A tunnel intersection safety construction method and auxiliary construction device

Abstract

The present invention discloses a safe construction method for tunnel intersections and an auxiliary construction device. An excavation opening is reserved at the intersection of a main tunnel and an intersecting transverse tunnel, a temporary support structure is pre-arranged at the excavation opening, and the main tunnel support structure is first cast based on the temporary support structure. Then, the intersecting transverse tunnel is excavated and the lining structure is cast under the protection of the main tunnel support structure. The casting construction of the lining structure of the main tunnel adopts the coordinated cooperation of a flexible formwork and a main tunnel formwork trolley. The lining structure of the intersecting transverse tunnel is then cast by the coordinated cooperation of a telescopic formwork trolley, a telescopic assembled formwork and the main tunnel formwork trolley. The present invention realizes the "lining first, then excavation" type safe tunnel intersection entry construction with the help of a series of auxiliary construction devices such as flexible formwork and telescopic assembled formwork, which can greatly improve the construction safety and structural reliability of the tunnel intersection, and significantly improve the standardization and normalization of lining casting construction at the tunnel intersection position, and is suitable for the field of tunnel intersection construction.

Description

Technical Field

[0001] The invention relates to a safe construction method for a tunnel cross passage intersection and an auxiliary construction device, belonging to the technical field of tunnel construction. Background Art

[0002] The construction process at the tunnel intersection is relatively complex, and the construction of the main tunnel and the cross tunnel is highly disruptive, resulting in significantly higher construction risks than other normal sections. The construction process for conventional tunnel intersections is as follows: first, initial support for the main tunnel is constructed, followed by tunnel entry for the cross tunnel. After the cross tunnel is penetrated or excavated to a certain depth, the lining formwork for the cross tunnel is installed from the cross tunnel toward the main tunnel. The secondary lining pouring of the main tunnel at the intersection is then completed with the lining formwork trolley located in the main tunnel. The above construction process provides the operating space required for the installation of conventional cross tunnel lining formwork, facilitating the template installation and lining pouring of the tunnel intersection section. However, constructing the cross tunnel with only primary support for the main tunnel presents significant construction risks. The primary support for the main tunnel is relatively suspended near the cross tunnel. If the construction disturbance is too large or the surrounding rock's self-stabilizing capacity deviates, the primary support for the main tunnel near the cross tunnel is likely to become unstable and sink, inducing cracking, deformation, or even large-scale instability and collapse. Furthermore, since the side walls of the main tunnel are mostly curved, the intersection boundary with the cross tunnel is a complex three-dimensional curve. Conventional rigid formwork is difficult to meet the requirements of the lining casting formwork in this nonlinear and complex space, making formwork erection at the tunnel intersection a relatively cumbersome construction process and low construction efficiency.

[0003] With the gradual increase in tunnel cross-sections and the increasing number of grade separations within tunnels, the frequency and difficulty of construction at tunnel intersections are rapidly increasing. This is especially true in complex underground structures such as cavern-type data centers, where large-section, three-dimensional grade separations, such as single-sided oblique intersections or double-sided intersections, often exist. Existing tunnel intersection construction suffers from certain technical deficiencies in process methods and auxiliary construction equipment, resulting in low construction efficiency and standardization at tunnel intersections, and an inability to effectively guarantee construction safety at tunnel intersections. In light of these considerations, the study of a safe tunnel intersection construction method and auxiliary construction equipment is of great practical significance. Summary of the Invention

[0004] In view of this, the purpose of the present invention is to provide a tunnel intersection cross hole safe construction method and auxiliary construction device, which can overcome the shortcomings of the existing technology.

[0005] The purpose of the present invention is achieved through the following technical solutions:

[0006] The present invention discloses a safe construction method for a tunnel cross tunnel, wherein an excavation opening is reserved at the intersection of the main tunnel and the cross tunnel, a temporary support structure is pre-installed at the excavation opening, and the main tunnel support structure is first cast based on the temporary support structure. Then, the cross tunnel is excavated and the lining structure is cast under the protection of the main tunnel support structure.

[0007] The pouring construction of the tunnel main tunnel lining structure uses flexible formwork in coordination with the main tunnel formwork trolley;

[0008] Then, the lining structure pouring construction of the cross tunnel is carried out through the coordinated cooperation of the telescopic formwork trolley, the telescopic assembly formwork and the main tunnel formwork trolley.

[0009] The method comprises the following steps:

