A subway shield tunnel station portal leakage treatment method

Abstract

The application discloses a subway shield tunnel station portal leakage treatment method and belongs to the technical field of subway tunnel leakage treatment, and comprises the following steps: S1, detecting defects in the interior of a station side wall, the interior of a portal ring beam and the back of a ring beam adjacent segment; S2, chiseling out inferior concrete in the joint interior of the portal ring beam, the ring beam adjacent segment and the station side wall; S3, grouting is performed on both sides of a waterproof layer between a cast-in-place pile at the back of the ring beam adjacent segment and the station side wall; S4, the joint in the step S2 is grouted; S5, the defects in the step S4 are grouted; and S6, the portal ring beam and the ring beam adjacent segment are surface closed. Four waterproof barriers are constructed from inside to outside, a complete closed plugging ring is formed, the inside leakage water channel of the portal is completely plugged and comprehensively repaired, and the problems of poor grouting plugging effect and inability to maintain treatment effect for a long time in the prior art are solved.

Description

A method for controlling leakage at the portal of a subway shield tunnel station. Technical Field

[0001] This invention relates to the field of subway tunnel leakage control technology, and in particular to a method for controlling leakage at the entrance of a subway shield tunnel station. Background Technology

[0002] The tunnel portal, a crucial component connecting the tunnel section and station structure, as well as the tunnel and ventilation shaft, is a complex post-cast reinforced concrete structure within the tunnel framework. It has contact surfaces with the tunnel segments, station sidewalls, and retaining structures. To prevent water leakage, these contact surfaces are typically waterproofed. However, due to factors such as construction quality, train vibration, and ground settlement, structural deformation can lead to water leakage at the contact surfaces, adjacent segment joints, and the ring beam itself. Prolonged water leakage not only affects train operation but also degrades the surrounding concrete, reducing structural durability. Therefore, timely treatment is essential when water leakage occurs at the portal. Currently, the primary method for controlling leakage is joint grouting to seal the joints at the leakage points. However, long-term observation of tunnel portals in multiple subway lines in a certain city revealed that portals treated with this method are prone to repeated leakage. This indicates that the water leakage channels in the portals treated with this method are not completely sealed, the risk of leakage cannot be completely eliminated, and the sealing effect cannot be maintained for a long period. Summary of the Invention

[0003] The purpose of this invention is to solve the above-mentioned technical problems and provide a method for treating leakage at the entrance of a subway shield tunnel station. This method constructs four waterproof barriers from the inside out, forming a complete closed sealing ring that completely seals and repairs the leakage channels inside the entrance. This solves the problems of poor grouting and sealing effects and the inability to maintain the treatment effect for a long time in the existing technology.

[0004] To achieve the above objectives, the present invention provides the following solution: The present invention discloses a method for controlling leakage at the portal of a subway shield tunnel station, comprising the following steps:

[0005] S1. Detect defects inside the station side wall, inside the portal ring beam, and on the back of the adjacent pipe section of the ring beam;

[0006] S2. Remove the inferior concrete inside the joints of the portal ring beam, the adjacent pipe section of the ring beam, and the station side wall;

[0007] S3. Grouting is performed on both sides of the waterproof layer between the cast-in-place pile on the back of the adjacent pipe section of the ring beam and the side wall of the station.

[0008] S4. Grout the joints in step S2;

[0009] S5. Grout the defects in step S4;

[0010] S6. The portal ring beam and the adjacent pipe segments of the ring beam are surface-sealed.

[0011] Preferably, in step S1, a high-precision ground-penetrating radar or flaw detection equipment is used to detect defects and mark the defect locations.

[0012] Preferably, in step S2, the original water collection box is removed before the inferior concrete inside is removed from the joint between the portal ring beam and the adjacent pipe segment of the ring beam; in step S6, after the surface sealing is completed, the joint between the portal ring beam and the adjacent pipe segment of the ring beam is sealed with organic caulking putty, and the water collection box is installed.

[0013] Preferably, in step S2, an electric hammer is used to remove the failed caulking material inside the joint and the surrounding deteriorated concrete until fresh concrete is exposed.

