Cleaning method for large-diameter shield shell consolidation mortar blocks

Abstract

The invention relates to a cleaning method for large-diameter shield shell consolidation mortar blocks. The cleaning method comprises the following steps that S1, a shield tunneling machine is adopted to excavate a working space at the front end of the shield tunneling machine; s2, a percussion drill is installed on the side, away from the tunnel face, of the cutterhead through the working space, and drilling is conducted on the consolidation mortar blocks on the shield shell in the opposite tunneling direction of the shield tunneling machine; s3, after the consolidated mortar blocks are loosened, the shield tunneling machine conducts tunneling forwards, and the shield shell consolidated mortar blocks are broken; compared with a traditional cleaning mode, the method has the advantages that the problem of'tortoise shells' on any part of the shield body can be solved, and a blind area exists in a traditional method; in addition, the method is high in treatment efficiency, and the working space formed by excavation of the shield tunneling machine is utilized, so that the time is very short; and finally, the method is relatively low in construction cost.

Description

Technical Field

[0001] The invention relates to the technical field of shield tunnel construction, and in particular to a method for cleaning a large-diameter shield shell consolidation mortar block. Background Art

[0002] During the tunneling process of the shield machine, the grout injected synchronously will flow into the shield area and even into the excavated soil bin. In order to control the floating of the super-large diameter shield segments and other problems, it is usually necessary to inject double liquid slurry (cement + water glass) on the shield body. The mortar or double liquid slurry consolidates on the large shield shell, which is easy to form a shield shell consolidation mortar block, that is, a "turtle shell", thus producing a back-soil effect.

[0003] The back-soil effect generally refers to the fact that during the construction of shallow rectangular pipe jacking, the top surface of the pipe jacking machine is horizontal, the unloading arch effect of the upper soil is not obvious, and the soil within the unloading arch height is weakly constrained by the surrounding soil. Under the action of its own weight, it directly collapses on the pipe jacking machine, making the pipe jacking machine more obviously affected by the friction resistance of this part of the soil during the forward advancement, causing difficulties in advancement. In shield construction, no researchers have proposed the concept of the back-soil effect. The main reasons are: under normal circumstances, the shield excavation diameter will be larger than the shield diameter, and there will be over-excavation. In addition, the shield is round, and the unloading arch effect of the upper soil is obvious, so the back-soil effect is not easy to occur. However, in the above construction conditions, due to the mortar consolidation of the shield body, the shield cutter head does not have over-excavation. The mortar that exceeds the cutter head diameter will produce a jacking effect on the upper soil, resulting in the back-soil effect. Although the mechanism of the back-soil effect is not consistent with the shallow rectangular pipe jacking construction process, the results are consistent, both of which lead to obvious uplift of the surface and subsequent large settlement.

[0004] The principle of its generation is as follows: there is a certain thickness of mortar consolidation body at the upper end of the shield shell. When the mortar consolidation wraps the shield, the cutter head excavation diameter is smaller than the equivalent diameter of the shield body + consolidation body, so that the space after the cutter head excavation at the front end of the shield is not enough for the shield body and the consolidation body to pass through, that is, there is no over-excavation in the shield excavation. At the same time, because the stratum where the shield is located is weak, the overlying soil layer is shallow, and the soil constraint is small, the soil near the top of the shield will move with the shield excavation direction due to friction and extrusion, causing the ground in front to bulge. Since the equivalent diameter is larger than the shield excavation diameter, the gap between the shield tail soil and the pipe segment increases, but the grouting volume is still maintained during excavation. At this time, the slurry is not enough to make up for the stratum loss caused by the forward movement of the shield body, and a large settlement deformation will occur, and finally a phenomenon similar to the jacking pipe back soil effect will occur.

[0005] In the prior art, a hole is generally drilled on the surface, and then the drill bit is inserted into the tunnel area to drill and loosen the shell. However, this method has a blind spot for clearing, and the "turtle shell" in the lower area of ​​the shield cannot be effectively cleared, resulting in poor clearing quality and low clearing efficiency. Summary of the invention

[0006] Based on the above description, the present invention provides a method for cleaning large-diameter shield shell consolidation mortar blocks to solve the technical problem in the prior art that continued excavation will cause large settlement deformation when consolidating mortar blocks of large-diameter shield shell.

