Pipeline renovation plan formulation system and pipeline renovation plan formulation method
Patent Information
- Application Number
- PCT/JP2026/008137
- Authority / Receiving Office
- WO · WO
- Patent Type
- Applications
- Current Assignee / Owner
- Priority Date
- 2025-03-25
- Filing Date
- 2026-03-04
- Publication Date
- 2026-10-01
Smart Images
Figure JP2026008137_01102026_PF_FP_ABST
Abstract
Description
Pipeline replacement planning system and pipeline replacement planning method
[0001] The present invention relates to a pipeline renewal plan formulation system and a pipeline renewal plan formulation method for preparing for natural disasters such as earthquakes.
[0002] It is desirable to rebuild a disaster-resilient pipeline network by predicting the damage to pipelines caused by natural disasters such as earthquakes, landslides, volcanic eruptions, and floods, and prioritizing the replacement of pipelines that are expected to suffer significant damage.
[0003] For example, as a method for predicting damage caused by earthquakes, the damage estimation formula Rm(v) shown in Figure 8A, proposed by the Japan Water Works Association (JWWA), and the damage estimation formula Rm(v) shown in Figure 8B, proposed by the Japan Water Research Center (JWRC), are used.
[0004] The former is the standard damage rate R(v) based on the maximum surface velocity v (= 3.11 × 10⁻¹⁰ ―３ × (v-15) １．３０ ) is obtained by multiplying by the pipe type correction coefficient Cp, the diameter correction coefficient Cd, the terrain correction coefficient Cg, and the liquefaction correction coefficient Cl. The latter is classified according to the presence or absence of liquefaction, and in the case of no liquefaction, the standard damage rate R(v) (= 9.92 × 10) is based on the maximum surface velocity v. ―３ × (v-15) １．１４ ) is obtained by multiplying by the pipe type correction coefficient Cp, the diameter correction coefficient Cd, and the terrain correction coefficient Cg, and in the case of liquefaction, the liquefaction standard damage rate R Ｌ It is obtained by multiplying this by the pipe type correction coefficient Cp and the bore diameter correction coefficient Cd.
[0005] In all cases, each correction coefficient is a value obtained using methods such as multiple regression analysis based on the energy and damage situation of past earthquakes (number of damage cases per pipe length (damage rate) [cases / km]).
[0006] Therefore, the values calculated using the damage estimation formula Rm(v) based on the terrain correction coefficient Cg set for each mesh were adopted as damage prediction information for pipelines laid in that mesh.
[0007] On the other hand, Patent Document 3 proposes a buried pipe replacement timing prediction device that includes a buried pipe attribute data acquisition unit for acquiring attribute data of buried pipes, the attribute data including a first environmental factor including the soil type and soil resistance of the buried pipe, a first burial period and an allowable corrosion depth, and a pipe replacement timing prediction unit that further calculates the time at which the corrosion depth of the buried pipe reaches the allowable corrosion depth from the corrosion depth prediction model for the first environmental factor, the first burial period and the allowable corrosion depth and outputs the time at which the corrosion depth reaches the allowable corrosion depth.
[0008] Japanese Patent Publication No. 2001-329574, Japanese Patent Publication No. 2004-310307, Japanese Patent Publication No. 2021-56224
[0009] However, with the pipeline damage prediction information calculated on a mesh basis as described in Patent Documents 1 and 2, the damage prediction information for multiple pipelines laid in the same mesh becomes the same value, making it difficult to properly evaluate which pipeline should be updated first.
[0010] Furthermore, Patent Document 3 discloses a buried pipe replacement timing prediction device that determines the timing of pipe replacement based on the leakage accident rate [incidents / year / km] that occurs due to deterioration such as corrosion of pipelines during normal times. However, the damage estimation formula Rm(v) for disasters has a unit of [incidents / km] and does not take time into account, making it difficult to treat it in the same way as the buried pipe replacement timing prediction during normal times when formulating pipeline replacement plans.
[0011] The objective of the present invention is to provide a pipeline renewal planning system and a pipeline renewal planning method that can formulate renewal plans with high economic efficiency while reducing the extent of damage, while utilizing damage estimation formulas for disasters.
[0012] To achieve the above objective, the first characteristic configuration of the pipeline renewal plan formulation system according to the present invention is a pipeline renewal plan formulation system that formulates a renewal plan for each pipeline constituting a pipeline network according to calculation processing by a processor, comprising: a pipeline data acquisition unit that acquires pipeline data constituting the pipeline network necessary for formulating the pipeline renewal plan; a disaster damage rate calculation unit that calculates a predicted value of the disaster damage rate [incidents / km] at a predetermined time for each pipeline; a hydraulic analysis unit that performs hydraulic analysis of the pipeline network based on the pipeline data; a first estimation process that starts the hydraulic analysis unit under the assumption that multiple leakage accidents have occurred simultaneously in multiple specific pipelines based on the predicted value of the disaster damage rate [incidents / km], and estimates the pipelines where water outages have occurred based on the results of the hydraulic analysis, and The system includes: a water outage pipeline estimation unit that selects one of several specified pipelines as the pipeline to be evaluated, activates the hydraulic analysis unit under the assumption that a water leakage accident occurred simultaneously in the specified pipelines excluding the pipeline to be evaluated, and repeats the process of estimating the pipeline where the water outage occurred based on the results of the hydraulic analysis for the multiple specified pipelines; a water outage impact calculation unit that calculates the difference between the first water outage impact of each water outage pipeline estimated in the first estimation process and the second water outage impact of each water outage pipeline estimated in the second estimation process as the water outage impact for the pipeline to be evaluated; and an update priority setting unit that sets the update priority for the pipeline to be evaluated based on the water outage impact calculated by the water outage impact calculation unit.