[0010] S1. First, excavate the main tunnel of the intersection tunnel, and then complete the installation of permanent I-beams, connecting blocks and detachable I-beams in the intersection section, and complete the shotcrete construction in the arrangement range of permanent I-beams in the intersection section; S2. With the help of connecting blocks, construct the locking foot pipe shed towards the surrounding rock side; S3. Carry out the waterproofing and drainage structure construction and secondary lining steel bar binding construction of the main tunnel of the intersection section; S4. Continuously install flexible formwork on the detachable I-beams, multiple connecting blocks and the last detachable I-beams in the intersection section to form a complete cross-hole blocking side formwork; S5. Move the main tunnel formwork trolley to the tunnel intersection section, and then carry out the pouring construction of the secondary lining of the main tunnel of the intersection section, and reserve the lining of the cross-hole. Build a gap; S6. After the secondary lining of the main tunnel reaches the designed strength, dismantle the detachable I-beam at the intersection section; S7. Excavate the cross tunnel and then construct the initial support of the cross tunnel; S8. After the cross tunnel is constructed to a certain depth, construct the drainage structure of the cross tunnel and weld the waterproof plate of the cross tunnel to the waterproof plate of the main tunnel of the tunnel to ensure the joint waterproof effect; S9. Arrange a telescopic formwork trolley at the end of the cross tunnel and switch it to the extended support state; S10. Move the main tunnel formwork trolley to the tunnel intersection section again, and then mechanically adjust the length of the telescopic plate of the telescopic formwork trolley so that it is in close contact with the secondary lining formwork of the main tunnel, and then cast the first mold secondary lining at the entrance end of the cross tunnel of the intersection section. Construction; S11, move the main tunnel formwork trolley, retract all the telescopic plates of the telescopic formwork trolley, switch it to the retracted moving state, and then move it to the second mold cross-transverse tunnel lining position; thereafter, switch the telescopic formwork trolley to the extended moving state again, and then carry out the pouring construction of the second mold lining of the cross-transverse tunnel; S12, refer to the steps of SS to carry out the relevant construction procedures of the intersection section at the exit end of the tunnel cross-transverse tunnel, and suspend the construction after the initial support construction of the exit end cross-transverse tunnel is about meters; at the same time, the excavation and initial support construction of the cross-transverse tunnel are carried out cyclically at the entrance end of the cross-transverse tunnel until the cross-transverse tunnel is completely penetrated, and then the construction of the initial support and waterproof board structure of the entire cross-transverse tunnel is completed; S13, through the retraction and movement of the telescopic formwork trolley Switch back and forth between the dynamic state and the extended support state, and carry out the pouring construction of the secondary lining of the cross-tunnel section by section, until the telescopic formwork trolley moves to the position of the last mold secondary lining at the exit end of the cross-tunnel of the intersection section, and switches it to the extended working state; S14, move the main tunnel formwork trolley to the intersection position at the exit end of the cross-tunnel, and then mechanically adjust the telescopic plate length of the telescopic formwork trolley so that it is in close contact with the secondary lining formwork of the main tunnel, and then carry out the pouring construction of the last mold secondary lining at the exit end of the cross-tunnel of the intersection section; S15, move the main tunnel formwork trolley, and retract all the telescopic formwork of the telescopic formwork trolley, and switch it to the retracted moving state, and move it to an empty place for standby, thus completing the construction of the cross-tunnel of the entire tunnel.

[0011] The above steps S1-S15 are applicable to the construction of single-sided intersection of the tunnel main tunnel 1 and the cross tunnel 2. When the tunnel main tunnel 1 and the cross tunnels 2 on the left and right sides form a double-sided intersection structure, in the step 1, the construction of the tunnel main tunnel 1 between the two cross tunnels 2 is first carried out, and then the lining structure construction of the tunnel main tunnel 1 is organized according to the steps S2-S5; in the step S6, the detachable I-beam 4 is first dismantled for the intersection section on one side, and the first and second mold lining casting construction of the single-sided cross tunnel 2 is completed according to the steps S7-S11; then, the entrance construction of the cross tunnel 2 on the other side of the tunnel main tunnel 1 and the casting construction of the first and second mold lining of the entrance section of the cross tunnel 2 on the other side are completed according to the steps S6-S11; the construction of the remaining sections of the intersection on both sides can be completed completely independently according to the steps S12-S15. The above-mentioned temporary support structure is a detachable I-beam, which is set within the intersection of the tunnel main hole and the cross-hole, and is temporarily rigidly connected to the permanent I-beam of the tunnel main hole through a connecting block.

[0012] An auxiliary construction device for the safe construction of a tunnel intersection tunnel comprises a connecting block arranged between a permanent I-beam and a detachable I-beam for connecting a locking foot pipe shed, a flexible formwork arranged at the intersection of the tunnel main tunnel and the intersection tunnel for reserving a gap in the lining of the tunnel main tunnel, a main tunnel formwork trolley arranged in the tunnel main tunnel for providing auxiliary support for the secondary lining of the tunnel main tunnel, and a telescopic formwork trolley arranged in the intersection tunnel for providing auxiliary support for the secondary lining of the intersection tunnel, wherein the telescopic formwork trolley is connected to the telescopic assembled formwork.

[0013] The above-mentioned connecting block is a solid steel block with an opening in the middle. The size of the opening matches the diameter of the locking foot pipe rack, and is then fixed to the bedrock through the locking foot pipe rack that penetrates into the rock formation; the connecting block is arranged correspondingly along the outer contour of the cross-hole, one side of which is connected to the permanent I-beam, and the other side is connected to the detachable I-beam by bolts.

[0014] The above-mentioned flexible formwork includes alternately connected L-shaped rigid support sections and L-shaped flexible deformation sections. The L-shaped rigid support section is composed of an external rubber layer and an L-shaped steel plate arranged inside the rubber layer, and screw holes are provided at corresponding positions of the L-shaped steel plate and the rubber layer; the L-shaped flexible deformation section is made entirely of rubber.

[0015] The above-mentioned telescopic template trolleys all include a frame, a moving device is provided at the lower end of the frame, and telescopic template supports are provided on the left and right sides and the upper end of the frame, and the telescopic template supports are connected to the inner side of the telescopic assembly template.

[0016] The telescopic assembly template includes a first splint and a second splint, which are fixedly connected at upper and lower sides, and a telescopic plate that can be telescoped along the longitudinal direction of the template is provided between the first splint and the second splint.

[0017] The aforementioned telescopic plate is a "convex" shaped strip, the convex parts of adjacent "convex" shaped strips are placed alternately in front and back and the side walls limit each other, and the "convex" shaped strip can be telescopic along its longitudinal direction.

[0018] Compared with the prior art, the present invention has the following beneficial effects:

[0019] 1. The flexible formwork described in the present invention is composed of a combination of polymer rubber and L-shaped steel plates intermittently embedded in the rubber, thereby combining good flexible deformation ability and reliable side formwork sealing ability, and can provide curved formwork support function. It is suitable for lining pouring construction of nonlinear complex structures such as tunnel intersections. The flexible formwork is highly versatile, recyclable, and economical.

