Ground improvement structure analysis method, ground improvement structure analysis program, and ground improvement structure analysis device

Abstract

This method enables analysis that directly reflects the physical property variations of the ground improvement body during construction as design parameters, and sets non-uniform design specifications for the ground improvement body by dividing the ground improvement area into multiple regions. [Solution] In the ground improvement body analysis device 10, the analysis unit 12 performs numerical analysis on the mechanical properties of the ground improvement body using multiple analysis conditions set using random numbers. The selection unit 13 selects from the multiple analysis results obtained by the numerical analysis that the required performance for the design target facility, including the ground improvement body, is not achieved. The extraction unit 14 extracts from the selected analysis results the ground improvement range in which the material properties of the ground improvement body do not conform to predetermined standards. The identification unit 15 identifies a critical partial region, which is a ground improvement area with a large impact on the required performance for the design target facility, based on the extracted ground improvement range. The output unit 16 outputs information regarding the identified critical partial region.

Description

Technical Field

[0001] The present invention relates to a technique for analyzing a ground improvement body and setting design specifications therefor.

Background Art

[0002] Regarding the design of ground improvement methods, for example, the deep mixing method in a caisson-type quay will be described as an example. The performance inspection procedure for the improved ground of a caisson-type quay is divided into external stability, internal stability, and deformation inspection by dynamic analysis. External stability assumes a rigid body integrating the caisson and the improved ground, and examines whether sufficient stability is achieved in each item of sliding, overturning, and bearing capacity. Internal stability examines whether the improved ground has sufficient stability in each item of toe pressure, shear strength, and extraction. Note that there are two types of load conditions in external stability and internal stability: the permanent state and the variable state for level 1 seismic motion. The deformation inspection by dynamic analysis examines whether the residual horizontal displacement amount when level 2 seismic motion acts is below the allowable value. In the present invention, the deformation inspection by dynamic analysis is the target.

[0003] When dynamic analysis is performed on a cross-section where the ground under the caisson is being improved to confirm the stress distribution, it has been found that large shear stresses occur in the ground area around the periphery directly below the front toe of the caisson. This indicates that the improvement specifications (strength in the case of the deep mixing method) of this part of the ground area have a great impact on the required performance such as the residual horizontal displacement amount at the upper end of the caisson and the bearing capacity safety factor.

[0004] Therefore, it is considered that an economical design can be realized while satisfying the required performance by making the design specifications such as the addition amount of the solidifying material and the penetration / withdrawal speed of the rod relatively high-quality in the part where the influence on the required performance is large, and making the design specifications relatively low-quality in the part where the influence is not so large.

[0005] Performance-based design methods have been used for civil engineering structures for quite some time, and various proposals have been made for methods of verifying the performance of target structures. For example, Patent Document 1 discloses a method for verifying the seismic performance of embankments. [Prior art documents] [Patent Documents]

[0006] [Patent Document 1] Japanese Patent Publication No. 2021-113430 [Overview of the Initiative] [Problems that the invention aims to solve]

[0007] However, in actual design, the practice of varying design specifications within a single cross-section underground is not carried out. Instead, the overall design specifications are uniformly made high-quality to match the critical areas in the design. For example, if a large shear stress is expected to occur in the ground region directly beneath the caisson's fore toe, and this shear force is expected to cause failure and result in a large caisson displacement, a design strength is determined to prevent failure in this ground region, and this is then applied to all ground improvement areas. Reasons for this include the difficulty in clearly identifying the parts that have a significant impact on the required performance, and the lack of established methods for setting different design specifications for different parts.

[0008] Therefore, the present invention uses the variation in the physical properties of the ground improvement body during construction as a design parameter. The aim is to achieve analysis that directly reflects the results, and to set non-uniform design specifications for the ground improvement body by dividing the ground improvement area into multiple sub-areas. [Means for solving the problem]

[0009] The ground improvement body analysis method according to the present invention is characterized by comprising: an analysis step of performing a numerical analysis of the mechanical properties of the ground improvement body using a plurality of analysis conditions set using random numbers; a selection step of selecting an analysis result from the plurality of analysis results obtained by the numerical analysis that does not meet the requirements for the design target facility; an extraction step of extracting clusters, which are ground improvement areas in which the material properties of the ground improvement body do not conform to a predetermined standard, from the selected analysis results; a identification step of identifying a critical sub-region, which is a ground improvement area that has a large impact on the required performance for the design target facility, based on the extracted ground improvement areas; a specification setting step of setting a main specification, which is a specification of high material properties of the ground improvement body, in the identified critical sub-region, and setting a secondary specification, which is a specification of lower material properties of the ground improvement body compared to the main specification, in a non-critical sub-region, which is an area other than the critical sub-region; a re-analysis step of performing a numerical analysis using the set specifications of the ground improvement body as analysis conditions; and a confirmation step of confirming the degree to which the required performance for the design target facility has been achieved from the analysis results obtained by the re-analysis step.