[0013] It can be assumed that leak accidents occur simultaneously in pipelines with relatively high predicted disaster damage rates [cases / km] calculated by the disaster damage rate calculation unit. The pipeline outage estimation unit performs a first estimation process by activating the hydraulic analysis unit based on the assumption that leak accidents occur simultaneously in multiple specific pipelines based on the predicted disaster damage rate [cases / km], and estimating pipelines with a high probability of water outages from the analysis results as pipelines where water outages occur. Furthermore, it selects one of the multiple specific pipelines as the pipeline to be evaluated, activates the hydraulic analysis unit based on the assumption that leak accidents occur simultaneously in the other specific pipelines, and performs a second estimation process by repeating the process of estimating pipelines where water outages occur based on the results of the hydraulic analysis for multiple specific pipelines. The water outage impact calculation unit can calculate the difference between the first water outage impact for each pipeline where water outages occur estimated in the first estimation process and the second water outage impact for each pipeline where water outages occur estimated in the second estimation process as the water outage impact for the pipeline to be evaluated. The renewal priority setting unit evaluates the pipelines under evaluation that show a relatively large impact from water outages as pipelines with a high damage reduction effect and sets the renewal priority accordingly.
[0014] The second characteristic configuration is that, in addition to the first characteristic configuration described above, the water outage occurrence pipeline estimation unit estimates the pipeline where the water pressure falls below a standard value as the water outage occurrence pipeline based on the results of the hydraulic analysis.
[0015] In a hypothetical leak, it can be estimated that a water outage will occur in a pipeline where the water pressure falls below a standard value due to the influence of the leak. The specific value of the standard is not limited and can be set as appropriate.
[0016] The third characteristic configuration is that, in addition to the second characteristic configuration described above, the degree of impact of the water outage is expressed as the product of the estimated value of the disaster damage rate [cases / km], the length of the pipeline in question [km], and the population affected by the water outage [people / case], which is calculated by dividing the amount of water out of the pipeline where the water outage occurred by the amount of water used per person.
[0017] By calculating the impact of water outages as the product of the estimated disaster damage rate [cases / km], the pipeline length [km] of the affected pipeline, and the population affected by the water outage [people / case] (calculated by dividing the amount of water outaged in the pipeline where the water outage occurred by the amount of water used per person), it becomes possible to objectively evaluate the degree of impact of water outages occurring in a hypothetical pipeline with a leak in an event of a water leak, in terms of population.
[0018] The fourth characteristic configuration is that, in addition to the second characteristic configuration described above, the degree of impact of the water outage is expressed as the product of the estimated value of the disaster damage rate [cases / km], the length of the pipeline in question [km], and the number of households affected by the water outage [households / case], which is calculated by dividing the amount of water out of the pipeline where the water outage occurred by the amount of water used per household.
[0019] By calculating the impact of water outages as the product of the estimated disaster damage rate [cases / km], the total length of the pipeline in question [km], and the number of affected households [households / case] obtained by dividing the amount of water outaged in the pipeline where the outage occurred by the amount of water used per household, it becomes possible to objectively evaluate the degree of impact of water outages occurring in a hypothetical pipeline with a water leak in terms of the number of households affected.
[0020] The fifth characteristic configuration is that, in addition to the second characteristic configuration described above, the degree of impact of the water outage is expressed as the product of the estimated value of the disaster damage rate [cases / km], the length of the pipeline in question [km], and the number of households affected by the water outage [households / case], which is the total number of water supply pipes connected to the pipeline where the water outage occurred.
[0021] By calculating the impact of a water outage as the product of the estimated disaster damage rate [cases / km], the pipeline length [km] of the affected pipeline, and the number of households affected by the outage [households / case] (the total number of water supply pipes connected to the pipeline where the outage occurred), it becomes possible to objectively evaluate the degree of impact of a water outage in a hypothetical pipeline with a leak in the number of households affected. This can be easily calculated under the assumption that one water supply pipe is laid to each household from the pipeline that functions as a water distribution pipe.
[0022] The sixth characteristic configuration is that, in addition to any of the third to fifth characteristic configurations described above, the impact of the water outage is also taken into account the number of days required to restore each pipeline in response to a water leak.
[0023] Knowing the estimated number of days required to repair a leak in a hypothetical pipeline allows for a more accurate assessment of the impact of the repair process.
[0024] The first characteristic configuration of the pipeline renewal plan formulation method according to the present invention is a pipeline renewal plan formulation method for formulating renewal plans for each pipeline constituting a pipeline network according to calculation processing by a processor, comprising: a pipeline data acquisition step for acquiring pipeline data constituting the pipeline network necessary for formulating the pipeline renewal plan; a disaster damage rate calculation step for calculating a predicted value of the disaster damage rate [incidents / km] at a predetermined time for each pipeline; a hydraulic analysis step for performing a hydraulic analysis of the pipeline network based on the pipeline data; a first estimation process for performing the hydraulic analysis step under the assumption that multiple leak accidents occurred simultaneously in multiple specific pipelines based on the predicted value of the disaster damage rate [incidents / km], and estimating the pipelines where water outages occurred based on the results of the hydraulic analysis; and evaluating one of the multiple specific pipelines. The system includes: a water outage-occurring pipeline estimation step which involves selecting a pipeline to be evaluated and performing the hydraulic analysis step under the assumption that a water leakage accident occurred simultaneously in the specified pipelines excluding the pipeline to be evaluated, and repeating the process of estimating the pipelines where water outages occurred based on the results of the hydraulic analysis for the multiple specified pipelines; a water outage impact calculation step which calculates the difference between the first water outage impact of each water outage-occurring pipeline estimated in the first estimation process and the second water outage impact of each water outage-occurring pipeline estimated in the second estimation process as the water outage impact to the pipeline to be evaluated; and an update priority setting step which sets an update priority for the pipeline to be evaluated based on the water outage impact calculated in the water outage impact calculation step.