[0020] 2. The telescopic formwork trolley described in the present invention is designed with two working states: retracted movement and extended support. By switching between the two states, the telescopic formwork trolley can realize mobile formwork support in a relatively narrow cross-hole. The equipment has high flexibility, strong operability and a wide range of uses. In addition, by adopting "convex" long strips that are placed alternately in positive and negative directions and whose side walls are limited to each other, an innovative telescopic formwork is provided that can be mechanically adjusted in the longitudinal direction of the trolley to have a telescopic length, thereby providing the function of oblique formwork for special-shaped structures, which can effectively meet the special needs of the three-dimensional complex space of tunnel intersections for formwork.

[0021] 3. The present invention provides an I-beam connecting block between the permanent I-beam and the detachable I-beam at the intersection, and then uses the connecting block to drive a locking foot pipe shed toward the surrounding rock. This effectively enhances the connection rigidity and support effect between the locking foot pipe shed and the I-beam, effectively ensuring the stability of the permanent I-beam at the intersection after the detachable I-beam is removed. The locking foot pipe shed can also serve as an advance pipe shed during the excavation of the cross-hole, effectively improving the self-stabilization capacity of the arch surrounding rock. In addition, the intermittently arranged connecting blocks can be directly arranged on the outer contour line of the cross-hole, providing high flexibility in the reserved lining opening, effectively meeting the size requirements of the main hole lining opening for intersections of different shapes. Compared with conventional support beams, it has reliable force, flexible arrangement, and strong construction operability.

[0022] 4. The present invention adopts the "lining first, excavation later" cross-tunnel entry method of first constructing the primary support of the main tunnel and the secondary lining of the main tunnel, and then excavating the cross-tunnel. By relying on the secondary lining of the main tunnel, the anti-disturbance ability of the surrounding rock and support structure of the tunnel intersection section is effectively improved, thereby effectively reducing the risk of surrounding rock collapse and instability and damage of the support structure, and greatly improving the safety of tunnel entry construction of the cross-tunnel.

[0023] 5. The present invention divides the secondary lining pouring construction of the intersection section into two parts: the pouring construction of the secondary lining of the main tunnel of the intersection section and the pouring construction of the secondary lining of the cross tunnel of the intersection section. The pouring construction of the secondary lining of the main tunnel of the intersection section adopts the coordinated cooperation of flexible formwork and main tunnel formwork trolley, while the pouring construction of the secondary lining of the cross tunnel of the intersection section adopts the coordinated cooperation of telescopic formwork trolley and main tunnel formwork trolley. The use of the above two new types of formwork has changed the existing construction status of temporary reinforcement using wooden formwork, and greatly improved the standardization and normalization of lining pouring construction at the intersection position.

[0024] Other advantages, objects, and features of the present invention will be described in part in the following description and, in part, will be apparent to those skilled in the art upon examination of the following description or may be learned from practice of the present invention. The objects and other advantages of the present invention may be realized and obtained through the following description. BRIEF DESCRIPTION OF THE DRAWINGS

[0025] In order to make the purpose, technical solutions and advantages of the present invention more clear, the present invention will be further described in detail below with reference to the accompanying drawings, in which:

[0026] Figure 1 It is a structural schematic diagram of the flexible template of the present invention.

[0027] Figure 2 It is a structural schematic diagram of the flexible formwork and the connecting block bolt connection of the present invention.

[0028] Figure 3 This is a schematic structural diagram of the flexible formwork and I-beam wing plate bolt connection of the present invention.

[0029] Figure 4 It is a schematic diagram of the three-dimensional connection structure of the telescopic template trolley of the present invention in the retracted and moving state.

[0030] Figure 5 It is a schematic diagram of the three-dimensional connection structure of the telescopic template trolley in the extended support state of the present invention.

[0031] Figure 6 It is a schematic diagram of the partial structure of the telescopic assembly template of the present invention.

[0032] Figure 7This is a structural schematic diagram of the initial support construction of the main tunnel of the intersection section tunnel of the present invention.

[0033] Figure 8 This is a structural schematic diagram of the secondary lining construction of the main tunnel of the intersection section of the present invention.

[0034] Figure 9 It is a structural schematic diagram of the initial support construction of the cross tunnel after the cross tunnel is excavated according to the present invention.

[0035] Figure 10 The present invention is a schematic diagram showing only the telescopic formwork trolley frame when arranging the telescopic formwork trolley in the cross-hole.

[0036] Figure 11 This is a structural schematic diagram of the telescopic formwork trolley and the main tunnel formwork trolley working together to carry out the secondary lining pouring construction of the intersection section cross tunnel.

[0037] Figure 12 This is a structural schematic diagram of the completion of the second lining pouring construction of the first mold of the intersection tunnel in the intersection section of the present invention.

[0038] Figure 13 This is a structural schematic diagram of the completion of the initial support construction of the main tunnel of the intersection section of the present invention.

[0039] Figure 14 This is a structural diagram of the flexible template installation of the present invention.

[0040] Figure 15 This is a structural schematic diagram of the secondary lining pouring construction of the tunnel main hole of the present invention.

[0041] Figure 16 This is a schematic diagram of the structure of the detachable I-beam for removing the intersection section according to the present invention.

[0042] Figure 17 This is a schematic structural diagram of the secondary lining casting of the cross-hole according to the present invention.

[0043] Figure 18 This is a top view of the structure of the main tunnel and the cross tunnel of the tunnel intersecting obliquely on one side of the present invention.

