Large diameter shield machine facilitates shield turning and closed groove

Abstract

The present invention discloses a shield machine with a large diameter and a closed groove that facilitates shield turning. The shield machine comprises a shield front end and a shield rear end forming a movable groove, an oil cylinder, an annular joint, and shield tail grease filled in the internal space formed by the annular joint and the movable groove. The front end of the annular joint is fixedly connected to the rear end of the shield front end, and the rear end is fixedly connected to the front end of the shield rear end by multiple weld points. The multiple weld points are evenly spaced around the circumference of the annular joint. When the shield machine turns, the weld points are disconnected; when the front and rear ends of the shield machine pass through the tunnel portal flush, the water-stop rubber curtain plate can be sealed against the outer periphery of the annular joint. The present invention not only ensures that the shield machine maintains a water-stop seal when passing through the tunnel portal, but also the shield tail grease after disconnection can effectively push the front and rear ends of the shield machine to turn relative to each other, thereby avoiding water-stop failure, reducing the probability of water leakage and tunnel portal collapse, and more conducive to the implementation of small-radius turns for shield excavation.

Description

Technical Field

[0001] The invention belongs to the technical field of shield tunnel construction, and in particular relates to a shield machine with a large diameter and closed grooves for easy shield turning. Background Art

[0002] In recent years, with the continuous advancement of national development strategies and infrastructure construction, as well as the further improvement of high-speed railway networks, highway networks, and urban road network structures, shield tunneling technology has become an indispensable key technology in the construction of major transportation and other infrastructure in my country.

[0003] At present, in shield construction, in order to enable the shield machine to turn, an active articulation device and an articulation cylinder are set on the shield machine to implement relative rotation of the front and rear of the shield machine. Therefore, a rotating active groove is formed between the front and rear of the shield machine. In this way, at the beginning of the shield machine, after the active groove of the shield machine enters the tunnel portal, the water-stop steel ring at the tunnel portal cannot fit the shield machine casing at the active groove, resulting in failure of the water-stop. At the same time, water leakage occurs at the tunnel portal, and severe cases may cause the tunnel portal to collapse. Summary of the Invention

[0004] The technical problem to be solved by the present invention is to overcome the deficiencies of the prior art and provide a new shield machine with a large diameter, convenient shield turning and closed groove.

[0005] In order to solve the above technical problems, the technical solutions adopted by the present invention are as follows: a shield machine with a large diameter and a closed groove that is convenient for shield turning, which includes a hinged shield front end and a shield rear end, and an oil cylinder, wherein a movable groove is formed between the shield front end and the shield rear end, and under the extension and contraction of the oil cylinder, the shield front end rotates relative to the shield rear end, the shield machine also includes an annular joint arranged at the movable groove, and a shield tail grease filled in the internal space formed by the annular joint and the movable groove, wherein the front end of the annular joint is fixedly connected to the tail of the shield front end, and the rear end of the annular joint is fixedly connected to the front end of the shield rear end by multiple welding points, and the multiple welding points are evenly spaced around the circumference of the annular joint. When the shield machine turns, the welding points are disconnected, and it is assumed that the number of extended oil cylinders is X, and the maximum design thrust of the oil cylinder is T max , the actual thrust reduction coefficient is K, the total tension on multiple welding points when the shield machine turns is N; the number of spot welding points on the shield machine shell steel plate is Y, the circumference of the shield machine shell is C, the maximum tension each welding point can withstand is F, and the arc length formed between each two adjacent welding points is L,

[0006] X×T max ×K=N Formula (1)

[0007] N / F=Y Formula (2)

[0008] C / Y=L Formula (3)

[0009] In the above formula, X, T max , K, and C are all known parameters of the shield machine, among which K is 0.2~0.5, and F can be obtained through a tensile test; and when the front end and the rear end of the shield pass through the tunnel portal flush, the water-stop rubber curtain plate can seal and resist the outer periphery of the annular joint.

