocking structure for tunnel construction in stages according to claim 3, characterized in that: The anti-seepage component adopts a centrally embedded steel-edged rubber waterstop, which is respectively arranged in the top plate tongue and groove, the side wall tongue and groove, and the bottom plate tongue and groove in a one-to-one correspondence.

5. The temporary blocking structure for tunnel construction in stages according to claim 1, characterized in that: The water-stopping member is a water-stopping curtain, and the water-stopping curtain is made of either a rotary jet pile or a mixing pile.

6. A construction method for a temporary blocking structure for tunnel construction in stages, applied to the temporary blocking structure for tunnel construction in stages as claimed in any one of claims 1 to 5, characterized in that: Including steps: S1, applying the water stop at a first preset distance from the early-construction tunnel section, wherein the water stop extends vertically and is located at one end of the later-construction tunnel section; wherein the water stop is a water-stop curtain; S2, constructing the enclosing and blocking wall; S3, excavating the foundation pit and constructing internal supports for the pre-constructed tunnel section; S4, constructing the bottom plate, side walls near the bottom, and main body blocking wall structures of the pre-constructed tunnel section, and reserving bottom plate tongue and groove and side wall tongue and groove; wherein the bottom plate tongue and groove are provided between the main body blocking wall and the bottom plate of the pre-constructed tunnel section, and the side wall tongue and groove are provided between the main body blocking wall and the side walls of the pre-constructed tunnel section; S5, pre-embed an anti-seepage member to the tongue-and-groove of the bottom plate and the tongue-and-groove of the side wall; wherein the anti-seepage member is a centrally embedded steel-edged rubber waterstop; S6, using a sequential method to remove the internal supports in sequence, and cast the side walls above the bottom of the previously constructed tunnel section and the main blocking wall structure in the middle; S7, pre-embed reinforced hidden beam steel bars and reserve top plate tongue and groove; wherein the top plate tongue and groove is set between the main body blocking wall and the top plate of the pre-constructed tunnel section; S8, pre-embedding the embedded steel-edge rubber waterstop to the top plate tongue and groove and the side wall tongue and groove; S9, pouring the top plate and the main blocking wall structure above the middle.

7. The construction method of a temporary blocking structure for phased tunnel construction according to claim 6, characterized in that: The step S9 further includes the following steps: S10, constructing the cantilever retaining wall; S11, backfilling the sand-filled space with fine sand and manually compacting the backfilled space with soil.

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