[0014] Preferably, in step S3, organic grout and inorganic grout are used sequentially during grouting.

[0015] Preferably, in step S3, during organic grouting, organic grouting holes are arranged circumferentially on the upper surface of the station side wall near the portal ring beam. The drilling angle of the organic grouting holes is perpendicular to the surface of the station side wall. The depth of the organic grouting holes extends to between the leveling layer and the waterproof layer of the station side wall. Grouting is carried out sequentially from the bottom on both sides of the organic grouting holes to the top. When grout appears at the joint between the station side wall and the portal ring beam, the organic grouting is stopped.

[0016] Preferably, in step S3, during inorganic grouting, inorganic grouting holes are arranged circumferentially above the organic grouting holes, with the inorganic grouting holes and organic grouting holes arranged alternately. The drilling angle of the inorganic grouting holes is perpendicular to the sidewall surface. The depth of the inorganic grouting holes extends to the leveling layer between the waterproof layer and the cast-in-place pile. Grouting holes are also provided on the adjacent pipe segments of the ring beam, extending to the back of the adjacent pipe segments of the ring beam. Grouting begins sequentially from the bottom of both sides of the inorganic grouting holes towards the top. When the grouting pressure rises steadily, grouting begins at the pipe segment grouting holes. Grouting stops when the grouting pressure at both ends is close.

[0017] Preferably, in step S4, joint grouting holes are sequentially arranged at the joint between the portal ring beam and the station side wall, and at the joint between the portal ring beam and the adjacent pipe section of the ring beam. First, organic grout is injected into the joint grouting holes between the portal ring beam and the station side wall, and then organic grout is injected into the joint grouting holes between the portal ring beam and the adjacent pipe section of the ring beam.

[0018] Preferably, in step S5, defect grouting holes are arranged on the surface of the portal ring beam away from the adjacent pipe segment of the ring beam. The drilling angle of the defect grouting holes is raised by 30 to 40 degrees, and the depth of the defect grouting holes is one-third to one-half of the thickness of the portal ring beam. Organic grout is injected, and grouting is stopped after grout overflows from the surface cracks of the portal ring beam.

[0019] Preferably, in step S6, all grouting needles are removed and all grouting holes are sealed, the surfaces of the portal ring beam and each joint are cleaned, and a layer of epoxy structural adhesive is evenly applied for sealing.

[0020] The present invention achieves the following technical effects compared to the prior art:

[0021] 1. The method for treating leakage at the entrance of a subway shield tunnel station in this invention forms a first waterproof barrier by grouting both sides of the waterproof layer between the cast-in-place pile and the station sidewall. Grouting at the joint seals the structural joints, forming a second waterproof barrier. Treating defects inside the ring beam seals the internal leakage channels, forming a third waterproof barrier. This also strengthens the structure. Sealing the structural surface establishes a fourth waterproof barrier. Under the protection of these four waterproof barriers, leakage at the station entrance can be comprehensively repaired, significantly improving the sealing effect. At the same time, the surrounding concrete is reinforced, forming a closed sealing ring, improving the long-term waterproofing capability of this area and eliminating the risk of recurrence of leakage.

[0022] 2. The method for treating leakage at the entrance of a subway shield tunnel station in this invention utilizes a waterproof layer as a boundary. An organic grout is poured between the waterproof layer and the station sidewall to form an elastic waterproof layer, while an inorganic grout is poured between the waterproof layer and the cast-in-place pile to form a rigid waterproof layer. This combination of rigidity and flexibility forms a complete waterproof system, significantly improving the resistance to leakage. On the one hand, it compensates for the shortcomings of inorganic grout, which is prone to damage and waterproofing failure in the later stages. On the other hand, it solves the problem of excessively high costs associated with using organic grout alone.

[0023] 3. In the method for treating leakage at the entrance of a subway shield tunnel station in this invention, when injecting inorganic grout or organic grout, the grouting sequence is selected from bottom to top. Due to gravity, low water flow, and other reasons, the grout spreads slowly, resulting in a better overall filling effect. Attached Figure Description

[0024] To more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the drawings used in the embodiments will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0025] Figure 1 is a schematic cross-sectional view of the station portal structure;

[0026] Figure 2 is a schematic diagram of the cross-sectional arrangement of grouting holes in the station portal;

[0027] Figure 3 is a schematic diagram of the grouting hole layout in the station portal;

[0028] Figure 4 is a schematic diagram of the treatment of internal defects in the central ring beam of the station portal;

[0029] Figure 5 is a schematic diagram of the surface closure of the station portal.