[0010] Furthermore, the ground improvement analysis method according to the present invention uses multiple FEMs (Finite Element Methods) set using random numbers to determine the mechanical properties of the ground improvement body. Method) The method is characterized by comprising: an analysis step of performing FEM analysis using analysis data; a selection step of selecting analysis results from multiple analysis results obtained from the FEM analysis that do not reach the required performance for the design target facility; an extraction step of extracting clusters from the selected analysis results that are ground improvement areas in which the material properties of the ground improvement body do not conform to predetermined standards for each of the selected analysis results; an identification step of identifying the smallest ground improvement area that includes the overlapping portion of the clusters as a critical sub-region when the selected analysis results are superimposed based on the position of each mesh in the FEM; a specification setting step of setting a main specification, which is a specification of high material properties of the ground improvement body, in the identified critical sub-region, and setting a secondary specification, which is a specification of lower material properties of the ground improvement body compared to the main specification, in the non-critical sub-region, which is an area other than the critical sub-region; a re-analysis step of performing FEM analysis using the set specifications of the ground improvement body as analysis conditions; and a confirmation step of confirming the degree to which the required performance for the design target facility has been achieved from the analysis results obtained from the re-analysis step.

[0011] The ground improvement body analysis program according to the present invention is a program for a computer to implement the following functions: an analysis function that performs numerical analysis on the mechanical properties of a ground improvement body using multiple analysis conditions set using random numbers; a selection function that selects analysis results from the multiple analysis results obtained by the numerical analysis that do not reach the required performance for the design target facility; an extraction function that extracts the ground improvement range in which the material properties of the ground improvement body do not conform to predetermined standards from the selected analysis results; an identification function that identifies a critical sub-region, which is a ground improvement area that has a large impact on the required performance for the design target facility, based on the extracted ground improvement range; and an output function that outputs information about the identified critical sub-region.

[0012] Furthermore, the ground improvement analysis program according to the present invention includes an analysis function that performs FEM analysis on a computer using multiple FEM analysis data set using random numbers to determine the mechanical properties of the ground improvement body; a selection function that selects analysis results from the multiple analysis results obtained from the FEM analysis that do not meet the required performance for the design target facility; an extraction function that extracts clusters, which are ground improvement areas where the material properties of the ground improvement body do not conform to predetermined standards, from the selected analysis results for each of the selected analysis results; and a specification function that identifies the smallest ground improvement area encompassing the overlapping portion of the clusters as the critical portion area when the selected analysis results are superimposed based on the position of each mesh in the FEM; and the identified This program implements an output function that outputs information about the critical subregion.

[0013] The ground improvement body analysis device according to the present invention is characterized by comprising: an analysis unit that performs numerical analysis of the mechanical properties of a ground improvement body using a plurality of analysis conditions set using random numbers; a selection unit that selects analysis results from the plurality of analysis results obtained by the numerical analysis that do not reach the required performance for the design target facility; an extraction unit that extracts a ground improvement range in which the material properties of the ground improvement body do not conform to a predetermined standard from the selected analysis results; a specification unit that identifies a critical partial region, which is a ground improvement area that has a large impact on the required performance for the design target facility, based on the extracted ground improvement range; and an output unit that outputs information regarding the specified critical partial region.

[0014] Furthermore, the ground improvement body analysis device according to the present invention is characterized by comprising: an analysis unit that performs FEM analysis on the mechanical properties of the ground improvement body using a plurality of FEM analysis data set using random numbers; a selection unit that selects from the plurality of analysis results obtained by the FEM analysis that the analysis results do not reach the required performance for the design target facility including the ground improvement body; an extraction unit that extracts clusters, which are ground improvement areas in which the material properties of the ground improvement body do not conform to predetermined standards, from the selected analysis results for each of the selected analysis results; an identification unit that identifies the smallest ground improvement area encompassing the overlapping portion of the clusters as a critical partial area when the selected analysis results are superimposed based on the position of each mesh in the FEM; and an output unit that outputs information regarding the identified critical partial area.

[0015] In the ground improvement analysis method according to the present invention, the identification step may be such that, when there are multiple overlapping parts of the cluster, the overlapping identification step identifies as the critical part region a ground improvement region corresponding to a figure circumscribing the overlapping parts where the distance between the overlapping parts is within a predetermined distance.

[0016] In the ground improvement body analysis method according to the present invention, the identification step may be such that, when the selected analysis results are superimposed based on the position of each of the meshes, the smallest ground improvement area that includes the overlapping portion of the cluster and includes the ground improvement width determined by the construction conditions is identified as the critical portion area.

[0017] In the ground improvement body analysis method according to the present invention, the identification step may be such that, when there are multiple overlapping parts of the cluster, the ground improvement region corresponding to the figure circumscribing the multiple overlapping parts that overlap when viewed from the direction of ground improvement construction is identified as the critical partial region.

[0018] In the ground improvement body analysis method according to the present invention, in the case where there are a plurality of the ground improvement regions, the critical partial region may be specified as a ground improvement region corresponding to a figure circumscribing a plurality of overlapping ground improvement regions as viewed from the direction of the ground improvement construction.

Effect of the Invention

[0019] According to the present invention, it is possible to realize an analysis that directly reflects the physical property variations of the ground improvement body in construction as design parameters, and to set a non-uniform design specification in which the ground improvement region is divided into a plurality of regions for the ground improvement body.