[0044] Figure 19 This is a top view of the structure of the main tunnel and the cross tunnel on both sides of the tunnel intersecting each other.

[0045] Among them, the main tunnel 1; the cross tunnel 2; the permanent I-beam 3; the detachable I-beam 4; the secondary lining formwork of the main tunnel 5; the formwork trolley of the main tunnel 6; the flexible formwork 7; the L-shaped rigid support section 7-1; the rubber layer 7-1-1; the L-shaped steel plate 7-1-2; the L-shaped flexible deformation section 7-2; the secondary lining of the main tunnel 8; the telescopic formwork trolley 9; the frame 9-1; the moving device 9-2; the telescopic formwork support 9-3; the telescopic assembled formwork 10; the first splint 10-1; the second splint 10-2; the telescopic plate 10-3; the connecting block 11; and the locking foot pipe shed 12. DETAILED DESCRIPTION

[0046] The preferred embodiments of the present invention will be described in detail below with reference to the accompanying drawings. It should be understood that the preferred embodiments are only for illustrating the present invention, and are not intended to limit the scope of protection of the present invention.

[0047] like Figures 1-19 As shown, the present invention discloses a method for safe construction of a tunnel intersection tunnel and an auxiliary construction device. The auxiliary construction device for safe construction of a tunnel intersection tunnel includes a connecting block 11 arranged between a permanent I-beam 3 and a detachable I-beam 4 for connecting a locking foot pipe shed 12, a flexible formwork 7 arranged at the intersection of the tunnel main tunnel 1 and the intersection transverse tunnel 2 for reserving a lining gap for the tunnel main tunnel 1, a main tunnel formwork trolley 6 arranged in the tunnel main tunnel 1 for providing secondary lining auxiliary support for the tunnel main tunnel 1, and a telescopic formwork trolley 9 arranged in the intersection transverse tunnel 2 for providing secondary lining auxiliary support for the intersection transverse tunnel 2, wherein the telescopic formwork trolley 9 is connected to the telescopic assembled formwork 10.

[0048] Specifically, the connecting block 11 comprises a solid steel block with a central opening, the size of which matches the diameter of the locking foot pipe shed 12. The locking foot pipe shed 12, which penetrates deep into the rock formation, is then fixed to the bedrock. The connecting block 11 is arranged along the outer contour of the intersecting transverse tunnel 2, with one side connected to the permanent I-beam 3 and the other side bolted to the detachable I-beam 4. The locking foot pipe shed 12, using the connecting block 11 as a connecting and positioning device, is driven into the arch of the intersecting transverse tunnel 2, acting as a locking foot pipe shed for the permanent I-beam 3 at the intersection section and also as a lead pipe shed during subsequent excavation of the intersecting transverse tunnel 2.

[0049] Furthermore, the flexible formwork 7 includes an L-shaped rigid support segment 7-1 and an L-shaped flexible deformation segment 7-2 that are alternately connected. The L-shaped rigid support segment 7-1 is composed of an external rubber layer 7-1-1 and an L-shaped steel plate 7-1-2 arranged inside the rubber layer 7-1-1, and screw holes are provided at corresponding positions of the L-shaped steel plate 7-1-2 and the rubber layer 7-1-1; the L-shaped flexible deformation segment 7-2 is made entirely of rubber. When in use, the permanent I-beam 3 of the intersection section and the detachable I-beam 4 of the intersection section are bolted together through the connecting block 11 of the I-beam. The connecting block 11 is located between the two and is located just on the outer contour of the tunnel intersection tunnel 2. The detachable I-beams 4 of the intersection section are all set within the outer contour of the tunnel intersection tunnel 2, and their setting length matches the size of the intersection tunnel 2. The first intersection section detachable I-beam 4, multiple connecting blocks 11 and the last intersection detachable I-beam 4 just form the outer contour of the tunnel intersection tunnel 2. The flexible formwork 7 is connected to the first intersection section detachable I-beam 4, multiple connecting blocks 14 and the last intersection detachable I-beam 4 in sequence through bolts, thereby forming a three-dimensional arc-shaped blocking formwork. Screw holes are provided at the corresponding positions of the L-shaped steel plate 7-1-2 and the rubber layer 7-1-1. The screw holes are set on the L-shaped rigid support section 7-1 as the relevant structure for bolting with other components. The flexible formwork 7 serves as a lateral blocking formwork at the cross-hole position during the pouring of the tunnel lining structure and is a key component for ensuring that a lining gap is initially reserved in the cross-hole.

[0050] Specifically, the telescopic formwork trolley 9 includes a frame 9-1, a moving device 9-2 is provided at the lower end of the frame 9-1, and telescopic formwork supports 9-3 are provided on the left and right sides and the upper end of the frame 9-1, and the telescopic formwork supports 9-3 are connected to the inner side of the telescopic assembly formwork 10; and the structure of the telescopic assembly formwork 10 includes a first splint 10-1 and a second splint 10-2, the first splint 10-1 and the second splint 10-2 are fixedly connected at the upper and lower sides, and a telescopic plate 10-3 that can be telescoped along the longitudinal direction of the formwork is provided between the first splint 10-1 and the second splint 10-2.

[0051] Furthermore, the specific structure of the telescopic plate 10-3 is a "convex" shaped strip, the raised parts of adjacent "convex" shaped strips are placed alternately in front and back and the side walls limit each other, and the "convex" shaped strip can be telescopic along its longitudinal direction.

[0052] When in use, the telescopic formwork support 9-3 connected to the telescopic assembly formwork 10 is extended and retracted to achieve the expansion support or retraction of the telescopic assembly formwork 10 for subsequent movement. The side walls of the telescopic plate 10-3 are limited by the first splint 10-1 and the second splint 10-2. By adjusting the different telescopic lengths of each telescopic plate 10-3, irregular intersections can be supported.