[0030] Explanation of reference numerals in the attached drawings: 1. Station side wall; 2. Portal ring beam; 3. Adjacent segments of the ring beam; 4. Leveling layer; 5. Waterproof layer; 6. Cast-in-place pile; 7. Water-swellable sealant; 8. Inorganic grouting hole; 9. Organic grouting hole; 10. Joint grouting hole; 11. Defect grouting hole; 12. Segment grouting hole; 13. Surface sealing layer. Detailed Implementation

[0031] 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.

[0032] This embodiment provides a method for controlling leakage at the portal of a subway shield tunnel station, as shown in Figures 1 to 5, including the following steps:

[0033] S1. Detect defects inside the station side wall 1, inside the portal ring beam 2, and on the back of the adjacent pipe section 3 of the ring beam;

[0034] S2. Remove the joint between the portal ring beam 2 and the adjacent pipe section 3, and remove the inferior concrete inside the joint between the portal ring beam 2 and the station side wall 1.

[0035] S3, Grouting is carried out on both sides of the waterproof layer 5 between the cast-in-place pile 6 on the back of the adjacent pipe section 3 of the ring beam and the station side wall 1 to form the first waterproof barrier;

[0036] S4. Grout the joints in step S2 to form a second waterproof barrier;

[0037] S5. Grout the defects in step S4 to form a third waterproof barrier;

[0038] S6, the portal ring beam 2 and the adjacent pipe segment 3 are sealed to form a surface sealing layer 13, which serves as the fourth waterproof barrier on the one hand and beautifies the surface of the structure on the other.

[0039] With the protection of four waterproof barriers, the internal defects, structural joints and voids behind the structure of the ring beam were fully repaired, the water leakage channels in the opening were completely sealed, and the surrounding concrete was reinforced to form a closed sealing ring, which improved the long-term waterproofing ability of the part, eliminated the risk of water leakage, and thus ensured that the sealing effect was maintained for a long time.

[0040] In this embodiment, as shown in Figures 1 to 5, in step S1, high-precision ground-penetrating radar or flaw detection equipment is used to detect defects, and the defects are marked. The markings must be prominent to facilitate subsequent treatment of the defects. The defects mainly refer to looseness and cracks inside the station side wall 1 and the portal ring beam 2, as well as local cavities on the back of the adjacent pipe section 3 of the ring beam.

[0041] In this embodiment, as shown in Figures 1 to 5, in step S2, the original water collection box is removed before the inferior concrete inside the joint between the portal ring beam 2 and the adjacent pipe segment 3 is removed. In step S6, after the surface sealing is completed, organic caulking putty is used to seal the joint between the portal ring beam 2 and the adjacent pipe segment 3, and the water collection box is reinstalled as a waterproof reserve.

[0042] Furthermore, in this embodiment, as shown in Figures 1 to 5, in step S2, an electric hammer is used to remove the failed caulking material (water-swellable caulking adhesive 7 in Figure 1) and the surrounding deteriorated concrete inside the joint until fresh concrete is exposed. Of course, besides using an electric hammer, other tools can also be used for removal. It should be noted that the existing structure must not be damaged during removal.

[0043] In this embodiment, as shown in Figures 1 to 5, in step S3, the grouting adopts a two-component sequential grouting method, that is, organic grout and inorganic grout are used for grouting in sequence. Organic grout can form a flexible layer, while inorganic grout can form a rigid layer. The combination of rigidity and flexibility makes the first waterproof barrier a tough composite waterproof barrier, which makes up for the shortcomings of cement-based grout which is prone to damage and waterproofing failure in the later stage. At the same time, it also solves the problem of excessive treatment cost caused by using organic grout alone.

