Visual circumferential orientation steel fiber shield segment concrete mold

Abstract

The invention provides a visual circumferential orientation steel fiber shield segment concrete mold, and belongs to the technical field of steel sheet concrete molds, and steel fiber concrete is filled in a steel tank and a cover plate to form concrete of a steel sheet structure containing steel fibers. After the closed coil is electrified, a directional magnetic field for guiding the steel fibers to be arranged in the length direction of the mounting groove is formed, so that the steel fibers are guided to be arranged in the length direction of the segment concrete, and cracking in the width direction of the shield steel sheet concrete is dealt with. The magnetic embedded bolt is arranged at the hand hole position, and the magnetic pole is opposite to the magnetic field direction of the closed coil, so that the directional magnetic field is counteracted, steel fibers at the hand hole position are arranged in a staggered mode, and the situation that complex cracks occur at the hand hole position is avoided. The coil module adopts a double-loop coil, and the double-loop coil forms a reverse current coil after being electrified to counteract a directional magnetic field on the surface layer of the steel fiber reinforced concrete, so that steel fibers on the surface layer of the shield segment concrete are arranged in a staggered manner to cope with collision in an uncertain direction.

Description

Technical Field

[0001] The invention belongs to the technical field of steel sheet concrete moulds, and more specifically, relates to a visual annular oriented steel fiber shield segment concrete mould. Background Art

[0002] The deformation of shield segments leads to structural cracking in the width direction, which is universal. Structural cracking and damage are one of the main forms of shield segment diseases, resulting in insufficient durability of the segments, shortened service life, and even structural instability and damage. Therefore, in the design of the segments, in addition to meeting the bearing capacity requirements, the amount of reinforcement should be increased to control the crack width. However, in engineering practice, reinforced concrete shield segments are difficult to adapt to the increasingly complex construction environment. The most prominent problem is that they are easy to damage and crack during production, transportation, and construction. Although most of these damages occur on the surface of the segments and do not penetrate into the inside of the segments, when cracks appear on the surface of the segments, the steel bars are easily corroded and the volume expands, reducing the bearing capacity of the segments. At the same time, under the action of various loads on the surface of the segments, large tensile strains are easily generated. When the ultimate tensile strength of the concrete is exceeded, the cracks will further expand, thereby aggravating the damage of the reinforced concrete segments, destroying the integrity of the lining structure, and ultimately causing leakage and collapse, which have an adverse effect on the safety and durability of the tunnel structure.

[0003] In addition, in a series of processes such as daily production, long-distance transportation and on-site construction of the segments, the segments will inevitably be subjected to collisions from different directions and with different strengths. Due to the lack of targeted optimization of the steel fiber distribution, the steel fibers on the surface of the segments often show a regular arrangement, which makes it difficult to effectively cope with the impact from uncertain directions, causing the segments to be prone to cracks, breakage and other defects after collision, greatly affecting the quality of the finished product and engineering safety of the segments. In addition, the existing technology also has shortcomings in the handholes of the segments. As a key node in the connection and installation process of the shield segments, the handholes need to withstand the shear loads imposed by the bolts, and the stress state is extremely complex. However, most of the current technical means fail to accurately design the distribution pattern of the steel fibers here, and only adopt a unified mode similar to other parts of the segments, so that the steel fibers cannot effectively exert their crack-blocking performance around the handholes. Once cracks are caused by complex stress at the handholes, the cracks are very likely to expand rapidly inside the segments, eventually threatening the stability of the entire shield structure. Summary of the invention

[0004] The purpose of the present invention is to provide a visual annular oriented steel fiber shield segment concrete mold, control the distribution direction of the steel fibers in the inner layer of the shield segment to be perpendicular to the longitudinal cracks, give full play to the reinforcement, toughening and crack resistance of the steel fibers, and control the random distribution of the steel fibers on the surface of the shield segment and the hand hole position to cope with collisions in uncertain directions and complex cracks at the hand hole position.

[0005] To achieve the above object, the technical solution adopted by the present invention is: to provide a visual annular oriented steel fiber shield segment concrete mold, including a steel base, a coil module and magnetic embedded bolts; The upper end of the steel base is provided with an installation groove, in which a steel groove and a cover plate are arranged in sequence from bottom to top, and steel fiber concrete is filled between the cover plate and the steel groove; The coil module is wound on the steel groove and the steel fiber concrete. The coil module is provided with a plurality of avoidance areas for avoiding the position of the hand hole along the length direction of the installation groove. The coil module forms a plurality of spiral closed coils after being energized. The closed coils form a directional magnetic field for guiding the arrangement of steel fibers along the length direction of the installation groove after being energized. The coil module adopts a double-loop coil. After being energized, the double-loop coil forms a reverse current coil to offset the directional magnetic field on the surface of the steel fiber concrete. The magnetic embedded bolt is placed at the hand hole position and the magnetic pole is opposite to the magnetic field direction of the closed coil.

[0006] In a possible implementation, the coil module includes a lower coil module, an upper coil module and a coil connection module; The lower coil module includes a plurality of lower enameled copper wires, the lower enameled copper wires are arranged along the width direction of the mounting groove, the plurality of lower enameled copper wires are arranged along the length direction of the mounting groove, and a plurality of lower avoidance areas are formed between the plurality of lower enameled copper wires; The upper coil module includes a plurality of upper enameled copper wires, the upper enameled copper wires are arranged along the width direction of the mounting groove, the plurality of upper enameled copper wires are arranged along the length direction of the mounting groove, a plurality of upper avoidance areas are formed between the plurality of upper enameled copper wires, and the upper avoidance areas and the lower avoidance areas constitute the avoidance area; The coil connection module includes a plurality of coil connection units symmetrically arranged in pairs at the upper ends of the left and right sides of the steel slot, and the plurality of coil connection units are used to connect the plurality of lower enameled copper wires and the plurality of upper enameled copper wires to form the plurality of spiral closed coils.

