JP2011052399A - Apparatus and program for extracting depressed location - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To extract a location causing ground subsidence which is not accompanied by the deformation of an underground structure, in the upper ground of the underground structure. <P>SOLUTION: An extraction section 15a performs first determination processing of determining whether or not an extracted location is a location where a hydraulic gradient may be generated between the ground of the upper section of the underground structure and the inside of the underground structure, because the ground of the upper section of the underground structure is put into the state of being saturated or almost saturated with groundwater and percolating water, and second determination processing of determining whether or not an extracted location is a location where deposits different in solid state come into contact with each other in the ground of the upper section of the underground structure, by using area information and various set values stored in an area information storage section 14a and a setting condition storage section 14b. The extraction section 15a computes a total score by sequentially adding a score indicating the degree of possibility of subsidence, depending on the result of each determination processing, and compares the computed total score with the predetermined set value, so as to extract the location (depressed location) where the degrees of the occurrence of the subsidence are classified. <P>COPYRIGHT: (C)2011,JPO&INPIT

Description

  The present invention relates to a depressed portion extraction apparatus and a depressed portion extraction program.

  Conventionally, ground subsidence has been caused by cavities left in the ground after mining, such as coal mines, underground structures with cavities inside, and cavities left during excavation for construction of underground structures. It is known that this occurs when the artificially formed cavity collapses and the upper ground of the collapsed cavity shifts. That is, it is known that the depression phenomenon in the ground is a shallow depression accompanied by the collapse of an artificially formed cavity. Hereinafter, an artificially formed cavity is described as an underground structure including a structure that supports the cavity.

  Here, the subsidence of the ground occurs when the ground from the place where the underground structure exists to the ground surface above the underground structure suddenly falls, and the cavity gradually rises while repeatedly collapsing. It is considered that it may occur (for example, see Non-Patent Document 1).

  For this reason, in order to prevent the subsidence, the underground structure whose location has become unknown or the underground structure that collapses and rises to the upper ground is discovered. Extraction of a place where a depression may occur is performed. As a result, it is possible to take measures to block or fill the found underground structures and cavities against ground depression.

Kawamoto: Geophysical exploration, Vol.58, No.6, pp.589-597, 2005, regarding ground subsidence disaster and underground cavern survey.

  By the way, in recent years, the depression events that have been scattered include a depression phenomenon in which the cause cannot be specified because the underground structure is not accompanied by a large deformation. In other words, it has been clarified that in the unconsolidated ground above the underground structure, the depression may occur by a mechanism other than the shallow depression accompanying the collapse of the underground structure as in the past.

  However, in the above-described conventional technology, since a ground depression occurs due to the collapse of an underground structure existing in the ground in advance, a portion that is likely to collapse is extracted. There is a problem that it is not always possible to extract a portion where a depression without a deformation of the intermediate structure occurs.

  Accordingly, the present invention has been made to solve the above-described problems of the prior art, and there is a possibility that a ground depression without deformation of the underground structure may occur in the upper ground of the underground structure. It is an object of the present invention to provide a depressed portion extraction apparatus and a depressed portion extraction program capable of extracting a portion.

  In order to solve the above-described problems and achieve the object, this apparatus includes geographical information, topographic information, and geological information of a predetermined area including an area where an underground structure is embedded, An area information storage means for storing area information consisting of information on underground structures, and the ground above the underground structures is saturated or near saturated by groundwater and seepage water, and the upper part of the underground structures A first determination process for determining whether or not a hydrodynamic gradient is likely to occur between the ground of the ground and the inside of the underground structure, and consolidation in the ground above the underground structure A second determination process for determining whether or not deposits of different degrees are in contact with each other based on the area information stored in the area information storage means, and the first determination process and the Based on the determination result of the second determination process, Extracting means for ground surface creation upper extracts depressions locations are likely to collapse, and the requirements to be provided with.

  The program also includes region information including geographical information, topographical information and geological information of a predetermined region including a region where the underground structure is embedded, and information on the underground structure. Storing information in a predetermined storage unit, and the ground above the underground structure is saturated or nearly saturated by groundwater and seepage water, and the ground above the underground structure and the ground A first determination process for determining whether or not a hydrodynamic gradient is likely to occur between the inside of the structure and deposits having different consolidation degrees on the ground above the underground structure. A second determination process for determining whether or not the portion is a contact point, based on the area information stored in the predetermined storage unit, and the first determination process and the second determination process Based on the judgment result, the ground surface above the underground structure is An extracting procedure for extracting a recessed portion that might submerged may be a requirement that causes a computer to execute the.

  According to the disclosed apparatus and program, it is possible to extract a portion where a ground depression that is not accompanied by deformation of the underground structure may occur in the upper ground of the underground structure.

FIG. 1 is a diagram for explaining shallow depressions. FIG. 2 is a diagram for explaining the typification of the piping structure. FIG. 3 is a diagram for explaining the result of the electrical exploration. FIG. 4 is a diagram (1) for explaining the region information storage unit. FIG. 5 is a diagram (2) for explaining the region information storage unit. FIG. 6 is a diagram (3) for explaining the region information storage unit. FIG. 7 is a diagram (4) for explaining the region information storage unit. FIG. 8 is a diagram (5) for explaining the region information storage unit. FIG. 9 is a diagram for explaining an example of the extraction result. FIG. 10 is a flowchart for explaining the processing of the depressed portion extraction apparatus in the present embodiment.

  Exemplary embodiments of a depressed portion extraction apparatus and a depressed portion extraction program according to the present invention will be described below in detail with reference to the accompanying drawings. In the following, a depressed portion extraction apparatus that executes a depressed portion extraction program according to the present invention will be described as an embodiment.