Brief Description of the Drawings

[0020] [Figure 1] Cross-sectional view illustrating the relationship between the caisson-type mooring quay and the ground improvement region. [Figure 2] Block diagram illustrating the hardware configuration of the ground improvement body analysis device according to an embodiment of the present invention. [Figure 3] Block diagram showing the functional configuration of the ground improvement body analysis device according to the embodiment. [Figure 4] Diagram showing mesh data for explaining a method for specifying a critical partial region in the embodiment. [Figure 5] Diagram showing mesh data for explaining a method for specifying a critical partial region in the embodiment. [Figure 6] Diagram showing mesh data for explaining a method for specifying a critical partial region in the embodiment. [Figure 7] Diagram showing mesh data for explaining a method for specifying a critical partial region in the embodiment. [Figure 8] Diagram showing mesh data for explaining a method for specifying a critical partial region in the embodiment. [Figure 9] Flowchart showing the operation of the ground improvement body analysis device according to the embodiment. [Figure 10]A diagram showing mesh data to illustrate a method for identifying critical subregions in modified examples. [Figure 11] A figure showing mesh data to illustrate other methods for identifying critical subregions in the modified example. [Figure 12] A mesh diagram for analysis in one embodiment of the present invention. [Figure 13(a)] This is a strength distribution map showing the variation in strength of the ground improvement body, with ground improvement area A as the spatial area, indicated by the difference in hue of each mesh, and is a strength distribution map obtained by the analysis method of this embodiment. [Figure 13(b)] This is a strength distribution map showing the variation in strength of the ground improvement body, with ground improvement area A as the spatial area, indicated by the difference in hue of each mesh, and is a strength distribution map obtained using a conventional analysis method. [Figure 14(a)] A figure showing the results of the analysis in the same embodiment. [Figure 14(b)] This figure compares the unit quantities of ground improvement materials (solidifying agents) used at construction sites in the design specifications of the examples and comparative examples. [Modes for carrying out the invention]

[0021] (composition) Figure 1 is a cross-sectional view illustrating the positional relationship between a caisson-type mooring quay, which is an example of a facility to be designed, and a ground improvement area. In Figure 1, the ground improvement area A is directly beneath the caisson C installed near the coast w. It is known that large shear stresses occur in the area surrounding the fore toe C1 of the caisson C within the ground improvement area A. In this invention, the facility to be designed is not limited to the caisson-type mooring quay exemplified in Figure 1, but can be any facility that requires ground improvement.

[0022] Figure 2 illustrates the hardware configuration of a ground improvement structure analysis device 10 according to one embodiment of the present invention. Physically, the ground improvement structure analysis device 10 is configured as a computer device including a processor 1001, memory 1002, storage 1003, communication device 1004, input device 1005, output device 1006, and a bus connecting these. Each of these devices operates on power supplied from a power source not shown.

[0023] Each function of the ground improvement analysis device 10 is realized by loading predetermined software (programs) onto hardware such as the processor 1001 and memory 1002, which allows the processor 1001 to perform calculations, control communication by the communication device 1004, acquire data transmitted from other devices, and control at least one of the reading and writing of data in the memory 1002 and storage 1003.

[0024] The processor 1001, for example, runs the operating system on the computer. It controls the entire system. The processor 1001 may consist of a central processing unit (CPU) that includes interfaces with peripheral devices, control units, arithmetic units, registers, etc.

[0025] The processor 1001 receives programs (program code), software modules, data, etc., from at least one of the storage 1003 and the communication device 1004 into memory 1. The data is read into 002, and various processes are executed accordingly. The program used is one that causes the computer to perform at least a part of the operations described later.

[0026] Memory 1002 is a computer-readable recording medium and may consist of at least one of the following: ROM (Read Only Memory), EPROM (Erasable Programmable ROM), EEPROM (Electrically Erasable Programmable ROM), RAM (Random Access Memory), etc. Memory 1002 may also be called a register, cache, main memory, etc. Memory 1002 can store executable programs (program code), software modules, etc., for carrying out the method according to this embodiment.

[0027] Storage 1003 is a computer-readable recording medium, such as a hard disk drive or flash memory.

[0028] The communication device 1004 is hardware (transmitting and receiving device) for communication between computers.

[0029] The input device 1005 is an input device that accepts input from an external source (e.g., a keyboard, mouse, switch, button, etc.). The output device 1006 is an output device that outputs to an external source (e.g., a display, speaker, LED lamp, etc.).

[0030] Figure 3 is a block diagram showing the functional configuration of the ground improvement structure analysis device 10. As shown in Figure 3, the ground improvement structure analysis device 10 implements the functions of an acquisition unit 11, an analysis unit 12, a selection unit 13, an extraction unit 14, a specific unit 15, and an output unit 16.

[0031] Here, we will explain the meaning of the terms used in this embodiment. Required performance refers to the performance that a designed facility must possess in order to achieve its purpose. For example, when a caisson-type mooring wall is the facility being designed, the residual horizontal displacement at the top of the caisson and the safety factor of bearing capacity required to maintain its purpose correspond to the required performance.