[0007] In a possible implementation, the lower coil module further includes a first lower silicon steel sheet and a plurality of second lower silicon steel sheets, the first lower silicon steel sheet is conformally attached to the bottom and outer side wall of the steel groove, the plurality of second lower silicon steel sheets are arranged at intervals along the length direction of the mounting groove and conformally attached to the bottom and outer side wall of the first lower silicon steel sheet, the lower avoidance area is located between two adjacent second lower silicon steel sheets, and the plurality of lower enameled copper wires are arranged between the first lower silicon steel sheet and the plurality of second lower silicon steel sheets along the length direction of the mounting groove; The upper coil module also includes a first upper silicon steel sheet and a plurality of second upper silicon steel sheets, the first upper silicon steel sheet is conformally arranged on the lower end surface of the cover plate, the plurality of second upper silicon steel sheets are arranged at intervals along the length direction of the mounting groove and conformally fitted between the first upper silicon steel sheet and the cover plate, the upper avoidance area is located between two adjacent second upper silicon steel sheets, and the plurality of upper enameled copper wires are arranged between the first upper silicon steel sheet and the plurality of second upper silicon steel sheets along the length direction of the mounting groove.

[0008] In a possible implementation, both side walls of the steel trough and both side walls of the first lower silicon steel sheet are provided with reserved hand holes, the two reserved hand holes are respectively located on both sides of the avoidance area, and the two ends of the magnetic embedded bolts are respectively connected to the two reserved hand holes.

[0009] In a possible implementation, the coil connection unit includes a silicon steel shell and a U-shaped copper wire, the silicon steel shells are arranged in pairs at the upper ends of the left and right sides of the steel groove, the silicon steel shell has an opening on the side facing the steel groove, the U-shaped copper wire is arranged in the silicon steel shell, and the two free ends of the U-shaped copper wire face the opening of the silicon steel shell, and the two free ends of the U-shaped copper wire are arranged up and down for respectively electrically connecting the lower enameled copper wire and the upper enameled copper wire on the same side.

[0010] In a possible implementation, the steel base, the steel trough, and the cover plate are all circumferentially provided with ear plates extending outward, and a plurality of bolts are circumferentially connected to the ear plates.

[0011] In a possible implementation, a moving component is provided at the bottom of the steel base, a magnetic probe is installed on the moving component, and the magnetic probe is electrically connected to an electromagnetic instrument to analyze the direction and distribution of steel fibers by measuring the inductance value of steel fiber concrete in various directions.

[0012] In a possible implementation, the moving assembly includes a sliding seat and a rotating seat, the magnetic probe is mounted on the rotating seat, the rotating seat is slidably disposed on the sliding seat to drive the magnetic probe to move in space, and the rotating seat is used to drive the magnetic probe to rotate in space.

[0013] In a possible implementation, the steel fiber concrete has built-in long fibers and short fibers, and the long fibers and the short fibers form a random arrangement and / or a directional arrangement under the action of electric currents of different intensities.

[0014] The beneficial effect of a visualized circumferentially oriented steel fiber shield segment concrete mold provided by the present invention is that: compared with the prior art, a steel groove and a cover plate are placed in the installation groove of the steel base, and the steel groove and the cover plate are filled with steel fiber concrete to form a concrete of a steel sheet structure containing steel fibers. The coil module is wound on the steel groove and the steel fiber concrete, and the coil module is provided with a plurality of avoidance areas. After the coil module is energized, a plurality of spiral closed coils are formed. After the closed coil is energized, a directional magnetic field is formed to guide the arrangement of the steel fibers along the length direction of the installation groove, thereby guiding the steel fibers to form an arrangement form along the length direction of the segment concrete to cope with cracking in the width direction of the shield steel sheet concrete. The magnetic embedded bolt is placed at the hand hole position and the magnetic pole is opposite to the magnetic field direction of the closed coil, thereby offsetting the directional magnetic field to make the steel fibers at the hand hole position arranged in a staggered manner to cope with the situation where complex cracks appear at the hand hole position. The coil module adopts a double-loop coil. When the double-loop coil is energized, a reverse current coil is formed to offset the directional magnetic field on the surface of the steel fiber concrete, so that the steel fibers on the surface of the shield segment concrete are arranged in a staggered manner to cope with collisions in uncertain directions. BRIEF DESCRIPTION OF THE DRAWINGS

[0015] In order to more clearly illustrate the technical solutions in the embodiments of the present invention, the drawings required for use in the embodiments or the description of the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying creative work.

[0016] Figure 1 An exploded view of a visualized circumferentially oriented steel fiber shield segment concrete mold provided by the present invention; Figure 2 A schematic diagram of the structure of the concrete mold provided by the present invention in a closed mold state; Figure 3 A schematic structural diagram of a coil connection unit provided by the present invention; Figure 4 A perspective view of a steel base provided for the present invention; Figure 5 A schematic diagram of the magnetic field distribution of the double-loop coil provided by the present invention.

[0017] In the figure: 1. steel base; 2. mounting groove; 3. steel groove; 4. cover plate; 5. upper enameled copper wire; 6. first upper silicon steel sheet; 7. second upper silicon steel sheet; 8. lower enameled copper wire; 9. first lower silicon steel sheet; 10. second lower silicon steel sheet; 11. reserved hand hole; 12. magnetic embedded bolt; 13. silicon steel shell; 14. U-shaped copper wire; 15. sliding seat; 16. rotating seat; 17. magnetic probe. DETAILED DESCRIPTION

[0018] In order to make the technical problems, technical solutions and beneficial effects to be solved by the present invention more clearly understood, the present invention is further described in detail below in conjunction with the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are only used to explain the present invention and are not intended to limit the present invention.