[0053] Construction method

[0054] The method involves reserving an excavation opening at the intersection of a tunnel main tunnel 1 and a cross tunnel 2, and pre-setting a temporary support structure at the excavation opening. The temporary support structure is a detachable I-beam 4, which is arranged within the intersection of the tunnel main tunnel 1 and the cross tunnel 2 and is temporarily rigidly connected to the permanent I-beam 3 of the tunnel main tunnel 1 through a connecting block 11. Based on the temporary support structure, the main tunnel support structure is first cast, and then the cross tunnel 2 is excavated and the lining structure cast under the protection of the main tunnel support structure.

[0055] The pouring construction of the lining structure of the main tunnel 1 adopts the flexible formwork 7 and the main tunnel formwork trolley 6 to cooperate with each other;

[0056] Then, the lining structure pouring construction of the cross tunnel 2 is carried out through the coordinated cooperation of the telescopic template trolley 9, the telescopic assembly template 10 and the main tunnel template trolley 6.

[0057] This method can be applied to the case where the tunnel main tunnel 1 and the cross tunnel 2 intersect on one side or on both sides. Specifically:

[0058] When the main tunnel 1 and the cross tunnel 2 intersect on one side, the construction steps include the following:

[0059] S1. First, excavate the main tunnel 1 at one end of the intersection tunnel 2, then complete the installation of the permanent I-beam 3, connecting block 11 and detachable I-beam 4 at the intersection, and complete the shotcrete construction within the arrangement range of the permanent I-beam 3 at the intersection;

[0060] S2, using the connecting block 11, construct the locking foot pipe shed 12 towards the surrounding rock side;

[0061] S3, carry out the waterproofing and drainage structure construction and secondary lining reinforcement binding construction of the main tunnel 1 of the intersection section;

[0062] S4, continuously installing the flexible formwork 7 on the detachable I-beam 4, multiple connecting blocks 11 and the detachable I-beam 4 of the last intersection to form a complete blocking side formwork of the intersection horizontal hole 2;

[0063] S5, moving the main tunnel formwork trolley 6 to the tunnel intersection section, and then pouring the secondary lining 8 of the main tunnel of the intersection section, and reserving a lining gap for the cross tunnel 2;

[0064] S6. After the secondary lining 8 of the main tunnel reaches the designed strength, the detachable I-beam 4 of the intersection section is removed.

[0065] S7, excavating the cross tunnel 2, and then constructing the initial support of the cross tunnel 2;

[0066] S8. After the cross tunnel 2 is constructed to a certain depth, the cross tunnel 2 waterproof structure is constructed, and the waterproof plate of the cross tunnel 2 is welded to the waterproof plate of the tunnel main tunnel 1 to form a whole to ensure a joint waterproof effect;

[0067] S9, arrange the telescopic template trolley 9 at the end of the cross-hole 2 and switch it to the extended support state;

[0068] S10, moving the main tunnel formwork trolley 6 to the tunnel intersection section again, and then mechanically adjusting the length of the telescopic plate 10-3 of the telescopic formwork trolley 9 so that it is in close contact with the main tunnel secondary lining formwork 5, and then performing the pouring construction of the first mold secondary lining at the entrance end of the intersection cross tunnel 2 of the intersection section;

[0069] S11, the main tunnel formwork trolley 6 is removed, and the telescopic plates 10-3 of the telescopic formwork trolley 9 are all retracted and switched to a retracted moving state, and then moved to the lining position of the second mold intersecting transverse tunnel 2; thereafter, the telescopic formwork trolley 9 is switched to an extended moving state again, and then the pouring construction of the second mold lining of the intersecting transverse tunnel 2 is carried out;

[0070] S12, referring to steps S1-S7, carry out the relevant construction procedures of the intersection section at the exit end of the tunnel intersection tunnel 2, and suspend construction after constructing the initial support of the exit intersection tunnel 2 for about 8-10 meters; at the same time, the excavation and initial support construction of the intersection tunnel 2 are carried out in a cycle at the entrance end of the intersection tunnel 2 until the intersection tunnel 2 is completely penetrated, and then the initial support and waterproofing board structure of the entire intersection tunnel 2 are completed;

[0071] S13, by switching back and forth between the retracted moving state and the extended supporting state of the telescopic formwork trolley 9, the secondary lining of the cross tunnel 2 is poured section by section, until the telescopic formwork trolley 9 moves to the position of the last mold secondary lining at the exit end of the cross tunnel 2 of the intersection section, and switches it to the extended working state;

[0072] S14, moving the main tunnel formwork trolley 6 to the intersection position at the exit end of the cross tunnel 2, and then mechanically adjusting the length of the telescopic plate 10-3 of the telescopic formwork trolley 9 so that it is in close contact with the main tunnel secondary lining formwork 5, and then performing the pouring construction of the last mold of the secondary lining at the exit end of the cross tunnel 2 of the intersection section;

[0073] S15. The main tunnel template trolley 6 is removed, and the telescopic templates of the telescopic template trolley 9 are all retracted and switched to a retracted moving state and moved to an idle place for standby use, thus completing the construction of the entire tunnel intersection tunnel 2.

[0074] When the main tunnel 1 and the cross tunnels 2 on the left and right sides form a double-sided intersection structure, the construction steps are as follows:

[0075] S1. First, excavate the main tunnel 1 between the two intersecting transverse tunnels 2. Then, complete the installation of the permanent I-beams 3, connecting blocks 11, and detachable I-beams 4 on both sides of the intersection section. Finally, complete the sprayed concrete construction within the area where the permanent I-beams 3 are arranged.