[0032] Material properties are the inherent characteristics of a substance, and can be broadly divided into physical properties, mechanical properties, and chemical properties. Physical properties are the physical properties of the substance itself, such as density and thermal conductivity. Mechanical properties are the properties of a substance in response to external forces, such as strength, stress, and strain. Chemical properties are the properties of a substance related to chemical reactions, such as the hydration reaction of a solidifying agent.

[0033] A specification is a set of requirements that a material or product must meet.

[0034] A standard is a benchmark used to compare and judge things or phenomena.

[0035] In Figure 3, the acquisition unit 11 acquires information necessary for various processing by the analysis unit 12, such as the physical properties of the ground at the site based on the ground investigation results and various analysis conditions.

[0036] The analysis unit 12 analyzes the mechanical properties of the ground improvement body using multiple analysis rules set with random numbers. Numerical analysis will be performed using the data. The numerical analysis referred to here is, for example, FEM (Finite Element Method) analysis using multiple FEM analysis data sets that were set using random numbers.

[0037] First, the analysis unit 12 generates mesh data that takes spatial variability into account as data for FEM analysis. The parameters necessary to generate mesh data that takes spatial variability into account include the average strength of the ground improvement body, the coefficient of variation, and the autocorrelation distance. For the average strength, multiple values ​​are set according to the structural type and required performance of the facility under design. For the coefficient of variation, at least two values ​​are set based on the type of construction method and past performance. One is the value expected when normal construction is carried out, and the other is the value when the quality of construction is intentionally reduced. The autocorrelation distance is a distance that serves as an indicator of how much of the ground can be considered to be probabilistically identical. In this embodiment, this autocorrelation distance is set, for example, once each in the vertical and horizontal directions based on the type of construction method and past performance, but multiple values ​​may be set in each direction. The analysis unit 12 generates multiple patterns of distribution of the above parameters based on a log-normal distribution using random numbers. This makes it possible to model various patterns of spatial variability in the ground improvement area based on the average strength of the ground improvement body, the coefficient of variation, and the autocorrelation distance.

[0038] The analysis unit 12 then performs FEM analysis on multiple mesh data sets that model multiple patterns of spatial variability, and obtains analysis results corresponding to each mesh data set. Monte Carlo simulation, one of the reliability design methods, is used in this analysis.

[0039] The selection unit 13 selects analysis results from multiple analysis results obtained from the above FEM analysis that do not reach the required performance for the facility under design. The required performance is, for example, the residual horizontal displacement at the top of the caisson or the safety factor of bearing capacity, and analysis results in which these do not reach the specified required performance values ​​are selected.

[0040] The extraction unit 14 extracts ground improvement areas from the analysis results selected by the selection unit 13 in which the material properties of the ground improvement bodies do not conform to predetermined standards. Specifically, the extraction unit 14 extracts clusters of ground improvement areas in which the material properties of the ground improvement bodies do not conform to predetermined standards for each selected analysis result. The material properties of the ground improvement bodies used here include, for example, the strength, shear strain, and shear stress of the ground improvement bodies, and ground improvement areas in which at least one of these does not conform to predetermined standards are extracted.

[0041] The identification unit 15 identifies the ground improvement area (hereinafter referred to as the critical area) that has a significant impact on the required performance of the facility under design, based on the ground improvement area extracted by the extraction unit 14.

[0042] Refer to Figures 4-8 to illustrate a specific method for identifying critical subregions. In Figures 4-8, each rectangle in the grid-like divisions corresponds to an individual mesh (also called an element).

[0043] Figures 4-6 show the analysis results for mesh data with different spatial variability, which were extracted by the extraction unit 14 as ground improvement areas where the material properties of the ground improvement bodies do not conform to predetermined standards. In Figure 4, the shaded cluster ca is a group of meshes that, as a result of FEM analysis on a certain first mesh data, contain meshes in which at least one of the strength, shear strain, or shear stress of the ground improvement bodies did not conform to predetermined standards. Here, if meshes in which at least one of the strength, shear strain, or shear stress of the ground improvement bodies does not conform to predetermined standards are touching each other vertically, horizontally, or diagonally, the smallest rectangle containing multiple meshes that are touching each other forms one cluster.

[0044] Failure to meet the specified strength criteria means, for example, that the mesh has a strength lower than the average strength. Failure to meet the specified shear stress criteria means that the shear stress generated in the mesh is greater than or equal to k*quck (where k is, for example, 1.0). Failure to meet the specified shear strain criteria means that the shear strain generated in the mesh is greater than or equal to n% (where n is, for example, 1.0).

[0045] Furthermore, in Figure 5, cluster cb is a group of meshes that, as a result of FEM analysis on the second mesh data, contain meshes in which at least one of the strength, shear strain, or shear stress of the ground improvement body did not meet the predetermined criteria. Similarly, in Figure 6, cluster cc is a group of meshes that, as a result of FEM analysis on the third mesh data, contain meshes in which at least one of the strength, shear strain, or shear stress of the ground improvement body did not meet the predetermined criteria. In Figures 5 and 6, if meshes in which at least one of the strength, shear strain, or shear stress of the ground improvement body did not meet the predetermined criteria are touching each other vertically, horizontally, or diagonally, the smallest rectangle containing all of these meshes forms a single cluster.

