A BIM-based water supply and drainage design method

Abstract

The application discloses a kind of based on BIM's water supply and drainage design method, specifically related to building water supply and drainage digital design technical field, the method extracts building information model, structure information model and building-municipal connection condition in water supply and drainage design object, constructs unified semantic object model, generates candidate installation corridor and continuous effective layout space unit, couples path group as same corridor with water supply candidate path and drainage candidate path that interval overlap is occupied is paired, in combination with the pressure margin of water supply candidate path, the elevation margin of drainage candidate path and access elevation condition, minimum clearance condition, crossing permission condition and maintenance operation headroom condition carry out joint feasibility determination and local correction, and result is written back to building information model, to improve the implementability, stability and reusability of water supply and drainage collaborative design in restricted space.

Description

Technical Field

[0001] This invention relates to the field of digital design technology for building water supply and drainage, and more specifically, to a BIM-based water supply and drainage design method. Background Technology

[0002] With the continuous improvement of digitalization and refined design in building engineering, Building Information Modeling (BIM) technology is increasingly widely used in the design of building water supply, drainage, and electromechanical pipelines. Leveraging its capabilities in 3D visualization, parametric modeling, and information integration, designers can pre-express pipeline layout relationships during the design phase and proactively check for spatial conflicts. Particularly in underground equipment areas, underground parking garage exits, ceiling areas between equipment rooms and shafts, and building-municipal connection areas, BIM technology has become an important tool for improving design expression and reducing construction rework.

[0003] Existing literature 1 (Research on Integrated Pipeline Layout Optimization Based on BIM, 2024) proposes a pipeline layout optimization method based on BIM and Revit secondary development, which can realize drawing recognition, automated modeling, collision detection, avoidance adjustment, and clearance analysis. This type of method shows that existing technology can solve the problems of collision recognition, local avoidance, and clearance control for general MEP pipelines. However, this type of method is mainly aimed at the integrated layout of general MEP pipelines, and lacks special treatment for the coordinated layout of building water supply and drainage paths in the same confined space. In particular, it is difficult to simultaneously take into account conditions such as residual pressure at the end of water supply, continuous slope of drainage, access elevation, minimum clearance, and maintenance operation space.

[0004] Existing public document 2 (Construction of a Collaborative BIM Modeling System for Underground 3D Pipeline Networks, 2024) proposes a collaborative BIM modeling system for underground 3D pipeline networks. Through automated parametric modeling, collision detection, and spatial analysis, it achieves collaborative modeling and visual management of underground 3D pipeline networks and related above-ground entities. Figure 1 As shown, this type of solution indicates that existing technologies have addressed the collaborative modeling of underground space and underground pipe networks. However, its focus remains on the construction, visualization, and spatial analysis of underground pipe network models. It has not established a collaborative design method for the building water supply and drainage design process that is geared towards specific layout results. In particular, it has not solved the problem of repeated rerouting and unstable results caused by the mutual influence between water supply and drainage paths in building-municipal junction areas and underground confined spaces.

[0005] Therefore, there is an urgent need in this field for a BIM-based water supply and drainage design method to solve the problems of repeated rerouting, mutual interference, and insufficient stability of design results in the process of coordinating water supply and drainage layout in confined spaces. Summary of the Invention

[0006] To overcome the aforementioned deficiencies of the prior art, this invention provides a BIM-based water supply and drainage design method. By constructing a path group coupled with the corridor, the water supply pressure margin, drainage elevation difference margin, access elevation conditions, minimum clearance conditions, crossing permission conditions, and maintenance operation clearance conditions are incorporated into the same judgment framework. During local corrections, the boundary feasibility conditions of another candidate path in the same group and the affected path group in the same candidate installation corridor are maintained simultaneously, thereby solving the problems mentioned in the background art.

[0007] To achieve the above objectives, the present invention provides the following technical solution:

[0008] A BIM-based water supply and drainage design method includes: extracting water supply and drainage design objects from building information model, structural information model, and building-municipal connection conditions, and constructing a unified semantic object model; generating candidate installation corridors in connection areas and restricted space areas, and determining continuous and effective spatial units through spatial screening; pairing water supply candidate paths and drainage candidate paths with overlapping occupancy intervals within the same candidate installation corridor to form a corridor-coupled path group; using the corridor-coupled path group as a processing unit, performing a joint feasibility determination based on the pressure margin of the water supply candidate path, the elevation difference margin of the drainage candidate path, as well as access elevation conditions, minimum clearance conditions, crossing permission conditions, and maintenance operation clearance conditions; performing local corrections based on the determination results, and re-performing the joint feasibility determination or re-pairing the affected path groups within the same candidate installation corridor after the local corrections; and writing the correction results back to the building information model and outputting the water supply and drainage design results when the correction results meet the preset boundary feasibility conditions.

[0009] Furthermore, the unified semantic object model identifies water supply and drainage design objects using hierarchical coding. The hierarchical coding includes at least system type, region, floor, and node or pipe segment number, and establishes a node-pipe segment topological association based on the hierarchical coding. The water supply and drainage design objects include at least water supply points, drainage points, equipment interfaces, candidate access nodes, structural obstacle zones, permitted crossing zones, maintenance operation zones, and equipment maintenance envelope zones. A unique identifier mapping relationship is established between nodes or pipe segments in the unified semantic object model and component instances in the building information model.