[0019] Unless explicitly defined otherwise, the use of terms such as "first," "second," or "third," etc., are intended to distinguish different objects rather than to describe a specific order.

[0020] Unless otherwise expressly defined, directional words such as the terms "center", "lateral", "longitudinal", "horizontal", "vertical", "top", "bottom", "inside", "outside", "up", "down", "front", "back", "left", "right", "clockwise", "counterclockwise", "high", "low", etc., indicating directions or positional relationships are based on the directions and positional relationships shown in the drawings, and are only for the convenience of describing the present invention and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific direction or be constructed and operated in a specific direction, so they cannot be understood as limiting the specific scope of protection of the present invention.

[0021] See also Figures 1 to 5 Now, a visualized circumferentially oriented steel fiber shield segment concrete mold provided by the present invention is described. A visualized circumferentially oriented steel fiber shield segment concrete mold comprises a steel base 1, a coil module and a magnetic embedded bolt 12; the upper end of the steel base 1 is provided with a mounting groove 2, in which a steel groove 3 and a cover plate 4 are arranged from bottom to top, and steel fiber concrete is filled between the cover plate 4 and the steel groove 3; the coil module is wound on the steel groove 3 and the steel fiber concrete, and the coil module is provided with a plurality of avoidance areas for avoiding the position of the hand hole along the length direction of the mounting groove 2, and the coil module forms a plurality of spiral closed coils after being energized, and the closed coil forms a directional magnetic field guiding the arrangement of steel fibers along the length direction of the mounting groove 2 after being energized, and the coil module adopts a double-loop coil, and the double-loop coil forms a reverse current coil after being energized to offset the directional magnetic field of the surface layer of the steel fiber concrete; the magnetic embedded bolt 12 is placed at the hand hole position and the magnetic pole is opposite to the magnetic field direction of the closed coil.

[0022] The present invention provides a visualized circumferentially oriented steel fiber shield segment concrete mold. Compared with the prior art, a steel groove 3 and a cover plate 4 are placed in the installation groove 2 of the steel base 1, and the steel groove 3 and the cover plate 4 are filled with steel fiber concrete to form a concrete of a steel sheet structure containing steel fibers. The coil module is wound on the steel groove 3 and the steel fiber concrete, and the coil module is provided with multiple avoidance areas. After the coil module is energized, multiple spiral closed coils are formed. After the closed coil is energized, a directional magnetic field that guides the arrangement of steel fibers along the length direction of the installation groove 2 is formed, thereby guiding the steel fibers to form an arrangement form along the length direction of the segment concrete to cope with cracking in the width direction of the shield steel sheet concrete. The magnetic embedded bolt 12 is placed at the hand hole position and the magnetic pole is opposite to the magnetic field direction of the closed coil, thereby offsetting the directional magnetic field so that the steel fibers at the hand hole position are arranged in a staggered manner to cope with the situation where complex cracks appear at the hand hole position. The coil module adopts a double-loop coil. When the double-loop coil is energized, a reverse current coil is formed to offset the directional magnetic field on the surface of the steel fiber concrete, so that the steel fibers on the surface of the shield segment concrete are arranged in a staggered manner to cope with collisions in uncertain directions.

[0023] It is worth noting that according to Ampere's law, when current passes through a solenoid, the current forms a circular flow in the wire, generating a magnetic field. The magnitude of the magnetic field generated by the current around the wire is proportional to the current intensity. According to the Biot-Savart law, for a finite field solenoid, the magnitude of the magnetic field generated inside is:

[0024]

[0025]

[0026] If the length of the solenoid is much larger than its diameter, the formula for the magnetic field generated inside can be simplified to:

[0027] In summary, when sufficient current passes through the spiral closed loop coil, a uniform annular magnetic field can be formed inside the concrete. Steel fiber, as a strong magnetic material, can achieve a directional effect during the pouring process. In order to ensure that the mold can be disassembled and reused multiple times, the spiral coil is divided into two parts, upper and lower.

[0028] Steel fibers are made of mild steel and exhibit ferromagnetic properties. Generally speaking, steel fiber reinforced concrete is a mixture of two materials with very different magnetic properties. , and the magnetic permeability of steel fiber ≥ (The losses caused by nonlinear hysteresis and eddy currents will not be considered). Define the macroscopic magnetic properties of the mixture and introduce the effective permeability of the two-phase mixture , we can get:

[0029] represents the average macroscopic magnetic flux density, and is the average macroscopic magnetic field. In general, the effective permeability is represented by a binary volume: this occurs when the inclusions are not randomly oriented; therefore, the material is anisotropic. Introducing the average magnetic polarization in the medium :

[0030]

[0031] represents the amount of dopant (steel fiber) per unit volume, and is the magnetic susceptibility of the inclusion (steel fiber), which is strictly related to the local field and depends on the average polarization around the inclusion and the shape of the inclusion.

[0032]

[0033] where the depolarization vector N is introduced. In general, the fiber can be approximated by a sphere with large eccentricity (spheroid) with three axes a, b and c, so

[0034] Let the ellipsoid axes a, b and c be aligned with the x, y and z coordinate axes. In this case, the depolarized dyadic vector becomes a diagonal.

[0035]

[0036]

[0037] This means that a magnetic field along the axis of the ellipsoid will produce an excitation field in the same direction. It can be seen that the magnetic susceptibility vector can be written as:

[0038] With some substitutions, the effective permeability tensor can be obtained:

[0039] As mentioned above, i=a, b, c. f=N V is the volume fraction of inclusions. The effective permeability depends on f and the aspect ratio, but not on the size of the fiber.

