JP3839029B2 - Concrete sleepers - Google Patents

Description

  The present invention relates to a concrete sleeper that does not affect the electrical performance of an automatic train stop device (ATS) ground element.

In the ballast track, the ATS ground unit is often installed on a sleeper so as not to hinder the track maintenance work by the machine.
In recent years, wooden sleepers have become less used due to the lack of resources due to resource depletion and short service life, and instead of wooden sleepers, concrete sleepers such as prestressed concrete (PC) sleepers have been widely used. ing. Therefore, the ATS ground element is installed on these concrete sleepers. In addition, when the ATS ground element is installed on the sleeper, a PC sleeper having a notch for accommodating the cable (“notched PC sleeper”) is provided so that the cable attached to the ATS ground element does not interfere with the track maintenance work. Etc.) have been put into practical use.

  A general PC sleeper secures the strength of the sleeper by introducing prestress into the sleeper body by tensioning a PC steel bar embedded along the longitudinal direction of the sleeper body after shaping the sleeper body. On the other hand, the notched PC sleepers have thinner notches than the other parts, so that the notches are reinforced by placing multiple reinforcing bars such as stirrups in addition to the PC steel bars so that the strength of the sleepers is not insufficient. Yes.

  However, when the ATS ground element is installed on a concrete sleeper, the Q value (Quality Factor) indicating the resonance sharpness of the resonance circuit of the ATS ground element decreases due to the influence of a metal body such as a reinforcing bar in the concrete sleeper. It is known that the resonance frequency of the ground element changes. When the Q value decreases, the space in which the signal display information can be transmitted from the ATS ground unit to the vehicle upper unit becomes narrower, and when the Q value falls below a certain value, the signal display information can be transmitted to the vehicle upper unit. Disappear. In general, the Q value gradually decreases with time, and when the Q value falls below a certain value, the ATS ground element is replaced. Therefore, the Q value decreases due to the influence of concrete sleepers. It means that the service life is shortened. The resonance frequency distinguishes information transmitted by the ATS ground element. If a change of a certain value or more occurs in the resonance frequency, accurate information cannot be transmitted to the vehicle upper element.

Therefore, in Patent Document 1, in order to solve the above-described problem, a high-permeability material is laid under the resonance circuit of the ATS ground element to suppress the influence of the metal body under the ATS ground element. A technique for preventing a decrease in value is disclosed.
JP-A-8-91217

  The resonance circuit of the ATS ground element installed on the concrete sleeper is electromagnetically coupled to a metal body such as a reinforcing bar in the concrete sleeper, and the vehicle upper element passes over the ATS ground element to become the resonance circuit of the ATS ground element. When a resonance current flows with the car upper, the induced current flows through the reinforcing bars in the concrete sleepers by mutual induction. The Q value of the ATS ground element is lowered by the mutual induction action between the resonance circuit of the ATS ground element and the reinforcing bar in the concrete sleeper, and the resonance frequency of the ATS ground element is changed.

  By the way, the reinforcing bars inside the notched PC sleepers are a plurality of reinforcing bars arranged along the longitudinal direction of the sleepers and a plurality of reinforcing bars arranged so as to surround these reinforcing bars from the side in order to ensure the strength of the notched portion. The stirrups are arranged in contact with each other. In addition to the notched PC sleepers, reinforcing bars are arranged in a lattice pattern on reinforced concrete sleepers that do not introduce prestress. In these bar arrangements, a large number of looped electrical closed circuits are formed by the rebars contacting each other, and these closed circuits are electromagnetically coupled to the resonance circuit of the ATS ground element, thereby ATS. The Q value of the ground element is lowered and the resonance frequency is changed. In particular, the closed circuit formed in the direction facing the loop coil surface of the resonance circuit of the ATS ground element has a large mutual inductance with the resonance circuit of the ATS ground element, and the rebar and the loop coil surface of the ATS ground element that do not form a closed circuit Compared to a closed circuit formed in a direction perpendicular to the vertical direction, the induced current tends to flow, so the influence on the Q value and resonance frequency of the ATS ground element is large.

  However, in order to prevent the Q value of the ATS ground element placed on the concrete sleepers from decreasing and the resonance frequency from changing, the reinforcing bars in the concrete sleepers are reduced or the reinforcing bars are not in contact with each other. If a closed circuit is not formed in the bar arrangement structure by changing the bar arrangement structure, the strength of the concrete sleepers will be reduced. May cause trouble. In addition, synthetic sleepers with no reinforcing bars are not only more expensive than concrete sleepers, but they are lower in strength than concrete sleepers, so they are also strong in sections where ATS ground pieces are concentrated. There is a risk of trouble.

