An Optimization Method for Construction Site Layout Planning Integrating the Advantages of BIM and GIS

Abstract

This application provides an optimization method for construction site layout planning that integrates the advantages of BIM and GIS, solving the technical problems of existing methods that cannot meet the high requirements of construction site spatial management, sophisticated planning, and comprehensive decision-making basis. It includes constructing a BIM model of the construction site, converting it into a Shapefile file and importing it into GIS to create a two-dimensional construction site layout map; combining the two-dimensional construction site layout map with the project schedule to obtain a dynamic layout planning map; defining optimization functions to optimize the total travel distance and safety level between facility points in the dynamic layout planning map, and using a population-guided whale optimization algorithm to perform bi-objective optimization of the optimization functions, thereby achieving optimization of the construction site layout at each stage. This application can be widely applied in the technical field of building construction and management.

Description

Technical Field

[0001] This application belongs to the technical field of building construction and management, and more specifically, it relates to an optimization method for construction site layout planning that integrates the advantages of BIM and GIS. Background Technology

[0002] Pumped storage power station projects are large in scale, with a high density of construction sites, many high-altitude and overlapping operations, and an exceptionally complex construction environment. The workload of coordination is enormous, and the requirements for construction management are very high. It is necessary to carry out reasonable construction site layout planning, optimize the spatial layout of on-site material storage facilities, equipment storage facilities, processing facilities and residential facilities, so as to improve production and construction efficiency, while ensuring zero conflict and safety in working conditions, thereby reducing project costs.

[0003] Currently, BIM technology, based on its advantages such as collaborative design, multi-dimensional information integration, and full-cycle digital management of projects, has been introduced to address the problem of construction site layout optimization, generating material and facility requirement data according to the construction phase. However, for large-scale projects such as pumped storage power stations, the practical application effect of existing BIM technology is limited, mainly due to the following three issues: First, pumped storage power stations are located in environments with complex terrain, wide construction areas, and involve many types of structures and buildings, requiring high spatial management standards; second, BIM technology has limited spatial analysis capabilities, and most optimization methods require simplification of the actual model to perform spatial analysis operations using BIM data, but model simplification leads to a loss of planning accuracy; finally, BIM model information lacks an effective platform for analysis and evaluation, and the trends and relationships between information sets lack linkage, resulting in incomplete decision-making basis for users. Summary of the Invention

[0004] The purpose of this application is to provide an optimization method for construction site layout planning that integrates the advantages of BIM and GIS, so as to solve the technical problems that existing technologies cannot meet the high requirements of construction site space management, sophisticated planning and comprehensive decision-making basis.

[0005] To achieve the above objectives, this application provides an optimization method for construction site layout planning that integrates the advantages of BIM and GIS, including the following steps: constructing a BIM model of the construction site, converting it to generate a Shapefile file and importing it into GIS, and creating a two-dimensional construction site layout map;

[0006] A dynamic layout planning diagram is obtained by combining a two-dimensional construction site layout map with a project schedule.

[0007] An optimization function is defined to optimize the total travel distance and safety level between facility points in the dynamic layout planning diagram. The optimization function is then optimized using a population-guided whale optimization algorithm to achieve bi-objective optimization, thereby optimizing the construction site layout at each stage.

[0008] Preferably, the process of performing dual-objective optimization includes:

[0009] Initialize the coordinates of the centroids of the facility points in the construction site and evaluate the fitness value of each search agent;

[0010] Identify non-dominated solutions and store them in an external archive set, and calculate the crowding distance for each non-dominated solution;

[0011] Sort the vectors in descending order based on their crowding distance and select the globally optimal location vector.

[0012] Update the external archive set and remove the most crowded non-dominated solutions. Repeat this process until the termination condition is met to obtain the optimized location of the construction site facility points.

[0013] Preferably, a combination method is used, assigning a unique activity code to each construction activity and using the unique activity code to link the project schedule.