[0007] The technical solution of the present invention to solve the above technical problems is as follows: A method for cleaning a large-diameter shield consolidation mortar block, comprising the following steps: S1, using a shield machine to dig out a working space at the front end of the shield machine; S2, through the working space, installing an impact drill on the side of the cutter head away from the tunnel face, and drilling into the consolidation mortar block on the shield shell in the opposite direction of the shield machine excavation; S3: After the consolidation mortar blocks are loosened, the shield machine advances forward to break the consolidation mortar blocks on the shield shell.

[0008] Compared with the prior art, the technical solution of this application has the following beneficial technical effects: The cleaning method provided in the present application digs out a working space at the front end of the shield machine, installs an impact drill on the side of the cutter head away from the face through the working space, and then uses the impact drill to drill the consolidation mortar blocks in the opposite direction of tunnel excavation. When the consolidation mortar blocks are loosened, the shield machine advances forward to break the consolidation mortar blocks on the shield shell. Compared with traditional cleaning methods, this method can solve the "turtle shell" on any part of the shield body. The traditional method has blind spots; in addition, this method has high processing efficiency and utilizes the working space formed by the excavation of the shield machine itself, and the time is very short; finally, the construction cost of this method is relatively low.

[0009] Based on the above technical solution, the present invention can also be improved as follows.

[0010] Furthermore, in step S1, excavating a working space at the front end of the shield machine includes: The cutter head of the shield machine is used to excavate the tunnel face forward a first predetermined distance.

[0011] Furthermore, in step S1, excavating a working space at the front end of the shield machine also includes: While the tunnel face is being excavated forward, the tunnel face of the shield machine is radially expanded by a second predetermined distance using the contour cutter of the shield machine cutter head.

[0012] Furthermore, in step S1, excavating a working space at the front end of the shield machine also includes: The side walls of the working space are reinforced.

[0013] Furthermore, the drilling into the consolidation mortar block on the shield shell in the opposite direction of the shield machine excavation includes: The impact drill drills along the four sides of the shield body in the opposite direction of the shield machine's excavation, according to the step-by-step method, drilling the third predetermined distance in each step cycle, and continues drilling until the consolidation mortar block loosens.

[0014] Furthermore, 2 to 3 impact drills are evenly distributed along the circumference of the cutter disc.

[0015] Further, installing the impact drill on the side of the cutter head away from the tunnel face includes: The cutter head is preset with a corresponding number of impact drill interfaces; After the working space is excavated, the staff temporarily installs the impact drill on the impact drill interface.

[0016] Furthermore, the impact drill interface is configured to fix the impact drill and provide working power to the impact drill.

[0017] The first predetermined distance is determined by the telescopic length of the cutter disc.

[0018] Furthermore, the second predetermined distance is 10-20 cm.

[0019] Furthermore, the third predetermined distance of drilling in each stepping cycle is 50±5 cm, and the drilling distance error of all impact drills in one stepping process does not exceed 5 cm. BRIEF DESCRIPTION OF THE DRAWINGS

[0020] Figure 1 This is a schematic diagram of the structure of the external consolidation mortar blocks of the shield machine before cleaning; Figure 2 A schematic diagram of the state of a method for cleaning a large-diameter shield consolidation mortar block provided in an embodiment of the present application when step S1 is implemented; Figure 3 A schematic diagram of the state of a cleaning method for a large-diameter shield consolidation mortar block provided in an embodiment of the present application when steps S2 and S3 are implemented; Figure 4 A schematic diagram of the state after cleaning of a method for cleaning a consolidation mortar block of a large-diameter shield provided in an embodiment of the present application; Figure 5 This is a schematic diagram of the structure of the impact drill on the cutter head in the embodiment of the present application. DETAILED DESCRIPTION

[0021] In order to facilitate understanding of the present application, the present application will be described more fully below with reference to the relevant drawings. Embodiments of the present application are provided in the drawings. However, the present application can be implemented in many different forms and is not limited to the embodiments described herein. On the contrary, the purpose of providing these embodiments is to make the disclosure of the present application more thorough and comprehensive.

[0022] Unless otherwise defined, all technical and scientific terms used herein have the same meaning as those commonly understood by those skilled in the art to which this application belongs. The terms used herein in the specification of this application are only for the purpose of describing specific embodiments and are not intended to limit this application.

