Construction method for freezing and reinforcing the tunnel portal of the shield tunneling starting shaft

Abstract

This invention discloses a method for breaking through a frozen and reinforced tunnel portal in a shield tunneling starting shaft. The portal body is divided into multiple breaking areas by marking lines, reducing the difficulty of the breaking process. The location of the frozen pipe is marked in each breaking area, and peripheral holes are drilled around the edges. Splitting holes are then drilled around the marked locations of the frozen pipes to protect them from rupture during drilling and to prevent the leakage of brine, thus improving the breaking effect. Furthermore, all splitting holes in each breaking area are simultaneously split, allowing for the breaking of all areas individually or simultaneously, effectively improving the efficiency of the breaking construction and ensuring the breaking effect.

Description

Technical Field

[0001] This invention relates to the field of tunnel boring machine (TBM) launching technology, specifically to the removal of frozen and reinforced tunnel portals. Background Technology

[0002] The launch of the tunnel boring machine (TBM) is one of the key steps in TBM construction. In soft, water-rich strata, freezing is often used to reinforce the strata where the launching shaft is located through freezing pipes. After the strata are reinforced by freezing, the tunnel portal needs to be removed within the TBM excavation face. The retaining structure at the launching shaft portal is generally a reinforced concrete diaphragm wall. The current method of removing the portal is usually done manually with pneumatic picks, which damages the existing freezing pipes within the excavation area, causing brine leakage and potentially leading to engineering accidents. In addition, manual pneumatic pick removal also has problems such as low efficiency and excessive dust.

[0003] Chinese patent application CN104314574A discloses a method for constructing portals in hard rock tunnels. The invention involves drilling holes along the tunnel excavation outline using corresponding external drilling angles. Adjacent holes interlock and overlap, eventually forming peripheral holes that cut each other. Parallel splitting holes are then drilled and cut using a splitting machine. When splitting each excavation block, a splitting force is applied to one of the splitting holes, causing the splitting hole to crack along the splitting surface. After the cracks in adjacent splitting holes are connected, a splitting surface is formed. The crack width on the splitting surface continues to widen until the entire excavation block is split and separated.

[0004] However, the construction method provided by the above scheme requires a large number of holes to be drilled, which takes a long time. The freezing pipes inside the tunnel are prone to breakage due to drilling, causing the brine inside the freezing pipes to flow out, resulting in poor demolition effect. At the same time, it is necessary to continuously apply splitting force to a splitting hole and wait for the crack to widen before it can be demolished and excavated into sections, which is inefficient and has poor demolition effect.

[0005] Therefore, how to effectively improve the efficiency of breaking through frozen and reinforced tunnel portals, protect the frozen pipes, and enhance the breaking effect has become an urgent problem to be solved in this field. Summary of the Invention

[0006] In view of the shortcomings of the existing technology, the purpose of this invention is to provide a construction method for breaking through the frozen and reinforced tunnel portal of the shield tunnel starting shaft that has high construction efficiency, can protect the frozen pipe from damage, and has a good breaking effect.

[0007] To achieve the above objectives, the present invention provides a method for breaking through a frozen and reinforced tunnel portal in a shield tunneling starting shaft, which is used in conjunction with the portal body and the freezing pipe inside the portal body. The portal body includes a diaphragm wall, which is composed of a reinforced concrete protective layer and a concrete layer. The construction method includes:

[0008] S1: Divide the main body of the tunnel into sections, forming several areas to be broken;

[0009] S2: Mark the location of the freezing pipes on the main body of the tunnel entrance, and form corresponding freezing pipe markings in each breached area;

[0010] S3: Drill holes along the excavation outline and markings of the tunnel portal body to form peripheral holes at the outer edge of each breached area;

[0011] S4: Drill holes around the frozen tube markings in each breach area to form split holes, the depth of which is no greater than the thickness of the concrete layer.

[0012] S5: Perform simultaneous splitting of all split holes in each breaking area to remove them one by one or simultaneously remove all breaking areas.

[0013] S6: Trim the excavation outline of the portal body.

[0014] Furthermore, lines are evenly drawn along the horizontal and vertical directions of the portal body to form a grid-like breaking area on the portal body.

[0015] Furthermore, the diameter of the peripheral holes is 20cm, and the distance between two adjacent peripheral holes is not less than 18cm.

[0016] Furthermore, the splitting holes are distributed in a quincunx pattern around the freezing tube markings, and the distance between the splitting holes and the freezing tube markings is greater than 40cm.