[0076] S2, using the connecting blocks 11 on both sides of the intersection section, construct the locking foot pipe shed 12 towards the surrounding rock side;

[0077] S3, carry out the waterproofing and drainage structure construction and secondary lining reinforcement binding construction of the main tunnel 1 of the intersection section;

[0078] S4, continuously installing flexible formwork 7 on the detachable I-beam 4, multiple connecting blocks 11 and the detachable I-beam 4 of the last intersection, forming complete blocking side formwork of the cross-hole 2 on both sides of the tunnel main hole 1;

[0079] S5, moving the main tunnel formwork trolley 6 to the tunnel intersection section, and then pouring the secondary lining 8 of the main tunnel of the intersection section, and at the same time reserving lining gaps for the cross tunnels 2 on both sides of the tunnel main tunnel 1;

[0080] Afterwards, based on the actual construction situation on site, the cross tunnels 2 on both sides of the tunnel main tunnel 1 were divided into the priority construction side and the later construction side. The construction of the cross tunnels 2 on both sides was then carried out in sequence:

[0081] S6-1. After the secondary lining 8 of the main tunnel reaches the design strength, the detachable I-beam 4 is first dismantled at the intersection section on the priority construction side;

[0082] S7-1, excavate the cross tunnel 2 on the priority construction side, and then perform the initial support of the cross tunnel 2 on the priority construction side;

[0083] S8-1. After the cross tunnel 2 on the priority construction side is constructed to a certain depth, the waterproofing and drainage structure of the cross tunnel 2 on the priority construction side is constructed, and the waterproofing plate of the cross tunnel 2 on the priority construction side is welded to the waterproofing plate of the tunnel main tunnel 1 to ensure a combined waterproofing effect;

[0084] S9-1. Arrange a telescopic formwork trolley 9 at the end of the cross tunnel 2 on the priority construction side and switch it to the extended support state;

[0085] S10-1. Move the main tunnel formwork trolley 6 to the tunnel intersection section again, and then mechanically adjust the length of the telescopic plate 10-3 of the telescopic formwork trolley 9 in the priority construction side cross tunnel 2 so that it is in close contact with the main tunnel secondary lining formwork 5. Then, pour the first mold secondary lining at the entrance end of the priority construction side cross tunnel 2;

[0086] S11-1, remove the main tunnel formwork trolley 6, and retract all the telescopic plates 10-3 of the telescopic formwork trolley 9 in the priority construction side cross tunnel 2, and switch it to the retracted moving state, and then move it to the lining position of the second mold cross tunnel 2; thereafter, switch the telescopic formwork trolley 9 to the extended moving state again, and then carry out the pouring construction of the second mold lining of the priority construction side cross tunnel 2, thereby completing the tunnel entry construction of the priority construction side cross tunnel 2;

[0087] S12-1. Refer to steps S1-S5, S6-1, and S7-1 to carry out the relevant construction procedures for the intersection section at the exit of the priority construction side cross tunnel 2. After the initial support construction of the exit of the priority construction side cross tunnel 2 is completed for about 8-10 meters, construction is suspended. At the same time, the excavation and initial support construction of the cross tunnel 2 are carried out in a loop at the entrance of the priority construction side cross tunnel 2 until the cross tunnel 2 is completely penetrated, and then the initial support and waterproofing board structure of the entire cross tunnel 2 are completed.

[0088] S13-1. By switching the telescopic formwork trolley 9 on the priority construction side between the retracted moving state and the extended supporting state, the secondary lining of the cross tunnel 2 on the priority construction side is poured section by section until the telescopic formwork trolley 9 moves to the position of the last mold of the secondary lining at the exit end of the cross tunnel 2 on the priority construction side and switches it to the extended working state.

[0089] S14-1. Move the main tunnel formwork trolley 6 to the intersection position at the exit end of the cross tunnel 2 on the priority construction side, and then mechanically adjust the length of the telescopic plate 10-3 of the telescopic formwork trolley 9 so that it is in close contact with the main tunnel secondary lining formwork 5. Then, pour the last mold of the secondary lining at the exit end of the cross tunnel 2 on the priority construction side;

[0090] S15-1. Move the main tunnel formwork trolley 6, and retract all the telescopic formwork of the telescopic formwork trolley 9 in the priority construction side cross tunnel 2, and switch it to the retracted moving state, and move it to an empty place for standby, thus completing the construction of the priority construction side cross tunnel 2.

[0091] After the S11-1 construction step of the priority construction side cross tunnel 2 is completed, you can choose whether to carry out the related construction of the subsequent construction side cross tunnel 2 simultaneously according to the construction progress. The construction steps are basically the same as those of the priority construction side cross tunnel 2. The specific steps are as follows:

[0092] S6-2, dismantle the detachable I-beam 4 at the intersection section on the rear construction side;

[0093] S7-2, excavate the cross tunnel 2 on the rear construction side, and then perform the initial support for the cross tunnel 2 on the rear construction side;

[0094] S8-2, after the cross tunnel 2 on the rear construction side is constructed to a certain depth, the waterproofing and drainage structure of the cross tunnel 2 on the rear construction side is constructed, and the waterproofing plate of the cross tunnel 2 on the rear construction side is welded to the waterproofing plate of the tunnel main hole 1 to ensure the combined waterproofing effect;

[0095] S9-2, arrange the telescopic formwork trolley 9 at the end of the cross-hole 2 on the rear construction side and switch it to the extended support state;

