A method for supporting construction of a disassembling hole

Abstract

The application discloses a dismounting hole excavation supporting construction method, and particularly relates to the technical field of TBM dismounting hole construction, and comprises the following steps: step one, dismounting hole excavation preparation; step two, adopting the drill-and-wedge method to preliminarily excavate the dismounting hole; step three, adopting the bench method to excavate and construct; step four, performing construction monitoring in the dismounting hole excavation process; step five, adopting the drill-and-wedge method to excavate and construct at a non-explosive dismounting hole excavation position; and step six, reinforcing mesh construction and shotcrete supporting. The drill-and-wedge method is used to excavate hard rocks and rock strata, and the rock excavation is fast, and the method is particularly suitable for large-scale excavation projects, improves the dismounting hole excavation construction efficiency, and after the drill-and-wedge method is used to complete the preliminary excavation of the dismounting hole, the bench method is used, so that the construction efficiency is ensured and the safety of subsequent construction is ensured. The bench method can reduce the risk of rock collapse and collapse due to the adoption of the step-by-step excavation mode, and improves the construction safety.

Description

Technical Field

[0001] This invention belongs to the field of TBM demolition tunnel construction technology, and particularly relates to a demolition tunnel excavation and support construction method. Background Technology

[0002] In the field of engineering construction, TBM stands for Tunnel Boring Machine, also known as a shield tunneling machine. It is a type of mechanical equipment used for underground tunnel construction. TBM dismantling hole refers to the cavity or hole created when the TBM needs to be dismantled from the tunnel after tunnel excavation is completed.

[0003] TBMs are expensive construction equipment that can be recycled after dismantling. For future tunnel projects, reusing TBMs partially or entirely can save costs and time. However, TBMs experience wear and damage during long-term construction. Sometimes, it is necessary to dismantle the TBM and remove it from the tunnel for maintenance, repair, or component replacement. Therefore, a dismantling tunnel needs to be excavated to facilitate the dismantling and removal of the TBM. The dismantling tunnel is important, but it is not part of the tunnel. Its use requires high efficiency in excavation and support construction, while ensuring good support effects and the robustness and safety of the dismantling tunnel. Therefore, a dismantling tunnel excavation and support construction method is proposed. Summary of the Invention

[0004] This invention provides a construction method for excavation and support of dismantling tunnels, aiming to solve the aforementioned problems.

[0005] This invention is implemented as follows, and the technical solution provided is as follows: A method for excavation and support construction of a dismantling tunnel, comprising the following steps:

[0006] Step 1: Preparation for dismantling tunnel excavation. Before excavating the dismantling tunnel, the surrounding environment should be properly organized and prepared. First, remove debris around the TBM, remove auxiliary facilities around the TBM, set up protective measures, build protective barriers around the dismantling tunnel excavation location, and set up warning signs. At the same time, reserve a guide tunnel platform in advance in the underground excavation section.

[0007] Step 2: Initial excavation of the dismantling tunnel is carried out using the drilling and splitting method. Multiple boreholes are evenly drilled at the excavation location of the dismantling tunnel using a drilling rig. After drilling is completed, explosives are loaded into pre-designed explosive charges, and the detonation device is installed through a fuse. The fuse is lit to detonate the explosives, causing the rocks to crack and split. The shock wave and stress generated by the blast cause the rocks to crack and fracture, forming the initial dismantling tunnel. Excavators are used to load the debris, and dump trucks are used to transport the debris. The rubble and slag inside the initial dismantling tunnel are then cleared.

[0008] Step 3: The step method is used for excavation. The elevation is set on the initial dismantling hole to determine the height and width of each step. An excavator is used to excavate the first step and then excavates layer by layer downwards to ensure that the height and slope of each step meet the design requirements. After each step is excavated, the excavation surface is cleaned and leveled to complete the excavation of the dismantling hole.

[0009] Step 4: Conduct construction monitoring during the excavation of the dismantling tunnel. By installing monitoring instruments at the excavation location of the dismantling tunnel, the vibration, displacement, noise, etc. generated in Step 2 and Step 3 can be monitored in real time.

[0010] Step 5: For the non-explosive excavation location of the dismantling tunnel, drilling and splitting excavation are carried out. A new free face is formed by continuous interlocking drilling in the middle of the tunnel face or along the outer contour. Down-the-hole drills are used to drill holes on the tunnel face. After drilling is completed, a rock splitter can be placed to break the rock. Starting from near the created free face, the rock is broken layer by layer. A hydraulic breaker is used for secondary crushing to break the rock into reasonable blocks, which are then transported by dump trucks.

