Apparatus, method and program for calculating pole unbalanced load

Abstract

The purpose of the present disclosure is to make it possible to calculate the change in an unbalanced load of a pole when installation conditions of a cable are changed.　In a device and a method according to the present disclosure, when installation conditions of a cable are changed, the pole on which said cable is installed is considered to be a target pole, and the tension of each cable installed on the target pole and an unbalanced load of the target pole are computed.

Description

[Technical field]

[0001] The present disclosure relates to a technique for eliminating unbalanced loads that occur on poles due to differences in the installation conditions of cables such as power lines and telephone lines that are installed on poles such as utility poles and signal poles that are mainly located outdoors. [Background technology]

[0002] Traditionally, when installing a pole, the resultant force of the tension generated by the cable to be installed on the pole and the load of other accessories is taken into consideration. This becomes the resultant load acting on the pole (unbalanced load). The type of pole to be used is then determined based on this unbalanced load, along with the effects of uncertain factors such as wind pressure and soil hardness.

[0003] Design loads are set for each type of pole as a standard for the load that can be tolerated, and when the designer actually constructs the pole, he or she selects a pole with a design load that can withstand the load that will occur after considering the unbalanced load mentioned above, as well as the effects of uncertainties such as the strength of wind pressure and the hardness of the soil. Also, depending on the direction of the unbalanced load, guys and supports may be installed in a direction that offsets the unbalanced load to prevent the pole from collapsing. In this way, the type of pole to be used is determined by assuming the unbalanced load acting on the pole depending on the magnitude and direction of the tension generated by the cable to be laid, and preventing the pole from deforming or cracking that could lead to destruction due to this unbalanced load.

[0004] Currently, it is assumed that the unbalanced load on the pole will not change from the design conditions (magnitude, direction) except when a new cable is laid. However, in reality, there is a risk that the unbalanced load conditions will worsen from the design conditions due to unevenness during construction or exposure to the external environment over time, causing deformation of the pole and cracks that may lead to destruction. The occurrence of such unbalanced loads and the resulting deformation and cracks in the pole are currently discovered through regular inspections, but in many cases the only solution is to replace the pole with one that can withstand a larger design load, which incurs huge renewal costs.

[0005] In addition, there are cases where construction is carried out to eliminate unbalanced loads by changing the cable slack if there is slack in the cable, or by changing the pole position if site negotiations are possible, but in actual construction, the extent to which the unbalanced load can be eliminated by changing the slack or pole position is not calculated, but is determined on-site at the time of construction.Currently, when attempting to evaluate unbalanced loads, the cable tension is calculated using the tension T (kN), cable load per unit length w (kN / m), span length S (= distance between cable installation positions) (m), actual cable length L (m), and cable slack d (m) (see Non-Patent Document 1). [Prior art documents] [Patent documents]

[0006] [Patent Document 1] Patent Publication 2020-98126, "Equipment status detection device, equipment status detection method, and program" (NTT) [Non-patent literature]

[0007] [Non-Patent Document 1] "Sag of Overhead Transmission Lines", Hideyo Takeshita, published September 15, 1966 Summary of the Invention [Problem to be solved by the invention]

[0008] In theory, it is possible to calculate the amount of change in span length required to adjust the tension as desired, but in reality, when the tension in the relevant span changes, the unbalanced load changes, causing the pole to deform and the span length to change, which will not match the tension calculated previously.

[0009] An object of the present disclosure is to make it possible to calculate the change in unbalanced load of a pole when the cable installation conditions are changed. [Means for solving the problem]

[0010] Therefore, this disclosure is characterized by taking advantage of the fact that the cable tension differs depending on the cable installation conditions, and evaluating the unbalanced load on the pole before and after changing the cable installation conditions by formulating the balance of forces acting on the pole.

[0011] The apparatus and method according to the present disclosure include: When the cable installation conditions are changed, the pole on which the cable is installed is considered as the target pole, The tension of each cable installed on the target pole and the unbalanced load on the target pole are calculated.