[0010] Preferably, in obtaining the above-mentioned F value, two steel plates are connected by three-point spot welding, and the two steel plates are pulled against each other until the welds are broken, and 1 / 3 of the tensile force obtained in the test is taken as F.

[0011] According to a specific embodiment and preferred aspect of the present invention, the annular joint is a 2-5mm thick annular steel plate. In this example, the steel plate is 3mm thick. If the steel plate is too thin, it will be easily bent by the waterstop steel plate when passing through the tunnel, forming a groove, which will also cause the tunnel gate waterstop ring to fail. If the steel plate is too thick, the strength will be greater, and the resistance to the shield body during turning will increase.

[0012] Preferably, the front end of the annular joint is fully welded to the rear end of the shield, and the surface of the fully welded area is polished to a smooth surface. This prevents the steel plate from scratching the water-stop rubber curtain when passing through the tunnel without affecting the seal.

[0013] According to another specific embodiment and preferred aspect of the present invention, the full weld thickness is greater than the thickness of the annular steel plate, and the thickness at the weld point is 1 / 3 to 2 / 3 of the annular steel plate. This not only ensures the firmness of the fixed end, but also facilitates the disconnection of the weld point under external force, facilitating cornering.

[0014] Preferably, the surface of the welding point should also be polished to form a smooth surface to avoid the welding point causing movement obstruction, which will also affect the sealing and water-stopping effect.

[0015] Furthermore, the annular steel plate is made up of multiple curved steel plates with the center of the shield front end as the center of the circle. This facilitates assembly and also allows for surface polishing of the welds.

[0016] According to another specific embodiment and preferred aspect of the present invention, the outer diameter of the annular steel plate is less than or equal to the outer diameter of the front end and the rear end of the shield, so as to prevent the steel plate from scratching the water-stop rubber curtain plate when passing through the tunnel.

[0017] Preferably, when the front end and the rear end of the shield machine pass through the tunnel portal flush with each other, the outer contours of the front end of the shield machine, the annular steel plate, and the rear end of the shield machine are flush with each other.

[0018] In addition, the movable groove gradually becomes smaller from the outside to the inside, ensuring that the shield tail grease can provide better support and effectively promote turning when disconnecting the weld point.

[0019] Due to the implementation of the above technical solution, the present invention has the following advantages compared with the prior art:

[0020] The present invention not only ensures that the shield machine maintains a water-stop seal when passing through the tunnel entrance, but also the shield tail grease after disconnection can effectively push the front end and the rear end of the shield to turn relative to each other, thereby avoiding water-stop failure, reducing the probability of water leakage and tunnel gate collapse at the tunnel entrance, and at the same time being more conducive to the implementation of small-radius turns during shield excavation. BRIEF DESCRIPTION OF THE DRAWINGS

[0021] Figure 1 This is a schematic front view of a shield machine with a large-diameter shield casing groove sealing structure according to this embodiment;

[0022] Figure 2 This is a schematic cross-sectional view of the structure of a shield machine with a large-diameter shield casing groove sealing structure according to this embodiment;

[0023] Among them: 1. Shield front end; 2. Shield rear end; 3. Movable trough; 4. Ring joint; 4a. Arc steel plate; 5. Shield tail grease; 6. Water-stop rubber curtain plate. DETAILED DESCRIPTION

[0024] To make the above-mentioned objects, features, and advantages of the present application more clearly understood, the specific embodiments of the present application are described in detail below with reference to the accompanying drawings. The following description sets forth many specific details to facilitate a full understanding of the present application. However, the present application can be implemented in many other ways than those described herein, and those skilled in the art can make similar improvements without violating the scope of the present application. Therefore, the present application is not limited to the specific embodiments disclosed below.