[0023] like Figure 1 As shown, before cleaning, the shield shell 12 of the shield machine 10 inside the tunnel has a certain thickness of consolidation mortar blocks 121. The present application provides a method for cleaning consolidation mortar blocks of a large-diameter shield shell, which includes the following steps: like Figure 2 As shown, S1, a shield machine 10 is used to dig out a working space A at the front end of the shield machine 10; like Figure 3 As shown, S2, through the working space A, an impact drill 20 is installed on the side of the cutter head 11 away from the tunnel face b, and drills into the consolidation mortar block 121 on the shield shell 12 in the opposite direction of the tunneling of the shield machine 10; S3, after the consolidation mortar blocks 121 are loosened, the shield machine 10 advances forward to break the consolidation mortar blocks of the shield shell.

[0024] After clearing is completed Figure 4 As shown, at this time, there are no more consolidation mortar blocks on the shield shell of the shield machine 10, and the shield machine 10 continues to advance without causing adverse effects similar to the soil backing effect.

[0025] Wherein, excavating the working space A at the front end of the shield machine 10 in step S1 includes: The cutter head 11 of the shield machine 10 is extended and retracted to excavate the tunnel face b forward by a first predetermined distance H1.

[0026] The cutterhead 11 of the shield machine 10 currently on the market can be extended and retracted a certain distance in the excavation direction to ensure the stability and reliability of excavation. In the present application, this feature of the shield machine 10 is utilized to keep the shield machine 10 as a whole stationary, and the tunnel face b is excavated forward a first predetermined distance H1 through the extension and retraction function of the cutterhead 11, thereby forming a working space A at the front end of the shield machine 10 with a diameter consistent with the diameter of the tunnel face b and a thickness of the first predetermined distance H1. The staff can enter the working space A, and then install an impact drill 20 on the side of the cutterhead 11 away from the tunnel face b, and utilize the retraction of the cutterhead 11 and the drilling of the impact drill 20 to break the consolidated mortar blocks 121.

[0027] In order to further expand the size of the working space A and ensure the safety and convenience of workers entering and exiting, the step S1 of excavating the working space A at the front end of the shield machine 10 also includes: like Figure 3 As shown, while the tunnel face b is excavated forward, the tunnel face b of the shield machine 10 is radially expanded by a second predetermined distance H2 using the contoured cutter 13 of the cutter head 11 of the shield machine 10, thereby expanding the radius of the original working space by the second predetermined distance H2, thereby obtaining a larger working space. Preferably, the second predetermined distance is 10 to 20 cm.

[0028] In order to ensure the working safety of the staff inside the working space A, the demolition work is generally carried out in an area with relatively hard strata. If the hard area cannot be found in time, the following method can be adopted: excavating the working space A at the front end of the shield machine 10 also includes reinforcing the side walls of the working space A. The reinforcement method includes but is not limited to injecting cement mortar into the side walls of the working space A.

[0029] For example, in actual operation, when the shield machine 10 reaches the preset stop point, the WSS (non-shrinkage double liquid) grouting process is used to reinforce the soil within a range of about 5 meters in front of the cutter head 11 to facilitate manual pressure entry and installation of the impact drill 20.

[0030] Among them, the drilling towards the consolidation mortar block 121 on the shield shell 12 in the opposite direction of the excavation of the shield machine 10 includes: the impact drill 20 drills along the four sides of the shield body in the opposite direction of the excavation of the shield machine 10 according to a step-by-step method, drilling a third predetermined distance in each step cycle, and continuing to drill until the consolidation mortar block 121 loosens.

[0031] Preferably, the impact drills 20 are evenly distributed along the circumference of the cutter disc 11. Due to the rotatability of the cutter disc 11, the consolidation mortar block 121 at any position of its circumference can be drilled by rotating the cutter disc 11. It is sufficient to have 2 to 3 impact drills 20. In the embodiment, as shown in FIG. Figure 5 As shown, the number of the impact drills 20 is two.

[0032] More preferably, in order to reduce the staff's stay time in the working space and improve the degree of automation and efficiency of demolition, an impact drill 20 is installed on the side of the cutter head 11 away from the face b, including: a corresponding number of impact drill interfaces 11a are preset on the cutter head 11; in this embodiment, two impact drill interfaces 11a are preset on the cutter head 11, and when the working space A is excavated, the staff temporarily installs the impact drill 20 on the impact drill interface 11a.

[0033] Among them, in order to facilitate the connection of the impact drill 20, the impact drill interface 11a is configured to fix the impact drill 20 and provide working power to the impact drill 20. For example, the impact drill 20 can be directly fixed on the cutter head through a threaded connection or a snap-on impact drill interface 11a, and when fixed, the power supply terminal on the impact drill interface 11a is connected to the power supply interface of the impact drill 20, thereby achieving the dual effects of fixing and power supply.