  First, the concept of processing of the depressed portion extraction apparatus in the present embodiment will be described with reference to FIGS. FIG. 1 is a diagram for explaining shallow depressions, FIG. 2 is a diagram for explaining the typification of piping structures, and FIG. 3 is a diagram for explaining the results of electrical exploration. It is.

  The depressed portion extraction apparatus according to the present embodiment extracts a portion where the ground surface above the underground structure may be depressed as a depressed portion in an area where the underground structure is embedded in the ground.

  Conventionally, the depression phenomenon in the ground above the underground structure was considered to be a shallow depression with a large deformation such as collapse in the underground structure. That is, as shown in FIG. 1, a part or all of the underground structure collapses, so that the ground surface above the underground structure is depressed.

  However, in recent years, there have been some events where the ground surface of the unconsolidated ground above the underground structure has collapsed. These cave-in events include a cave-in phenomenon in which the cause cannot be specified because there is no major deformation in the underground structure. That is, it has been clarified that in the unconsolidated ground above the underground structure, the depression may occur by a mechanism other than the shallow depression as in the past.

  On the other hand, the depression, which was supposed to be unidentifiable because it was not accompanied by deformation of the underground structure, could be caused by sediment loss in the upper ground of the underground structure due to piping. It was out. Specifically, in this depression phenomenon, the rainwater that falls on the ground surface above the underground structure penetrates into the unconsolidated sediments in the ground, forming a pipe-shaped water channel (pipe), It has been suggested that depressions occur due to the formation of cavities at locations close to the ground surface due to the ground soil and sand being drawn by the flow of water in the water path.

  In other words, in order to extract the depressions where depressions may occur, it is verified that the depression phenomenon in the upper part of the underground structure without deformation of the underground structure is a phenomenon predisposed to piping. For this reason, a field survey was actually conducted on the area where depression occurred in the upper part of the underground structure.

  Below, the phenomenon which became clear by investigating the location where the depression generate | occur | produced is demonstrated using FIG. 2 and FIG.

  First, by investigating trenches at several locations where depressions occurred, the ground displacement due to shallow depressions was not observed, and depressions (pits) occurred due to the formation of cavities near the ground surface. It was confirmed that the pipes were formed so that permeated water and groundwater permeated from the ground surface by rainfall would permeate underground structures at all locations. The trench survey is a survey method for directly observing the underground condition by excavating the ground at a point of interest into a groove shape.

  Furthermore, by analyzing the results of the trench survey at the depression, it was clarified that the piping structure can be categorized according to the type of sediment on the ground above the underground structure. Specifically, as shown in FIG. 2 (A), unconsolidated deposits in the ground above the underground structure are rocky rocks such as terrace deposits, fan deposits, and riverbed deposits, as shown in FIG. When it is a material, that is, when the ground above the underground structure is a ground containing a lot of gravel, it was confirmed that a pipe having a structure like a masonry (interlock structure) was formed. Here, since the pipe with interlock structure is highly permeable, the depression is caused by the outflow of coarse sand and fine pebbles that formed the substrate part between the gravel and the gravel. It is presumed that the pipes of the structure grew, and as a result, the fine particles of the ground near the ground surface were washed away.

  In addition, as shown in FIG. 2 (B), when the unconsolidated sediment on the ground at the top of the underground structure is made of a rock-soiled soil material such as debris flow deposit and cliff cone deposit, as shown in FIG. That is, it was confirmed that a pipe having a cylindrical structure was formed when the ground above the underground structure was a ground containing a large amount of fine particles. Here, the pipe having a cylindrical structure has low water permeability, but the pipe portion has relatively high permeability compared to the surrounding ground, so it is estimated that water penetrates preferentially into the pipe. Is done. Therefore, it is presumed that depression is caused even by a pipe having a cylindrical structure.

  In summary, the structure of the pipes found in the depressions can be classified according to the origin and nature of the unconsolidated sediment, and the difference in the pipe structure is the particle size composition constituting the unconsolidated sediment, It became clear that it was strongly influenced by material strength and water permeability. In addition, it is estimated that the flow rate of groundwater and permeated water flowing through the pipe and the size of the particles that flow out are determined by the structure of the pipe.

  Next, the result of electrical exploration of a plurality of locations where depressions have occurred will be described. Here, prior to the electric exploration, a borehole was drilled by a borehole survey to measure the groundwater level at the place where the depression occurred. At that time, the type of basement rock and the basement surface position (basement depth) were Confirm. And since the kind of basement rock became known, the specific resistance value of the basement where the depression occurred is known.

  In the two-dimensional electric exploration, a specific resistance cross section obtained by measuring the specific resistance (unit: Ωm) in the two-dimensional cross section of the region where the underground structure is buried is obtained. Here, since the resistivity value of the basement rock is known, when the resistivity cross section is obtained, it is possible to estimate the surface where the basement is located in the region where the underground structure is embedded (FIG. 3). (See “Estimated base plane” shown in (A)). Note that FIG. 3A shows the result of a two-dimensional electrical exploration performed before the trench investigation was performed at the depressed portion where the interlock structure pipe was confirmed.

  After the estimated base plane was determined by two-dimensional electric exploration, three-dimensional electric exploration was performed. The three-dimensional electric exploration is a technique described in, for example, “Japanese Patent Laid-Open No. 2008-281404”, and measures the three-dimensional specific resistance value of the ground to be explored before and after spraying a liquid such as salt water. This is a technique for detecting a change in the specific resistance value and detecting a location where the liquid penetrates by protruding from the detected change in the specific resistance value in the ground. That is, in the three-dimensional electric exploration, it is possible to estimate a water penetration path with a high flow velocity.