[0025] In the description of the present application, it should be understood that the terms "center", "longitudinal", "lateral", "length", "width", "thickness", "up", "down", "front", "back", "left", "right", "vertical", "horizontal", "top", "bottom", "inside", "outside", "clockwise", "counterclockwise", "axial", "radial", "circumferential" and the like indicate orientations or positional relationships based on the orientations or positional relationships shown in the accompanying drawings, and are only for the convenience of describing the present application and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore should not be understood as a limitation on the present application.

[0026] Furthermore, the terms "first" and "second" are used for descriptive purposes only and should not be construed as indicating or implying relative importance or implicitly specifying the number of the technical features being referred to. Thus, a feature defined as "first" or "second" may explicitly or implicitly include at least one of such features. Throughout the description of this application, "plurality" means at least two, for example, two, three, etc., unless otherwise specifically defined.

[0027] In this application, unless otherwise specified or limited, the terms "installed," "connected," "connect," "fixed," etc. should be understood in a broad sense. For example, they can refer to fixed connection, detachable connection, or integration; mechanical connection or electrical connection; direct connection or indirect connection through an intermediate medium; internal communication between two elements or interaction between two elements, unless otherwise specified. Those skilled in the art will understand the specific meanings of the above terms in this application based on specific circumstances.

[0028] In this application, unless otherwise expressly specified or limited, when a first feature is "above" or "below" a second feature, it may mean that the first and second features are in direct contact, or the first and second features are in indirect contact through an intermediate medium. Furthermore, when a first feature is "above," "above," or "above" a second feature, it may mean that the first feature is directly above or diagonally above the second feature, or simply means that the first feature is at a higher level than the second feature. When a first feature is "below," "below," or "below" a second feature, it may mean that the first feature is directly below or diagonally below the second feature, or simply means that the first feature is at a lower level than the second feature.

[0029] It should be noted that when an element is referred to as being "fixed to" or "disposed on" another element, it may be directly on the other element or there may be an intermediate element. When an element is considered to be "connected to" another element, it may be directly connected to the other element or there may be an intermediate element. The terms "vertical," "horizontal," "upper," "lower," "left," "right," and similar expressions used herein are for illustrative purposes only and do not represent the only implementation methods.

[0030] like Figure 1 and Figure 2 As shown, the large-diameter shield shell groove sealing structure shield machine of this embodiment includes a hinged shield front end 1 and a shield rear end 2, and an oil cylinder, wherein a movable groove 3 is formed between the shield front end 1 and the shield rear end 2, and under the extension and contraction of the oil cylinder, the shield front end 1 rotates relative to the shield rear end 2.

[0031] In this example, the shield machine also includes an annular joint 4 arranged at the movable groove 3, and a shield tail grease 5 filled in the internal space formed by the annular joint 4 and the movable groove 3, wherein the front and rear ends of the annular joint 4 are respectively connected to the tail of the shield front end 1 and the front of the shield rear end 2, and during the relative movement of the shield front end 1 and the shield rear end 2, after the force applied to the rear end of the annular joint 4 is greater than its own limit force, the annular joint 4 is disengaged from the shield rear end 2, and when the shield front end 1 and the shield rear end 2 pass through the tunnel entrance flush, the water-stop rubber curtain plate 6 of the tunnel entrance can be sealed against the outer periphery of the annular joint 4.

[0032] The annular joint 4 is a circular steel plate. In this example, it is made of multiple curved steel plates 4a spliced together with the center of the shield front end 1 as the center of the circle. This facilitates assembly. At the same time, to prevent scratching the water-stop rubber curtain plate 6, the surface of the spliced weld needs to be polished.

[0033] In this example, the steel plate is 3mm thick. If the steel plate is too thin, it will be easily bent by the water-stop steel plate when passing through the tunnel portal, resulting in grooves, which will also cause the tunnel portal water-stop ring to fail; if the steel plate is too thick and the strength is greater, the resistance to the shield body will increase when turning.

[0034] The outer diameter of the annular steel plate is smaller than the outer diameter of the shield front end 1 and the shield rear end 2. In this way, the steel plate is prevented from scratching the water-stop rubber curtain plate 6 when passing through the tunnel without affecting the sealing.