  The prior art as disclosed in Patent Document 1 is to prevent the Q value from being lowered by improving the ATS ground element, and the technology to prevent the Q value from being lowered by improving the sleepers is There is no conventional. However, in concrete sleepers that have a large effect on the electrical performance of the ATS ground element by having many closed circuits in the internal bar arrangement structure like the above-mentioned notched PC sleepers and reinforced concrete sleepers, only the ATS ground element side Since it is effective to improve not only the improvement but also the sleeper to improve the electrical performance of the ATS ground element, it has been desired to develop a sleeper that does not affect the electrical performance of the ATS ground element.

  This invention is made in view of such a problem, and it aims at providing the concrete sleeper which does not affect the electrical property of an ATS ground element, maintaining intensity | strength, without changing the reinforcement structure of a concrete sleeper. Yes.

  When installing an ATS ground element on a concrete sleeper, a plurality of reinforcing bars arranged along the longitudinal direction of the concrete sleeper and a plurality of reinforcing bars arranged along the short direction of the sleeper are in contact with each other. The closed circuit constituted by the formed ring arrangement structure is formed in a direction facing the loop coil surface of the resonance circuit of the ATS ground element. Therefore, the mutual inductance with the resonance circuit of the ATS ground element is large, and the induced current flows more easily than other reinforcing bar portions. Therefore, the closed circuit formed in the direction facing the resonance circuit loop coil surface of the ATS ground element greatly affects the Q value reduction and the change of the resonance frequency of the ATS ground element. However, from the viewpoint of ensuring the strength of the sleepers, it is desirable that the reinforcing bars are in contact with each other, and it is not preferable in terms of strength to prevent a closed circuit from being formed by a reinforcing bar structure in which the reinforcing bars do not contact each other.

  Therefore, as described in claim 1, at least a contact portion between the reinforcing bars is insulated with an insulating material so that the reinforcing bars do not come into electrical contact with each other, and a closed circuit is not formed in the annular reinforcing bar structure. By configuring, the mutual inductance with the resonance circuit of the ATS ground element can be reduced, and the induced current flowing in the reinforcing bar can be kept low. Accordingly, it is possible to suppress the Q value lowering of the ATS ground element and the change of the resonance frequency. Therefore, the signal display information can be more reliably transmitted from the ATS ground unit to the vehicle upper unit, and the service life of the ATS ground unit can be extended. In addition, since the reinforcing bars are not in electrical contact but are in physical contact, it is possible to maintain the strength of the sleepers while suppressing a decrease in the Q value of the ATS ground element and a change in the resonance frequency. Note that “physical contact” as used herein means that even if the reinforcing bars are not in direct contact with each other, the reinforcing bars are mechanically connected to each other as in the case where the reinforcing bars are in direct contact with each other through an insulating material. It refers to the state of maintaining the strength of the concrete by acting on.

  As a means for insulating the reinforcing bars, epoxy resin or the like is used as an insulating material, and this is applied to the reinforcing bars, or a synthetic resin spacer or the like is used as an insulating material. There are methods such as wearing or interposing.

  By the way, the notch PC sleeper used as a sleeper for installing the ATS ground element is provided with a notch for accommodating the cable of the ATS ground element. In order to reinforce the notch, the notched PC sleeper has a plurality of reinforcing bars such as reinforcing bars and stirrups arranged along the longitudinal direction of the sleeper, in addition to the PC steel bar that is a tension material for the PC sleeper. Has been placed. A plurality of reinforcing bars arranged along the longitudinal direction of the sleepers, including at least a PC steel bar, and a plurality of stirrups arranged so as to surround the reinforcing bars from the side contact each other to form an annular arrangement. Many muscle structures are formed. The annular bar arrangement structure forms a closed circuit, so that an induced current easily flows through the reinforcing bar inside the sleeper, and greatly affects the Q value decrease and the resonance frequency change of the ATS ground element. Especially, the influence by the closed circuit formed in the direction facing the loop coil surface of the resonance circuit of the ATS ground element is particularly large.