[0014] Preferably, the optimization function for optimizing the total travel distance between facility points is:

[0015] ;

[0016] In the formula, This is an optimization function for the total travel distance between each facility point. For travel frequency, t represents the actual distance between construction facility points i and j at stage t of the project, and T represents the total number of construction stages of the power station.

[0017] Preferably, the optimization function for optimizing the safety level is:

[0018] ;

[0019] In the formula, MinZ2 is the optimization function for the safety level. and , i and j respectively represent the proximity weight and Euclidean distance between construction facilities i and j, n is the total number of facilities, and T is the total number of power plant construction stages.

[0020] Preferably, the Euclidean distance formula is:

[0021] ;

[0022] In the formula, and This represents the centroid coordinates of available pixels at construction facility points i and j in stage t.

[0023] Preferably, the optimization function for the safety level is defined based on the proximity weight matrix;

[0024] The proximity weight matrix is ​​obtained from the proximity weight coefficient reference table, which is obtained by experts through qualitative judgment.

[0025] Preferably, the creation process involves selecting polygonal elements from the BIM model in the Shapefile file to obtain a two-dimensional polygon of the construction site, i.e., a two-dimensional construction site layout map.

[0026] Preferably, the selection refers to selecting based on the elevation value of the polygonal element.

[0027] Preferably, a frequency estimation matrix needs to be obtained before optimizing the total travel distance between construction site facilities.

[0028] The frequency estimation matrix is ​​obtained from multiple trip frequency estimates;

[0029] Formula for obtaining travel frequency estimates:

[0030] ;

[0031] In the formula, Let r be the frequency of material travel from facility i to facility j using transport equipment t during construction phase g. Let r be the total quantity of materials r transported between facility i and facility j during construction phase g. This indicates the capacity of the transportation equipment t.

[0032] The beneficial effects of this application are as follows: This application imports the BIM model of the construction site into GIS and creates a two-dimensional construction site layout map. By combining the two-dimensional construction site layout map with the project schedule, a dynamic layout planning map is obtained. This dynamic layout planning map visualizes the construction scene, thus meeting the high requirements of construction site management. Furthermore, this application defines different optimization functions based on the total travel distance and safety level between facility points in the dynamic layout planning map, greatly optimizing the total travel distance and safety level between facility points. This ensures the shortest travel distance to each facility point in the dynamic layout planning map and the safety of the construction process, making all planning schemes in the dynamic layout planning map optimal solutions, thus meeting the ingenious requirements of planning. Finally, the optimization function is optimized in two objectives, meeting the requirement of comprehensive decision-making basis for the construction site. Attached Figure Description

[0033] To more clearly illustrate the technical solutions in the embodiments of this application, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of this application. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0034] Figure 1 This is a schematic diagram of the overall process of an optimization method for construction site layout planning that integrates the advantages of BIM and GIS, provided as an embodiment of this application. Detailed Implementation

[0035] To make the technical problems, technical solutions, and beneficial effects to be solved by this application clearer, the following detailed description is provided in conjunction with the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are merely illustrative and are not intended to limit the scope of this application.

[0036] Please see Figure 1 An optimization method for construction site layout planning that integrates the advantages of BIM and GIS, provided as an embodiment of this application, includes:

[0037] S1: Construction site modeling.

[0038] A BIM model of the construction site is constructed, and a Shapefile file is obtained by converting it using DIA. A two-dimensional construction site layout map is then created based on the imported BIM model from the GIS.

[0039] 1. Construct a BIM model of the construction site, convert it to generate a Shapefile file, and import it into GIS to obtain a 3D BIM model in GIS format.

[0040] Using Autodesk Revit software, a 3D model of the pumped-storage power station was created based on the construction drawings, construction details, geological conditions, and actual site conditions, resulting in a complete BIM model. It is worth noting that the construction site in this embodiment refers specifically to the pumped-storage power station; however, the choice of construction site is not limited and can be made according to actual circumstances.