[0017] Furthermore, in S5, several metal rods of the hydraulic splitter are simultaneously inserted into all the splitting holes in one of the breaking areas, causing the splitting columns on the metal rods to pop out from the metal rods, simultaneously splitting all the splitting holes in the corresponding breaking area to remove the corresponding breaking area.

[0018] Furthermore, a hydraulic splitter is used to chisel away each of the areas to be broken, in order to remove the main body of the doorway.

[0019] Furthermore, the diameter of the splitting hole is adapted to the metal rod, and the length of the metal rod is adapted to the depth of the splitting hole.

[0020] Furthermore, the metal rod is provided with no less than 10 splitting pillars, which pop out one by one from the outer layer to the inner layer along the depth of the splitting hole.

[0021] Furthermore, the hydraulic rock splitter proceeds from top to bottom, first from both sides and then from the middle, to chisel away each of the breaking areas one by one.

[0022] Furthermore, in S5, breaking agent is simultaneously filled into all splitting holes in all breaking areas, and the breaking agent is allowed to expand, causing all splitting holes to burst simultaneously, so as to simultaneously remove all breaking areas.

[0023] The present invention provides a method for breaking through a frozen and reinforced tunnel portal in a shield tunneling starting shaft. The portal body is divided into multiple breaking areas by marking lines, thereby reducing the difficulty of breaking through. The location of the freezing pipe is marked in each breaking area, and peripheral holes are opened at the edges. Splitting holes are opened around the marked locations of the freezing pipe to protect the freezing pipe from cracking due to drilling and to prevent the brine inside the freezing pipe from flowing out, thereby improving the breaking effect.

[0024] Furthermore, by simultaneously splitting all the split holes in each demolition area, all demolition areas can be demolished one by one or simultaneously, which can effectively improve the demolition construction efficiency and ensure the demolition effect. Attached Figure Description

[0025] The present invention will be further described below with reference to the accompanying drawings and specific embodiments.

[0026] Figure 1 This is a flowchart of the construction method for breaking through the frozen and reinforced tunnel portal of the shield tunneling starting shaft in this invention;

[0027] Figure 2 This is a schematic diagram of the construction process for breaking through the frozen and reinforced tunnel portal of the shield tunneling starting shaft in this invention;

[0028] Figure 3 This is a cross-sectional view of the portal body in this invention;

[0029] Figure 4 This is a schematic diagram of the hydraulic splitter in this invention.

[0030] Figure label:

[0031] 1. Portal body; 11. Diaphragm wall; 12. Reinforcing steel protective layer; 121. Reinforcing steel bars; 13. Concrete layer;

[0032] 2. Demolition area; 3. Frozen pipe markings; 4. Peripheral holes; 5. Splitting holes; 6. Excavation outline; 7. Sidewalls;

[0033] 8. Hydraulic rock splitter; 81. Metal rod; 811. Air guide pipe; 82. Rock splitting column. Detailed Implementation

[0034] To make the technical means, creative features, objectives and effects of this invention easier to understand, the invention will be further described below with reference to specific illustrations.

[0035] See Figure 1 and Figure 2The illustration shows an example of the shield tunneling starting shaft freezing and reinforcement tunnel portal breaking construction method provided by the present invention.

[0036] As shown in the figure, the method for freezing and reinforcing the tunnel portal in this example is used in conjunction with the portal body 1 and the freezing pipe inside the portal body 1. The portal body 1 includes a diaphragm wall 11, which is composed of a steel reinforcement protective layer 12 and a concrete layer 13.

[0037] This construction method mainly involves marking and dividing the main body 1 of the tunnel into multiple demolition areas 2 to reduce the demolition difficulty. The location of the freezing pipe is marked in each demolition area 2, and peripheral holes 4 are opened at the edge. Splitting holes 5 are opened around the marked location 3 of the freezing pipe to protect the freezing pipe and prevent it from breaking due to drilling, thus preventing the brine inside the freezing pipe from flowing out and improving the demolition effect.

[0038] Furthermore, by simultaneously splitting all the splitting holes 5 in each breaking area 2, all breaking areas 2 can be broken one by one or simultaneously, which can effectively improve the efficiency of the breaking construction and ensure the breaking effect.

[0039] Among them, combined Figure 3 The diaphragm wall 11 of the portal body 1 is composed of a steel reinforcement protective layer 12 and a concrete layer 13. The steel reinforcement protective layer 12 is located inside the diaphragm wall 11 and cooperates with the freezing pipe. It contains reinforcing steel bars 121. The concrete layer 13 is located outside the diaphragm wall 11. When breaking the portal body 1, the concrete layer 13 needs to be removed. At the same time, it is necessary to ensure that the freezing pipe will not break during the breaking process.