[0025] The second characteristic configuration is that, in addition to the first characteristic configuration described above, the water outage occurrence pipeline estimation step estimates the pipeline where the water pressure falls below a standard value based on the results of the hydraulic analysis as the water outage occurrence pipeline.
[0026] The third characteristic configuration is that, in addition to the second characteristic configuration described above, the degree of impact of the water outage is expressed as the product of the estimated value of the disaster damage rate [cases / km], the length of the pipeline in question [km], and the population affected by the water outage [people / case], which is calculated by dividing the amount of water out of the pipeline where the water outage occurred by the amount of water used per person.
[0027] Said fourth characteristic feature consists in that, in addition to the above-mentioned second characteristic feature, the water outage impact degree is represented by the product of the estimated value of said disaster damage rate [cases / km], the pipeline length [km] of the target pipeline, and the number of water outage affected households [households / cases] obtained by dividing the water outage volume in the water outage-occurring pipeline by the water consumption per household.
[0028] Said fifth characteristic feature consists in that, in addition to the above-mentioned second characteristic feature, the water outage impact degree is represented by the product of the estimated value of said disaster damage rate [cases / km], the pipeline length [km] of the target pipeline, and the number of water outage households [households / cases] which is the total number of water supply pipes connected to the water outage-occurring pipeline.
[0029] Said sixth characteristic feature consists in that, in addition to any one of the above-mentioned third to fifth characteristic features, the water outage impact degree takes into account the number of recovery days for water leakage accidents in each pipeline.
[0030] As explained above, according to the present invention, it becomes possible to provide a pipeline renewal planning system and a pipeline renewal planning method capable of formulating a renewal plan with high economic efficiency while reducing the degree of damage, even while utilizing a disaster damage estimation formula.
[0031] Fig. 1 is an explanatory diagram of the pipeline renewal planning system according to the present invention. Figs. 2A and 2B are explanatory diagrams of a hydraulic analysis method. It is a flowchart showing a pipeline renewal planning procedure. Figs. 4A and 4B are explanatory diagrams of mapping processing for grasping water supply pipes connected to each pipeline (water distribution pipe) from a pipeline diagram. Figs. 5A and 5B are explanatory diagrams of the water outage impact degree caused by water outage-occurring pipelines generated with respect to a hypothetical water leakage accident pipeline. It is an explanatory diagram of water outage damage degree. It is an explanatory diagram of table data used for calculating the water outage impact degree. Fig. 8A is an explanatory diagram of a damage estimation formula according to JWWA. Fig. 8B is an explanatory diagram of a damage estimation formula according to JWRC.
[0032] Hereinafter, the pipeline renewal planning system and the pipeline renewal planning method according to the present invention will be described with reference to the drawings.
[0033] [Configuration of the Pipeline Replacement Planning System] The pipeline replacement planning system can be configured using a general-purpose personal computer, for example, one that incorporates a motherboard with a CPU and a memory board with semiconductor memory. This personal computer is connected to storage devices such as hard disks and SSDs, a touch-panel LCD display as a display unit, and input / output devices such as a keyboard and mouse as input units via input / output interface circuits, and is also configured to connect to a cloud server that functions as an external database via a communication interface circuit.
[0034] The storage device has an OS program installed to manage the system, and application programs such as a pipeline renewal planning program, a hydraulic analysis program, and a disaster damage rate analysis program are installed and executed by the CPU under the management of the OS program. These application programs may be pre-written to optical discs such as CD-ROMs or DVD-ROMs, or to non-volatile semiconductor memory such as USB memory, and configured to be read to the storage device via a personal computer, or they may be downloaded to the storage device from a cloud server via a communication interface circuit.
[0035] As shown in Figure 1, the pipeline renewal planning system 1 comprises a calculation processing unit 2, a storage unit 3, a display unit 4, an input unit 5, etc., and is connected to a cloud server that functions as a database server. The calculation processing unit 2 includes functional blocks such as a job management unit 20, a pipeline data acquisition unit 21, a disaster damage rate calculation unit 22, a hydraulic analysis unit 23, a pipeline outage estimation unit 24, a water outage impact calculation unit 25, a renewal priority setting unit 26, and a mapping processing unit 27. These functional blocks are realized by application programs such as a pipeline renewal planning program, a hydraulic analysis program, and a deterioration analysis program, and integrated circuits including a CPU that executes these application programs.
[0036] The storage unit 3 is constituted by a storage device, and is divided into a plurality of data storage areas including a pipeline diagram storage unit 30, a pipeline attribute data storage unit 31, a pipeline laying environment data storage unit 32, a disaster damage rate data storage unit 33, a water outage impact degree calculation data storage unit 34, an update plan data storage unit 35, and the like.
[0037] The job management unit 20 is a block that manages the basic operations of the pipeline renewal planning system 1. When the power is turned on and the pipeline renewal planning system 1 is started up, it manages the work of formulating a pipeline renewal plan by operating the pipeline data acquisition unit 21, the disaster damage rate calculation unit 22, the hydraulic analysis unit 23, the water outage occurrence pipeline estimation unit 24, the water outage impact degree calculation unit 25, and the update priority setting unit 26 as necessary.