[0040] Therefore, the measurement of parameters affected by effective permeability can be used to evaluate the content and orientation of steel fibers in steel fiber concrete samples. Based on this principle, the equivalent inductance caused by the magnetic flux passing through the steel fiber concrete sample can be measured.

[0041] A C-shaped core with N turns of winding is placed under the concrete to provide the magnetic field. The inductance of the winding is affected by the fiber concentration: the higher the concentration, the greater the inductance. In addition, it is also affected by the orientation of the magnetic flux lines relative to the average direction of the fibers (the orientation of the core). When the magnetic axis of the coil is aligned with the average direction of the steel fibers, the magnetic field in the concrete has a significant component in the direction of maximum permeability.

[0042] In simple terms, the steel fiber dosage and distribution can be determined by the average inductance value of the magnetic probe 17. When the average inductance values ​​of each area are the same, it means that the steel fibers are well dispersed. On the contrary, the area with a larger average inductance value needs to be further vibrated and dispersed. By rotating the direction of the magnetic probe 17, the arrangement direction of the steel fibers is determined according to the maximum and minimum inductance values. After orientation by the external coil magnetic field, the inductance value along the circumferential direction of the shield segment reaches the maximum, and the inductance value perpendicular to the circumferential direction is the minimum. At this time, the steel fiber orientation effect is good.

[0043] In the specific embodiment, please see Figure 1 The coil module includes a lower coil module, an upper coil module and a coil connection module; the lower coil module includes a plurality of lower enameled copper wires 8, which are arranged along the width direction of the mounting groove 2, and the plurality of lower enameled copper wires 8 are arranged along the length direction of the mounting groove 2, and a plurality of lower avoidance areas are formed between the plurality of lower enameled copper wires 8; the upper coil module includes a plurality of upper enameled copper wires 5, which are arranged along the width direction of the mounting groove 2, and the plurality of upper enameled copper wires 5 are arranged along the length direction of the mounting groove 2, and a plurality of upper avoidance areas are formed between the plurality of upper enameled copper wires 5, and the upper avoidance areas and the lower avoidance areas constitute avoidance areas; the coil connection module includes a plurality of coil connection units symmetrically arranged in pairs at the upper ends of the left and right sides of the steel groove 3, and the plurality of coil connection units are used to connect the plurality of lower enameled copper wires 8 and the plurality of upper enameled copper wires 5 to form a plurality of spiral closed coils.

[0044] The multiple lower enameled copper wires 8 of the lower coil module are arranged along the width direction of the installation groove 2 and are closely arranged in the length direction. This layout lays the foundation for forming a specific magnetic field. The lower avoidance area formed between the enameled copper wires leaves space for the hand hole position to avoid the magnetic field from interfering with the steel fiber arrangement at the hand hole. The first lower silicon steel sheet 9 is conformally fitted with the bottom and outer side wall of the steel groove 3, and the multiple second lower silicon steel sheets 10 are arranged at intervals and fit to the first lower silicon steel sheet 9, which not only plays a good magnetic conductivity role, but also can effectively gather and guide the magnetic field, so that the magnetic field generated by the lower enameled copper wire 8 acts more concentratedly and stably on the steel fiber concrete. In actual production, if the spacing of the lower enameled copper wire 8 is unreasonable, it may lead to uneven distribution of the magnetic field and affect the directional effect of the steel fiber. If the silicon steel sheet is not tightly fitted or the material is not good, the magnetic field will leak, reduce the magnetic field intensity, and then weaken the guiding ability of the steel fiber. The multiple upper enameled copper wires 5 of the upper coil module are also arranged along the width direction of the installation groove 2 and arranged in order in the length direction. The upper avoidance area and the lower avoidance area formed by them together constitute a complete avoidance area to ensure that the magnetic field at the hand hole position is not disturbed. The first upper silicon steel sheet 6 is arranged on the lower end surface of the cover plate 4, and multiple second upper silicon steel sheets 7 are spaced and fitted. This structure cooperates with the silicon steel sheet structure of the lower coil module to constrain and guide the magnetic field from the upper and lower directions, so that the steel fibers can be arranged more accurately in the concrete according to the preset direction. In actual application, if the arrangement of the upper enameled copper wires 5 deviates, such as the spacing between some copper wires is too large or too small, the magnetic field in the upper area will be abnormal, resulting in chaotic arrangement of the steel fibers in this area; the installation of the silicon steel sheet is not standardized, such as the presence of gaps or misalignment, which will affect the uniformity of the magnetic field and ultimately affect the quality of the entire pipe segment.