[0044] Organic grouting materials include epoxy resin grouting materials, while inorganic grouting materials include cement-based grouting materials. Traditionally, quick-setting cement-based grouting is used to fill cavities behind tunnel portals. Although this grout typically achieves a strength of 20 MPa after solidification, it is prone to brittle fracture when settlement or deformation occurs at the portal, creating multiple leakage channels and rendering the waterproofing effect essentially ineffective. In contrast, two-component, sequential grouting uses a waterproof layer 5 as a boundary. First, epoxy resin grouting material is injected, forming a layer that is elastic and resistant to damage. Then, cement-based grouting is injected to fill the voids. This way, even if the cement-based grouting material fails, the presence of the epoxy resin layer maintains the waterproofing effect, while also overcoming the high cost of using organic grouting materials alone.

[0045] Furthermore, in this embodiment, as shown in Figures 1 to 5, during organic grouting in step S3, organic grouting holes 9 need to be arranged circumferentially on the upper surface of the station side wall 1 near the portal ring beam 2. The drilling angle of the organic grouting holes 9 is perpendicular to the outer surface of the station side wall 1, and the depth of the organic grouting holes 9 extends to between the leveling layer 4 and the waterproof layer 5 of the station side wall 1. The waterproof layer 5 is usually composed of two layers of SBS waterproofing. During grouting, grouting needs to start from the bottom on both sides of the organic grouting holes 9 and proceed sequentially to the top. When grout appears at the joint between the station side wall 1 and the portal ring beam 2, the organic grouting is stopped. Preferably, the organic grouting holes 9 are located 20cm away from the upper surface of the portal ring beam 2, the hole spacing of the organic grouting holes 9 is 50cm, and the grouting pressure is no more than 0.4MPa. Of course, the above values ​​can be adjusted according to the actual project.

[0046] Furthermore, in this embodiment, as shown in Figures 1 to 5, in step S3, during inorganic grouting, inorganic grouting holes 8 are arranged circumferentially above the organic grouting holes 9. The inorganic grouting holes 8 and the organic grouting holes 9 are arranged alternately. The grouting hole angle of the inorganic grouting holes 8 is perpendicular to the side wall surface. The depth of the inorganic grouting holes 8 extends to the leveling layer 4 between the waterproof layer 5 and the cast-in-place pile 6. Grouting holes 12 are set on the adjacent pipe segments 3 of the ring beam. The depth of the grouting holes 12 extends to the back of the adjacent pipe segments 3 of the ring beam. Grouting is carried out sequentially from the bottom of both sides of the inorganic grouting holes 8 to the top. When the grouting pressure rises steadily, the grouting holes 12 begin to grout. Grouting is stopped when the grouting pressure at both ends is close. Preferably, the inorganic grout injection hole 8 is located 20cm above the organic grout injection hole 9, the spacing between the inorganic grout injection holes 8 is 50cm, the depth penetrates the waterproof layer 5, and extends into the area between the waterproof layer 5 and the leveling layer 4 of the cast-in-place pile 6, and the grouting pressure is no greater than 0.4MPa. Of course, the above values ​​can be adjusted according to the actual project.

[0047] The reason why the grouting sequence from bottom to top is chosen when grouting inorganic grout and organic grout is that when water leakage is severe at the tunnel entrance, the leakage volume is large and the flow rate is fast. At this time, the top is the most serious. If grouting starts from the top, the grout will spread out with the water quickly, causing material waste and environmental pollution. However, grouting from the bottom to the top on both sides, due to gravity and smaller water flow, the grout spreads slowly, resulting in a better overall filling effect.

[0048] Furthermore, in this embodiment, in step S4, joint grouting holes 10 are sequentially arranged at the joint between the portal ring beam 2 and the station side wall 1, and at the joint between the portal ring beam 2 and the adjacent pipe section 3. First, organic grout is injected into the joint grouting holes 10 between the portal ring beam 2 and the station side wall 1, followed by the injection of organic grout into the joint grouting holes 10 between the portal ring beam 2 and the adjacent pipe section 3. Preferably, the spacing between the joint grouting holes 10 is 50cm, and the hole depth is 15-25cm. Epoxy resin grout can be used as the organic grout. First, epoxy resin or other organic grout is injected into the joint grouting holes 10 between the portal ring beam 2 and the station side wall 1 until all joint grouting holes 10 are fully grouted. Then, grouting begins in the joint grouting holes 10 between the portal ring beam 2 and the adjacent pipe section 3. The grouting method remains consistent with the above, and the grouting pressure must not exceed 0.3MPa. The above values ​​and materials can be adjusted according to the actual project.