[0038] The pipeline data acquisition unit 21 is a functional block that acquires pipeline data necessary for formulating a pipeline renewal plan, accumulated data of past water leakage accidents, and the like from a pipeline network database provided in a geographic information system (GIS) managed by, for example, a pipeline network administrator, and stores the acquired data in the pipeline diagram storage unit 30, the pipeline attribute data storage unit 31, the pipeline laying environment data storage unit 32, and the disaster damage rate data storage unit 33, respectively.
[0039] The pipeline diagram storage unit 30 stores map information and pipeline diagrams constituting an existing pipeline network associated with the map information. The pipeline attribute data storage unit 31 stores attribute data including connection information such as the pipe type, nominal diameter, pipeline length, position of connection points (intersections), burial year (which enables grasping of the number of years elapsed since burial) of each pipe constituting the pipeline diagram, and the number of water supply pipes connected to each pipe. The pipeline laying environment data storage unit 32 stores partition data (for example, polygon data managed by a geographic information system (GIS)) indicating the burial environment characterized by the geology and / or ground of the area where the pipeline is buried.
[0040] The disaster damage rate calculation unit 22 is a functional block that calculates a predicted value of the disaster damage rate [cases / km] at a predetermined time for each pipeline, and stores the calculated predicted value in the disaster damage rate data storage unit 33. The disaster damage rate calculation unit 22 estimates pipelines with a high possibility of water leakage accidents during a disaster by calculating the disaster damage rate [cases / km] for disasters such as earthquakes based on the estimation formula shown below.
[0041] FIG. 8A shows a damage estimation formula Rm(v) [cases / km] proposed by Japan Water Works Association (JWWA). The standard damage rate R(v) based on the maximum ground surface velocity v (=3.11×10 ―３ ×(v-15) １．３０ ) is obtained by multiplying the pipe type correction coefficient Cp, the diameter correction coefficient Cd, the topography correction coefficient Cg, and the liquefaction correction coefficient Cl.
[0042] FIG. 8B shows a damage estimation formula Rm(v) [cases / km] proposed by Japan Water Research Center (JWRC). The formula is classified according to the presence or absence of liquefaction. When there is no liquefaction, the standard damage rate R(v) based on the maximum ground surface velocity v (=9.92×10 ―３ ×(v-15) １．１４ ) is obtained by multiplying the pipe type correction coefficient Cp, the diameter correction coefficient Cd, and the topography correction coefficient Cg. When there is liquefaction, it is obtained by multiplying the liquefaction standard damage rate R Ｌ by the pipe type correction coefficient Cp and the diameter correction coefficient Cd.
[0043] In addition to these, a machine learning unit is provided that generates a decision tree model by, for example, ensemble learning a plurality of data sets composed of pipe attribute data specifying the type, nominal diameter, length, and laying year of pipes constituting a pipe network, ground characteristic data indicating the degree of influence on disasters, and past disaster damage data, and damage prediction information [cases / km] generated based on the decision tree model generated by the machine learning unit may be adopted.
[0044] These damage estimation formulas and damage prediction information do not include time information and show the number of accidents per unit pipeline length [accidents / km] for each pipeline. The probability of occurrence of rare events such as earthquakes is thought to follow a Poisson distribution. The Poisson distribution shows the probability that an event with an annual probability of occurrence of x will occur k times in N years. The probability of an earthquake or similar event occurring in N years is mutually exclusive with the case where it does not occur (k=0), and is defined by the following formula: Pr(k>1) = 1 - Pr(k=0) = 1 - exp(-xN) For example, if the assumed earthquake information is an A fault earthquake, assumed seismic motion: seismic intensity: 7, probability of occurrence: 5% within 50 years, then N=50, x=5%, and the number of occurrences in 50 years is 0.918. In other words, a 5% probability of occurrence in 50 years is roughly equivalent to a probability of once every 54 years. By dividing the probability of damage caused by an earthquake by the interval until one such earthquake occurs, the annual earthquake damage rate [cases / year / km], or disaster damage rate, can be calculated. This same model can be applied to the probability of various disasters occurring [cases / km], not just earthquakes, to calculate the annual disaster damage rate [cases / year / km]. Based on this annual disaster damage rate, the water outage pipeline estimation unit 24 can then perform the first and second estimation processes described later.
[0045] The hydraulic analysis unit 23 is a functional block that calculates the flow direction, flow velocity, and water pressure at each intersection of the water flowing through each pipeline constituting the pipeline network using a predetermined hydraulic analysis algorithm. For example, when calculating the head at each node using the nodal head method in hydraulic analysis, the Hazen-Williams formula H = 10.666 × (L × Q) is used. １．８５ ) / (C １．８５ ×d ４．８７ ) and the flow rate equation Σ(±Q), which is the continuity condition equation for the flow rate at the node illustrated in Figure 2A. ｉｊ ) = P ｉ And the closed pipe equation shown in Figure 2B is Σ(±H ｉ )-δE ｋ It can be found as a system of equations where = 0.
[0046] Here, a node refers to an intersection of pipes, H is the pipe's frictional head loss (m), L is the pipe length (m), and Q is the flow rate (m). ３Q is the flow velocity coefficient, where d is the actual inner diameter of the pipe (m) and C is the flow velocity coefficient. ｉ P is the flow rate in each pipe connected to the node of interest. ｉ is the water supply from the node. Furthermore, the closed pipe equation states that the water within the pipeline network is distributed such that the total energy loss is minimized; that is, in a pipeline network with J pipelines, ΣQ ｊ H ｊ The flow is minimized from j=1 to J. The flow equation is used as a constraint condition for ΣQ. ｊ H ｊ →By solving for min, the closed-pipe equation can be obtained.