[0035] The annular joint 4 is fully welded from its front end to the rear of the shield front end 1, and spot welded from its rear end to the front of the shield rear end 2. Multiple spot welds are spaced around the circumference of the annular steel plate. This facilitates the forced disconnection between the annular joint and the shield rear end.

[0036] In this example, after welding, the annular steel plate, the front end of the shield, and the rear end of the shield are flush. This not only improves the relative sliding effect, but also prevents the steel plate from scratching the water-stop rubber curtain when passing through the tunnel, ensuring a tight seal.

[0037] At the same time, the full weld at the front end of the steel plate should be polished into a smooth surface.

[0038] In addition, in this example, the layout of the solder joints is as follows:

[0039] The number of spot welding points is the ratio of the actual tensile force on the spot welding points when the shield machine turns to the maximum tensile force borne by each spot welding point, and the number of welding points is an integer.

[0040] When the shield machine turns, the actual tensile force on the spot welding points is equal to the product of the number of cylinders, the maximum thrust designed for the cylinders, and the actual thrust reduction coefficient. The number of cylinders, the maximum thrust designed for the cylinders, and the actual thrust reduction coefficient are all known numbers.

[0041] The maximum tensile force that each spot weld can withstand can be obtained through testing. In this way, the number of welds can be designed according to the needs to ensure that the welds can fall off when turning.

[0042] The arc lengths between each two adjacent spot welds are equal, making construction easier and also facilitating the release effect under stress and assisting in turning.

[0043] The arc length between each two adjacent weld points is equal to the ratio of the circumference of the annular steel plate to the number of weld points. Therefore, the corresponding arc length can be obtained according to the number of weld points.

[0044] At the same time, force calculation: When the shield machine is turning, assuming that the number of extended cylinders is X, the maximum thrust of the cylinder design is T max , the actual thrust reduction coefficient is K, the total tension on multiple welds when the shield machine turns is N; the number of spot welding points on the shield machine shell steel plate is Y, the circumference of the shield machine shell is C, the maximum tension each weld bears is F, and the arc length formed between each two adjacent welds is L.

[0045] X×T max ×K=N (Formula 1)

[0046] N / F=Y (Equation 2)

[0047] C / Y=L (Equation 3)

[0048] In the above formula, X, T max , K, and C are all known parameters of the shield machine, where K is taken as 0.2~0.5, and F can be obtained through tensile testing.

[0049] Specifically, two steel plates are connected by three-point spot welding, and the two steel plates are pulled against each other until the welding points are broken, and 1 / 3 of the tensile force obtained in the test is taken as F.

[0050] In addition, it should be noted that the value of K is directly related to the formation strength and the curve radius. When the formation strength is high and the curve radius is small, a large value should be taken; when the formation strength is low and the curve radius is large, a small value should be taken; when the formation strength is high and the curve radius is large, or when the formation strength is low and the curve radius is small, an intermediate value should be taken.

[0051] Therefore, this embodiment has the following advantages:

[0052] Filling the groove with a turn-loaded disconnectable annular joint not only ensures a watertight seal when the shield machine passes through the tunnel entrance, but also allows the grease at the shield tail after disconnection to effectively push the front and rear ends of the shield machine toward each other in relative turns. Surface treatment also prevents movement obstructions and damage to the watertight rubber curtain, thus preventing watertightness failure and reducing the probability of water leakage and tunnel collapse at the tunnel entrance. This also facilitates turning during shield tunneling.

[0053] By properly selecting the K value and combining it with the F test, the number and accurate position distribution of the weld points are determined. This ensures that the weld points will not be damaged during stress, allowing the car to turn at a smaller turning radius.

[0054] The thickness of the annular steel plate used in this application mainly forms an effective match with the movable groove shape and the shield tail grease filling. When passing through the tunnel portal, it is not easily bent by the water-stop steel plate to produce grooves, causing the tunnel portal water-stop ring to fail; it is also easy to break when turning, and will not increase the resistance of shield excavation.