[0012] The program of the present disclosure is a program for causing a computer to realize each functional unit of an apparatus of the present disclosure, and is a program for causing a computer to execute each step of a method performed by an apparatus of the present disclosure. Effect of the Invention

[0013] According to the present disclosure, it is possible to calculate the change in the unbalanced load on the pole when the cable installation conditions are changed, and to determine the cable installation conditions that eliminate the unbalanced load. [Brief description of the drawings]

[0014] [Figure 1] FIG. 13 is a flow diagram of the process for eliminating an unbalanced load performed by the device of the present disclosure. [Diagram 2] FIG. 11 is an explanatory diagram of information required for calculating cable tension. [Diagram 3] FIG. 1 is an explanatory diagram of mechanical elements acting on a pole. [Figure 4] 11A and 11B are explanatory diagrams showing examples of deformation of a pole. [Diagram 5] FIG. 13 is a flow chart of an example of convergence calculation of a force balance equation. [Figure 6] FIG. 13 is an explanatory diagram of feedback to cable tension T due to changes in pole deformation Δ. [Figure 7]FIG. 13 is an explanatory diagram of an image of eliminating an unbalanced load by changing the actual length. [Figure 8] Here is an example of the relationship between cable tension T and actual length L. [Figure 9] FIG. 13 is an explanatory diagram of an image of eliminating unbalanced load by changing the span length. [Figure 10] FIG. 13 is an explanatory diagram of an image of eliminating unbalanced load by changing the sag. [Figure 11] FIG. 11 is an explanatory diagram of an example of the impact when the cable installation conditions (actual length, span length, sag, etc.) of the facility system are changed. (a) shows the cable installation conditions before the change, and (b) shows the cable installation conditions after the change. [Figure 12] FIG. 13 is an explanatory diagram of an example of an unbalanced load generated on a pole. [Figure 13] These are examples of pole-to-cable connection configurations, where (a) shows a retained connection and (b) shows a pulled-through connection. [Figure 14] FIG. 2 is a functional block diagram of the first embodiment. [Figure 15] FIG. 11 is a functional block diagram of a second embodiment. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0015] Hereinafter, the embodiments of the present disclosure will be described in detail with reference to the drawings. Note that the present disclosure is not limited to the embodiments shown below. These implementation examples are merely illustrative, and the present disclosure can be implemented in various forms with various modifications and improvements based on the knowledge of those skilled in the art. Note that components with the same reference numerals in this specification and drawings are assumed to indicate the same components.

[0016] (Example 1) A functional block diagram for implementing this embodiment is shown in FIG. 14. The device according to this embodiment includes an unbalanced load calculation unit 12 and a cable installation condition calculation unit 13. A method executed by the device according to this embodiment is shown in FIG. 1. In the device according to this embodiment, the unbalanced load calculation unit 12 calculates the unbalanced load acting on the pole (S11), the cable installation condition calculation unit 13 determines the cable installation conditions (actual length, span length, sag, etc.) for eliminating the unbalanced load (S12), and determines an implementation method for realizing the above cable installation conditions (actual length, span length, sag, etc.) (S13). The device of the present disclosure can also be realized by a computer and a program, and the program can be recorded on a recording medium or provided via a network. The following will explain in detail.

[0017] First, step S11 will be described. To calculate the unbalanced load acting on the pole 91, it is necessary to calculate the tension of the cable 92 laid on the pole 91. Figure 2 illustrates the conditions required to calculate the tension of the cable 92 laid between two poles 91. Here, T is the tension (kN), w is the load of the cable 92 per unit length (kN / m), S is the span length (i.e., the distance between the laying positions of the poles 91) (m), L is the actual length of the cable 92 (m), and d is the slackness of the cable 92 (m). At this time, the tension T generated in the cable 92 is expressed by formula (1) or formula (2).

number

number

[0018] Here, w is a numerical value defined for each cable 92 to be laid. S, L, and d represent the laying conditions of the cable 92, and an example of a method for measuring S, L, and d is to obtain them as three-dimensional point cloud data in which the surface of the cable 92 is expressed by points in three-dimensional coordinates (see Patent Document 1).