[0045] The multiple coil connection units of the coil connection module are symmetrically arranged on the upper ends of the left and right sides of the steel slot 3. The core component U-shaped copper wire 14 cleverly connects the lower enameled copper wire 8 and the upper enameled copper wire 5 on the same side to form multiple spiral closed coils. The silicon steel shell 13 not only provides protection for the U-shaped copper wire 14, but also enhances the magnetic field gathering effect and reduces the magnetic field loss. When the mold is powered on, the magnetic fields generated by these spiral closed coils are superimposed on each other to form a strong and stable directional magnetic field, which efficiently guides the arrangement of steel fibers. Taking actual engineering as an example, if the connection of the coil connection unit is not firm, and there is a virtual connection or short circuit, the closed coil will not work properly, the magnetic field cannot be generated or the magnetic field strength is unstable, and the steel fibers cannot be arranged in a directional manner, which seriously affects the performance of the pipe segment. The lower coil module, the upper coil module and the coil connection module work closely together. The magnetic fields generated by the lower and upper coil modules overlap and complement each other in the steel fiber concrete, forming a unified, strong directional magnetic field along the length direction of the installation slot 2, which promotes the arrangement of steel fibers along the length direction of the segment concrete, effectively resisting the cracking of the shield steel segment concrete in the width direction. The coil connection module ensures that the current flows smoothly throughout the coil system and maintains the stability of the magnetic field. The collaborative work of the coil modules not only realizes the directional and staggered arrangement of steel fibers, but also improves the performance of the shield segment as a whole. By optimizing the distribution of steel fibers, the segments can show better mechanical properties under different stress scenarios. During the production, transportation and construction process, the segments are inevitably subject to various collisions and vibrations. Due to the effect of the coil module, the steel fibers on the surface of the segments are randomly and staggeredly distributed, which can effectively disperse and absorb the collision energy and reduce the risk of cracks and damage to the segments due to collisions. During the service of the segments, the steel fibers arranged in a directional manner inside and the steel fibers arranged in a staggered manner at the hand holes work together to enable the segments to better withstand complex external loads, improve the bearing capacity and structural stability of the segments, and provide a solid guarantee for the safe operation of the tunnel project.

[0046] See also Figure 1, the lower coil module also includes a first lower silicon steel sheet 9 and a plurality of second lower silicon steel sheets 10, the first lower silicon steel sheet 9 is conformally attached to the bottom and outer side wall of the steel slot 3, and the plurality of second lower silicon steel sheets 10 are arranged at intervals along the length direction of the mounting slot 2 and conformally attached to the bottom and outer side wall of the first lower silicon steel sheet 9, the lower avoidance area is located between two adjacent second lower silicon steel sheets 10, and a plurality of lower enameled copper wires 8 are arranged between the first lower silicon steel sheet 9 and the plurality of second lower silicon steel sheets 10 along the length direction of the mounting slot 2. The first lower silicon steel sheet 9 is tightly attached to the bottom and outer side wall of the steel slot 3, and its conformally attached design can perfectly fit the shape of the steel slot 3, ensuring that there is no gap between the two, thereby minimizing magnetic field leakage. In actual production, this close fit is like creating a closed channel for the magnetic field, allowing the magnetic field to propagate in a preset direction, thereby enhancing the utilization rate of the magnetic field. The plurality of second lower silicon steel sheets 10 are arranged at intervals along the length direction of the mounting slot 2, and the spacing between them is precisely calculated. Appropriate spacing can not only ensure the continuity of the magnetic field, but also keep the magnetic field at a relatively uniform strength at different positions. These second lower silicon steel sheets 10 further enhance the gathering effect of the magnetic field, allowing the magnetic field to act more concentratedly on the steel fiber concrete. Each lower enameled copper wire 8 is arranged in order between the first lower silicon steel sheet 9 and the plurality of second lower silicon steel sheets 10, and their positions and directions are carefully planned. The wire diameter, material and other parameters of the enameled copper wire are also strictly screened to ensure that a stable and appropriately strong magnetic field can be generated when current is flowing.

[0047] The upper coil module also includes a first upper silicon steel sheet 6 and a plurality of second upper silicon steel sheets 7, the first upper silicon steel sheet 6 is arranged in a conformal manner on the lower end surface of the cover plate 4, the plurality of second upper silicon steel sheets 7 are arranged at intervals along the length direction of the mounting groove 2 and conformally fit between the first upper silicon steel sheet 6 and the cover plate 4, the upper avoidance area is located between two adjacent second upper silicon steel sheets 7, and the plurality of upper enameled copper wires 5 are arranged in a conformal manner between the first upper silicon steel sheet 6 and the plurality of second upper silicon steel sheets 7 along the length direction of the mounting groove 2. The first upper silicon steel sheet 6 is conformally arranged on the lower end surface of the cover plate 4, and its existence provides a stable conduction path for the magnetic field generated by the upper enameled copper wire 5, so that the magnetic field can act uniformly downward on the steel fiber concrete. The plurality of second upper silicon steel sheets 7 are arranged at intervals and closely fit between the first upper silicon steel sheet 6 and the cover plate 4, which further optimizes the distribution of the magnetic field, making the magnetic field more uniform and stable in the area below the cover plate 4. The upper enameled copper wire 5 is arranged in order between the first upper silicon steel sheet 6 and the plurality of second upper silicon steel sheets 7, and corresponds to the lower enameled copper wire 8. During installation, the position of the upper enameled copper wire 5 needs to be precisely aligned with the lower enameled copper wire 8 to ensure that the upper and lower magnetic fields can be effectively superimposed.

[0048] See also Figure 1, the two side walls of the steel trough 3 and the two side walls of the first lower silicon steel sheet 9 are both provided with reserved hand holes 11, which are respectively located on both sides of the avoidance area, and the two ends of the magnetic embedded bolts 12 are respectively connected to the two reserved hand holes 11. During the manufacturing stage of the steel trough 3, the reserved hand holes 11 are accurately opened at the relative positions of the two side walls. The size of the hand holes should not only meet the installation requirements of the magnetic embedded bolts 12, but also should not affect the structural strength of the steel trough 3 due to being too large. At the same time, the position should be accurate and perfectly correspond to the reserved hand holes 11 on the first lower silicon steel sheet 9. When processing the first lower silicon steel sheet 9, the reserved hand holes 11 are also opened at the corresponding positions of the two side walls. The silicon steel sheet is brittle in texture. During processing, the edges of the hand holes should be neat and crack-free to prevent affecting the magnetic conductivity of the silicon steel sheet. The two ends of the magnetic embedded bolts 12 are specially designed with structures such as threads or slots to ensure a firm connection with the reserved hand holes 11. During installation, the magnetic embedded bolts 12 are accurately installed in the two reserved hand holes 11 with the help of professional tools to ensure that the bolts and the hand holes are tightly matched without looseness or shaking.