[0046] As can be seen by comparing Figures 4-6, the spatial variability differs in each mesh data, resulting in different distributions of clusters where the material properties of the ground improvement bodies do not meet the specified standards.

[0047] Figure 7 shows how clusters ca, cb, and cc overlap when the analysis results exemplified in Figures 4-6 are superimposed based on the positions of each mesh. In Figure 7, the mesh group m with the darkest shading represents the mesh group corresponding to the overlapping portion where clusters ca, cb, and cc overlap. In this case, where there are multiple mesh groups m where clusters ca, cb, and cc overlap and do not touch each other, the identification unit 15 identifies the region corresponding to the figure (circumscribed rectangle CR) that all of the mesh groups m circumscribe as the critical partial region, as exemplified in Figure 8. In other words, the identification unit 15 identifies the smallest ground improvement area that includes the overlapping portion of the clusters described above when the analysis results selected by the selection unit 13 are superimposed based on the positions of each mesh in the FEM as the critical partial region.

[0048] Returning to the explanation of Figure 3, the output unit 16 outputs information regarding the identified critical subregion. Specifically, the output unit 16 outputs information indicating the location and details of the critical subregion within the ground improvement area, such as by displaying it.

[0049] (operation) Next, the operation of this embodiment will be described. The designer selects the structural type and ground improvement method of the facility to be designed, and determines the physical properties of the ground based on the ground investigation results, and inputs the analysis conditions including this data into the ground improvement body analysis device 10. In the ground improvement body analysis device 10, the acquisition unit 11 acquires this data (step S11).

[0050] Next, in the ground improvement body analysis device 10, the analysis unit 12 performs the FEM analysis described above based on the acquired data (step S12).

[0051] Next, in the ground improvement analysis device 10, the selection unit 13 selects from multiple analysis results obtained by FEM analysis that do not meet the required performance for the facility under design (step S13).

[0052] Next, in the ground improvement body analysis device 10, the extraction unit 14 selects the ground from the selected analysis results. Step S14 identifies the area of ​​ground improvement where the material properties of the ground improvement body do not conform to the prescribed standards.

[0053] Next, in the ground improvement analysis device 10, the identification unit 15 identifies critical areas that have a significant impact on the required performance of the design target facility based on the extracted ground improvement range (step S15). Then, the output unit 16 outputs information regarding the identified critical areas.

[0054] The designer sets the design specifications for the ground improvement body by referring to the information output from the ground improvement body analysis device 10 (step S16). Specifically, in the critical region, a main specification is set, which is the specification for the high material properties of the ground improvement body, and in the non-critical region, which is the region other than the critical region, a secondary specification is set, which is the specification for the lower material properties of the ground improvement body compared to the main specification. For example, a large average strength and a small coefficient of variation may be set for the critical region, and a relatively small average strength and a large coefficient of variation may be set for the non-critical region. Regarding the average strength, the more solidifying agent is added, the greater the strength of the ground improvement body and therefore the higher the quality, while the less solidifying agent is added, the less the strength of the ground improvement body and therefore the lower the quality. Also, the coefficient of variation differs depending on the construction method, but for example, in the deep mixing method, the more times the mixing blades are cut, the more uniformly the improvement is achieved and therefore the higher the quality, while the fewer times the mixing blades are cut, the less uniform the improvement is achieved and therefore the lower the quality.

[0055] Next, based on the specifications set for each section of the ground improvement body, the ground improvement body analysis device 10 performs the processing steps S11 to S15 again (step S17). In other words, the FEM is re-analyzed.

[0056] Then, based on the analysis results from the reanalysis, the designer confirms the degree to which the required performance for the facility being designed has been achieved (Step S18). Here, for example, the degree to which the facility has been achieved in relation to criteria such as performance, cost, construction period, constructability, and CO2 emissions is compared and examined, and the optimal specification that satisfies the required performance is identified.

[0057] According to the embodiments described above, by directly considering the coefficient of variation based on probabilistic methods such as Monte Carlo simulation, it becomes possible to realize an analysis that directly reflects the variation in the physical properties of the ground improvement body during construction as a design parameter. Furthermore, by evaluating the analysis results with different specifications set for each part, it becomes possible to set non-uniform design specifications for the ground improvement body by dividing the ground improvement area into multiple sub-regions. This makes it possible to achieve an economical design while satisfying the required performance.

[0058] (modified version) The present invention is not limited to the embodiments described above. The embodiments described above may be modified as follows. Furthermore, two or more of the following modifications may be combined and implemented.

[0059] If the size of the identified critical sub-region is very small (for example, below a predetermined threshold), the critical sub-region may be identified to be of a size that at least includes the minimum ground improvement width determined by the construction conditions during ground improvement. In other words, the identification unit 15 may identify the minimum ground improvement region that includes the overlapping portion of the cluster and includes the ground improvement width determined by the construction conditions as the critical sub-region.