[0040] Specifically, S1: The portal body 1 is divided into sections by marking lines, forming several breaching areas 2 on the portal body 1.

[0041] Furthermore, lines are drawn evenly along the horizontal and vertical directions of the portal body 1 to form a grid-like breaking area 2 on the portal body 1. Preferably, in this example, nine breaking areas 2 are formed on the portal body 1 and distributed in a nine-square grid pattern, so that the distribution area of ​​each breaking area 2 is relatively uniform, thereby allowing the freezing tube to correspond relatively evenly with each breaking area 2.

[0042] Meanwhile, breaking down each of the two areas 2 one by one can reduce the area to be removed in a single operation, thereby effectively controlling the removal quality of each area 2.

[0043] Here, when marking the sections of the portal body 1, it is necessary to ensure that the freezing pipe does not correspond to the marked area, that is, the boundary between adjacent demolition areas 2, to prevent damage to the freezing pipe when demolishing demolition areas 2 and to ensure the demolition effect.

[0044] S2: Mark the location of the freezing pipe on the main body 1 of the tunnel, and form a corresponding freezing pipe mark 3 in each broken area 2.

[0045] Specifically, the positions corresponding to the freezing pipes are marked on the outside of the concrete layer 13, so that each breaking area 2 has a freezing pipe marking 3 corresponding to the breaking area, in order to protect the freezing pipes, so that the freezing pipes will not be damaged when the breaking area 2 is chiseled out, and to prevent the brine inside the freezing pipes from flowing out, which would affect the construction efficiency and breaking effect.

[0046] S3: Drill holes along the excavation outline 6 and the marked lines of the portal body 1 to form peripheral holes 4 at the outer edge of each breaking area 2.

[0047] Furthermore, the diameter of the peripheral holes 4 is preferably 20cm, and the distance between two adjacent peripheral holes 4 is not less than 18cm, so that the peripheral holes 4 on the outer edge of the breaking area 2 can cooperate with each other, ensuring the structural integrity of the breaking area 2 before chiseling, and preventing it from breaking due to the opening of the peripheral holes 4. Moreover, during chiseling, it can break as the cracks on the breaking area 2 increase, so that the breaking area 2 can be chiseled out as a whole, thereby improving the breaking effect.

[0048] At the same time, the peripheral holes 4 on the outer edge of the adjacent demolition area 2 can cooperate with each other to loosen the connection between the adjacent demolition areas 2. Correspondingly, the peripheral holes 4 on the excavation outline 6 of the portal body 1 can also loosen the connection between the portal body 1 and the side wall 7, making the portal body 1 easier to be chiseled away, thereby improving construction efficiency.

[0049] S4: Drill holes around the frozen tube markings 3 in each breaking area 2 to form split holes 5, so that the split holes 5 are distributed around the frozen tube markings 3, and the frozen tube will not break due to the opening of the frozen tube markings 3.

[0050] As a preferred configuration, the splitting holes 5 are distributed in a quincunx pattern around the frozen pipe markings 3, and the distance between the splitting holes 5 and the frozen pipe markings 3 is configured to be greater than 40cm. The diameter of the splitting holes 5 is configured to be 5cm. The distance between two adjacent splitting holes 5 can be adaptively adjusted according to the strength of the concrete layer 13, preferably configured to be 0.8m to 1.2m. This ensures that the splitting holes 5 serve as the chisel-off points, and the chisel-off points of each breaking area 2 are distributed around the frozen pipe, ensuring that the frozen pipe is not affected when the splitting holes 5 are split.

[0051] As a result, the splitting hole 5 splits and creates a crack, which will gradually increase and extend to the peripheral hole 4 at the edge of the breaking area 2, thereby splitting the peripheral hole 4 and removing the breaking area 2.

[0052] Combination Figure 3Furthermore, the depth of the splitting hole 5 is not greater than the thickness of the concrete layer 13 to prevent the splitting depth of the splitting hole 5 from being too large and affecting the reinforcing steel protective layer 12 and the freezing pipe. Preferably, the depth of the splitting hole 5 is equal to the thickness of the concrete layer 13, so that when the splitting hole 5 splits and the area to be broken is chiseled away, the concrete layer 13 can be removed, thereby breaking the portal body 1.

[0053] S5: Simultaneously split all the split holes 5 in each breaking area 2 to remove them one by one or simultaneously remove all breaking areas 2.

[0054] To improve the breaking effect, in this example, a hydraulic splitter 8 is preferred to chisel away the breaking area 2 one by one, so as to reduce construction noise, save manpower, and avoid the situation where fragments fall and injure workers when breaking with a pneumatic hammer.