[0011] Step Six: Reinforcing Mesh Construction and Shotcrete Support:

[0012] S1. Before spraying concrete and steel mesh, clean the sprayed surface to ensure that there are no loose rocks and no loose debris at the base of the wall. Install the steel mesh on the sprayed surface, with the bottom of the steel mesh inserted into the bottom of the demolition hole.

[0013] S2. Use 42.5 grade ordinary Portland cement, quick-setting agent, river sand and stone materials. Use an automatic metering mixer to mix. During construction, add the sieved sand, crushed stone and cement in sequence, then add water and start mixing. Strictly control the specified quick-setting agent dosage and concrete mix ratio during mixing. The water-cement ratio is generally controlled at 1:2. After the concrete mix is ​​evenly mixed, it is transported to the wet spraying machine by a concrete truck.

[0014] S3. For initial spraying, spray the arch first and then the wall; for re-spraying, spray the wall first and then the arch. The spraying sequence should be from bottom to top to avoid the rebounding concrete blocking the unsprayed rock surface. Two hours after the final setting of the sprayed concrete, effective measures should be taken for curing in a timely manner, and the curing time should not be less than 7 days.

[0015] In a preferred embodiment, the cut-and-cover section in step one refers to the hidden or semi-hidden excavation work carried out during tunnel construction to avoid surface subsidence or excessive impact on the surrounding environment. The pilot tunnel platform in step one is used to assist in guiding and controlling the position and direction of drilling or excavation equipment during underground excavation.

[0016] In a preferred embodiment, the step method in step three is used for steeper earth and rock slopes or trench excavation.

[0017] In a preferred embodiment, in step five, the rock splitter uses the enormous thrust generated by the ultra-high oil pressure output by the hydraulic power station to drive the middle wedge in the wedge block group to extend forward, pushing the splitting blocks to expand to both sides, thereby creating a strong expansion force on the borehole wall to cause the rock to fracture.

[0018] In a preferred embodiment, in step six, the reinforcing mesh is processed centrally in the reinforcing bar processing yard. First, the reinforcing bars are straightened using a reinforcing bar straightening machine, then cut into reinforcing bar strips, and welded to form a reinforcing mesh. Before welding the reinforcing bars, oil stains, paint stains, cement slurry, and loose skin and rust that can be peeled off by hammering must be cleaned from the surface of the reinforcing bars and the test must be qualified. The processed reinforcing mesh should be flat and the surface of the reinforcing bars should not have any marks that weaken the cross-section of the reinforcing bars.

[0019] In a preferred embodiment, the accelerator in step six has an initial setting time of no more than 5 minutes and a final setting time of no more than 10 minutes, and the stone material in step six is ​​hard crushed stone.

[0020] In a preferred embodiment, the shotcrete curing method in step six involves keeping the concrete surface moist by spraying water, covering with a damp cloth, or using a sprayer. This shotcrete curing method in step six is ​​used to prevent premature evaporation of moisture and to control the temperature of the concrete within a suitable range.

[0021] In a preferred embodiment, the monitoring instruments in step four are a surrounding structure deformation monitoring instrument, a vibration monitoring instrument, and a noise monitoring instrument. The monitoring instruments in step four are used to monitor the deformation of surrounding buildings, underground pipelines, and other structures. The vibration monitoring instrument is used to monitor the vibration generated during the construction of the demolition tunnel, and the degree of impact on surrounding structures and underground pipelines. The noise monitoring instrument is used to monitor the noise generated during the construction of the demolition tunnel, and the degree of impact on the surrounding environment and personnel.

[0022] Compared with the prior art, the beneficial effects of the present invention are:

[0023] 1. The drilling and splitting method is used to excavate harder rocks and strata. By igniting the fuse, the explosive is detonated, causing the rock to fracture and split. The shock wave and stress generated by the blast are enough to crack and break the rock. At the same time, the drilling and splitting method can quickly excavate rocks, which is particularly suitable for large-scale excavation projects and improves the construction efficiency of demolition tunnels. After the initial excavation of the demolition tunnel is completed using the drilling and splitting method, the bench method is used. This ensures both construction efficiency and the safety of subsequent construction. The bench method, because it adopts a staged excavation method, can reduce the risk of rock collapse and improve construction safety.