  FIG. 3B shows the result of conducting a three-dimensional electrical survey on the region where the interlock structure pipe was confirmed by the trench investigation. Note that the two-dimensional electric exploration and the three-dimensional electric exploration are performed prior to the trench investigation. As shown in FIG. 3B, a portion where the rate of change of the specific resistance value is large is detected near the horizontal axis (left-right direction in the figure) “16 m”. Here, around the horizontal axis “16m” is a place where terrace deposits exist just below the thin surface soil layer or cultivated soil layer from the trench survey, and salt water concentrated and penetrated into the highly permeable gravel layer. It can be seen that the results of the three-dimensional electrical exploration are consistent with the results of the trench survey.

  On the other hand, the location where the interlock structure is confirmed to be generated from the result of the trench investigation (interlock structure location) is expected despite the high water permeability as shown in FIG. On the other hand, a portion with a small change rate of the specific resistance value and a high change rate of the specific resistance value was detected at a position where the tip of the grown interlock structure portion was in contact with the substrate. That is, it is inferred that the pipe is generated from the unconsolidated sediment and is growing toward the base surface.

  The change rate of the interlock structure part was smaller than that of the surrounding area because the amount of salt water sprinkled was insufficient and the permeability was too high. It is guessed that salt water penetrated.

  Here, when the results of the trench survey and electric exploration described above and the survey results of the groundwater level using the borehole are summarized, the following two factors are caused by the occurrence of piping, It is suggested that it becomes a condition for the occurrence of the depression of the upper part of the underground structure without deformation.

  The groundwater level is considered to be located on the ground surface where the underground structure is buried or on the ground surface side from the ground surface, but rises according to the amount of rainfall. Therefore, in a heavy rainy season, water is held between unconsolidated sediment particles in the ground due to groundwater and infiltration water due to rainfall, that is, the ground above the underground structure is saturated or saturated with water. When a state close to the state is reached, a hydrodynamic gradient is generated between the atmospheric pressure inside the underground structure (inside the excavation space and inside the wall surface of the underground structure) and the ground above the underground structure. Piping having any of the structures described is likely to occur.

  From the results of three-dimensional electrical exploration, high-velocity water tends to flow at locations where basement rocks and unconsolidated sediments contact, in other words, where coarse and fine particles contact. An environment is formed in which water that has permeated through poor sediments easily moves deep into the ground, and piping tends to occur in the ground.

  In other words, it is a place where there is a high possibility of causing a hydrodynamic gradient depending on the state of the water held by the ground, and where sediments with different consolidation degrees (unconsolidated sediments and hard basement rocks) are in contact. Then, it can be determined that the environment is likely to cause piping, and the possibility of occurrence of depression due to piping is high.

  Based on the concept of such processing, the depressed portion extraction apparatus according to the present embodiment is configured to detect the depressed portion in a predetermined region including a region in which the underground structure is embedded (hereinafter referred to as an underground structure embedded peripheral region). Perform the extraction process.

  Next, a specific example of processing executed by the depressed portion extraction apparatus according to the present embodiment will be described with reference to FIGS. FIG. 4 is a block diagram illustrating a configuration of the depressed portion extraction apparatus according to the present embodiment, FIGS. 5 to 8 are diagrams for explaining the region information storage unit, and FIG. 9 is an example of an extraction result. It is a figure for doing.

  As shown in FIG. 4, the depressed portion extraction apparatus 10 in this embodiment includes an input unit 11, an output unit 12, an input / output control I / F unit 13, a storage unit 14, and a processing unit 15.

  The input unit 11 receives and inputs various types of information from the user. Particularly, as closely related to the present invention, the input unit 11 receives and inputs the region information described above, or the processing unit 15 described later performs processing. Accept and enter various setting conditions. The area information and various setting conditions received by the input unit 11 will be described in detail later.

  The output unit 12 outputs various types of information, includes a monitor, and displays a processing result of the processing unit 15 described later, particularly as closely related to the present invention.

  The input / output control I / F unit 13 controls data transfer between the input unit 11 and the output unit 12, the storage unit 14, and the processing unit 15.

  The storage unit 14 stores data used for various types of processing by the processing unit 15 and various types of processing results by the processing unit 15, and as particularly closely related to the present invention, as shown in FIG. 14a, a setting condition storage unit 14b, and an extraction result storage unit 14c.

  The area information storage unit 14 a stores area information received from the user via the input unit 11. Here, the area | region information storage part 14a memorize | stores the area | region information which consists of the topographical information and geological information of an underground structure embedding peripheral area | region, and the information of the underground structure provided from the installer.

  Specifically, as shown in FIG. 5, the area information storage unit 14 a has, as geographical information, rainfall information (an average annual rainfall and an annual maximum rainfall) in an area surrounding an underground structure buried by the Japan Meteorological Agency. Memorize rainfall. In addition, as shown in FIG. 5, the area information storage unit 14 a is embedded position information, which is information on the position where the underground structure is embedded in the underground structure embedded peripheral area provided by the installer, The underground structure elevation that is the top elevation of the structure and the presence or absence of spring water in the underground structure that is the presence or absence of spring water to the underground structure are stored. Here, the burying position information is used to extract a buried area around the underground structure.

  Further, as shown in FIG. 5, the area information storage unit 14 a has, as topographical information, for example, the ground elevation of the area surrounding the buried underground structure extracted by the user from a 1 / 5,000 topographic map, The basement depth in the catchment area, unconsolidated sediment distribution area, and unconsolidated sediment distribution area is stored.