[0041] Use the ArcGIS software extension tool Data Interoperability extension for ArcGIS (DIA) to convert the IFC format BIM model into a spatial vector data format Shapefile file and import it into GIS.

[0042] Specifically, Shapefile is an open spatial data format developed by the Environmental Systems Research Institute in the United States. It is a vector data format used to represent point, line, and polygon features, while recording their coordinates and attribute information. It can store Geographic Information System (GIS) data, and this application is used to represent polygon features.

[0043] 2. Create a two-dimensional construction site layout plan based on the imported GIS BIM model.

[0044] Using ArcGIS's ArcMap component, the imported 3D BIM model is placed on satellite imagery of the project area. A 2D construction site layout map is created using a coordinate system consistent with the actual location on the construction site map. The specific steps are as follows:

[0045] (1) In the 3D IFC format BIM model, each component is defined as a polygonal feature in the Shapefile file, and selection is made based on the maximum and minimum Z-values ​​of the elevation of each polygonal feature. The outlines of the selected polygonal features (the boundaries of the polygons in two dimensions) form the two-dimensional polygons of the construction site layer, resulting in a two-dimensional construction site layout map. Here, elevation refers to the vertical height of the ground or object relative to a certain reference plane.

[0046] (2) A grid system is used to represent the site space. Pixel areas are created based on the actual coordinate system of the construction site map layer. The site space is divided into multiple units using the pixel areas. In the total construction site unit, pixels that cannot be used to set up construction facilities for the construction project, such as trees and columns, are identified and their status is changed to occupied. The remaining area is defined as available pixels.

[0047] (3) Assign a unique ID number to each cell and add the actual area, elevation value, x-coordinate value and y-coordinate value of the cell centroid to the attribute table.

[0048] S2: Dynamic layout planning.

[0049] The project schedule is combined with a two-dimensional construction site layout diagram to define the time dimension in the construction site layout. The specific steps are as follows:

[0050] Based on the project schedule, the entire project is divided into multiple phases, each containing specific construction activities, with the nature and target location of each activity determined. The specific construction tasks within each activity are identified, their logical relationships and priorities are clarified, ultimately resulting in a project construction schedule. The procedures for each phase of the schedule are then mapped to the required resources, which in this implementation refer to materials, manpower, and equipment. Based on these resources, they are further mapped to the different facilities needed during the construction activities, thereby determining the activity time attributes for each facility.

[0051] Each construction activity is assigned a unique activity code, including information such as location, component type, and task type, to link data in the project schedule, project timeline, and BIM model. The construction date of each part of the project is added to the attribute table of each project. Using ArcGIS's Time Slider tool, the layers in the 2D construction site layout map are visualized at different points in time, simulating construction sequencing and showing changes in the construction project.

[0052] S3: Optimize the layout of the construction site.

[0053] Optimization functions for optimizing the total travel distance between facility points and the safety level are defined respectively. The population-guided whale optimization algorithm is used to optimize the optimization functions in two objectives, thereby achieving the optimization of the construction site layout at each stage.

[0054] 1. Optimize the total travel distance between facility points.

[0055] Based on the project schedule data, VBA analysis was used to estimate the travel frequency of material transportation-related facilities at each stage of the construction project. These travel frequency estimates were stored in a travel frequency matrix. A grid method was used to estimate the actual shortest travel distance between facilities. An optimization function was defined to optimize the total travel distance between each facility.

[0056] Specifically, the process of obtaining the estimated travel frequency using VBA analysis is as follows:

[0057] Based on the data in the project schedule and BIM model, and according to the activity codes, assign two pairs of facilities, material types and quantities, and corresponding capacity of material handling equipment to each task. Then, use the following formula to calculate the estimated trip frequency between the two pairs of facilities:

[0058] ;

[0059] In the formula, Let r be the frequency of material travel from facility i to facility j using transport equipment t during construction phase g. Let r be the total quantity of materials r transported between facility i and facility j during construction phase g. This indicates the capacity of the transportation equipment t.