[0024] 2. By installing a steel mesh on the sprayed surface of the demolition hole, and then supporting it with shotcrete between the steel mesh and the sprayed surface, the shotcrete combined with the steel mesh has the characteristics of high strength and good compactness, which can provide a good support effect, further improve the support effect of the demolition hole, and avoid the risk of collapse of the demolition hole.

[0025] 3. By conducting construction monitoring during the excavation of the demolition tunnel, and using instruments for monitoring structural deformation, vibration, and noise, the surrounding environment is monitored to ensure the safety of the demolition construction and the stability of the surrounding buildings. Sufficient preparations are made before excavation, including erecting protective barriers around the excavation site of the demolition tunnel, setting up warning signs, clearing debris around the TBM, removing auxiliary facilities around the TBM, and setting up protective measures to improve construction safety. Attached Figure Description

[0026] Figure 1 This is a schematic diagram of the process structure of the present invention. Detailed Implementation

[0027] To make the objectives, technical solutions, and advantages of this invention clearer, the invention will be further described in detail below with reference to the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are merely illustrative and not intended to limit the invention.

[0028] The technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0029] Example:

[0030] A method for constructing a support structure for a dismantling tunnel includes the following steps:

[0031] Step 1: Preparation for dismantling tunnel excavation. Before excavating the dismantling tunnel, the surrounding environment should be properly organized and prepared. First, remove debris around the TBM, remove auxiliary facilities around the TBM, set up protective measures, build protective barriers around the dismantling tunnel excavation location, and set up warning signs. At the same time, reserve a guide tunnel platform in advance in the underground excavation section.

[0032] In Step 1, the cut-and-cover section refers to the hidden excavation work carried out during tunnel construction to avoid surface subsidence or excessive impact on the surrounding environment. In Step 1, the pilot tunnel platform is used to assist in guiding and controlling the position and direction of drilling or excavation equipment during underground excavation.

[0033] Step 2: Initial excavation of the dismantling tunnel is carried out using the drilling and splitting method. Multiple boreholes are evenly drilled at the excavation location of the dismantling tunnel using a drilling rig. After drilling is completed, explosives are loaded into pre-designed explosive charges, and the detonation device is installed through a fuse. The fuse is lit to detonate the explosives, causing the rocks to crack and split. The shock wave and stress generated by the blast cause the rocks to crack and fracture, forming the initial dismantling tunnel. Excavators are used to load the debris, and dump trucks are used to transport the debris. The rubble and slag inside the initial dismantling tunnel are then cleared.

[0034] Step 3: The step method is used for excavation. The elevation is set on the initial dismantling hole to determine the height and width of each step. An excavator is used to excavate the first step and then excavates layer by layer downwards to ensure that the height and slope of each step meet the design requirements. After each step is excavated, the excavation surface is cleaned and leveled to complete the excavation of the dismantling hole.

[0035] In step three, the step method is used for steeper earth and rock slopes or trench excavation;

[0036] Step 4: Conduct construction monitoring during the excavation of the demolition tunnel. By installing monitoring instruments at the excavation location of the demolition tunnel, the vibration, displacement, noise, etc. generated in Step 2 and Step 3 are monitored in real time to ensure the safety of the demolition construction and the stability of the surrounding buildings.

[0037] The monitoring instruments in step four are surrounding structure deformation monitoring instruments, vibration monitoring instruments, and noise monitoring instruments. The monitoring instruments in step four are used to monitor the deformation of surrounding buildings, underground pipelines, and other structures. The vibration monitoring instruments are used to monitor the vibration generated during the construction of the demolition tunnel and the degree of impact on surrounding structures and underground pipelines. The noise monitoring instruments are used to monitor the noise generated during the construction of the demolition tunnel and the degree of impact on the surrounding environment and personnel.

[0038] Step 5: For the non-explosive excavation location of the dismantling tunnel, drilling and splitting excavation are carried out. A new free face is formed by continuous interlocking drilling in the middle of the tunnel face or along the outer contour. Down-the-hole drills are used to drill holes on the tunnel face. After drilling is completed, a rock splitter can be placed to break the rock. Starting from near the created free face, the rock is broken layer by layer. A hydraulic breaker is used for secondary crushing to break the rock into reasonable blocks, which are then transported by dump trucks.

[0039] In step five, the rock splitter uses the enormous thrust generated by the ultra-high oil pressure output by the hydraulic power station to drive the middle wedge in the wedge block group to extend forward, pushing the splitting block to expand to both sides, thereby creating a strong expansion force on the hole wall to cause the rock to fracture.