[0096] S10-2, move the main tunnel formwork trolley 6 to the tunnel intersection section again, and then mechanically adjust the length of the telescopic plate 10-3 of the telescopic formwork trolley 9 in the rear construction side cross tunnel 2 so that it is in close contact with the main tunnel secondary lining formwork 5, and then carry out the pouring construction of the first mold secondary lining at the entrance end of the rear construction side cross tunnel 2;

[0097] S11-2, remove the main tunnel formwork trolley 6, and retract all the telescopic plates 10-3 of the telescopic formwork trolley 9 in the rear construction side cross tunnel 2, and switch it to a retracted moving state, and then move it to the lining position of the second mold cross tunnel 2; thereafter, switch the telescopic formwork trolley 9 to an extended moving state again, and then carry out the pouring construction of the second mold lining of the rear construction side cross tunnel 2, thereby completing the tunnel entry construction of the rear construction side cross tunnel 2;

[0098] S12-2, refer to steps S1-S5 and S6-2, S7-2 to carry out the relevant construction procedures of the intersection section at the exit end of the cross tunnel 2 on the rear construction side, and suspend construction after constructing the initial support for about 8-10 meters at the exit end of the cross tunnel 2 on the rear construction side; at the same time, repeat the excavation and initial support construction of the cross tunnel 2 at the entrance end of the cross tunnel 2 on the rear construction side until the cross tunnel 2 is completely penetrated, and then complete the construction of the initial support and waterproof board structure of the entire cross tunnel 2;

[0099] S13-2, by switching back and forth between the retracted moving state and the extended supporting state of the telescopic formwork trolley 9 on the rear construction side, the secondary lining of the cross tunnel 2 on the rear construction side is poured section by section until the telescopic formwork trolley 9 moves to the position of the last mold of the secondary lining at the exit end of the cross tunnel 2 on the rear construction side and switches it to the extended working state;

[0100] S14-2, move the main tunnel formwork trolley 6 to the intersection position of the exit end of the cross tunnel 2 on the rear construction side, and then mechanically adjust the length of the telescopic plate 10-3 of the telescopic formwork trolley 9 so that it is in close contact with the main tunnel secondary lining formwork 5, and then perform the pouring construction of the last mold of the secondary lining at the exit end of the cross tunnel 2 on the rear construction side;

[0101] S15-2, remove the main tunnel formwork trolley 6, and retract all the telescopic formwork of the telescopic formwork trolley 9 in the rear construction side cross tunnel 2, and switch it to a retracted moving state, and move it to an empty place for standby, thus completing the construction of the rear construction side cross tunnel 2.

[0102] The above description is only a preferred embodiment of the present invention and does not constitute any form of confidentiality restriction on the present invention. Any simple modification, equivalent change and modification of the above embodiment that does not deviate from the content of the technical solution of the present invention and is based on the technical essence of the present invention still fall within the scope of the technical solution of the present invention.

Claims

1. A tunnel intersection safety construction method, characterized by: By reserving an excavation opening at the intersection of the main tunnel (1) and the cross tunnel (2), a temporary support structure is pre-installed at the excavation opening, and the main tunnel support structure is first cast based on the temporary support structure, and then the cross tunnel (2) is excavated and the lining structure is cast under the protection of the main tunnel support structure; The pouring construction of the lining structure of the main tunnel (1) uses a flexible formwork (7) in coordination with the main tunnel formwork trolley (6); Then, the lining structure pouring construction of the cross tunnel (2) is carried out by cooperating with the telescopic template trolley (9), the telescopic assembly template (10) and the main tunnel template trolley (6); The method comprises the following steps: S1, first excavate the main tunnel (1) at one end of the intersection tunnel (2), then complete the installation construction of the permanent I-beam (3), the connecting block (11) and the detachable I-beam (4) of the intersection section, and complete the sprayed concrete construction within the arrangement range of the permanent I-beam (3) of the intersection section; S2, using the connecting block (11), construct the locking foot pipe shed (12) toward the surrounding rock side; S3, carry out the construction of drainage structure and secondary lining reinforcement of the main tunnel (1) of the intersection section; S4, continuously installing the flexible formwork (7) on the first intersection section detachable I-beam (4), the plurality of connecting blocks (11) and the last intersection detachable I-beam (4) to form a complete cross-hole (2) blocking side formwork; S5, moving the main tunnel template trolley (6) to the tunnel intersection section, and then performing the pouring construction of the secondary lining (8) of the main tunnel of the intersection section, and reserving a lining gap for the cross tunnel (2); S6. After the secondary lining (8) of the main tunnel reaches the designed strength, the detachable I-beam (4) of the intersection section is removed; S7, excavating the cross tunnel (2), and then constructing the initial support of the cross tunnel (2); S8, after the cross-hole (2) is constructed to a certain depth, the cross-hole (2) waterproofing and drainage structure is constructed, and the waterproofing plate of the cross-hole (2) is welded to the waterproofing plate of the tunnel main hole (1) to form a whole, so as to ensure the joint waterproofing effect; S9, arranging a telescopic template trolley (9) at the end of the cross-hole (2) and switching it to an extended support state; S10, moving the main tunnel formwork trolley (6) to the tunnel intersection section again, and then mechanically adjusting the length of the telescopic plate (10-3) of the telescopic formwork trolley (9) so that it is closely attached to the main tunnel secondary lining formwork (5), and then performing the pouring construction of the first mold secondary lining at the entrance end of the cross tunnel (2) of the intersection section; S11, remove the main hole formwork trolley (6), retract all the telescopic plates (10-3) of the telescopic formwork trolley (9), and switch it to a retracted moving state, and then move it to the lining position of the second mold cross-transverse hole (2); thereafter, switch the telescopic formwork trolley (9) to an extended moving state again, and then carry out the pouring construction of the second mold lining of the cross-transverse hole (2); S12, referring to the steps of S1-S7, the relevant construction procedures of the intersection section of the exit end of the tunnel cross tunnel (2) are carried out, and the construction is suspended after the initial support construction of the exit end cross tunnel (2) is about 8-10 meters; at the same time, the excavation and initial support construction of the cross tunnel (2) are carried out cyclically at the entrance end of the cross tunnel (2) until the cross tunnel (2) is completely penetrated, and then the construction of the initial support and waterproof board structure of the entire cross tunnel (2) is completed; S13, by switching back and forth between the retracted moving state and the extended supporting state of the telescopic formwork trolley (9), the secondary lining of the cross tunnel (2) is poured section by section until the telescopic formwork trolley (9) moves to the position of the last secondary lining at the exit end of the cross tunnel (2) in the intersection section, and switches it to the extended working state; S14, moving the main tunnel formwork trolley (6) to the intersection position at the exit end of the cross tunnel (2), and then mechanically adjusting the length of the telescopic plate (10-3) of the telescopic formwork trolley (9) so that it is closely attached to the main tunnel secondary lining formwork (5), and then performing the pouring construction of the last mold secondary lining at the exit end of the cross tunnel (2) of the intersection section; S15, the main tunnel template trolley (6) is removed, and the telescopic templates of the telescopic template trolley (9) are all retracted and switched to a retracted moving state, and moved to an idle place for standby use, thus completing the construction of the entire tunnel intersection tunnel (2).