[0060] The grid method is used to estimate the actual shortest travel distance between facilities. The total travel distance between each facility is taken as the optimization objective, and the optimization function for the total travel distance between each facility is defined as follows:

[0061] ;

[0062] In the formula, This is an optimization function for the total travel distance between each facility point. For travel frequency, t represents the actual distance between construction facility points i and j at stage t of the project, and T represents the total number of construction stages of the power station.

[0063] 2. Optimize the safety level during construction based on the proximity weight matrix, and set regional constraints and interference constraints.

[0064] Ten technical experts from the pumped storage power station construction project made a qualitative judgment on the necessity of proximity relationships between different facilities, converted the proximity weight coefficient comparison table into numerical weights, created a proximity weight matrix, defined an optimization function to optimize the safety level during construction, and set regional constraints and interference constraints.

[0065] Specifically, the proximity weight of facilities indicates the site planner's tendency to place facilities close to or far from each other. The qualitative expected relationship between facilities is divided into six levels: absolutely important (A), extremely important (E), important (I), average (O), unimportant (U), and undesirable (X).

[0066] The proximity weighting coefficient table is as follows. When two facilities tend to be close to each other, their proximity weighting value will be higher.

[0067]

[0068] Create a proximity weight matrix, and use the safety level as another optimization objective. Define the optimization function for the safety level as follows:

[0069] ;

[0070] In the formula, MinZ2 is the optimization function for the safety level. and , i and j respectively represent the proximity weight and Euclidean distance between construction facilities i and j, n is the total number of facilities, and T is the total number of power plant construction stages.

[0071] The Euclidean distance between the two facilities is calculated using the following formula:

[0072] ;

[0073] In the formula, and This represents the centroid coordinates of available pixels at construction facility points i and j in stage t.

[0074] Furthermore, area constraints refer to comparing the length and width of the facility points and the predetermined dimensions of each facility with the pixel attributes of the construction placement area, defining them within a sufficient area. Interference constraints refer to defining the spatial relationships between objects on the construction site to prevent overlap.

[0075] 3. The optimization function is optimized using a population-guided whale optimization algorithm with dual objectives.

[0076] The population-guided whale optimization algorithm (GPA-WOA) is used to perform bi-objective optimization on the optimization function, obtaining a Pareto front solution set. A solution is selected from the Pareto front solution set as the final optimization scheme. The optimized locations of temporary facilities at the construction site are provided in the form of a Shapefile.

[0077] Specifically, in the GPA-WOA algorithm, the whale represents the coordinates of the centroid of the construction facility point, and the dimension of each search agent is the number of construction facilities. The specific steps are as follows:

[0078] (1) Initialize the whale population, that is, the coordinate value of each construction facility is randomly selected from the coordinates of the available cell centroids. The coordinate values ​​of these construction facilities represent the location of the facility in the construction area. The direction of the construction facilities is randomly set, and the orientation is defined according to its length. There is no limitation on the orientation here. It can be parallel to the x-axis or perpendicular to the x-axis.

[0079] (2) Evaluate the fitness value of each search agent in the whale population.

[0080] (3) Identify non-dominated solutions and store them in an external archive set, where non-dominated solutions refer to the best solution found and the optimal solution of the optimization objective.

[0081] (4) Calculate the congestion distance of each non-dominated solution in the external archive set and sort them in descending order according to the congestion distance.

[0082] (5) Update the coefficient vector based on the following formula and .

[0083] ;

[0084] ;

[0085] (6) Randomly select a leader vector from the top of the sorted external archive set as the global optimal position vector.

[0086] (7) Update the location of all search agents based on the following formula:

[0087] ;

[0088] (8) Update the external archive set and remove the most crowded solution, repeating (2)-(7) until the algorithm terminates. Finally, return the external archive set as the final Pareto front, which gives the optimized location of the temporary facility points at the construction site.