  Here, the ground elevation is extracted from a 50 m mesh numerical map created from a 1 / 5,000 topographic map. In addition, the catchment area is determined by the user by connecting the ridge line in the 15,000th topographical map of the area surrounding the buried underground structure. In addition, the unconsolidated sediment distribution area is extracted by the user inside the catchment area from the slope line of the slope gradient, etc. in the 15,000th topographical map of the area surrounding the buried underground structure. The In addition, the basement depth in the unconsolidated sediment distribution area is a preset value (unit: in accordance with the topography estimated from the 15,000 topographic map of the area surrounding the buried underground structure) m) is set. For example, when the topography where the underground structure is buried is weathered quasi-plain, the basement depth is set to “20 m”, and when the topography is a river terrace with low sediment discharge, the basement depth is “ In the case of a terrace of a river that is set as “1 m” and has a large amount of sediment discharge (a river in the uplift zone), the base depth is set as “2 m”. If it is a childhood terrain, the basement depth is set as “2 m”. If it is a middle-aged terrain, the basement depth is set as “0 m”. Is set as “3 m”.

  Further, as shown in FIG. 5, the region information storage unit 14 a has, as geological information, for example, 1 / 25,000 in the unconsolidated sediment distribution region in the underground structure buried peripheral region. The type of unconsolidated sediment and the type of basement rock extracted by the user referring to the geological map are stored. For example, the area information storage unit 14a may be configured such that the unconsolidated sediment in the unconsolidated sediment distribution area is a rocky material such as a terrace deposit, a fan deposit, and a riverbed sediment, or a debris flow deposit and a cliff. It remembers whether it is a rock-soil-like soil-like material like a cone deposit, and remembers whether the type of basement (basement rock) in the unconsolidated sediment distribution area is sedimentary rock or igneous rock.

  In addition, as shown in FIG. 5, the area information storage unit 14a includes information on water paths (such as underground water and air) in the area surrounding the underground structure burial, and water collecting facilities on the surface of the area surrounding the underground structure burial. Information. Even if information on underground water and information on water collection facilities is extracted from a 1 / 5,000 topographic map, which is a larger scale than a 1 / 25,000 topographic map, as shown in FIG. It may be the case extracted by a field survey. In addition, the installation location of the water collection facility is a place where it is expected to further increase the amount of infiltration water due to rainfall, and the water collection facility includes roads paved with paddy fields, gutters, water tanks, asphalt and concrete. The area around the yard, such as tennis courts and playgrounds that are faced with asphalt, is extracted.

  Hereinafter, a specific example of the area information stored in the area information storage unit 14a will be described with reference to the drawings. For example, as shown in FIG. 6A, the area information storage unit 14a stores water catchment area data representing the catchment area as one polygon data. Further, as shown in FIG. 6B, the area information storage unit 14a displays unconsolidated sediment distribution areas color-coded for each type of unconsolidated sediment as one polygon data. Store the sediment data.

  In addition, as shown in FIG. 7A, the region information storage unit 14a has a base depth that represents each region having a base depth in the same range in the unconsolidated sediment distribution region as one polygon data. Store the data. Further, as shown in FIG. 7B, the region information storage unit 14a represents each region having the same base type (basement geology) as one polygon data in the unconsolidated sediment distribution region. Store basement geological data. In the basement geological data shown in FIG. 7B, different numbers (legend numbers) and different patterns are assigned to each basement geology. For example, a pattern indicated by diagonal lines from the upper left to the lower right is assigned. It is shown that the basement geology of the assigned area is the basement geology assigned with “Legend No. 006”.

  In addition, as shown in FIG. 8A, the area information storage unit 14a includes information on the ground depth, the embedded position information of the underground structure, and the information about the top elevation of the underground structure. The underground structure base crossing data in which the points where the intermediate structure crosses the base is extracted is stored. In addition, as shown in FIG. 8B, the area information storage unit 14a is configured to identify each location where the buried position of the underground structure intersects with the water path as information on the water path in the area surrounding the buried underground structure. The water path data expressed as one polygon data is stored.

  In addition, as shown in FIG. 8C, the area information storage unit 14a is configured as information on the water collection facility in the area surrounding the underground structure embedding for each location where the underground position of the underground structure intersects with the water collection facility. Is stored as one polygon data.

  Here, the area | region information storage part 14a has memorize | stored the surface elevation data (not shown) extracted from the 50m mesh numerical map. However, since the ground elevation data is data arranged in a grid at intervals of 50 m, it is an accurate height if it is a location corresponding to each corner of the grid (mesh), but a location other than each corner of the grid If it is, accuracy will become low. Therefore, the area information storage unit 14a stores correction data for correcting the land surface elevation as shown in (D) of FIG. 8 in addition to the area information shown in FIG.

  In the correction data shown in FIG. 8D, the ground elevations “h (1) to h (4)” of the adjacent mesh used for correcting the elevation mesh “h0” to be corrected are stored. Here, the extraction unit 15a, which will be described later, calculates a difference “Δh = (h0−h (i)), i = 1 to 4” between “h0” and the local table elevation, and among the calculated Δh, A value that is a positive value is determined as a correction coefficient, and a value obtained by subtracting the determined correction coefficient from “h0” is set as a corrected ground elevation of the altitude mesh “h0”.

  Returning to FIG. 4, the setting condition storage unit 14 b stores various setting values set in advance by the user of the depressed portion extraction apparatus 10, and the extraction unit 15 a described later includes the area information stored in the area information storage unit 14 a and Using the various setting values stored in the setting condition storage unit 14b, the depressed portion is extracted.

  The extraction result storage unit 14c stores the extraction result of the depressed portion extracted by the extraction unit 15a described later. The various setting values stored in the setting condition storage unit 14b and the extraction results stored in the extraction result storage unit 14c will be described in detail later.