[0049] Furthermore, in this embodiment, as shown in Figures 1 to 5, in step S5, based on the detection results of S1, defect grouting holes 11 are installed at the defect location of the portal ring beam 2. The defect grouting holes 11 are installed from the surface of the portal ring beam 2 away from the adjacent pipe segment 3 and extend inward. The drilling angle of the defect grouting holes 11 needs to be raised by 30 to 40 degrees, and the depth of the defect grouting holes 11 is one-third to one-half of the thickness of the portal ring beam 2. Organic grout is injected, and grouting is stopped after grout overflows from the surface cracks of the portal ring beam 2. Preferably, epoxy resin grout is used as the organic grout, and the grouting pressure is 0.2 MPa. Of course, the above values ​​and materials can be adjusted according to the actual project.

[0050] Furthermore, in this embodiment, as shown in Figures 1 to 5, in step S6, all grouting needles are removed and all grouting holes are sealed. The surfaces of the portal ring beam 2 and each joint are cleaned, and a layer of epoxy structural adhesive is evenly applied for sealing. Quick-drying cement can be used to seal the grouting holes, and the epoxy structural adhesive dosage is 0.5 kg / m². 2 The number of coats is 3.

[0051] In this embodiment, as shown in Figures 1 to 5, when this method is applied to the treatment of subway structural leakage during operation, attention should be paid to the operating hours, and construction should be carried out within the working window as much as possible. A detailed construction plan is provided below for reference. One working window for this subway is from 0:00 to 3:30, or 3.5 hours. Reasonable allocation of human resources and procedures is necessary to complete the treatment of leakage at one tunnel entrance within one working window, without affecting normal subway operation, thus saving a significant amount of manpower and resources. Since site setup and cleanup take approximately 0.5 hours, the effective construction time is only 3 hours, or 180 minutes.

[0052] The number of workers in one construction operation is 10.

[0053] Time analysis for each step:

[0054] Step S1: This step is usually a pre-construction survey and does not take up construction time.

[0055] Step S2: This step is performed simultaneously with step S3. Based on on-site experience, this step takes 45 minutes and requires 4 people.

[0056] Step S3: The perimeter of the portal area is approximately 18.5m. The grouting holes for this step are generally arranged from the arch waist towards the arch crown, with a hole length of approximately 9m and a hole spacing of 50cm. Therefore, a total of 36 grouting holes are laid out in this step (including 8 inorganic grouting holes and 9 organic grouting holes). Four people are assigned to each area to drill 9 holes each. The average time per hole is 4 minutes, so the hole layout in Step S3 takes 36 minutes. Similarly, grouting is divided into 3 groups, grouting from both sides towards the arch crown. The specific grouting time is determined based on the internal characteristics of the structure, and it takes approximately 60 minutes. Therefore, the total time is 96 minutes, and the total number of people is 6.

[0057] Step S4: In this step, the drilling process is carried out simultaneously with step S3, specifically after step S2 is completed. There are 36 joint grouting holes (10 holes per hole), averaging 9 holes per person, which takes 36 minutes. Grouting is carried out from both sides towards the arch top, which takes about 50 minutes. The total time is 86 minutes, and the number of people is 4.

[0058] Step S5: Usually, about 3 to 5 defect grouting holes 11 are set at the top of the arch of the portal ring beam 2. The whole process takes 20 minutes and requires 2 people.

[0059] Step S6: Requires 4 people; 15 minutes

[0060] Time calculation: Due to the overlap of each process, the total time is: 45+86+20+15=166min. The treatment time is very short and fully meets the operation window.