[0040] Step Six: Reinforcing Mesh Construction and Shotcrete Support:

[0041] S1. Before spraying concrete and steel mesh, clean the sprayed surface to ensure that there are no loose rocks and no loose debris at the base of the wall. Install the steel mesh on the sprayed surface, with the bottom of the steel mesh inserted into the bottom of the wall inside the dismantling hole.

[0042] The steel mesh is processed centrally in the steel bar processing yard. First, the steel bars are straightened using a steel bar straightening machine, then cut into steel bars, and welded to form a steel mesh. Before welding the steel bars, oil stains, paint stains, cement slurry, loose skin and rust that can be peeled off by hammering must be cleaned from the surface of the steel bars and the test must be qualified. The finished steel mesh should be flat and the surface of the steel bars should not have any marks that weaken the cross section of the steel bars.

[0043] S2. Use 42.5 grade ordinary Portland cement, quick-setting agent, river sand and stone materials. Use an automatic metering mixer to mix. During construction, add the sieved sand, crushed stone and cement in sequence, then add water and start mixing. Strictly control the specified quick-setting agent dosage and concrete mix ratio during mixing. The water-cement ratio is generally controlled at 1:2. After the concrete mix is ​​evenly mixed, it is transported to the wet spraying machine by a concrete truck.

[0044] The accelerator should set for no more than 5 minutes initially and no more than 10 minutes finally. In step six, the stone material should be hard crushed stone.

[0045] S3. For initial spraying, spray the arch first and then the wall; for re-spraying, spray the wall first and then the arch. The spraying sequence should be from bottom to top to avoid the rebounding concrete blocking the unsprayed rock surface. Two hours after the final setting of the sprayed concrete, effective measures should be taken for curing in a timely manner, and the curing time should not be less than 7 days.

[0046] Shotcrete curing methods involve keeping the concrete surface moist by spraying water, covering it with a damp cloth, or using a sprayer. In step six, shotcrete curing is used to prevent premature evaporation of moisture and to control the temperature of the concrete within a suitable range.

[0047] In this embodiment, after the initial excavation of the demolition hole using the drilling and splitting method, the subsequent detailed excavation is carried out using the step method. This approach ensures both construction efficiency and safety during subsequent construction. Sufficient preparatory work is carried out before excavation, including erecting protective barriers and setting up warning signs around the excavation site, clearing debris and removing auxiliary facilities around the TBM, and implementing protective measures to improve construction safety. Excavators are used for loading excavated material, and dump trucks are used to further improve construction efficiency, avoiding the accumulation of debris that could affect efficiency. Reinforcing mesh and shotcrete are used for support, greatly improving the stability and strength of the demolition hole and enhancing construction quality. Furthermore, during construction, the surrounding environment is monitored using instruments for structural deformation, vibration, and noise to ensure the safety of the demolition work and the stability of surrounding buildings.

[0048] The above are merely preferred embodiments of the present invention and are not intended to limit the present invention. Any modifications, equivalent substitutions, and improvements made within the spirit and principles of the present invention should be included within the scope of protection of the present invention.

Claims

1. A method for constructing a support structure for a dismantling tunnel, characterized in that: Includes the following steps: Step 1: Preparation for dismantling tunnel excavation. Before excavating the dismantling tunnel, the surrounding environment should be properly organized and prepared. First, remove debris around the TBM, remove auxiliary facilities around the TBM, set up protective measures, build protective barriers around the dismantling tunnel excavation location, and set up warning signs. At the same time, reserve a guide tunnel platform in advance in the underground excavation section. Step 2: Initial excavation of the dismantling tunnel is carried out using the drilling and splitting method. Multiple boreholes are evenly drilled at the excavation location of the dismantling tunnel using a drilling rig. After drilling is completed, explosives are loaded into pre-designed explosive charges, and the detonation device is installed through a fuse. The fuse is lit to detonate the explosives, causing the rocks to crack and split. The shock wave and stress generated by the blast cause the rocks to crack and fracture, forming the initial dismantling tunnel. Excavators are used to load the debris, and dump trucks are used to transport the debris. The rubble and slag inside the initial dismantling tunnel are then cleared. Step 3: The step method is used for excavation. The elevation is set on the initial dismantling hole to determine the height and width of each step. An excavator is used to excavate the first step and then excavates layer by layer downwards to ensure that the height and slope of each step meet the design requirements. After each step is excavated, the excavation surface is cleaned and leveled to complete the excavation of the dismantling hole. Step 4: Conduct construction monitoring during the excavation of the dismantling tunnel. By installing monitoring instruments at the excavation location of the dismantling tunnel, the vibration, displacement, and noise generated in Step 2 and Step 3 can be monitored in real time. Step 5: For the non-explosive excavation location of the dismantling tunnel, drilling and splitting excavation are carried out. A new free face is formed by continuous interlocking drilling in the middle of the tunnel face or along the outer contour. Down-the-hole drills are used to drill holes on the tunnel face. After drilling is completed, a rock splitter can be placed to break the rock. Starting from near the created free face, the rock is broken layer by layer. A hydraulic breaker is used for secondary crushing to break the rock into reasonable blocks, which are then transported by dump trucks. Step Six: Reinforcing Mesh Construction and Shotcrete Support: S1. Before spraying concrete and steel mesh, clean the sprayed surface to ensure that there are no loose rocks and no loose debris at the base of the wall. Install steel mesh on the sprayed surface, with the bottom of the steel mesh inserted into the bottom of the wall inside the dismantling hole. S2. Use 42.5 grade ordinary Portland cement, quick-setting agent, river sand and stone materials. Use an automatic metering mixer to mix. During construction, add the sieved sand, crushed stone and cement in sequence, then add water and start mixing. Strictly control the specified quick-setting agent dosage and concrete mix ratio during mixing. The water-cement ratio is controlled at 1:

2. After the concrete mix is ​​evenly mixed, it is transported to the wet spraying machine by a concrete truck. S3. For initial spraying, spray the arch first and then the wall; for re-spraying, spray the wall first and then the arch. The spraying sequence should be from bottom to top to avoid the rebounding concrete blocking the unsprayed rock surface. Two hours after the final setting of the sprayed concrete, effective measures should be taken for curing in a timely manner, and the curing time should not be less than 7 days.

2. The method for construction of excavation and support for dismantling tunnels according to claim 1, characterized in that: The cut-and-cover section in step one refers to the hidden or semi-hidden excavation work carried out during tunnel construction to avoid surface subsidence or excessive impact on the surrounding environment. The pilot tunnel platform in step one is used to assist in guiding and controlling the position and direction of drilling or excavation equipment during underground excavation.

3. The method for construction of excavation and support for dismantling tunnels according to claim 1, characterized in that: The step method in step three is used for steeper earth and rock slopes or trench excavation.

4. The construction method for excavation and support of a dismantling tunnel according to claim 1, characterized in that: In step five, the rock splitter uses the enormous thrust generated by the ultra-high oil pressure output by the hydraulic power station to drive the middle wedge in the wedge block group to extend forward, pushing the splitting blocks to expand to both sides, thereby creating a strong expansion force on the borehole wall to cause the rock to fracture.

5. The construction method for excavation and support of a dismantling tunnel according to claim 1, characterized in that: In step six, the steel mesh is processed centrally in the steel processing yard. First, the steel bars are straightened using a steel bar straightening machine, then cut into steel bars, and welded to form a steel mesh. Before welding the steel bars, oil stains, paint stains, cement slurry, loose skin and rust that can be peeled off by hammering must be cleaned from the surface of the steel bars and tested to be qualified. The processed steel mesh should be flat and the surface of the steel bars should not have any marks that weaken the cross section of the steel bars.

6. The method for construction of excavation and support for dismantling tunnels according to claim 1, characterized in that: In step six, the accelerator's initial setting time shall not exceed 5 minutes, and its final setting time shall not exceed 10 minutes. The stone material used in step six shall be hard crushed stone.

7. The construction method for excavation and support of a dismantling tunnel according to claim 1, characterized in that: In step six, the shotcrete curing method involves keeping the concrete surface moist by spraying water, covering it with a damp cloth, or using a sprayer. This shotcrete curing method is used to prevent premature evaporation of moisture and to control the temperature of the concrete within a suitable range.

8. The construction method for excavation and support of a dismantling tunnel according to claim 1, characterized in that: The monitoring instruments in step four are a surrounding structure deformation monitoring instrument, a vibration monitoring instrument, and a noise monitoring instrument. The monitoring instruments in step four are used to monitor the deformation of the surrounding buildings and underground pipeline structures of the demolition tunnel. The vibration monitoring instrument is used to monitor the vibration generated during the construction of the demolition tunnel and the degree of impact on the surrounding structures and underground pipelines. The noise monitoring instrument is used to monitor the noise generated during the construction of the demolition tunnel and the degree of impact on the surrounding environment and personnel.

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