[0055] Specifically, the construction method for removing S51 using the hydraulic splitter 8 includes:

[0056] Combination Figure 4 S511: First, several metal rods 81 of the hydraulic splitter 8 are simultaneously inserted into all the splitting holes 5 in one of the breaking areas 2 to split all the splitting holes 5 in the breaking area 2 simultaneously.

[0057] Here, the metal rod 81 is connected to the air pressure valve through the air guide pipe 811. The metal rod 81 is also equipped with a splitting column 82. After the metal rod 81 is inserted into the splitting hole 5, the air pressure valve is activated, and air can be injected into the metal rod 8 through the air guide pipe 811. When the air reaches the preset threshold, the splitting column 82 will pop out from the metal rod 81 and apply a splitting force to the splitting hole 4, thereby splitting the splitting hole 4.

[0058] Therefore, when several metal rods 81 are simultaneously inserted into all the splitting holes 5 in one of the breaking areas 2, the splitting pillars 82 on all the metal rods 81 pop out simultaneously, causing all the splitting holes 5 in the breaking area 2 to generate cracks simultaneously, and the cracks generated by the splitting holes 5 at different positions gradually increase along the periphery, thereby quickly extending to all the peripheral holes 4 at the edge of the breaking area 2, causing the peripheral holes 4 to split, so as to quickly remove the breaking area 2, thereby improving the breaking efficiency.

[0059] Furthermore, the diameter of the splitting hole 5 is adapted to the metal rod 81, and the length of the metal rod 81 is adapted to the depth of the splitting hole 5, so that the metal rod 81 can stably fit with the splitting hole 5 to ensure the chiseling depth and breaking effect.

[0060] Meanwhile, the metal rod 81 is provided with no less than 10 splitting columns 82. When the metal rod 81 is inserted into the splitting hole 5, the 10 splitting columns 82 pop out one by one from the outer layer to the inner layer along the depth of the splitting hole 5, so that the splitting hole 5 is split layer by layer from the outer layer to the inner layer, making the splitting hole 5 easier to split, thereby quickly chiseling away the broken area 2 and improving construction efficiency.

[0061] Therefore, the main body of the tunnel portal 1 is removed in layers to avoid the problem of insufficient splitting pressure and poor splitting effect of the entire main body of the tunnel portal 1.

[0062] S512: The hydraulic rock splitter 8 chisels away all the demolition areas 2 one by one from top to bottom, first the two sides and then the middle. This provides a better working space for subsequent demolition work, and also makes it easier for construction personnel to monitor and adjust the demolition process. At the same time, it can also ensure the stability of the tunnel portal body 1, thereby reducing the possibility of deformation and collapse of the tunnel portal body 1.

[0063] Therefore, by using the hydraulic splitter 8, several metal rods 81 cooperate with all the splitting holes 5 in one of the breaking areas 2 to simultaneously split all the splitting holes 5 in the breaking area 2, so as to quickly remove the breaking area 2. Then, all the breaking areas 2 are gradually removed in the same way to avoid excessive stress changes caused by breaking a large area of ​​the portal body 1 at one time, to ensure the safety of the breaking and improve the breaking effect.

[0064] As an example, in the specific application process, the metal rod 81 and the splitting column 82 are used in advance to test split the splitting hole 5 to determine the model of the splitting column 82. This ensures that the maximum force applied by the splitting column 82 to the splitting hole 5 after it pops out from the metal rod 81 can meet the requirements for effective splitting of the splitting hole 5, thereby ensuring the rapid removal of the demolition area 2 and ensuring the demolition effect.

[0065] In some embodiments, a fracturing agent can be used to simultaneously split all the split holes 5 in all the breaking areas 2, thereby breaking the portal body 1 in one go.

[0066] Specifically, for the removal of the fracturing agent S52, the construction method includes:

[0067] S521: Prepare the fracturing agent and stir it; here, the fracturing agent may be composed of shield stripping agent or shield mudstone dispersant, etc.

[0068] S522: The prepared fracturing agent is filled into all the splitting holes 5 in all the fracturing areas 2 within ten minutes;

[0069] S523: Let the fracturing agent stand for 20-30 minutes to allow it to expand, thereby causing all the splitting holes 5 to break simultaneously, so as to simultaneously remove all the breaking areas 2 and break the main body of the tunnel portal 1 in one go.

[0070] This effectively breaks through the main body of the tunnel entrance 1.

[0071] S6: Trim the excavation outline 6 of the portal body 1.

[0072] After all the demolition areas 2 are removed, they are trimmed using manual pneumatic picks or hydraulic impact hammers until the excavation outline 6 is met.