[0047] The value of the flow velocity coefficient C remains constant regardless of the time of day or the amount of water, and varies depending on the roughness of the inner wall of the pipe. For example, in the case of cast iron pipes, it is 130-140 for newer pipes, and decreases to 60-70 for older pipes with rust deposits on the inner wall.
[0048] The hydraulic analysis unit 23 reads necessary information such as pipe length, pipe diameter, and height of each node including the reservoir from the pipeline diagram storage unit 30 and the pipeline attribute data storage unit 31. After setting the amount of water flowing into the inflow intersection and the amount of water taken out from the water demand point (takeout intersection), it substitutes these values into the above-mentioned formula to obtain a simultaneous solution, thereby determining the flow direction through each pipeline and identifying the pipelines necessary for distributing water from the reservoir to the nodes (water demand points).
[0049] The water outage pipeline estimation unit 24 is a functional block that performs the following: a first estimation process, which, based on the predicted value of the disaster damage rate [incidents / km] calculated by the disaster damage rate calculation unit 22, activates the hydraulic analysis unit 23 under the assumption that water leakage accidents occurred simultaneously in multiple specific pipelines and estimates the water outage pipelines based on the results of the hydraulic analysis; and a second estimation process, which selects one of the multiple specific pipelines as the pipeline to be evaluated, activates the hydraulic analysis unit 23 under the assumption that water leakage accidents occurred simultaneously in the other specific pipelines, and repeats the process of estimating the water outage pipelines based on the results of the hydraulic analysis for multiple specific pipelines. The number of specific pipelines is not particularly limited; a threshold can be set for the predicted value of the disaster damage rate [incidents / km], and pipelines showing a predicted value exceeding the threshold can be selected as specific pipelines. Furthermore, if valves are placed in the pipeline network, pipelines showing a predicted value exceeding the threshold can be selected as specific pipelines for each pipeline grouped with the valves as the boundary.
[0050] The first estimation process involves selecting multiple specific pipelines that show relatively high predicted values based on the predicted disaster damage rate [incidents / km] for each pipeline at a predetermined time, specifically at the time when pipeline renewal plans are formulated, as calculated by the disaster damage rate calculation unit 22. Assuming that a water leakage accident occurs simultaneously in all of the specific pipelines, the hydraulic analysis unit 23 is activated under the condition that the entire volume of water flowing through the specific pipelines has leaked, and the above-mentioned simultaneous solution is obtained. Pipelines where the water pressure at the nodes is below the standard value are estimated to be pipelines where water outages have occurred. For example, in the flow rate Q of the formula shown in Figure 2A, the flow rate related to the specific pipelines is set to 0.
[0051] The second estimation process involves selecting one of the specified pipelines mentioned above as the pipeline to be evaluated, assuming that water leakage occurs simultaneously in the other specified pipelines, and similarly activating the hydraulic analysis unit 23 to obtain the simultaneous solution mentioned above. The process of estimating the pipeline where the water pressure at the node falls below the standard value as the pipeline where the water outage occurred is repeated for each of the specified pipelines, with the pipeline being the pipeline to be evaluated.
[0052] The water outage impact calculation unit 25 is a functional block that calculates the water outage impact for the pipeline under evaluation as the difference between the first water outage impact for each pipeline experiencing a water outage estimated in the first estimation process and the second water outage impact for each pipeline experiencing a water outage estimated in the second estimation process. In other words, the water outage impact for each pipeline under evaluation can be calculated by the difference between the first water outage impact estimated in the first estimation process and the second water outage impact obtained for the pipeline under evaluation in the second estimation process.
[0053] In the first embodiment, the impact of a water outage can be expressed as the product of the estimated disaster damage rate [cases / km], the pipeline length [km] of the pipeline in question, and the population affected by the water outage [people / case], which is the amount of water out of the pipeline where the water outage occurred divided by the amount of water used per person. This makes it possible to objectively evaluate the degree of impact of a water outage caused by a leak in a pipeline where a leak accident is assumed to have occurred (hereinafter referred to as the assumed leak accident pipeline) as the population affected by the water outage. For example, the amount of water used per person can be the planned amount of water per person set at the time of equipment planning, or the amount of water supplied under normal conditions from the pipeline where the water outage is estimated to have occurred divided by the population of the water supply area.
[0054] As a second aspect, the impact of a water outage can also be expressed as the product of the estimated disaster damage rate [cases / km], the pipeline length [km] of the pipeline in question, and the number of affected households [households / case], which is the amount of water outaged in the pipeline where the outage occurred divided by the amount of water used per household. This allows for an objective evaluation of the degree of impact of a water outage caused by a leak in a hypothetical pipeline in which a leak occurred, as the number of households affected. For example, the amount of water used per household can be a predetermined planned amount of water per household, the amount of water supplied under normal conditions from the pipeline where the outage is estimated to have occurred divided by the number of households in the water supply area, or the average of the normal metered water volume for each household supplied from the pipeline where the outage is estimated to have occurred.
[0055] As a third aspect, the impact of a water outage can also be expressed as the product of the estimated disaster damage rate [cases / km], the pipeline length [km] of the pipeline in question, and the number of households affected by the water outage [households / case], which represents the total number of water supply pipes connected to the pipeline where the water outage occurred. As described above, this allows for an objective evaluation of the degree of impact of a water outage caused by a leak in a hypothetical pipeline in terms of the number of households affected by the water outage.