[0034] In order to ensure the quality of the breaking work, the third predetermined distance of each stepping cycle drilling is 50±5cm, and the drilling distance error of all impact drills in one stepping process does not exceed 5cm.

[0035] The first predetermined distance is determined by the telescopic length of the cutter disc, which is generally 50-60 cm.

[0036] The cleaning method provided in the present application excavates a working space A at the front end of the shield machine 10, and installs multiple impact drills 20 on the side of the cutter head 11 away from the face b through the working space A. Then, the impact drills 20 are used to drill the consolidation mortar blocks 121 in the opposite direction of tunnel excavation. When the consolidation mortar blocks 121 are loosened, the shield machine 10 advances forward, and the loosened mortar blocks rub against the side walls of the working space A to remove the consolidation mortar blocks 121 on the shield shell. Compared with traditional cleaning methods, this method can solve the "turtle shell" on any part of the shield body, and the traditional method has blind spots; in addition, this method has high processing efficiency and utilizes the working space formed by the excavation of the shield machine itself, and the time is very short; and this method does not require longitudinal drilling, and the impact drill 20 always works inside the tunnel space, and the construction cost is relatively low.

[0037] The above description is only a preferred embodiment of the present invention and is not intended to limit the present invention. Any modifications, equivalent substitutions, improvements, etc. made within the spirit and principle of the present invention should be included in the protection scope of the present invention.

Claims

1. A method for cleaning large-diameter shield consolidation mortar blocks, comprising the following steps: S1, using a shield machine to dig out a working space at the front end of the shield machine; S2, through the working space, installing an impact drill on the side of the cutter head away from the tunnel face, and drilling into the consolidation mortar block on the shield shell in the opposite direction of the shield machine excavation; S3: After the consolidation mortar blocks are loosened, the shield machine advances forward to break the consolidation mortar blocks on the shield shell.

2. The method for cleaning the large-diameter shield consolidation mortar blocks according to claim 1 is characterized in that: In step S1, excavating a working space at the front end of the shield machine includes: The cutter head of the shield machine is used to excavate the tunnel face forward a first predetermined distance.

3. The method for cleaning the large-diameter shield consolidation mortar blocks according to claim 1 or 2, characterized in that: Excavating a working space at the front end of the shield machine in step S1 also includes: While the tunnel face is being excavated forward, the tunnel face of the shield machine is radially expanded by a second predetermined distance using the contour cutter of the shield machine cutter head.

4. The method for cleaning the large-diameter shield consolidation mortar blocks according to claim 1 or 2 is characterized in that: Excavating a working space at the front end of the shield machine in step S1 also includes: The side walls of the working space are reinforced.

5. The method for cleaning large-diameter shield consolidation mortar blocks according to any one of claims 1 to 3, characterized in that: The drilling of the consolidation mortar block on the shield shell in the opposite direction of the shield machine excavation includes: The impact drill drills in the opposite direction of the shield machine's excavation near the edge of the shield body, according to the step-by-step method, drilling the third predetermined distance in each step cycle, and continues drilling until the consolidation mortar block loosens.

6. The method for cleaning the large-diameter shield consolidation mortar blocks according to claim 5 is characterized in that: 2 to 3 impact drills are evenly distributed along the circumference of the cutter disc.

7. The method for cleaning the large-diameter shield consolidation mortar blocks according to claim 6 is characterized in that: Installing the impact drill on the side of the cutterhead away from the tunnel face includes: The cutter head is preset with a corresponding number of impact drill interfaces; After the working space is excavated, the staff temporarily installs the impact drill on the impact drill interface.

8. The method for cleaning large-diameter shield consolidation mortar blocks according to claim 5 is characterized in that: The impact drill interface is configured to fix the impact drill and provide working power to the impact drill. The first predetermined distance is determined by the telescopic length of the cutter disc.

9. The method for cleaning large-diameter shield consolidation mortar blocks according to claim 5, characterized in that: The second predetermined distance is 10-20 cm.

10. The method for cleaning large-diameter shield consolidation mortar blocks according to claim 5, characterized in that: The third predetermined distance of drilling in each stepping cycle is 50±5 cm, and the drilling distance error of all impact drills in one stepping process does not exceed 5 cm.

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