[0073] The present invention provides a method for breaking through a frozen and reinforced tunnel portal in a shield tunneling starting shaft. The portal body 1 is divided into multiple breaking areas 2 to reduce the difficulty of breaking through. The location of the frozen pipe is marked in each breaking area 2, and peripheral holes 4 are opened at the edge. Splitting holes 5 are opened around the marked location 3 of the frozen pipe to protect the frozen pipe, so that the frozen pipe will not break due to drilling and prevent the brine inside the frozen pipe from flowing out, thereby improving the breaking effect.

[0074] Furthermore, by simultaneously splitting all the splitting holes 5 in each breaking area 2, all breaking areas 2 can be broken one by one or simultaneously, which can effectively improve the efficiency of the breaking construction and ensure the breaking effect.

[0075] The foregoing has shown and described the basic principles, main features, and advantages of the present invention. Those skilled in the art should understand that the present invention is not limited to the above embodiments. The embodiments and descriptions in the specification are merely illustrative of the principles of the invention. Various changes and modifications can be made to the invention without departing from its spirit and scope, and all such changes and modifications fall within the scope of the present invention as claimed. The scope of protection of this invention is defined by the appended claims and their equivalents.

Claims

1. A method for breaking through a frozen and reinforced tunnel portal in a shield tunneling starting shaft, used in conjunction with the portal body and the freezing pipe inside the portal body, the portal body including a diaphragm wall, said diaphragm wall being composed of a reinforced concrete protective layer and a concrete layer, characterized in that, The construction method includes: S1: Divide the main body of the tunnel into sections, forming several areas to be broken; S2: Mark the location of the freezing pipes on the main body of the tunnel entrance, and form corresponding freezing pipe markings in each breached area; S3: Drill holes along the excavation outline and markings of the tunnel portal body to form peripheral holes at the outer edge of each breached area; S4: Drill holes around the frozen tube markings in each breach area to form split holes, the depth of which is no greater than the thickness of the concrete layer. S5: Perform simultaneous splitting of all split holes in each breaking area to remove them one by one or simultaneously remove all breaking areas. S6: Trim the excavation outline of the portal body.

2. The method for breaking through the frozen and reinforced tunnel portal of the shield tunneling starting shaft according to claim 1, characterized in that, Evenly draw lines along the horizontal and vertical directions of the tunnel entrance to form a grid-like area for breaking through.

3. The method for breaking through the frozen and reinforced tunnel portal of the shield tunneling starting shaft according to claim 1, characterized in that, The diameter of the peripheral holes is 20cm, and the distance between two adjacent peripheral holes is not less than 18cm.

4. The method for breaking through the frozen and reinforced tunnel portal of the shield tunneling starting shaft according to claim 1, characterized in that, The split holes are distributed in a quincunx pattern around the frozen tube markings, and the distance between the split holes and the frozen tube markings is greater than 40cm.

5. The method for breaking through the frozen and reinforced tunnel portal of the shield tunneling starting shaft according to claim 1, characterized in that, In S5, several metal rods of the hydraulic splitter are simultaneously inserted into all the splitting holes in one of the breaking areas, causing the splitting columns on the metal rods to pop out from the metal rods and simultaneously split all the splitting holes in the corresponding breaking area to remove the corresponding breaking area.

6. The method for breaking through the frozen and reinforced tunnel portal of the shield tunneling starting shaft according to claim 5, characterized in that, The doorway itself is removed by chiseling away each area individually using a hydraulic splitter.

7. The method for breaking through the frozen and reinforced tunnel portal of the shield tunneling starting shaft according to claim 5, characterized in that, The diameter of the splitting hole is adapted to the metal rod, and the length of the metal rod is adapted to the depth of the splitting hole.

8. The method for breaking through the frozen and reinforced tunnel portal of the shield tunneling starting shaft according to claim 5, characterized in that, The metal rod is provided with no less than 10 splitting pillars, which pop out one by one from the outer layer to the inner layer along the depth of the splitting hole.

9. The method for breaking through the frozen and reinforced tunnel portal of the shield tunneling starting shaft according to claim 6, characterized in that, The hydraulic rock splitter removes all the rock fragments one by one, starting from top to bottom and working from the sides to the middle.

10. The method for breaking through the frozen and reinforced tunnel portal of the shield tunneling starting shaft according to claim 1, characterized in that, In S5, the fracturing agent is simultaneously filled into all split holes in all the breaking areas, and the fracturing agent is allowed to expand, causing all split holes to burst simultaneously, so as to remove all the breaking areas at the same time.

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