[0060] Furthermore, if there are multiple overlapping parts in a cluster, these overlapping parts may be far apart from each other. In such cases, a critical region that includes all of these overlapping parts would contain a large amount of ground area that does not correspond to a cluster, and therefore would be considered inappropriate. Therefore, if there are multiple overlapping parts of the cluster, the identification unit 15 may identify as the critical part area a ground improvement area corresponding to a figure that is circumscribed by the overlapping parts whose mutual distance is within a predetermined distance.

[0061] Furthermore, if there are multiple overlapping parts of the cluster, the specific unit 15 may identify the ground improvement region as the critical portion region, which corresponds to the figure circumscribing the multiple overlapping parts when viewed from the direction of ground improvement construction.

[0062] Here, Figure 10 illustrates a mesh group m, which is the overlapping portion where each cluster overlaps. In Figure 10, arrow a indicates the direction of construction during ground improvement work. It is more efficient to determine the specifications for ground improvement work according to this direction of construction. Mesh groups m1 and m2 overlap when viewed from the direction of ground improvement work, so the ground improvement area corresponding to the figure circumscribing these mesh groups m1 and m2 is identified as critical sub-region CR1. Mesh group m3 does not overlap with any other mesh groups when viewed from the direction of ground improvement work, so the ground improvement area corresponding to the figure circumscribing this mesh group m3 is identified as critical sub-region CR2. Similarly, mesh group m4 does not overlap with any other mesh groups when viewed from the direction of ground improvement work, so the ground improvement area corresponding to the figure circumscribing this mesh group m4 is identified as critical sub-region CR3.

[0063] Furthermore, the specific unit 15 may also identify a critical sub-region in cases where there are multiple ground improvement regions including overlapping parts of clusters (i.e., regions of geometric shapes circumscribing the mesh groups corresponding to the overlapping parts of clusters), where the ground improvement region corresponding to the geometric shape circumscribing the multiple overlapping ground improvement regions when viewed from the direction of ground improvement construction is the critical sub-region.

[0064] Here, Figure 11 illustrates multiple ground improvement areas (circumscribed rectangular areas circumscribed by mesh groups corresponding to the overlapping areas of clusters) including overlapping cluster portions. In Figure 11, arrow a indicates the direction of construction during ground improvement work, and it is more efficient to determine the specifications for ground improvement work for each construction direction. L is the minimum ground improvement width determined from the construction conditions during ground improvement. Therefore, the critical area has a width of at least L or greater. Note that the width here refers to the length in the direction perpendicular to the direction of construction during ground improvement work.

[0065] In Figure 11, mesh groups m1 and m2 overlap when viewed from the direction of ground improvement construction. The ground improvement area corresponding to the shape circumscribing these mesh groups m1 and m2 (the rectangle represented by the dashed-dotted and double-dotted lines in Figure 11) is identified as the ground improvement area CRa, where the mesh groups overlap when viewed from the direction of ground improvement construction, because its width is greater than or equal to the ground improvement width L.

[0066] Mesh group m3 does not overlap with any other mesh groups when viewed from the direction of ground improvement construction, but its width is smaller than the ground improvement width L. In such cases, the smallest ground improvement area (represented by the dotted and dashed lines in Figure 11) that includes mesh group m3 and the ground improvement width L is identified as the ground improvement area CRb.

[0067] Furthermore, ground improvement areas CRa and CRb overlap when viewed from the direction of ground improvement construction. In this case, the ground improvement area corresponding to the figure (the rectangle represented only by the dashed line in Figure 11) that is circumscribing these ground improvement areas CRa and CRb is identified as the critical sub-area CR1.

[0068] Furthermore, mesh group m4 does not overlap with any other mesh groups when viewed from the direction of the ground improvement work, and its width is equal to or greater than the ground improvement width L. Therefore, the figure circumscribing mesh group m4 is The corresponding ground improvement area (represented by a rectangle with only a dashed line in Figure 11) is identified as the critical sub-region CR2.

[0069] As described above, the identification unit 15 may identify the smallest ground improvement area that includes the overlapping portion of the cluster (i.e., the group of meshes) and the ground improvement width determined by the construction conditions, when the analysis results selected by the selection unit 13 are superimposed based on the position of each mesh, as the critical sub-region.

[0070] (Analysis example) As an example of an embodiment of the present invention, we will explain the analysis results for a caisson-type mooring quay, shown in Figure 12, as the facility to be designed.

[0071] In Figure 12, CP is the upper end of the caisson, which is the point of focus for verifying the required performance of the facility under design. The design specifications are determined so that the residual horizontal displacement of this upper end CP of the caisson after a Level 2 earthquake satisfies the predetermined required performance.

[0072] In Figure 12, CR represents the critical region identified by the specific section 15. NCR, which is the area remaining after excluding the critical region CR from the ground improvement region A, represents the non-critical region.