  The processing unit 15 executes various processes based on the data stored in the storage unit 14, and has an extraction unit 15a as shown in FIG. 4 as particularly closely related to the present invention.

  Based on the concept of the processing described above, the extraction unit 15a extracts a depressed portion where a depression that is not accompanied by deformation of the underground structure may occur in the upper ground of the underground structure.

  First, in the area surrounding the underground structure embedding, the extraction unit 15a is in a state where the ground above the underground structure is saturated or nearly saturated by groundwater and infiltration water, and the ground and the underground structure above the underground structure. A first determination process is performed to determine whether or not a hydrodynamic gradient is likely to occur between the inside of the object and the object.

  Specifically, in the extraction unit 15a, “the groundwater level estimated from the depth of the basement and the rainfall information (annual average rainfall)” and “the infiltrated water penetrating from the ground surface of the catchment area by the rainfall” are in contact with each other. A first determination process is performed to determine whether or not each part of the underground structure-embedded peripheral region is. Even if the groundwater level in the normal state is set at the same position as the “basement depth (see FIG. 7A)”, the “basement depth” and “annual average rainfall” It may be a case where it is set to be in a higher position for the water level considered from the “quantity”.

  More specifically, the extraction unit 15a includes the “surface elevation”, the “penetration depth estimated from the type of unconsolidated sediment”, and the “unconsolidated sediment distribution region in the catchment area”. Of the groundwater level estimated from the area of the ground, the width of the catchment area where the underground structure exists, the type of unconsolidated sediment and the rainfall information (maximum annual rainfall) Using the value, it is determined whether or not there is a possibility that the groundwater and the permeated water are in contact with each other.

  The extraction part 15a acquires the ground elevation of each location in the underground structure embedding peripheral area from the ground elevation data.

  Moreover, the extraction part 15a acquires the penetration depth of each location in an underground structure embedding peripheral area from the setting value which the setting condition memory | storage part 14b shown in FIG. 4 memorize | stores. Here, the setting condition storage unit 14b has a penetration depth set in advance by the user for each type of unconsolidated sediment based on the size of the water permeability estimated according to the type of unconsolidated sediment. Is remembered. For example, the setting condition storage unit 14b sets the “penetration depth” to “5 m” when the unconsolidated sediment is a rocky material with high permeability such as terrace deposit, fan deposit, and riverbed deposit. Stores the set value. On the other hand, the setting condition storage unit 14b sets the “penetration depth” to “0.5 m” when the unconsolidated sediment is a rock-penetrating soil material with low permeability such as a debris flow deposit and a cliff cone deposit. Is stored. Thereby, the extraction unit 15a identifies the type of the unconsolidated deposit in the determination target portion with reference to the unconsolidated sediment data illustrated in FIG. 6B, and is associated with the identified type. The penetration depth is acquired from the setting condition storage unit 14b.

  In addition, the extraction unit 15a calculates the amount of increase in the groundwater level by, for example, a first determination process described below. First, the extraction unit 15a calculates the catchment area (area A) and the width (length L) of the catchment area at the position where the underground structure exists from the catchment data (see FIG. 6A). . The permeated water that has been submerged in the ground by rain from the area A passes through a section of length L and contributes to an increase in the groundwater level around the underground structure.

  Therefore, when rainfall information stored as area information (R: annual maximum rainfall) is given to area A, the groundwater level increase (H) due to rainfall equivalent to the annual maximum rainfall is: It is proportional to R and A, and inversely proportional to L. Here, since the amount of seepage water can be estimated by the type of unconsolidated sediment as described above, the “groundwater level rise amount: H” is a coefficient value (α) determined for each type of unconsolidated sediment. ) Can be calculated as “α × R × A / L”.

  For this reason, the setting condition storage unit 14b sets the “coefficient value when the unconsolidated sediment is a rocky material” and “the unconsolidated sediment is a stone-mixed soil material” set in advance by the user. Is stored. That is, the extraction unit 15a is associated with “R” acquired from the region information, “A, L” calculated from the region information, and the corresponding unconsolidated sediment type in the setting condition storage unit 14b. The amount of increase in the groundwater level at each location in the area surrounding the buried underground structure is calculated using the coefficient value.

  With this process, after acquiring three types of values, the extraction unit 15a determines whether or not the groundwater and the permeated water come into contact with each location (each determination target location) in the underground structure-embedding peripheral region. Determine. The above is the content of the first determination process.

  Here, the extraction unit 15a gives a score (for example, 4 points) for evaluating the degree of possibility of depression for a portion determined to be in contact with groundwater and permeated water in the first determination process. to add. Note that the score added when the first determination result is affirmative is stored in the setting condition storage unit 14b.

  And in the location where the 1st determination result was a negative determination, the extraction part 15a uses the kind of unconsolidated sediment ((B of FIG. 6B) used for the said 1st determination process. After adding and correcting the increase in groundwater due to the capillary phenomenon estimated from ()), the first determination process is re-executed. Note that the amount of increase in groundwater due to capillary phenomenon estimated from the type of unconsolidated sediment is set in advance by the user and stored in the setting condition storage unit 14b.

  In addition, the extraction unit 15a corrects the correction data (the area information storage unit 14a stores the value of the ground elevation used in the first determination process at a location where the first determination result is negative determination ( The first determination process is re-executed after correction based on (see (D) of FIG. 8).

  Here, the extraction unit 15a adds a score (e.g., 2 points) for evaluating the degree of the possibility of depression to a portion determined to be affirmative in the re-executed first determination process. In addition, the score added when the result of the re-executed first determination process is affirmative is stored in the setting condition storage unit 14b.