[0049] When the coil module is energized to generate a directional magnetic field, the magnetic embedded bolt 12 forms a local reverse magnetic field around the hand hole because its magnetic pole is opposite to the direction of the closed coil magnetic field. In this special magnetic field environment, the steel fibers at the hand hole position, which may have been regularly arranged due to the influence of the directional magnetic field, will be in a state of disorderly arrangement due to the interference of the reverse magnetic field. This disordered arrangement is carefully designed, and the steel fibers are distributed in all directions, interweaving with each other to form a complex and stable structure. In actual engineering, the hand hole position is subjected to complex forces, including shear force generated by bolt connections, as well as tension and pressure from the deformation of the surrounding concrete. The disorderly arrangement of steel fibers is like a tight protective net, which can provide effective support and crack resistance in different directions.

[0050] See also Figures 1 to 3The coil connection unit includes a silicon steel shell 13 and a U-shaped copper wire 14. The silicon steel shell 13 is arranged at the upper ends of the left and right sides of the steel slot 3 in pairs. The silicon steel shell 13 has an opening on the side facing the steel slot 3. The U-shaped copper wire 14 is arranged in the silicon steel shell 13. The two free ends of the U-shaped copper wire 14 face the opening of the silicon steel shell 13. The two free ends of the U-shaped copper wire 14 are arranged up and down for respectively electrically connecting the lower enameled copper wire 8 and the upper enameled copper wire 5 on the same side. The silicon steel shell 13 is made of high-strength and high-permeability silicon steel material and is made through precision machining. It is arranged at the upper ends of the left and right sides of the steel slot 3 in pairs to ensure that it is in the best connection and magnetic field enhancement position in the entire mold structure. The opening of the shell facing the side of the steel slot 3 can minimize the obstruction and interference of the magnetic field while ensuring the smooth installation and connection of the U-shaped copper wire 14. The size and shape of the opening are optimized to match the shape of the U-shaped copper wire 14, so that the installation between the two is tighter. The U-shaped copper wire 14 is formed into a U-shaped structure by a bending process. The lengths, bending angles, and upper and lower arrangement spacings of the two free ends of the U-shaped copper wire 14 can achieve a stable and good electrical connection with the lower enameled copper wire 8 and the upper enameled copper wire 5 on the same side. During the installation process, the U-shaped copper wire 14 is placed in the silicon steel housing 13, and its two free ends extend through the openings and are connected to the corresponding lower enameled copper wire 8 and upper enameled copper wire 5, respectively. The connection method adopts reliable processes such as welding and crimping to ensure the stability and conductivity of the connection and reduce resistance and energy loss.

[0051] The U-shaped copper wire 14 connects the lower enameled copper wire 8 and the upper enameled copper wire 5 on the same side to form a complete spiral closed coil loop. This connection method ensures that the current can flow stably and continuously in the entire coil system, providing the necessary conditions for generating a stable and strong directional magnetic field. The stable current passes through the closed coil, so that the magnetic field is evenly distributed around the steel fiber concrete, effectively guiding the steel fibers to be arranged along the length direction of the segment concrete, and improving the segment's ability to resist cracking in the width direction.

[0052] See also Figure 1 and Figure 2 The steel base 1, steel trough 3 and cover plate 4 are all provided with lugs extending outwards in the circumference, and the lugs are connected circumferentially with multiple bolts. The length and width of the lugs extending outwards are designed to ensure sufficient connection strength without affecting the overall size and operation convenience of the mold. During the installation process, according to the specifications and use requirements of the mold, tighten the bolts one by one in a certain order and torque standard, so that the connection between the steel base 1, steel trough 3 and cover plate 4 is evenly stressed, avoiding structural deformation or poor sealing caused by uneven tightening of the bolts.

[0053] The steel base 1, steel trough 3 and cover plate 4 are connected by bolts, making the assembly and disassembly process of the mold simple and quick. During the mold manufacturing, transportation and maintenance process, this detachable connection method facilitates the handling and installation of various components. During the concrete pouring and vibration process, the mold will be subjected to greater pressure and vibration. If the connection is not firm, it is easy to cause displacement and looseness between the components, affecting the forming accuracy of the pipe segment. However, through the circumferentially evenly distributed bolt connection, these forces can be effectively dispersed, so that the mold maintains a stable structural form and ensures the dimensional accuracy and appearance quality of the pipe segment.

[0054] See also Figure 4 , a mobile component is provided at the bottom of the steel base 1, and a magnetic probe 17 is installed on the mobile component. The magnetic probe 17 is electrically connected to the electromagnetic instrument, and the inductance value of the steel fiber concrete in each direction is measured to analyze the direction and distribution of the steel fiber. By measuring the inductance value of the steel fiber concrete in each direction, the distribution of the steel fiber in the concrete can be obtained in real time and accurately. If the inductance value of a certain area is abnormal, it means that the distribution of the steel fiber in the area may be uneven, such as steel fiber aggregation or sparseness. The operator can find these problems in time and take corresponding measures, such as adjusting the vibration method or supplementing steel fibers, to ensure that the steel fibers are evenly distributed in the concrete and improve the quality stability of the pipe segment. According to the change of the inductance value, the orientation effect of the steel fiber can also be judged. When the steel fibers are arranged in a directional manner along the length direction of the pipe segment concrete according to the design requirements, the inductance value in a specific direction will show a specific change pattern. By comparing the actually measured inductance value with the standard value, it is possible to evaluate whether the orientation of the steel fiber achieves the expected effect. If the orientation effect is not good, the current, magnetic field strength and other parameters of the coil module can be adjusted in time to ensure that the orientation of the steel fiber meets the requirements, thereby enhancing the ability of the pipe segment to resist cracks in a specific direction. In the production process of pipe segments, the data of each measurement is recorded and analyzed to establish a quality traceability system. When there are quality problems in the pipe segments, the historical measurement data can be consulted to trace back to each link in the production process and analyze the causes of the problems, such as mold failure, raw material quality problems, etc., to provide a strong basis for improving production processes and product quality.