[0019] Next, step S12 will be described. Specifically, a method for determining cable installation conditions (actual length, span length, sag, etc.) for eliminating the unbalanced load based on the calculated unbalanced load will be described. Figure 3 shows the mechanical elements acting on a pole 91, and includes tensions T1, T2, etc. of a cable 92 installed on the pole 91 and a reaction force F caused by deformation of the pole 91 due to the unbalanced load. The balance of forces between these forces can be considered as given by the following formula (3). (Number 3) (ΣT n )+F=0 (3)

[0020] Equation (3) can be considered for each pole 91. Also, the reaction force F caused by the deformation of the pole 91 due to the unbalanced load can be considered as in equation (4). (Number 4) F = f(Δ) (4) Here, Δ represents the deformation of the pole 91 and can be expressed, for example, by the head displacement 83 of the pole 91 (FIG. 4). The head displacement 83 can be calculated, for example, from the horizontal distance between the vertical axis 81 of the pole 91 and the cable installation position 82.

[0021] In this case, consider calculating each element of equation (3) from equations (1), (2) and (4) when the cable installation conditions (actual length, span length, sag, etc.) are changed. The flow for determining the cable tension T and unbalanced load after changing the cable installation conditions (actual length L, span length S, sag d, etc.) is shown in Fig. 5. The cable tension when the cable installation conditions (actual length, span length, sag, etc.) are changed can be calculated from formula (1) or formula (2) using the changed actual length L, span length S, and sag d (Fig. 5, step b). On the other hand, when the tension of the cable 92 changes, the unbalanced load changes, and the reaction force F of the pole 91 also changes (F'), which can be calculated from equation (3) (FIG. 5, step c).

[0022] At this time, the reaction force of the pole changes to F', and so the "pole deformation Δ" also changes (Step d in Figure 5). Now consider the effect on the tension T of cable 92 of the change in pole deformation Δ. For example, if the horizontal distance (= head displacement 83) between the "vertical axis 81 of the pole from the ground" and the "cable installation position 82" is considered as the "pole deformation Δ," then "head displacement 83 = change in span length" (Figure 6), and based on the changed span length, the tension T of cable 92 is recalculated using formula (1) or formula (2) (Step e in Figure 5).

[0023] At this time, the convergence of the equilibrium equation is judged by equation (5) using the tension of cable 92 and the reaction force of pole 91 obtained from steps c and e in FIG. 5 (step f in FIG. 5). (Number 5) (ΣT n )+F≦A (5)

[0024] Here, A is a threshold for determining convergence and is set to a sufficiently small value. Repeated calculations are performed (Figure 5-c→d→e→f→c...) until formula (5) is satisfied.

[0025] The cable tensions T1', T2'... when equation (5) is satisfied can be considered as the cable tensions after the change in cable installation conditions (actual length, span length, sag, etc.). Using this, the unbalanced load after the change in cable installation conditions (actual length, span length, sag, etc.) can be calculated using equation (6). (Number 6) Unbalanced load = (ΣT n ') (6)

[0026] Here, the convergent calculations in Figure 5 can be considered as a group of calculations, and can be considered as function g that calculates the “unbalanced load on the pole” from the “changed cable installation conditions (actual length, span length, sag, etc.)” (equation (7)). (Number 7) (Unbalanced load on the pole) = g (changed cable installation conditions) ≦ B (7)

[0027] Here, B is a threshold value that is set to a sufficiently small value. By determining the cable installation conditions (actual length, span length, sag, etc.) that satisfy equation (7), it is possible to calculate the cable installation conditions (actual length, span length, sag, etc.) that eliminate the unbalanced load.

[0028] The above series of processes can be considered as function h, which calculates the "cable installation conditions (actual length, span length, sag, etc.) after the unbalanced load is eliminated" from the "unbalanced load on the pole" (equation (8)). (Number 8) (Cable installation condition after removing the unbalanced load) = h (unbalanced load on the pole) (8)

[0029] Since there are multiple cable installation conditions (actual length, span length, sag, etc.) that satisfy equation (8) depending on the calculation conditions, the optimal cable installation conditions and how to actually achieve them are described below.

[0030] First, actual construction methods for changing the parameters of the cable installation conditions, namely, actual length, span length, and sag, will be considered in the following steps S31 to S33.

[0031] Step S31: Changing the actual length Let us consider the elimination of the unbalanced load by "changing the actual length of the high tension span." Since the actual length and tension of the cable 92 are inversely proportional (Equation (2) and Figure 8), it is possible to eliminate the unbalanced load by "extending the actual length of the high tension span." Therefore, the unbalanced load can be eliminated by increasing the actual length to the result calculated by Equation (8).