  Subsequently, the extraction unit 15a determines whether or not deposits having different consolidation degrees are in contact with each other on the ground above the underground structure in the surrounding area where the underground structure is embedded. To do.

  Specifically, the extraction unit 15a refers to the underground structure base intersection data shown in FIG. 8A to determine whether or not the underground structure intersects the base. The determination is made at each location in the peripheral area.

  Here, the extraction unit 15a adds a score (e.g., 3 points) for evaluating the degree of possibility of depression to a portion determined as affirmative in the second determination process. Note that the score added when the second determination result is affirmative is stored in the setting condition storage unit 14b.

  The above is a specific example of the first determination process and the second determination process. Here, the extraction unit 14a may extract the depressed portion from the determination results of the first determination process and the second determination processing, but in the present embodiment, the extraction unit 15a extracts the depressed portion more accurately. In order to do this, third to sixth determination processes described below are executed.

  First, the extraction unit 15a refers to the basement geological data shown in FIG. 7B to identify the type of basement rock in the determination target location, and whether the basement is permeable from the specified type of basement rock. A third determination process is performed to determine whether or not. Here, the extraction unit 15a determines that a higher hydrodynamic gradient is generated when the specified type of basement rock is a fractured rock, and evaluates the degree of possibility of depression (for example, two points) ) Is added. Note that the score to be added when the third determination result is affirmative is stored in the setting condition storage unit 14b.

  Further, the extraction unit 15a refers to the “presence / absence of spring water in the underground structure” of the area information illustrated in FIG. 5, and fourth determination processing for determining the presence / absence of spring water in the underground structure at the determination target location Execute. Here, in the case of “with spring water”, the extraction unit 15a determines that the groundwater is actually penetrating toward the underground structure, and evaluates the degree of possibility of sinking. (For example, 2 points) are added. Note that the score to be added when the fourth determination result is affirmative is stored in the setting condition storage unit 14b.

  When the determination result from the first determination process to the fourth determination process is found, the extraction unit 15a sums the points added at the determination target location, and the total value is stored in the setting condition storage unit 14b in advance. If it is smaller than the “first set value (for example, 7 points)”, the determination target location is extracted as a “normal inspection” location with a low possibility of depression.

  On the other hand, if the total value is equal to or greater than the “first set value (for example, 7 points)”, the extraction unit 15a determines that the determination target location is a depressed portion that is highly likely to be depressed. The determination process and the sixth determination process are continuously executed.

  First, the extraction unit 15a performs a fifth determination process for determining whether there is a water channel at the determination target location with reference to the water channel data illustrated in FIG. Here, the extraction unit 15a determines that the possibility of the occurrence of the depression is higher in the case of “has a water path”, and adds a score (for example, 4 points) for evaluating the degree of the possibility of the depression. . Note that the score to be added when the fifth determination result is affirmative is stored in the setting condition storage unit 14b.

  Moreover, the extraction part 15a performs the 6th determination process which refers to the water collection equipment data shown by (C) of FIG. 8, and determines whether there exists a water collection equipment in a determination target location. Here, in the case of “with water collection equipment”, the extraction unit 15a determines that the possibility of the occurrence of the depression is further increased, and adds a score (for example, 4 points) for evaluating the degree of the possibility of the depression. To do. Note that the score added when the sixth determination result is affirmative is stored in the setting condition storage unit 14b.

  When the determination result of the sixth determination process is found, the extraction unit 15a sums up the points added at the determination target location where the fifth and sixth determination processes are executed, and the total value is stored in the setting condition storage If it is smaller than the “second set value (for example, 11 points)” stored in advance in the part 14b, the determination target location is extracted as a “follow-up” location where there is a high possibility that depression will occur in the future. To do.

  On the other hand, if the total value is equal to or greater than the “second set value (for example, 11 points)”, the extraction unit 15a determines that the determination target portion is a “observation required” portion that is highly likely to be depressed soon. Extract as there is.

  Then, the extraction unit 15a stores the extracted “normal inspection” location, “follow-up observation” location, and “required observation” location in the extraction result storage unit 14c, and displays the extraction result on the monitor of the output unit 12. .

  For example, as illustrated in FIG. 9, the extraction unit 15 a performs topographic maps in the area surrounding the underground structure, “normal inspection: black frame”, “follow-up observation: white frame”, and “need investigation: hatched” The extraction result obtained by superimposing the underground structure color-coded according to the degree of the possibility of depression, such as “frame”, is displayed on the monitor of the output unit 12.

  In the above-described embodiment, the case where the fifth determination process and the sixth determination process are executed for a portion that has not been extracted as a normal inspection has been described. However, the present invention is not limited to this. Instead, all the determination processes from the first determination process to the sixth determination process may be executed for all the determination target portions. Further, the execution order of the above-described determination processing can be arbitrarily changed by the user. Further, whether or not to execute a determination process other than the first and second determination processes described above can be arbitrarily changed by the user.

  Next, processing of the depressed portion extraction apparatus 10 in the present embodiment will be described with reference to FIG. FIG. 10 is a flowchart for explaining the processing of the depressed portion extraction apparatus in the present embodiment. In the following, processing after the area information and various setting values are stored in the area information storage unit 14a and the setting condition storage unit 14b by the user of the depressed portion extraction apparatus 10 will be described.

  As illustrated in FIG. 10, first, when the depressed portion extraction apparatus 10 according to the present embodiment receives a depressed portion extraction request from the user via the input unit 11 (Yes in step S101), the extraction unit 15a In step S102, it is determined whether or not groundwater and permeated water come into contact with each other (step S102, first determination process).

  Here, when it is determined that the groundwater and the permeated water are in contact with each other at the determination target portion (Yes at Step S102), the extraction unit 15a adds points (Step S103).