  Therefore, as described in claim 2, at least the contact portion between the reinforcing bar and the stirrup arranged in the longitudinal direction of the sleeper is insulated with an insulating material so as not to form a closed circuit in the annular bar arrangement structure. As a result, the mutual inductance with the resonance circuit of the ATS ground element can be reduced, and the induced current flowing in the reinforcing bar can be kept low. Accordingly, it is possible to suppress the Q value lowering of the ATS ground element and the change of the resonance frequency. In addition, since the reinforcing bars are not in electrical contact but are in physical contact, it is possible to maintain the strength of the sleepers while suppressing a decrease in the Q value of the ATS ground element and a change in the resonance frequency.

  In order to prevent a closed circuit from being formed in the annular reinforcing bar structure by insulating the contact portion between the reinforcing bar and the stirrup arranged in the longitudinal direction of the sleeper with an insulating material, At least a part of the stirrup may be insulated with an insulating material as described, or at least a part of the plurality of reinforcing bars arranged along the longitudinal direction of the sleeper as described in claim 4 is insulated with an insulating material By doing so, a closed circuit may not be formed in the above-described annular reinforcing structure. In addition, as a method for insulating these reinforcing bars by attaching an insulating material, epoxy resin or the like is used as the insulating material, and this is applied to the reinforcing bars, or a synthetic resin spacer or the like is used as the insulating material. There is a method of attaching this to the reinforcing bar of the part to be done.

  Embodiments to which the present invention is applied will be described below with reference to the drawings. The embodiments of the present invention are not limited to the following examples, and can take various forms as long as they belong to the technical scope of the present invention.

[Configuration of cutout PC sleeper 1]
FIG. 1 is a perspective view showing a configuration of a notched PC sleeper 1 according to an embodiment of the present invention. Here, the long side direction is defined as the long side direction and the short side direction as the short side direction as viewed from above the cutout PC sleeper 1.

  The notched PC sleeper 1 of the embodiment is a PC sleeper for installing an ATS ground element (not shown), and the ATS ground element is disposed above the center portion of the concrete main body 2. The upper surface of the main body 2 is notched along the longitudinal direction so that the cross section of the main body 2 has a convex shape, and the cable is obstructed in the track maintenance work by accommodating the cable attached to the ATS ground element in this notched portion. It is trying not to become.

  As shown in FIG. 2, inside the notch PC sleeper 1 are four PC steel bars 20 which are tension members of known PC sleepers, and along the longitudinal direction at predetermined intervals so as to surround the PC steel bars 20. Two types of square stirrups 10a and 10b arranged side by side, eight assembly stirrups 30 arranged in the longitudinal direction so as to be inscribed in the ends of the stirrup 10b, and a PC Four supporting pressure plates 40 that are respectively engaged with both ends of the steel bar 20 are arranged. Thus, in the notched PC sleeper 1, in addition to the PC steel rod 20 and the bearing plate 40 for introducing prestress into the notched PC sleeper 1, the stirrups 10 a and 10 b and the assembly bars 30 are provided at the center inside the main body 2. By arranging the cable, the notch for accommodating the cable is reinforced so that the strength is not insufficient. In this embodiment, the PC steel bar 20 and the assembly bar 30 correspond to a plurality of reinforcing bars arranged along the longitudinal direction in claim 1, and the stirrups 10a and 10b are arranged along the short direction in claim 1. It corresponds to a plurality of reinforcing bars.

In addition, in the notch PC sleeper 1 of an Example, the star wrap 10a, 10b is entirely coat | covered with the insulating material 50, as shown in FIG.
As shown in FIG. 2, a total of four PC steel bars 20 are arranged along the longitudinal direction at predetermined intervals in two rows in the vertical direction of the notched PC sleeper 1 and in two rows in the short direction. One end of the PC steel bar 20 is provided with a bulging portion that engages with an edge of a hole provided in the bearing plate 40, and the other end is provided with a screw. The PC steel rod 20 is inserted into two holes provided in the bearing plate 40 as a pair of upper and lower two pieces, and is engaged with the bearing plate 40 at the bulge portion provided at one end of the PC steel rod 20, Further, a nut (not shown) is engaged with a screw provided at the other end to engage with the bearing plate 40. After the body 2 is molded, the nut is rotated in the tightening direction, and the bulging portion of the PC steel bar 20 and the nut are fixed to the bearing plate 40, whereby the PC steel bar 20 is tensioned and prestressed in the notched PC sleeper 1. It has been introduced.