[0055] See also Figure 4The mobile assembly includes a sliding seat 15 and a rotating seat 16. The magnetic probe 17 is installed on the rotating seat 16. The rotating seat 16 is slidably arranged on the sliding seat 15 to drive the magnetic probe 17 to move in space. The rotating seat 16 is used to drive the magnetic probe 17 to rotate in space. The sliding seat 15 is welded by a plurality of transverse slide rails and a plurality of longitudinal slide rails, and can realize the transverse and longitudinal displacement of the rotating seat 16. A slider matching the transverse and longitudinal slide rails is installed at the bottom of the rotating seat 16, and a high-precision rolling bearing or sliding bearing is used inside the slider. Preferably, a positioning and locking device is also provided between the rotating seat 16 and the sliding seat 15. After the rotating seat 16 moves to the specified position, the accuracy of its position is ensured by the positioning device, and then the rotating seat 16 is fixed to the sliding seat 15 by the locking device to prevent the rotating seat 16 from moving during the measurement process and affecting the measurement result. The positioning device can use a high-precision positioning pin or sensor, and the locking device can use a hydraulic or mechanical locking mechanism to ensure a reliable fixing effect. In terms of operation control, the entire mobile assembly is controlled by an automatic control system. The operator can input precise instructions through the operating console or computer software to control the lateral and longitudinal displacement of the sliding seat 15 and the rotation angle of the rotating seat 16. The control system has two modes: manual operation and automatic programming operation. The manual operation mode allows the operator to flexibly adjust the position and angle of the magnetic probe 17 according to actual conditions on site; the automatic programming operation mode is suitable for standardized and repetitive detection of pipe segments, thereby improving detection efficiency and accuracy.

[0056] Preferably, steel fiber concrete is built with long fibers and short fibers, and the long fibers and short fibers form a staggered arrangement and / or a directional arrangement under the action of currents of different intensities. Long fibers usually have higher strength and a larger aspect ratio, and can play a good bridging role in concrete. When the pipe segment is subjected to a large external force and cracks appear in the concrete, the long fibers can cross the cracks, like the cables of a bridge, to withstand the tension and prevent the cracks from further expanding, thereby enhancing the overall bearing capacity of the pipe segment. Although the short fibers are short in length, they are numerous in the concrete and can effectively fill the gaps between the long fibers and inhibit the generation of micro cracks. They form a fine network structure inside the concrete, increasing the density of the concrete. By changing the current intensity, the magnetic field intensity and characteristics generated by the coil module can be adjusted. At lower current intensities, the magnetic field is weaker, and the magnetic field force on the long fibers and short fibers is relatively small, and they mainly present a staggered arrangement in the concrete. This arrangement allows the fibers to provide a certain degree of reinforcement in all directions, just like building an all-round protective net inside the concrete, which improves the toughness of the segment and enables it to better disperse stress and reduce the occurrence of cracks when it is impacted or vibrated. When the current intensity increases, the magnetic field intensity increases, and the long fibers and short fibers will gradually tend to be oriented under the action of the magnetic field. For long fibers, the oriented arrangement makes their reinforcement effect in a specific direction more significant. For example, the oriented arrangement along the length direction of the segment concrete can effectively resist cracking in the width direction of the shield steel sheet concrete. During the oriented arrangement process, the short fibers can also cooperate with the long fibers to a certain extent to enhance the performance of the segment in this direction.

[0057] The staggered and directional arrangement of long and short fibers under different currents can comprehensively improve the mechanical properties of the segments. The staggered arrangement of fibers enhances the toughness of the segments, allowing them to effectively absorb energy and reduce damage when they are hit in uncertain directions. The directional arrangement of fibers strengthens the main force direction of the segments, improving the bearing capacity and crack resistance of the segments. In actual engineering, this improvement in mechanical properties means that the segments can better withstand various loads during tunnel construction and operation, reduce deformation and damage of the segments, and extend the service life of the segments. By adjusting the current intensity to achieve different fiber arrangements, targeted designs can be made according to the force characteristics of different parts of the segments. At the handhole position, a lower current is used to arrange the fibers in a staggered manner to cope with complex force conditions and prevent cracks at the handhole. In the main structure of the segment, a higher current is used to arrange the fibers in a directional manner to enhance the segment's ability to resist major cracks. This refined design can give full play to the reinforcing effect of the fibers, improve the use efficiency of steel fibers, and reduce material costs. The synergy of long and short fibers and the adjustable arrangement make the segments more adaptable to complex environments. Whether in a humid underground environment or in areas subject to large vibrations, the segments can maintain good performance with their optimized fiber arrangement structure to ensure safe and stable operation of the tunnel.

[0058] 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 and improvements made within the spirit and principles of the present invention should be included in the protection scope of the present invention.