  On the other hand, when it is determined that the groundwater and the permeated water do not contact with each other in the determination target portion (No in step S102), the extraction unit 15a determines whether the groundwater and the permeated water are in contact with each other by correction using a capillary phenomenon. (Step S104, re-execution of the first determination process).

  Here, when it is determined that the groundwater and the permeated water are in contact with each other by the correction by the capillary phenomenon (Yes at Step S104), the extraction unit 15a adds points (Step S105).

  On the other hand, when it is determined that the groundwater and the permeated water are not in contact with each other due to the capillary phenomenon (No in step S104), the extraction unit 15a determines whether the groundwater and the permeated water are in contact with each other through the topographic correction ( Step S106, re-execution of the first determination process).

  Here, when it is determined in the topographic correction that the groundwater and the permeated water come into contact with each other (Yes at Step S106), the extraction unit 15a adds points (Step S107).

  On the other hand, when it is determined by the topographic correction that the groundwater and the permeated water do not contact (No at Step S106), and after performing the point addition processing at Step S103 and Step S105, the extraction unit 15a determines that the determination target location is underground. It is determined whether or not the structure and the base intersect (step S108, second determination processing).

  Here, when the determination target location is a location where the underground structure and the base intersect (Yes at Step S108), the extraction unit 15a adds points (Step S109).

  On the other hand, when the determination target location is a location where the underground structure and the base do not intersect (No at Step S108), and after the point addition processing at Step S109, the extraction unit 15a performs the underground structure at the determination target location. It is determined whether or not the upper substrate has water permeability (step S110, third determination process).

  Here, when the base of the determination target portion has water permeability (Yes at Step S110), the extraction unit 15a adds points (Step S111).

  On the other hand, when the base of the determination target location is not permeable (No at Step S110), and after the point addition processing at Step S111, the extraction unit 15a determines whether there is spring water in the underground structure at the determination target location. Is determined (step S112, fourth determination process).

  Here, when there is spring water in the underground structure (Yes at Step S112), the extraction unit 15a adds points (Step S113).

  On the other hand, when there is no spring water in the underground structure (No at Step S112) and after the point addition process at Step S114, the extraction unit 15a calculates the total score at the determination target location (Step S114).

  Then, the extraction unit 15a determines whether or not the calculated total score is greater than or equal to the first set value (step S115). If the calculated total score is smaller than the first set value (No at step S115), The determination target part is extracted as a normal inspection part (step S116), and the process ends.

  On the other hand, when the calculated total score is greater than or equal to the first set value (Yes at Step S115), the extraction unit 15a determines whether or not there is a water path at the determination target location (Step S117, fifth determination process). ).

  Here, when there is a water path in the determination target portion (Yes at Step S117), the extraction unit 15a adds points (Step S118).

  On the other hand, when there is no water channel at the determination target location (No at Step S117), and after the point addition processing at Step S118, the extraction unit 15a determines whether there is a water collection facility at the determination target location (Step S119). , Sixth determination process).

  Here, when there is a water collection facility at the determination target location (Yes at Step S119), the extraction unit 15a adds points (Step S120).

  On the other hand, when there is no water collection facility at the determination target location (No at Step S119), and after the point addition processing at Step S120, the extraction unit 15a calculates the total score at the determination target location (Step S121).

  And the extraction part 15a determines whether the calculated total score is more than a 2nd setting value (step S122), and when the calculated total score is smaller than a 2nd setting value (step S122 negative), The determination target part is extracted as a follow-up observation part (step S124), and the process is terminated.

  On the other hand, when the calculated total score is greater than or equal to the second set value (Yes at Step S122), the extraction unit 15a extracts the determination target location as a location requiring investigation (Step S123), and ends the process. And the depression location extraction apparatus 10 in a present Example performs the process demonstrated in FIG. 10 for every determination target location of an underground structure embedding peripheral area, and if a process is performed in all the determination target locations, extraction will be performed. The result is stored in the extraction result storage unit 14c.

  As described above, according to the present embodiment, the extraction unit 15a uses the region information and various setting values stored in the region information storage unit 14a and the setting condition storage unit 14b by the user to embed underground structures. The first determination process for determining whether or not groundwater and seepage water are in contact with each other at the determination target location in the surrounding area, and whether the determination target location is a location where the underground structure and the base intersect Two determination processes are performed. In addition, the extraction unit 15a performs the first determination process again after performing the correction by the capillary phenomenon and the terrain correction for the portion where the first determination result is negative.

  Moreover, the extraction part 15a is the 3rd determination process which determines whether the base | substrate on the underground structure in a determination target location has water permeability, and there exists spring water in the underground structure in a determination target location A fourth determination process for determining whether or not there is a fifth determination process for determining whether or not there is a water path at the determination target location, and a sixth determination for determining whether or not there is a water collecting facility at the determination target location. The determination process is executed. Then, the extraction unit 15a calculates a total score by sequentially adding points indicating the degree of possibility of depression according to the determination result of each determination process, and calculates the calculated total score and a predetermined set value. By comparing, a portion (depression portion) where the degree of occurrence of the depression is classified is extracted.

  Therefore, it is possible to extract not the shallow depression that was previously caused, but the depression where the depression may occur due to piping, and the underground structure changes in the ground above the underground structure. It is possible to extract a place where a ground depression without a shape may occur. In addition, it is possible to extract the degree of the possibility of the occurrence of depressions, and to prevent recurrence at the depressions and to take preventive measures for areas adjacent to the depressions where there is a high possibility of third party damage. It is possible to carry out a typical countermeasure work.