  The stirrups 10a and 10b are formed by bending reinforcing bars into a square shape, and are arranged side by side in the longitudinal direction at predetermined intervals so as to surround the PC steel bar 20 and the assembly bar 30 from the side. The stirrups 10a and 10b have different widths and heights, and by combining them, a convex shape corresponding to the cross-sectional shape of the main body 2 is formed, and the PC steel rod 20 and the assembly bar are formed on the combined stirrups 10a and 10b. 30 is inscribed. Note that the stirrups 10a and 10b are joined by overlapping the ends of the reinforcing bars to ensure strength, and the stirrups 10a and 10b themselves form a closed circuit. However, when the stirrups 10a and 10b are installed in the main body 2, the closed circuit is positioned in a direction perpendicular to the loop coil surface of the ATS ground element and does not face each other. The impact on performance is small.

  FIG. 3A shows a state in which an annular bar arrangement structure is formed by contacting the upper two of the four PC steel bars 20 with the upper portion of the stirrup 10a. b) shows a state in which an annular bar arrangement structure is formed by contacting the lower two of the four PC steel bars 20 and the assembly bars 30 with the lower portions of the stirrups 10a and 10b. Yes. Thus, the annular bar arrangement structure formed by contacting the stirrups 10a, 10b with the PC steel bar 20 and the assembly bar 30 is the loop coil of the ATS ground unit installed on the notched PC sleeper 1. It is formed in the direction facing the surface.

  However, in the cutout PC sleeper 1 of the embodiment, the stirrups 10a and 10b are entirely covered with the insulating material 50 as shown in FIG. Accordingly, as shown in FIGS. 3 (a) and 3 (b), the stirrup 10a, 10b, the PC steel rod 20 and the assembly bar 30 are brought into contact with each other to form the stirrup 10a. Since 10b is insulated by the insulating material 50, an electrical closed circuit is not formed. In addition, in the Example, the epoxy resin etc. are used as the insulating material 50, and this is apply | coated to the whole star wrap 10a, 10b, and the contact part of reinforcing bars is insulated.

[Test results]
In order to verify the effect of the cutout PC sleeper 1 of the example, the ATS ground piece was installed in the cutout PC sleeper 1 of the example and the cutout PC sleeper that did not insulate the reinforcing bars, and was installed on each sleeper. A test for measuring the Q value of the ATS ground element and the resonance frequency f [Hz] was performed, and the results will be described.

  The cutout PC sleepers used in the test are the sleeper A which is the cutout PC sleeper 1 of the embodiment (the epoxy resin is applied to the entire star wrap 10a, 10b), and the cutout PC sleeper which does not insulate the reinforcing bars. There are two types of sleepers B. The sleeper A and the sleeper B have the same size, shape, bar arrangement structure, and the like except that there is a difference in whether or not the reinforcing bars are insulated.

  As shown in FIG. 5 (a), the ATS ground element is installed at the center of each of the sleepers A and B so that the upper surface of the ATS ground element is located at a height of 137 mm from the upper surface of the central part of the sleeper. A test was conducted. In the test, the ATS ground installed on the sleepers A and B under initial conditions of Q = 150, 200 as the initial value of Q and f = 103 kHz, 130 kHz as initial values of the resonance frequency f [Hz]. The Q value of the child and the resonance frequency f [Hz] were measured.

  FIG. 5B shows the Q value and the resonance frequency f for each initial condition of the ATS ground pieces installed on the sleepers A and B calculated based on the Q value and the resonance frequency f [Hz] measured by the test. It is a table | surface which shows the change rate of [Hz]. In addition, about the numerical value of the change rate in a table | surface, the positive numerical value has shown that it increased from the initial value, and the negative numerical value shows that it fell from the initial value. As apparent from the table of FIG. 5 (b), the sleeper A in which the stirrups 10a and 10b are insulated as compared with the sleeper B in which the reinforcing bars are not insulated has a change rate of the Q value of about 9 to 13%, The change rate of the resonance frequency f [Hz] is improved by about 0.13 to 0.15%. From this test result, it has been demonstrated that the ATS ground element's Q value reduction and resonance frequency change can be suppressed by insulating the reinforcing bars inside the sleepers so that a closed circuit is not formed in the annular reinforcement structure. It was done.

[effect]
The cutout PC sleeper 1 of the embodiment has the following effects.
(1) Since the stirrups 10a and 10b are insulated with the insulating material 50 so as not to form a closed circuit in the annular bar arrangement inside the notched PC sleeper 1, mutual connection with the resonance circuit of the ATS ground unit is achieved. The inductance can be reduced, and the induced current flowing in the reinforcing bar can be kept low. Accordingly, it is possible to suppress the Q value lowering of the ATS ground element and the change of the resonance frequency. By suppressing the decrease in the Q value and the change in the resonance frequency, the signal display information can be transmitted more reliably, and the service life of the ATS ground unit can be extended.