[0061] Specific examples have been used to illustrate the principles and implementation methods of this invention. The descriptions of the above embodiments are only for the purpose of helping to understand the method and core ideas of this invention. Furthermore, those skilled in the art will recognize that, based on the ideas of this invention, there will be changes in the specific implementation methods and application scope. Therefore, the content of this specification should not be construed as a limitation of this invention.

Claims

1. A method for controlling leakage at the portal of a subway shield tunnel station, characterized in that, Includes the following steps: S1. Detect defects inside the station side wall, inside the portal ring beam, and on the back of the adjacent pipe section of the ring beam; S2. Remove inferior concrete from the joints of the portal ring beam, the adjacent pipe section of the ring beam, and the station side wall; S3. Grout both sides of the waterproof layer between the cast-in-place pile on the back of the adjacent pipe section of the ring beam and the station side wall. S4. Grout the joints in step S2; S5. Grout the defects in step S4; S6. Seal the surface of the portal ring beam and the adjacent pipe section of the ring beam; In step S2, the original water collection box is removed before chiseling out the inferior concrete inside the joint between the portal ring beam and the adjacent pipe section of the ring beam; In step S3, organic grout and inorganic grout are used for grouting in sequence; In step S3, when grouting with organic grout, organic grouting holes are arranged circumferentially on the upper surface of the portal ring beam near the station side wall. The drilling angle of the organic grouting holes is perpendicular to the surface of the station side wall. The depth of the organic grouting holes is between the leveling layer and the waterproof layer of the station side wall. Grouting starts from the bottom on both sides of the organic grouting holes and proceeds to the top. Grouting continues until the joint between the station side wall and the portal ring beam appears. When grouting, stop the organic grouting; in step S3, when grouting with inorganic grout, inorganic grouting holes are arranged circumferentially above the organic grouting holes, and the inorganic grouting holes are staggered with the organic grouting holes. The drilling angle of the inorganic grouting holes is perpendicular to the surface of the station side wall. The depth of the inorganic grouting holes reaches between the waterproof layer and the leveling layer of the cast-in-place pile. Grouting holes are set on the adjacent pipe segments of the ring beam. The depth of the grouting holes reaches behind the adjacent pipe segments of the ring beam. Grouting starts from the bottom on both sides of the inorganic grouting holes and proceeds sequentially to the top. When the grouting pressure rises steadily, the grouting holes of the pipe segments begin to grout. Grouting stops when the grouting pressure at both ends is close. In step S6, after the surface sealing is completed, organic caulking putty is used to seal the joint between the portal ring beam and the adjacent pipe segments of the ring beam, and a water collection box is installed.

2. The method for controlling leakage at the portal of a subway shield tunnel station according to claim 1, characterized in that, In step S1, high-precision ground-penetrating radar or flaw detection equipment is used to detect defects and mark the defect locations.

3. The method for controlling leakage at the portal of a subway shield tunnel station according to claim 1, characterized in that, In step S2, an electric hammer is used to remove the failed caulking material inside the joint and the surrounding deteriorated concrete until fresh concrete is exposed.

4. A method for controlling leakage at the portal of a subway shield tunnel station according to claim 1, characterized in that, In step S4, joint grouting holes are sequentially arranged at the joint between the portal ring beam and the station side wall, and at the joint between the portal ring beam and the adjacent pipe segment of the ring beam. First, organic grout is injected into the joint grouting holes between the portal ring beam and the station side wall, and then organic grout is injected into the joint grouting holes between the portal ring beam and the adjacent pipe segment of the ring beam.

5. A method for controlling leakage at the portal of a subway shield tunnel station according to claim 4, characterized in that, In step S5, defect grouting holes are arranged on the surface of the portal ring beam away from the adjacent pipe segment of the ring beam. The drilling angle of the defect grouting holes is raised by 30 to 40 degrees, and the depth of the defect grouting holes is one-third to one-half of the thickness of the portal ring beam. Organic grout is injected, and grouting is stopped after grout overflows from the surface cracks of the portal ring beam.

6. A method for controlling leakage at the portal of a subway shield tunnel station according to claim 5, characterized in that, In step S6, all grouting needles are removed and all grouting holes are sealed. The surfaces of the portal ring beam and each joint are cleaned and a layer of epoxy structural adhesive is evenly applied for sealing.

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