  Note that each component of each illustrated apparatus is functionally conceptual and does not necessarily need to be physically configured as illustrated. In other words, the specific form of distribution / integration of each device is not limited to that shown in the figure, and all or a part thereof may be functionally or physically distributed or arbitrarily distributed in arbitrary units according to various loads or usage conditions. Can be integrated and configured. Further, all or any part of each processing function performed in each device may be realized by a CPU and a program analyzed and executed by the CPU, or may be realized as hardware by wired logic.

  As described above, the depressed portion extraction apparatus and the depressed portion extraction program according to the present invention are useful for extracting a portion where a depression is likely to occur, particularly in the upper ground of the underground structure. It is suitable for extracting a place where there is a possibility of ground depression without deformation of the structure.

DESCRIPTION OF SYMBOLS 10 Depression location extraction apparatus 11 Input part 12 Output part 13 Input / output control I / F part 14 Storage part 14a Area information storage part 14b Setting condition storage part 14c Extraction result storage part 15 Processing part 15a Extraction part

Claims (7)

A region information storage for storing region information composed of geographical information, topographical information and geological information of a predetermined region including a region where the underground structure is embedded, and information on the underground structure Means,
There is a possibility that the ground above the underground structure becomes saturated or nearly saturated due to groundwater and seepage water, and a hydrodynamic gradient occurs between the ground above the underground structure and the inside of the underground structure. A first determination process for determining whether or not there is a second location, and a second determination for determining whether or not a deposit having a different consolidation degree is in contact with the ground above the underground structure. The determination process is executed based on the area information stored in the area information storage means, and the ground surface above the underground structure is determined based on the determination results of the first determination process and the second determination process. An extraction means for extracting a depressed portion that may be depressed,
A depressed portion extraction apparatus characterized by comprising: The area information storage means stores rainfall amount information in the predetermined area as the geographical information, and the underground structure in the predetermined area is embedded as information on the underground structure. Storing the buried position information which is position information and the elevation of the underground structure, and as the topographical information, the ground elevation of the predetermined area specified from the topographic map, the catchment area in the predetermined area, An unconsolidated sediment distribution area in a predetermined region and a depth of a base in the unconsolidated sediment distribution area are stored, and the unconsolidated sediment distribution specified from a geological map is stored as the geological information. Remember the type of unconsolidated sediment in the area,
The extraction means refers to each location of the underground structure embedded peripheral area specified in the predetermined area with reference to the area information,
Infiltration depth estimated from the surface elevation, the type of unconsolidated sediment, the area of unconsolidated sediment distribution area in the catchment area, and underground structures in the catchment area exist Estimated from the depth of the basement and the rainfall information using the width of the catchment area at the position where the groundwater is collected, the type of unconsolidated sediment and the groundwater level rise estimated from the rainfall information The first determination process is performed by determining in each determination target location whether or not the groundwater at the water level and the permeated water that permeates through rainfall from the surface of the catchment area come into contact,
Using the elevation of the underground structure and the depth of the base, the second determination process is executed by determining at each determination target location whether the underground structure intersects the base. The depressed portion extraction apparatus according to claim 1, wherein   The extraction means is configured to determine the amount of increase in the groundwater level used in the first determination process in the determination target location determined that the groundwater and the permeated water do not contact with each other in the first determination process. After correcting by adding the amount of increase in groundwater due to capillary phenomenon estimated from the type of sediment, and / or the value of the ground elevation used in the first determination process is the estimation source After correcting according to the distance resolution of the topographic map, the first determination process is re-executed, and the first determination process, the re-executed first determination process, and the second determination process are determined. The depressed portion extracting apparatus according to claim 2, wherein the depressed portion is extracted based on a result. The area information storage means includes, as the geological information, the type of base in the unconsolidated sediment distribution area estimated from the geological map, and the underground structure as information on the underground structure. Further memorize the presence or absence of spring water in
The extraction means determines whether or not the base has water permeability from the type of the base at each determination target location by referring to the region information together with the first determination process and the second determination process. And a third determination process for determining whether or not spring water is generated in the underground structure at each determination target location, and a determination result that has already been determined and the third determination process. The depressed portion extraction apparatus according to claim 2, wherein the depressed portion is extracted based on the determination process and the determination result of the fourth determination process. The area information storage means further stores, as the area information, information on water paths in the predetermined area and information on water collection facilities on the surface of the predetermined area,
The extraction means refers to the region information, and determines in each determination target location whether or not there is a fifth determination process in each determination target location, and whether there is a water collection facility. And the sixth determination process is further performed, and the depressed portion is extracted based on the already determined determination result and the results of the fifth determination process and the sixth determination process. The depressed portion extraction apparatus according to claim 4.   The extraction means calculates a total score by sequentially adding scores indicating the degree of possibility of depression according to the determination result of each determination process, and compares the calculated total score with a predetermined set score. Thus, the degree of possibility that the ground surface will be depressed at each determination target position is classified, and the depressed portion extraction apparatus according to any one of claims 1 to 5. Area information consisting of geographical information, topographic information and geological information of a predetermined area including an area where the underground structure is embedded, and information on the underground structure is stored in a predetermined storage unit. The area information storage procedure to store,
There is a possibility that the ground above the underground structure becomes saturated or nearly saturated due to groundwater and seepage water, and a hydrodynamic gradient occurs between the ground above the underground structure and the inside of the underground structure. A first determination process for determining whether or not there is a second location, and a second determination for determining whether or not a deposit having a different consolidation degree is in contact with the ground above the underground structure. The determination process is executed based on the area information stored in the predetermined storage unit, and the ground surface above the underground structure is determined based on the determination results of the first determination process and the second determination process. An extraction procedure to extract the depression where there is a possibility of depression,
A depressed part extraction program characterized in that a computer is executed.