[0032] Specifically, as shown in Fig. 7, a member 71 is inserted into the connection between a pole 91 and a cable 92 to increase the actual length L of the cable 92. By preparing members 71 of multiple lengths and selecting an appropriate member 71, it is possible to achieve a desired increase in the actual length L. This method can also be implemented when there is no interference from other accessories 73 such as metal fittings at the connection between the pole 91 and the cable 92 (= the laying position), the connection between the pole 91 and the cable 92 is in a "retaining" form (Fig. 13(a)), and the cable 92 has slack. When the connection between the pole 91 and the cable 92 is in a "retaining" form, the support 72 for the cable 92 is divided into the left and right sides of the pole 91 and is connected to the pole 91 via other accessories 73.

[0033] Step S32: Changing the span length Let us consider the elimination of the unbalanced load by changing the position of the pole 91. The unbalanced load can be eliminated by relocating the pole 91 to a position that satisfies the cable installation conditions (actual length, span length, sag, etc.) calculated by formula (8) (Fig. 9). This method can be implemented if the conditions such as the extra cable length, land negotiations with the landowner, and the ground conditions at the new location are met.

[0034] Step S33: Changing the slack Let us consider the elimination of unbalanced load by changing the sag. When there is sag in the cable 92 at the cable fixing point of the pole 91, the sag can be changed using the sag in the cable installation conditions (actual length, span length, sag, etc.) calculated by formula (8), thereby eliminating the unbalanced load (Fig. 10). This method can also be implemented when there is no obstruction from other metal fittings or other accessories 72 at the connection point (=laying position) between the pole 91 and the cable 92, the connection between the pole 91 and the cable 92 is "pulled through" (Fig. 13(b)), and the cable 92 has sag. When the connection between the pole 91 and the cable 92 is "pulled through", the support 72 for the cable 92 is not separated between the left and right sides of the pole 91, and is fixed to the pole 91 via other accessories 73.

[0035] In this way, whether the cable installation conditions (actual length, span length, slack, etc.) can be realized depends on the (i) The condition of the cradle position; (ii) The connection form (pulling through, retaining) of the pole 91 and the cable 92; (iii) the status of surrounding land negotiations; Varies depending on various conditions such as:

[0036] These can be collectively referred to as the "implementation conditions of the construction method", and can be specified as a function k that determines the "optimum cable installation conditions (actual length, span length, sag, etc.) and implementation method to eliminate the unbalanced load" from the "unbalanced load of the pole" and the "implementation conditions of the construction method" (Equation 9). (Number 9) (Optimal cable installation conditions and implementation methods for eliminating unbalanced loads) = k (unbalanced load of pole, construction method implementation condition)) (9)

[0037] As described above, the device and method according to the present embodiment include: Step S1 of calculating the cable tension T based on the installation conditions of the cable 92 using formula (1) or formula (2); Step S2 of calculating the reaction force F and the deformation amount Δ of the pole 91 based on the tension T of the cable 92 obtained by using the formulas (3) and (4); Step S3 of recalculating the tension T of the cable 92 based on the calculated deformation amount Δ of the pole 91; Step S4: determining whether or not the balance equation (5) has converged based on the reaction force F of the pole 91 obtained in step S2 and the tension T of the cable 92 obtained in step S3; If it is determined in step S4 that convergence has not occurred, steps S2 to S4 are repeatedly executed, and if it is determined that convergence has occurred, an unbalanced load on the pole is calculated based on the tension of the cable thus obtained in step S5; This makes it possible to calculate the change in the unbalanced load on the pole 91 when the installation conditions of the cable 92 are changed, and to obtain the installation conditions of the cable 92 that eliminate the unbalanced load.