Claims

1. A visual circumferentially oriented steel fiber shield segment concrete mold, characterized in that: It comprises a steel base (1), a coil module and magnetic embedded bolts (12); The upper end of the steel base (1) is provided with a mounting groove (2), and a steel groove (3) and a cover plate (4) are arranged in sequence from bottom to top in the mounting groove (2), and steel fiber concrete is filled between the cover plate (4) and the steel groove (3); The coil module is wound on the steel groove (3) and the steel fiber concrete. The coil module is provided with a plurality of avoidance areas for avoiding the position of the hand hole along the length direction of the installation groove (2). When the coil module is energized, a plurality of spiral closed coils are formed. When the closed coils are energized, a directional magnetic field for guiding the arrangement of steel fibers along the length direction of the installation groove (2) is formed. The coil module adopts a double-loop coil. When the double-loop coils are energized, a reverse current coil is formed to offset the directional magnetic field on the surface of the steel fiber concrete. The magnetic embedded bolt (12) is placed at the hand hole position and the magnetic pole is in the opposite direction to the magnetic field of the closed coil.

2. A visual circumferentially oriented steel fiber shield segment concrete mold according to claim 1, characterized in that: The coil module includes a lower coil module, an upper coil module and a coil connection module; The lower coil module comprises a plurality of lower enameled copper wires (8), the lower enameled copper wires (8) are arranged along the width direction of the mounting groove (2), the plurality of lower enameled copper wires (8) are arranged along the length direction of the mounting groove (2), and a plurality of lower avoidance areas are formed between the plurality of lower enameled copper wires (8); The upper coil module comprises a plurality of upper enameled copper wires (5), the upper enameled copper wires (5) are arranged along the width direction of the mounting groove (2), the plurality of upper enameled copper wires (5) are arranged along the length direction of the mounting groove (2), a plurality of upper avoidance areas are formed between the plurality of upper enameled copper wires (5), and the upper avoidance areas and the lower avoidance areas constitute the avoidance area; The coil connection module comprises a plurality of coil connection units symmetrically arranged in pairs at the upper ends of the left and right sides of the steel slot (3), and the plurality of coil connection units are used to connect the plurality of lower enameled copper wires (8) and the plurality of upper enameled copper wires (5) to form the plurality of spiral closed coils.

3. A visual circumferentially oriented steel fiber shield segment concrete mold according to claim 2, characterized in that: The lower coil module further comprises a first lower silicon steel sheet (9) and a plurality of second lower silicon steel sheets (10), the first lower silicon steel sheet (9) being conformably attached to the bottom and outer side walls of the steel groove (3), the plurality of second lower silicon steel sheets (10) being arranged at intervals along the length direction of the mounting groove (2) and conformably attached to the bottom and outer side walls of the first lower silicon steel sheet (9), the lower avoidance zone being located between two adjacent second lower silicon steel sheets (10), and the plurality of lower enameled copper wires (8) being arranged between the first lower silicon steel sheet (9) and the plurality of second lower silicon steel sheets (10) along the length direction of the mounting groove (2); The upper coil module further comprises a first upper silicon steel sheet (6) and a plurality of second upper silicon steel sheets (7); the first upper silicon steel sheet (6) is arranged conformally on the lower end surface of the cover plate (4); the plurality of second upper silicon steel sheets (7) are arranged at intervals along the length direction of the mounting groove (2) and conformally fit between the first upper silicon steel sheet (6) and the cover plate (4); the upper avoidance zone is located between two adjacent second upper silicon steel sheets (7); and the plurality of upper enameled copper wires (5) are arranged between the first upper silicon steel sheet (6) and the plurality of second upper silicon steel sheets (7) along the length direction of the mounting groove (2).

4. A visual circumferentially oriented steel fiber shield segment concrete mold according to claim 3, characterized in that: The two side walls of the steel trough (3) and the two side walls of the first lower silicon steel sheet (9) are both provided with reserved hand holes (11) facing each other, the two reserved hand holes (11) are respectively located on both sides of the avoidance area, and the two ends of the magnetic embedded bolt (12) are respectively connected to the two reserved hand holes (11).

5. The visual circumferentially oriented steel fiber shield segment concrete mold according to claim 2, characterized in that: The coil connection unit comprises a silicon steel shell (13) and a U-shaped copper wire (14), wherein the silicon steel shells (13) are arranged opposite to each other at the upper ends of the left and right sides of the steel slot (3), and the silicon steel shell (13) has an opening on one side facing the steel slot (3). The U-shaped copper wire (14) is arranged in the silicon steel shell (13), and the two free ends of the U-shaped copper wire (14) face the opening of the silicon steel shell (13). The two free ends of the U-shaped copper wire (14) are arranged up and down for respectively electrically connecting the lower enameled copper wire (8) and the upper enameled copper wire (5) on the same side.

6. The visual circumferentially oriented steel fiber shield segment concrete mold according to claim 1, characterized in that: The steel base (1), the steel trough (3) and the cover plate (4) are all provided with lug plates extending outward in the circumferential direction, and the lug plates are circumferentially connected with a plurality of bolts.

7. A visual circumferentially oriented steel fiber shield segment concrete mold according to any one of claims 1 to 6, characterized in that: A moving component is arranged at the bottom of the steel base (1), and a magnetic probe (17) is installed on the moving component. The magnetic probe (17) is electrically connected to an electromagnetic instrument, and the direction and distribution of the steel fibers are analyzed by measuring the inductance values ​​of the steel fiber concrete in various directions.

8. A visualized circumferentially oriented steel fiber shield segment concrete mold according to claim 7, characterized in that: The moving assembly comprises a sliding seat (15) and a rotating seat (16), the magnetic probe (17) is mounted on the rotating seat (16), the rotating seat (16) is slidably arranged on the sliding seat (15) for driving the magnetic probe (17) to move in space, and the rotating seat (16) is used to drive the magnetic probe (17) to rotate in space.

9. The visual circumferentially oriented steel fiber shield segment concrete mold according to claim 7, characterized in that: The steel fiber concrete has long fibers and short fibers built therein, and the long fibers and the short fibers form a random arrangement and / or a directional arrangement under the action of electric currents of different intensities.

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