[0056] The number of water supply pipes connected to the pipelines that make up the pipeline network is basically one per household, and one water tap is provided for each water supply pipe. Therefore, the number of water supply pipes connected to each pipeline (distribution pipe) or the number of water taps attached to the water supply pipes can be considered equivalent to the number of households without water. In the case of apartment buildings supplied by a single water supply pipe, each household has a water tap, so the total number of taps can be used as a substitute.
[0057] The number of water supply pipes and taps can be determined from the water supply pipe connection information included in the attribute data of each pipeline, which is obtained from the pipeline network database by the pipeline data acquisition unit 21. Once a pipeline diagram showing pipelines (distribution pipes) and water supply pipes is obtained, and water supply pipe connection information is not present in the attribute data of each pipeline, the job management unit 20 activates the mapping processing unit 27, and the number of water supply pipes is calculated through the mapping process.
[0058] For example, Figure 4A shows a pipeline diagram of a portion of the pipeline network M obtained from the pipeline network database. Multiple water supply pipes S1 and S2 are drawn near pipeline Pn, but it is not possible to identify the pipeline to which water supply pipes S1 and S2 are actually connected. In such a case, as shown in Figure 4B, the mapping processing unit 27 expands the pipeline (distribution pipe) Pn near where water supply pipes S1 and S2 are located, determines whether the ends of water supply pipes S1 and S2 intersect with the expanded pipeline (distribution pipe) Pn, and determines that water supply pipes S1 and S2 are connected to pipeline (distribution pipe) Pn if they intersect.
[0059] Although the impact of water outages in three different ways has been described above, it is preferable to calculate the final impact of water outages by multiplying each impact level by the degree of damage from the water outage, which takes into account the probability of water outages occurring and / or the number of days required for water restoration.
[0060] The probability of water outage refers to the probability that a water outage will occur due to leakage from a target pipeline selected from specific pipelines based on the disaster damage rate calculated by the disaster damage rate calculation unit 22. The reliability of the results can be increased by multiplying the disaster damage rate by the probability of water outage. The probability of water outage can be calculated from the history of past water leakage accidents (cumulative water leakage accident data) obtained from the pipeline network database. For example, the probability of water outage for a past water leakage accident in a pipeline with similar attributes to the target pipeline can be used as the probability of water outage for the target pipeline.
[0061] The water outage damage level is a value calculated by considering the number of days required to restore water leaks in each pipeline and converting the duration of the water outage during the restoration phase into a daily water outage impact. This value is prepared in advance as table data based on the type of pipeline, nominal diameter, pipeline length, connection point location, and buried environment. It takes into account that construction cannot be easily carried out during the day in areas with heavy traffic or near critical infrastructure, and that restoration work cannot be completed in a short period of time for pipelines with large nominal diameters and long pipeline lengths.
[0062] Figure 6 shows the degree of water outage damage when the water flow rate of the pipeline network is 30% at the start of restoration, and it takes 10 days to restore 100% water flow. In this example, when the duration of the water outage during the restoration phase is converted to the impact of the water outage per day, the impact of the water outage caused by one earthquake is 3.5 times the impact at the time of the water outage.
[0063] Figure 7 shows an example of a portion of the evaluation table under the conditions of an earthquake interval of 54 years and a water outage damage degree of 350%. The number of households affected by water outages is used as the measure of the impact of water outages during a disaster. For each pipeline No. that makes up the pipeline network, the pipeline length [km], disaster damage rate [cases / km], the annual disaster damage rate [cases / year / km] obtained by dividing the disaster damage rate [cases / km] by 54, the number of households affected by water outages [households / cases], the degree of water outage damage, and the impact of water outages during a disaster [households / day / year] are shown.
[0064] The renewal priority setting unit 26 sets the priority order for replacing the pipelines under evaluation with earthquake-resistant pipelines based on the water outage impact calculation unit 25, and stores this information in the renewal plan data storage unit 35. By setting pipelines with a high water outage impact among the pipelines under evaluation as pipelines with a high renewal priority, it is possible to prevent major water outages caused by disasters. Note that pipeline renewal work is carried out as a group, including the pipeline under evaluation and several nearby existing pipelines.
[0065] [Explanation of Pipeline Replacement Plan Formulation Method] The pipeline replacement plan formulation method performed by the pipeline replacement plan formulation system described above will be explained based on the flowchart shown in Figure 3. When the pipeline replacement plan formulation system 1 is started up, the job management unit 20 starts each functional block in a predetermined order. First, the pipeline data acquisition step is executed by the pipeline data acquisition unit 21 to acquire pipeline data that constitutes the pipeline network necessary for formulating the pipeline replacement plan (SA1).
[0066] Next, the disaster damage rate calculation unit 22 is activated and a disaster damage rate calculation step is performed to calculate a predicted value of the disaster damage rate [incidents / km] for each pipeline at the scheduled time of pipeline replacement work or at a predetermined time after a predetermined period thereafter (SA2). The water outage pipeline estimation unit 24 performs a leak pipeline identification step (SA3) to identify multiple pipelines that show relatively high predicted values as specific pipelines where water leakage accidents occur, based on the predicted values of the disaster damage rate for each pipeline calculated in the disaster damage rate calculation step.
[0067] The water outage pipeline estimation unit 24 activates the hydraulic analysis unit 23 and executes a hydraulic analysis step (SA4) under the condition that a water leak has occurred in all of the specified pipelines, and then executes a first hydraulic analysis process (SA5) to estimate the pipelines where the water outage occurred based on the results of the hydraulic analysis. Figure 5A shows an example in which, when multiple pipelines Pm, Pn+4, Pn+5, and Pn+6 constituting the pipeline network M are selected as specified pipelines, the hydraulic analysis results indicate that a water outage occurred in the pipelines Pm, Pn, ..., Pn+6, shown by the thick lines. The water outage impact calculation unit 25 calculates the first water outage impact based on the results of the first hydraulic analysis process (SA6).