[0089] Those skilled in the art will recognize that the units and algorithm steps of the various examples described in conjunction with the embodiments disclosed herein can be implemented in electronic hardware, or a combination of computer software and electronic hardware. Whether these functions are implemented in hardware or software depends on the specific application and design constraints of the technical solution. Those skilled in the art can use different methods to implement the described functions for each specific application, but such implementation should not be considered beyond the scope of this application.

[0090] The above-described embodiments are only used to illustrate the technical solutions of this application, and are not intended to limit them. Although this application has been described in detail with reference to the foregoing embodiments, those skilled in the art should understand that modifications can still be made to the technical solutions described in the foregoing embodiments, or equivalent substitutions can be made to some of the technical features. Such modifications or substitutions do not cause the essence of the corresponding technical solutions to deviate from the spirit and scope of the technical solutions of the embodiments of this application, and should all be included within the protection scope of this application.

Claims

1. An optimization method for construction site layout planning that integrates the advantages of BIM and GIS, characterized in that, Includes the following steps: Build a BIM model of the construction site, convert it to generate a Shapefile file, import it into GIS, and create a two-dimensional construction site layout map. The dynamic layout planning diagram is obtained by combining the two-dimensional construction site layout map with the project schedule. The optimization functions are defined to optimize the total travel distance and safety level between facility points in the dynamic layout planning diagram. The population-guided whale optimization algorithm is used to optimize the optimization functions in a dual-objective manner, thereby achieving the optimization of the construction site layout at each stage. The process of performing dual-objective optimization includes: Initialize the coordinates of the centroids of the facility points in the construction site and evaluate the fitness value of each search agent; Identify non-dominated solutions and store them in an external archive set, and calculate the crowding distance for each of the non-dominated solutions; Sort the locations in descending order based on the crowding distance and select the globally optimal location vector. Update the external archive set and remove the most crowded non-dominated solution, repeat this process until the termination condition is met, and obtain the optimized location of the construction site facility point; The aforementioned combination refers to assigning a unique activity code to each construction activity and using the unique activity code to connect the project schedule. The optimization function for optimizing the total travel distance between the facility points is: ； In the formula, This is an optimization function for the total travel distance between each facility point. For travel frequency, is the actual distance between construction facility points i and j at stage t of the project, and T is the total number of power station construction stages; The optimization function for optimizing the security level is: ； In the formula, MinZ2 is the optimization function for the safety level. and These are the proximity weights and Euclidean distances between construction facilities i and j, respectively; n is the total number of facilities; and T is the total number of power plant construction stages. Before optimizing the total travel distance between the construction site facilities, it is necessary to obtain the frequency estimation matrix. The frequency estimation matrix is ​​obtained from multiple travel frequency estimates; The formula for obtaining the estimated travel frequency is: ； In the formula, Let r be the frequency of material travel from facility i to facility j using transport equipment t during construction phase g. Let r be the total quantity of materials r transported between facility i and facility j during construction phase g. This indicates the capacity of the transportation equipment t.

2. The optimization method for construction site layout planning integrating the advantages of BIM and GIS as described in claim 1, characterized in that: The Euclidean distance formula is as follows: ； In the formula, and This represents the centroid coordinates of available pixels at construction facility points i and j in stage t.

3. The optimization method for construction site layout planning integrating the advantages of BIM and GIS as described in claim 1, characterized in that: The optimization function for the security level is defined based on the proximity weight matrix. The proximity weight matrix is ​​obtained from the proximity weight coefficient lookup table, which is obtained by experts through qualitative judgment.

4. The optimization method for construction site layout planning integrating the advantages of BIM and GIS as described in claim 1, characterized in that: The creation process involves selecting polygonal elements from the BIM model in the Shapefile file to obtain a two-dimensional polygon of the construction site, i.e., a two-dimensional construction site layout map.

5. The optimization method for construction site layout planning integrating the advantages of BIM and GIS as described in claim 4, characterized in that: The selection refers to selecting based on the elevation value of the polygonal feature.

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