[0038] (Example 2) A functional block diagram for implementing this embodiment is shown in Fig. 15. When the cable installation conditions (actual length, span length, sag, etc.) are changed to eliminate the unbalanced load, the tension of the cable installed on the adjacent pole also changes, so the effect of this can be considered by replacing the flow of step S12 in the first embodiment with the following:

[0039] The poles and the cables installed on those poles are collectively referred to as the "facility system," and an example is shown in Figure 11. In order to eliminate the unbalanced load on pole 91-3, consider changing the installation conditions of cable 92-3 between poles 91-3 and 91-4. The loads T1' and T2' of the cable installed on pole 91-3, which are caused by changing the installation conditions of cable 92-3 between poles 91-3 and 91-4, can be considered as shown in formula (10). (Number 10) (Tension of cable laid on pole 91-3: T1', T2') =g (changed cable installation conditions between poles 91-3 and 91-4) (10)

[0040] In this way, starting from pole 91-3 for which it is desired to eliminate the unbalanced load, the tension of the cable 92 laid on each pole 91 due to changes in the cable laying conditions (actual length, span length, sag, etc.) can be calculated in order. As a series of these calculations, a function j for calculating the unbalanced load on each pole of the facility system when the laying conditions (actual length, span length, sag, etc.) of a certain cable 92 are changed can be considered (Equation (11)). (Number 11) (Unbalanced load on pole X) = j (changed cable installation condition) (11)

[0041] As in the first embodiment, by considering h as a function that calculates “cable installation conditions (actual length, span length, sag, etc.) after eliminating the unbalanced load” from “unbalanced load on the pole,” it is possible to obtain the cable installation conditions (actual length, span length, sag, etc.) for eliminating the unbalanced load on a certain pole X in terms of an equipment system (Equation 12). (Number 12) (Cable installation conditions after unbalanced load is eliminated) =h(unbalanced load on pole X) (12)

[0042] (Effects of the present disclosure) According to the present disclosure, it is possible to calculate how the unbalanced load generated in pole 91 changes when the installation conditions (actual length, span length, slack, etc.) of cable 92 connected to pole 91 on which an unbalanced load is generated are changed.

[0043] Specifically, the balance of forces between the tension of the cable 92 connected to the pole 91 and the reaction force caused by the deformation of the pole 91 due to an unbalanced load can be considered as a mechanical element acting on each pole 91. In addition, by determining the relationship between the "tension of the cable" and the cable installation conditions (actual length, span length, sag, etc.) and the relationship between the "reaction force caused by the deformation of the pole due to an unbalanced load" and the displacement of the cable installation position on the pole (head displacement), it is possible to calculate the unbalanced load on the pole 91 before and after the change in cable installation conditions more accurately than before.

[0044] As a result of the above, when an unbalanced load occurs on the pole 91, it is possible to calculate what kind of cable 92 installation conditions would be necessary to eliminate the unbalanced load. This can also be used to consider materials and efficient construction methods to achieve the cable 92 installation conditions, contributing to the efficiency and cost reduction of current construction methods for eliminating unbalanced loads. Furthermore, from the perspective of early elimination of unbalanced loads, it can contribute to the prevention of future cracks and pole breakage, i.e., the realization of long-term safe use of facilities. [Industrial Applicability]

[0045] The present disclosure can be applied to the information and communications industry. [Explanation of symbols]

[0046] 71: Materials 72:Support 73: Attachments 91: Paul 92: Cable

Claims

1. Using the actual length of the cable when a member of a different length is inserted into the connection between the target pole and the cable and the reaction force caused by the deformation of the target pole, the tension of the cable when a member of a different length is inserted is calculated, Calculate the unbalanced load of the target pole using the calculated tension of the cable; selecting an actual length of the cable at an appropriate unbalanced load among a plurality of unbalanced loads obtained by calculation as the actual length of the cable to be connected to the target pole; Device.

2. The device calculates the tension of the cable when a member of a different length is inserted into the connection between the target pole and the cable, using the actual length of the cable when the member of a different length is inserted, and the reaction force caused by the deformation of the target pole, The device calculates the unbalanced load of the target pole using the calculated tension of the cable; The device selects an actual length of the cable at an appropriate unbalanced load among a plurality of unbalanced loads obtained by calculation as an actual length of the cable to be connected to the target pole. method.

3. A step of calculating the tension of the cable when a member of a different length is inserted into the connection between the target pole and the cable, using the actual length of the cable when a member of a different length is inserted into the connection between the target pole and the cable, and the reaction force caused by the deformation of the target pole; calculating an unbalanced load on the target pole using the calculated tension of the cable; a step of selecting an actual length of the cable at an appropriate unbalanced load among a plurality of unbalanced loads obtained by calculation as an actual length of the cable to be connected to the target pole; A program for causing a computer to execute the following.

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