[0073] Figure 13 is an intensity distribution diagram showing the variation in the strength of the ground improvement body, with the ground improvement area A as the spatial area, indicated by the difference in hue of each mesh. Figure 13(a) is the result of the analysis method of this embodiment, and the small change in hue of the critical area CR means that the variation in strength is small. Figure 13(b) is an intensity distribution diagram using a conventional analysis method, but because the variation in the physical properties of the ground improvement body (physical property variation) cannot be reflected in the analysis as a design parameter, the ground improvement area A has a uniform strength.

[0074] Figure 14 shows an example of the analysis results according to the present invention. The comparative example is based on a conventional analysis method that cannot reflect spatial variability. Example (1) evaluates whether the required performance can be met even when the average strength of the noncritical partial region NCR is lowered from the average strength of the ground improvement body of the comparative example. Example (2) evaluates whether the required performance can be met even when the coefficient of variation of the noncritical partial region NCR is increased from Example (1), that is, when the variability in strength increases (the quality of construction is low). As mentioned above, conventional analysis methods cannot reflect material variations in the ground improvement body (indicated by "*" in the figure).

[0075] As shown in Figure 14(a), both Example (1) and Example (2) meet the required performance criterion of a residual displacement of 1.0 m or less at the top of the caisson. This indicates that the design specifications for the non-critical partial region NCR can be set to a lower level.

[0076] Figure 14(b) compares the unit quantities of ground improvement materials (solidifying agents) used at construction sites according to the design specifications of the examples and comparative examples. Mix strength refers to the strength that takes into account the variation in quality during construction. In this example, a coefficient of variation of 0.33 is included in the process of increasing the mix strength from the average strength in Figure 14(a).

[0077] In the comparative example, which uses a conventional analysis method, the variation in the strength of the ground improvement structure is not reflected in the analysis, so it is necessary to increase the mix strength. On the other hand, in the example, which reflects the variation in the strength of the ground improvement structure during the analysis, the aforementioned increase is unnecessary.

[0078] Furthermore, the amount of solidifying agent used is the strength qu (kN / m 2 ) and unit cement content C (kg / m 3 ) The following equation, which is a relation between the two, was used to calculate it. q u =-0.0714C 2 +34.254C

[0079] According to Figure 14(b), the unit solidification material content (cement-based) of the comparative example was 137 kg / m³. 3 In this example, the value is 33.8 (kg / m 3 This results in a 75.3% reduction in the amount of solidifying agent compared to the comparative example.

[0080] Furthermore, Example (2) shows a larger coefficient of variation in the non-critical region NCR compared to Example (1). In other words, it suggests the possibility of shortening construction time, which is one of the factors affecting construction quality, while satisfying the required performance.

[0081] The present invention may be implemented as a program for a computer. This program may be provided recorded on a computer-readable recording medium such as a CD-ROM (Compact Disc Read Only Memory), or it may be downloaded via a communication network such as the Internet. [Explanation of symbols]

[0082] 10: Ground improvement analysis device, 11: Acquisition unit, 12: Analysis unit, 13: Selection unit, 14: Extraction unit, 15: Identification unit, 16: Output unit, 1001: Processor, 1002: Memory, 1003: Storage, 1004: Communication device, 1005: Input device, 1006: Output device, w: Coast, C: Caisson, C1: Foretoe of caisson, A: Ground improvement area, ca, cb, cc: Cluster, m, m1, m2, m3, m4: Mesh group, CRa, CRb, CRc: Ground improvement area including overlapping part of cluster, CR, CR1, CR2, CR3: Critical part area, a: Construction direction, CP: Upper end of caisson, NCR: Non-critical part area, L: Minimum ground improvement width determined by construction conditions.

Claims

1. The analysis step involves performing a numerical analysis on the mechanical properties of the ground improvement body using multiple analysis conditions set using random numbers, and A selection step involves selecting analysis results from multiple analysis results obtained from the aforementioned numerical analysis that do not meet the required performance for the facility under design, From the selected analysis results, an extraction step is performed to extract clusters that represent ground improvement areas in which the material properties of the ground improvement body do not conform to predetermined standards, Based on the extracted ground improvement area, the process involves identifying a critical sub-region, which is a ground improvement area with a significant impact on the required performance of the facility under design, and A specification setting step involves setting a main specification, which is a specification of high material properties of the ground improvement body, for the identified critical partial region, and setting a secondary specification, which is a specification of lower material properties of the ground improvement body compared to the main specification, for the non-critical partial region, which is the region other than the critical partial region. A re-analysis step in which numerical analysis is performed using the specifications of the ground improvement body set as analysis conditions, A confirmation step is taken to confirm the degree to which the required performance for the design target facility has been achieved based on the analysis results from the aforementioned re-analysis step. A method for analyzing ground improvement bodies, characterized by comprising the following features.