[0068] The water outage pipeline estimation unit 24 further excludes one of the specified pipelines mentioned above as the pipeline to be evaluated (SA7), activates the hydraulic analysis unit 23 under the condition that a water leak has occurred in all of the specified pipelines excluding the pipeline to be evaluated, and executes the hydraulic analysis step (SA8), and then executes a second hydraulic analysis process to estimate the pipelines where the water outage occurred based on the results of the hydraulic analysis (SA9). Figure 5B shows an example in which, when pipeline Pm is selected as the pipeline to be evaluated from among the multiple specified pipelines Pm, Pn+4, Pn+5, and Pn+6 that constitute the pipeline network M, the hydraulic analysis results indicate that a water outage has occurred in the four pipelines Pn+3, ..., Pn+6, shown by the thick lines. The water outage impact calculation unit 25 calculates the second water outage impact based on the results of the second hydraulic analysis process (SA10).
[0069] The water outage impact calculation unit 25 calculates the water outage impact if the pipeline under evaluation is damaged (leaks) on its own during a disaster by subtracting the second water outage impact from the first water outage impact (SA11). By repeating the process from step SA7 to step SA11 each time a pipeline under evaluation is selected from the specified pipelines, the water outage impact for each pipeline under evaluation is obtained (SA12).
[0070] Subsequently, the renewal priority setting unit 26 sets renewal priorities in order of the evaluation target pipelines with the greatest impact on water outage (SA13), and these priorities are stored in the renewal plan data storage unit 35 (SA14). When the renewal priority setting unit 26 sets renewal priorities for multiple specific pipelines, it is preferable to set renewal priorities for multiple pipelines buried near at least one of the target specific pipelines as a single group.
[0071] The pipeline renewal plan formulation program installed on the storage device described above is an application program that causes the processor to execute each step of the pipeline renewal plan formulation method described above, and includes: a pipeline data acquisition step to acquire pipeline data constituting the pipeline network necessary for formulating the pipeline renewal plan; a disaster damage rate calculation step to calculate a predicted value of the disaster damage rate [incidents / km] at a predetermined time for each pipeline; a hydraulic analysis step to perform a hydraulic analysis of the pipeline network based on the pipeline data; a first estimation process that executes the hydraulic analysis step assuming that multiple leak accidents have occurred simultaneously in multiple specific pipelines based on the predicted value of the disaster damage rate [incidents / km], and estimates the pipelines where water outages have occurred based on the results of the hydraulic analysis; and the multiple specific pipelines The system includes: a water outage pipeline estimation step which involves selecting one of the pipelines to be evaluated, performing the hydraulic analysis step under the assumption that a water leakage accident occurred simultaneously in the specified pipelines excluding the pipeline to be evaluated, and repeating the process of estimating the pipelines where water outages occurred based on the results of the hydraulic analysis for the multiple specified pipelines; a water outage impact calculation step which calculates the difference between the first water outage impact of each water outage pipeline estimated in the first estimation step and the second water outage impact of each water outage pipeline estimated in the second estimation step as the water outage impact for the pipeline to be evaluated; and an update priority setting step which sets an update priority for the pipeline to be evaluated based on the water outage impact calculated in the water outage impact calculation step.
[0072] In the embodiments described above, an example was described in which multiple specific pipelines are extracted based on the predicted value of the disaster damage rate [cases / km] calculated by the disaster damage rate calculation unit, and the water outage impact is calculated based on the extracted specific pipelines. However, it is also possible to configure the system to create multiple water outage damage patterns by employing the Monte Carlo simulation method based on the predicted value, and to calculate the first average water outage impact.
[0073] Furthermore, for a pipeline network in which one of the pipelines designated for replacement has been changed to an earthquake-resistant pipe, the disaster damage rate calculation unit may calculate a predicted value of the disaster damage rate [cases / km], and based on the predicted value, multiple water outage damage patterns may be created using Monte Carlo simulation to calculate a second average water outage impact, and the difference between the two may be calculated as the degree of water outage impact on the pipeline designated for replacement.
[0074] In the embodiments described above, an example was explained in which the earthquake damage rate was used as the disaster damage rate. However, it is also possible to apply the disaster damage rates related to other natural disasters such as ground collapse, volcanic eruptions, and floods to the present invention.
[0075] The embodiments described above represent one aspect of the present invention, and the technical scope of the present invention is not limited based on this description. Furthermore, it goes without saying that the specific configuration of each part can be appropriately modified and designed within the scope that the effects of the present invention are achieved.