[0055] The above detailed description of the present invention is intended to enable persons familiar with the art to understand the contents of the present invention and implement them. It does not limit the scope of protection of the present invention. Any equivalent changes or modifications made based on the spirit of the present invention should be included in the scope of protection of the present invention.

Claims

1. A shield machine with a large diameter and a closed groove for easy shield turning, comprising a hinged shield front end and a hinged shield rear end, and an oil cylinder, wherein a movable groove is formed between the shield front end and the shield rear end, and the shield front end rotates relative to the shield rear end under the extension and contraction of the oil cylinder, characterized in that: The shield machine also includes an annular joint provided at the movable groove, and a shield tail grease filled in the internal space formed by the annular joint and the movable groove, wherein the front end of the annular joint is fixedly connected to the tail of the front end of the shield, and the rear end of the annular joint is fixedly connected to the front end of the rear end of the shield in a multi-weld manner, and the multiple welds are evenly spaced around the circumference of the annular joint. When the shield machine turns, the welds are disconnected, and it is assumed that the number of extended cylinders is X, and the maximum thrust of the cylinder design is T max , the actual thrust reduction coefficient is K, the total tension on multiple welding points when the shield machine turns is N; the number of spot welding points on the shield machine shell steel plate is Y, the circumference of the shield machine shell is C, the maximum tension each welding point can withstand is F, and the arc length formed between each two adjacent welding points is L, X×T max ×K=N Formula (1) N / F=Y Formula (2) C / Y=L Formula (3) In the above formula, X, T max , K, and C are all known parameters of the shield machine, among which K is 0.2~0.5, and F is obtained through a tensile test. When the front end and the rear end of the shield pass through the tunnel portal flush, the water-stop rubber curtain plate can seal and contact the outer periphery of the annular joint for the shield machine to advance.

2. The shield machine with large diameter and closed groove for easy shield turning according to claim 1, characterized in that: In obtaining the above-mentioned F value, two steel plates are connected by three-point spot welding, and the two steel plates are pulled against each other until the weld point is broken, and 1 / 3 of the tensile force obtained in the test is taken as F.

3. The shield machine with large diameter and closed groove for easy shield turning according to claim 1, characterized in that: The annular joint is an annular steel plate with a thickness of 2 to 5 mm.

4. The shield machine with large diameter and closed groove for easy shield turning according to claim 3, characterized in that: The front end portion of the annular joint is fully welded to the tail portion of the front end of the shield, and the surface of the full weld is polished to form a smooth surface.

5. The shield machine with large diameter and closed groove for easy shield turning according to claim 4, characterized in that: The thickness of the full weld is greater than the thickness of the annular steel plate, and the thickness at the weld point is 1 / 3 to 2 / 3 of the annular steel plate.

6. The shield machine with large diameter and closed groove for easy shield turning according to claim 5, characterized in that: The surface at the welding point should also be polished to form a smooth surface.

7. The shield machine with large diameter and closed groove for easy shield turning according to claim 3, 4, 5 or 6, characterized in that: The annular steel plate is formed by splicing a plurality of arc-shaped steel plates with the center of the front end of the shield as the center of the circle.

8. The shield machine with large diameter and closed groove for easy shield turning according to claim 7, characterized in that: The outer diameter of the annular steel plate is smaller than or equal to the outer diameters of the front end of the shield and the rear end of the shield.

9. The shield machine with large diameter and closed groove for easy shield turning according to claim 8, characterized in that: When the front end of the shield and the rear end of the shield pass through the tunnel portal in a flush manner, the outer contours of the front end of the shield, the annular steel plate, and the rear end of the shield are flush with each other.

10. The shield machine with large diameter and closed groove for easy shield turning according to claim 1, characterized in that: The movable groove gradually becomes smaller from the outside to the inside.

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