2. The analysis step involves performing an FEM (Finite Element Method) analysis on the mechanical properties of the ground improvement body using multiple FEM (Finite Element Method) analysis data sets generated using random numbers, and A selection step involves selecting analysis results from multiple analysis results obtained by the aforementioned FEM analysis that do not meet the required performance for the facility under design, From the selected analysis results, an extraction step is performed to extract clusters for each selected analysis result that represent ground improvement areas where the material properties of the ground improvement body do not conform to predetermined standards. The process involves identifying the smallest ground improvement area encompassing the overlapping portion of the clusters as the critical area when the selected analysis results are superimposed based on the position of each mesh in the FEM, and A specification setting step involves setting a main specification, which is a specification of high material properties of the ground improvement body, for the identified critical partial region, and setting a secondary specification, which is a specification of lower material properties of the ground improvement body compared to the main specification, for the non-critical partial region, which is the region other than the critical partial region. A re-analysis step in which FEM analysis is performed using the specified specifications of the ground improvement body as analysis conditions, A confirmation step is taken to confirm the degree to which the required performance for the design target facility has been achieved based on the analysis results from the aforementioned re-analysis step. A method for analyzing ground improvement bodies, characterized by comprising the following features.

3. The aforementioned identification step, in cases where there are multiple overlapping parts of the cluster, identifies the ground improvement area corresponding to the figure circumscribing the overlapping parts, where the distance between the overlapping parts is within a predetermined distance, as the critical partial area. The method for analyzing a ground improvement structure according to feature 2.

4. The aforementioned identification step involves superimposing the selected analysis results based on the positions of each of the meshes, and identifying the smallest ground improvement area that includes the overlapping portion of the cluster and the ground improvement width determined by the construction conditions as the critical portion area. The method for analyzing a ground improvement structure according to feature 2.

5. The aforementioned identification step, in cases where there are multiple overlapping parts of the cluster, identifies the ground improvement region corresponding to the figure circumscribing the multiple overlapping parts when viewed from the direction of ground improvement construction as the critical partial region. The method for analyzing a ground improvement body according to claim 3 or 4.

6. The aforementioned identification step, in cases where there are multiple ground improvement areas, identifies the ground improvement area corresponding to the figure circumscribing multiple overlapping ground improvement areas when viewed from the direction of ground improvement construction as the critical sub-area. The method for analyzing a ground improvement body according to feature 4.

7. On the computer, The analysis function performs numerical analysis on the mechanical properties of the ground improvement body using multiple analysis conditions set with random numbers, A selection function that selects analysis results from multiple analysis results obtained from the aforementioned numerical analysis that do not meet the required performance for the facility under design, An extraction function that extracts clusters from the selected analysis results that represent ground improvement areas where the material properties of the ground improvement body do not conform to predetermined standards, Based on the extracted ground improvement area, the system identifies critical areas, which are ground improvement areas that have a significant impact on the required performance of the facility under design. An output function that outputs information about the identified critical subregion. A ground improvement analysis program to achieve this.

8. On the computer, The analysis function performs FEM analysis on the mechanical properties of the ground improvement body using multiple FEM analysis data sets set using random numbers, A selection function that selects analysis results from multiple analysis results obtained by the aforementioned FEM analysis that do not meet the required performance for the design target facility, An extraction function that extracts clusters from the selected analysis results that represent ground improvement areas where the material properties of the ground improvement body do not conform to predetermined standards, for each selected analysis result, A function to identify the smallest ground improvement area encompassing the overlapping portion of the cluster when the selected analysis results are superimposed based on the position of each mesh in the FEM, and to identify the critical sub-region. An output function that outputs information about the identified critical subregion. A ground improvement analysis program to achieve this.

9. The aforementioned identification function identifies the ground improvement region corresponding to the figure scribing the overlapping portions of the cluster, where the distance between the overlapping portions is within a predetermined distance, as the critical portion region when there are multiple overlapping portions of the cluster. The ground improvement body analysis program according to claim 8.

10. The analysis unit performs numerical analysis on the mechanical properties of the ground improvement body using multiple analysis conditions set with random numbers, A selection unit that selects from multiple analysis results obtained from the aforementioned numerical analysis that do not meet the required performance for the facility under design, An extraction unit extracts the area of ​​ground improvement in which the material properties of the ground improvement body do not conform to predetermined standards, based on the selected analysis results. Based on the extracted ground improvement area, a specific unit identifies a critical area, which is a ground improvement area that has a significant impact on the required performance of the facility under design. An output unit that outputs information regarding the identified critical subregion, A ground improvement body analysis device characterized by being equipped with the following features.

11. The analysis unit performs FEM analysis on the mechanical properties of the ground improvement body using multiple FEM analysis data sets set using random numbers, A selection unit that selects from multiple analysis results obtained from the FEM analysis that do not meet the required performance for the facility under design, An extraction unit extracts clusters from the selected analysis results that represent ground improvement areas where the material properties of the ground improvement body do not conform to predetermined standards, for each selected analysis result. A selection unit that, when the selected analysis results are superimposed based on the position of each mesh in the FEM, identifies the smallest ground improvement area encompassing the overlapping portion of the cluster as the critical area, An output unit that outputs information regarding the identified critical subregion, A ground improvement body analysis device characterized by being equipped with the following features.

12. The identifying unit identifies the ground improvement region corresponding to the figure scribing the overlapping portions of the cluster, where the distance between the overlapping portions is within a predetermined distance, as the critical portion region when there are multiple overlapping portions of the cluster. The ground improvement body analysis device according to claim 11.

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