[0076] 1: Pipeline renewal plan formulation system 2: Calculation processing unit 3: Memory unit 20: Job management unit 21: Data acquisition unit 22: Disaster damage rate calculation unit 23: Hydraulic analysis unit 24: Water outage occurrence pipeline estimation unit 25: Water outage impact calculation unit 26: Renewal priority setting unit
Claims
1. A pipeline renewal plan formulation system for formulating renewal plans for each pipeline constituting a pipeline network according to calculations performed by a processor, comprising: a pipeline data acquisition unit that acquires pipeline data constituting the pipeline network necessary for formulating a pipeline renewal plan; a disaster damage rate calculation unit that calculates a predicted value of the disaster damage rate [incidents / km] at a predetermined time for each pipeline; a hydraulic analysis unit that performs a hydraulic analysis of the pipeline network based on the pipeline data; a first estimation process that starts the hydraulic analysis unit under the assumption that multiple leak accidents occurred simultaneously in multiple specific pipelines based on the predicted value of the disaster damage rate [incidents / km], and estimates the pipelines where water outages occurred based on the results of the hydraulic analysis; and a second estimation process that selects one of the multiple specific pipelines as a pipeline to be evaluated, starts the hydraulic analysis unit under the assumption that leak accidents occurred simultaneously in the other specific pipelines excluding the pipeline to be evaluated, and repeats the process of estimating the pipelines where water outages occurred based on the results of the hydraulic analysis for the multiple specific pipelines, A pipeline renewal planning system comprising: a water outage impact calculation unit that calculates the difference between a first water outage impact for each pipeline experiencing a water outage estimated in the first estimation process and a second water outage impact for each pipeline experiencing a water outage estimated in the second estimation process as the water outage impact for the pipeline to be evaluated; and a renewal priority setting unit that sets a renewal priority for the pipeline to be evaluated based on the water outage impact calculated by the water outage impact calculation unit.
2. The pipeline renewal planning system according to claim 1, wherein the pipeline estimation unit for water outages estimates a pipeline where the water pressure is below a standard value based on the results of the hydraulic analysis to be the pipeline where a water outage occurred.
3. The pipeline renewal planning system according to claim 2, wherein the degree of impact of the water outage is expressed as the product of the estimated value of the disaster damage rate [cases / km], the pipeline length [km] of the pipeline in question, and the population affected by the water outage [people / case] obtained by dividing the amount of water out of the pipeline where the water outage occurred by the amount of water used per person.
4. The pipeline renewal planning system according to claim 2, wherein the degree of impact of the water outage is expressed as the product of the estimated value of the disaster damage rate [cases / km], the pipeline length [km] of the pipeline in question, and the number of households affected by the water outage [households / case] obtained by dividing the amount of water out of the pipeline where the water outage occurred by the amount of water used per household.
5. The pipeline renewal planning system according to claim 2, wherein the degree of impact of the water outage is expressed as the product of the estimated value of the disaster damage rate [cases / km], the pipeline length [km] of the pipeline in question, and the number of households affected by the water outage [households / case], which is the total number of water supply pipes connected to the pipeline where the water outage occurred.
6. The pipeline renewal planning system according to any one of claims 3 to 5, wherein the impact of the water outage takes into account the number of days required to restore each pipeline in response to a water leakage accident.
7. A pipeline renewal plan formulation method for formulating renewal plans for each pipeline constituting a pipeline network according to calculation processing by a processor, comprising: a pipeline data acquisition step for acquiring pipeline data constituting the pipeline network necessary for formulating the pipeline renewal plan; a disaster damage rate calculation step for calculating a predicted value of the disaster damage rate [incidents / km] at a predetermined time for each pipeline; a hydraulic analysis step for performing a hydraulic analysis of the pipeline network based on the pipeline data; a first estimation process for estimating the pipelines where water outages occurred based on the results of the hydraulic analysis, by performing the hydraulic analysis step under the assumption that water leakage accidents occurred simultaneously in multiple specific pipelines based on the predicted value of the disaster damage rate [incidents / km]; and a second estimation process for estimating the pipelines where water outages occurred based on the results of the hydraulic analysis, by selecting one of the multiple specific pipelines as a pipeline to be evaluated, performing the hydraulic analysis step under the assumption that water leakage accidents occurred simultaneously in the other specific pipelines excluding the pipeline to be evaluated, and repeating the process for estimating the pipelines where water outages occurred based on the results of the hydraulic analysis for the multiple specific pipelines, A pipeline renewal plan formulation method comprising: a water outage impact calculation step of calculating the difference between a first water outage impact for each pipeline experiencing a water outage estimated in the first estimation process and a second water outage impact for each pipeline experiencing a water outage estimated in the second estimation process as the water outage impact for the pipeline to be evaluated; and a renewal priority setting step of setting a renewal priority for the pipeline to be evaluated based on the water outage impact calculated in the water outage impact calculation step.
8. The pipeline renewal plan formulation method according to claim 7, wherein the step of estimating the pipeline where the water outage occurred is to estimate the pipeline where the water pressure falls below a standard value based on the results of the hydraulic analysis as the pipeline where the water outage occurred.
9. The pipeline renewal plan formulation method according to claim 8, wherein the degree of impact of the water outage is expressed as the product of the estimated value of the disaster damage rate [cases / km], the pipeline length [km] of the pipeline in question, and the population affected by the water outage [people / case] obtained by dividing the amount of water out of the pipeline where the water outage occurred by the amount of water used per person.
10. The pipeline renewal plan formulation method according to claim 8, wherein the degree of impact of the water outage is expressed as the product of the estimated value of the disaster damage rate [cases / km], the pipeline length [km] of the pipeline in question, and the number of households affected by the water outage [households / case] obtained by dividing the amount of water out of the pipeline where the water outage occurred by the amount of water used per household.
11. The method for formulating a pipeline renewal plan according to claim 8, wherein the degree of impact of the water outage is expressed as the product of the estimated value of the disaster damage rate [cases / km], the pipeline length [km] of the pipeline in question, and the number of households affected by the water outage [households / case], which is the total number of water supply pipes connected to the pipeline where the water outage occurred.
12. The method for formulating a pipeline replacement plan according to any one of claims 9 to 11, wherein the impact of the water outage is taken into account the number of days required to restore water leaks for each pipeline.