2. The tunnel intersection safety construction method according to claim 1, characterized in that: The steps S1-S15 are applicable to the construction of a single-sided intersection between the tunnel main hole (1) and the cross-hole (2); when the tunnel main hole (1) and the cross-holes (2) on the left and right sides form a double-sided intersection structure, in the step 1, the tunnel main hole (1) between the two cross-holes (2) is first constructed, and then the lining structure construction of the tunnel main hole (1) is organized according to the steps S2-S5; in the step S6, the detachable I-beam (4) is first removed from the intersection section on one side, and the first and second mold linings of the single-sided cross-hole (2) are poured according to the steps S7-S11; then, the entrance construction of the cross-hole (2) on the other side of the tunnel main hole (1) and the pouring construction of the first and second mold linings of the entrance section of the cross-hole (2) on the other side are completed according to the steps S6-S11; the construction of the remaining sections of the intersection on both sides can be completed completely independently according to the steps S12-S15.

3. The tunnel intersection safety construction method according to claim 1, characterized in that: The temporary support structure is a detachable I-steel (4), which is arranged within the intersection of the tunnel main hole (1) and the cross-hole (2), and is temporarily rigidly connected to the permanent I-steel (3) of the tunnel main hole (1) through a connecting block (11).

4. An auxiliary construction device for the tunnel intersection safety construction method according to claim 1, characterized in that: The invention comprises a connecting block (11) arranged between a permanent I-steel (3) and a detachable I-steel (4) for connecting a locking foot pipe shed (12), a flexible template (7) arranged at the intersection of a tunnel main hole (1) and a cross-hole (2) for reserving a lining gap for the tunnel main hole (1), a main hole template trolley (6) arranged in the tunnel main hole (1) for providing auxiliary support for the secondary lining of the tunnel main hole (1), and a telescopic template trolley (9) arranged in the cross-hole (2) for providing auxiliary support for the secondary lining of the cross-hole (2), wherein the telescopic template trolley (9) is connected to a telescopic assembled template (10).

5. The auxiliary construction device for the tunnel intersection safety construction method according to claim 4, characterized in that: The connecting block (11) is a solid steel block with an opening in the middle, the size of the opening matches the diameter of the locking foot pipe shed (12), and is fixed to the bedrock through the locking foot pipe shed (12) that penetrates into the rock formation; the connecting block (11) is arranged along the outer contour of the cross-hole (2), one side of which is connected to the permanent I-beam (3), and the other side is connected to the detachable I-beam (4) by bolts.

6. The auxiliary construction device for the tunnel intersection safety construction method according to claim 4, characterized in that: The flexible template (7) comprises an L-shaped rigid support section (7-1) and an L-shaped flexible deformation section (7-2) that are alternately connected. The L-shaped rigid support section (7-1) is composed of an external rubber layer (7-1-1) and an L-shaped steel plate (7-1-2) arranged inside the rubber layer (7-1-1). Screw holes are provided at corresponding positions of the L-shaped steel plate (7-1-2) and the rubber layer (7-1-1). The L-shaped flexible deformation section (7-2) is made entirely of rubber.

7. The auxiliary construction device for the tunnel intersection safety construction method according to claim 4, characterized in that: The telescopic formwork trolley (9) comprises a frame (9-1), a moving device (9-2) is provided at the lower end of the frame (9-1), and telescopic formwork supports (9-3) are provided on the left and right sides and the upper end of the frame (9-1), and the telescopic formwork supports (9-3) are connected to the inner side of the telescopic assembly formwork (10).

8. The auxiliary construction device for the tunnel intersection safety construction method according to claim 4, characterized in that: The telescopic assembly template (10) comprises a first splint (10-1) and a second splint (10-2), wherein the first splint (10-1) and the second splint (10-2) are fixedly connected at upper and lower sides, and a telescopic plate (10-3) is provided between the first splint (10-1) and the second splint (10-2) and is telescopic along the longitudinal direction of the template.

9. The auxiliary construction device for the tunnel intersection safety construction method according to claim 8, characterized in that: The telescopic plate (10-3) is a "convex" shaped strip, the convex parts of adjacent "convex" shaped strips are staggered in front and back, and the side walls are mutually limited, and the "convex" shaped strips can be telescoped along their longitudinal direction.

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