  (2) Since the reinforcing bars are in physical contact even if they are not in electrical contact, the sleeper strength can be maintained while suppressing a decrease in the Q value of the ATS ground element and a change in the resonance frequency.

[Another embodiment]
As a configuration in which a closed circuit is not formed in an annular bar arrangement structure in a sleeper, various other embodiments as shown below can be considered.

  (1) As shown in FIG. 6 (a), an annular reinforcing bar is provided by insulating only the vicinity of the portions of the stirrups 10a, 10b in contact with the PC steel rod 20 and the assembly bar 30 with an insulating material 50. You may comprise so that a closed circuit may not be formed in a structure.

(2) As shown in FIG. 6B, the PC steel bar 20 and the assembly bar 30 may be insulated by an insulating material 50 so that a closed circuit is not formed in the annular bar arrangement structure.
(3) As shown in FIG. 6 (c), an insulating material 50 is used to insulate only the vicinity of the portions of the PC steel bar 20 and the assembly bar 30 that are in contact with the stirrups 10a and 10b. You may comprise so that a closed circuit may not be formed.

  As a means for insulating the reinforcing bar, when insulating a part of the reinforcing bar as shown in FIGS. 6A and 6C, a synthetic resin spacer or the like is used as the insulating material 50, and this is used as the reinforcing bar. In the case of mounting or insulating the entire reinforcing bar as shown in FIG. 6B, various methods are conceivable, such as using an epoxy resin or the like as the insulating material 50 and applying it to the entire reinforcing bar.

  (4) In the embodiment, the stirrups 10a and 10b are joined by overlapping the ends of the reinforcing bars to ensure strength, and the stirrups 10a and 10b themselves form a closed circuit. These closed circuits are positioned in a direction perpendicular to the loop coil surface of the ATS ground element and do not face each other, so that they do not interfere with each other and have little influence on the electrical performance of the ATS ground element. However, in order to eliminate the influence of the closed circuit, the joint portions between the end portions of the stirrups 10a and 10b may be insulated with the insulating material 50, or may be separated without joining the end portions.

It is a perspective view of the notch PC sleeper 1 of an Example. It is a perspective view which shows the whole bar arrangement structure inside the notch PC sleeper 1 of an Example. It is a perspective view which shows the cyclic | annular bar arrangement structure inside the notch PC sleeper 1 of an Example, (a) is the upper two of the four PC steel bars 20, and the upper part of the stirrup 10a. Shows a state in which an annular bar arrangement structure is formed by contact with each other, (b) shows the lower two of the four PC steel bars 20 and the assembly bars 30 and the lower portions of the stirrups 10a and 10b. Shows that a ring-shaped bar arrangement structure is formed. It is a figure which shows the state which insulated the whole star wrap 10a, 10b of the notch PC sleeper 1 of an Example with the insulating material 50. FIG. It is a figure explaining the test done in order to verify the effect of the notch PC sleeper 1 of an Example. It is a figure which shows another Example of this invention.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 ... Notch PC sleeper, 2 ... Main body, 10a, 10b ... Stirrup, 20 ... PC steel bar, 30 ... Assembly rod, 40 ... Bearing plate, 50 ... Insulating material

Claims (4)

A concrete sleeper for installing an ATS ground unit,
A plurality of reinforcing bars arranged along the longitudinal direction and a plurality of reinforcing bars arranged along the short direction have an annular reinforcing structure formed by contacting each other,
A concrete sleeper characterized in that at least a contact portion between the reinforcing bars is insulated by an insulating material so that the reinforcing bars are not in electrical contact with each other and a closed circuit is not formed in the annular reinforcing bar structure. . In the concrete sleeper of Claim 1,
The plurality of reinforcing bars arranged along the longitudinal direction includes at least a PC steel bar that is a tension material of a prestressed concrete sleeper,
The plurality of reinforcing bars arranged along the short direction are a plurality of stirrups arranged so as to surround the plurality of reinforcing bars arranged along the longitudinal direction from the side. Sleepers. In the prestressed concrete sleeper according to claim 2,
A prestressed concrete sleeper, wherein a contact portion between the reinforcing bars is insulated by attaching an insulating material to at least a part of the stirrup. In the prestressed concrete sleeper according to claim 2,
A prestressed concrete sleeper, wherein a contact portion between the reinforcing bars is insulated by attaching an insulating material to at least a part of the reinforcing bars arranged in the longitudinal direction of the sleepers.