[0010] Furthermore, the candidate installation corridor is generated based on one or more of the following: beam bottom elevation, slab bottom elevation, wall boundary, equipment maintenance envelope, reserved opening range, shaft boundary, and building-municipal connection point elevation. It is also characterized by the corridor centerline, the allowable horizontal width range, and the allowable vertical elevation range. The continuous and effective layout space unit is a continuous and deployable subspace formed after removing structural obstacle areas, non-permitted crossing areas, equipment maintenance envelope areas, and fixed maintenance restricted areas from the candidate installation corridor.

[0011] Furthermore, the construction method of the same corridor coupled path group is as follows: within the same candidate installation corridor, water supply candidate paths and drainage candidate paths are generated according to the water supply access direction, drainage access direction, and access node candidate positions; the projection length segment of each candidate path along the center line of the candidate installation corridor within the continuous effective deployment space unit is determined as the occupied interval; for water supply candidate paths and drainage candidate paths with overlapping occupied intervals, pairing and scoring are performed according to access node consistency, overlap length, and total path cost, and the path pairs with higher scores and mutual independence are selected to form the same corridor coupled path group, wherein each same corridor coupled path group consists of one water supply candidate path and one drainage candidate path; mutual independence means that different path pairs do not share the same water supply candidate path or the same drainage candidate path.

[0012] Furthermore, the pressure margin of the water supply candidate path is determined based on the starting pressure, path length, pipe diameter, friction loss, local resistance, and elevation difference of the water supply candidate path. When the pressure at the end of the water supply candidate path is lower than the preset minimum residual pressure threshold, it is determined to be a residual pressure conflict. The elevation difference margin of the drainage candidate path is determined based on the starting elevation, ending elevation, path length, and minimum design slope of the corresponding pipe diameter of the drainage candidate path. When the available elevation difference of the drainage candidate path is less than the required elevation difference, it is determined to be a slope conflict. When the ending elevation of the drainage candidate path exceeds the allowable range of the access elevation corresponding to the access node candidate position, it is determined to be an access elevation conflict.

[0013] Furthermore, the joint feasibility determination is achieved by constructing a corridor conflict determination matrix. The corridor conflict determination matrix uses the same corridor coupled path group as the row object and pressure status, elevation difference status, access elevation status, minimum clearance status, crossing permission status, and maintenance operation clearance status as column dimensions. Based on the combined status of each column dimension, it outputs a conflict-free result, a single conflict type, or a compound conflict type. The conflict types include residual pressure conflict, slope conflict, access elevation conflict, clearance conflict, crossing conflict, and maintenance conflict.

[0014] Furthermore, the local correction includes one or more of the following: adjusting the access elevation, switching access node candidate positions, local rerouting, adjusting pipe diameter, switching water supply access points, adjusting inspection ports, and adjusting the orientation of valves or equipment; the preset boundary feasibility conditions include at least: the lower limit of pressure margin corresponding to the water supply candidate path, the lower limit of elevation difference margin corresponding to the drainage candidate path, the allowable range of access elevation corresponding to the access node candidate position, the minimum clearance threshold, the maintenance operation clearance threshold, the crossing permission status, and the spatial boundary condition that the occupied section is located within a continuous and effective deployment space unit; any local correction is accepted only if all of the above boundary feasibility conditions are met.

[0015] Furthermore, when a local correction causes changes in the occupied area, access node candidate position, or path independence relationship of candidate paths within the same candidate installation corridor, the affected candidate paths are re-performed with pairing scoring, and the corridor-coupled path group is updated; the water supply and drainage design results include at least the corrected building information model and one or more of the pipe segment parameters, node elevations, or connection node parameters corresponding to the local correction; the termination condition of the local correction is any one of the following: all corridor-coupled path groups meet the joint feasibility judgment requirements; the preset maximum number of correction iterations is reached; or a residual conflict list is output after the preset maximum number of correction iterations is reached.

[0016] It should be noted that in this invention, quantifiable continuous constraints are characterized by margin, and permissible or range-based constraints are characterized by conditions or states. A unified joint feasibility determination is achieved through a corridor conflict determination matrix. Thus, the collaborative deployment of water supply and drainage in shared confined spaces is no longer limited to collision avoidance along a single path, but is transformed into a group-level collaborative decision-making process with groups of paths coupled to the same corridor as processing units and boundary feasibility conditions as acceptance criteria.

[0017] The technical effects and advantages of the BIM-based water supply and drainage design method of this invention are as follows: This invention first defines the shared layout space by candidate installation corridors and continuous effective layout space units. Then, it binds water supply candidate paths and drainage candidate paths with continuous spatial competition into a unified processing unit by using the same corridor coupled path group. Water supply pressure margin, drainage elevation difference margin, access elevation conditions, minimum clearance conditions, crossing permission conditions, and maintenance operation clearance conditions are incorporated into the same joint feasibility judgment framework. After local correction, not only is it checked whether the corrected path meets the corresponding requirements, but also the boundary feasibility conditions of another candidate path in the same group and the affected coupled path group in the same candidate installation corridor are checked simultaneously. This avoids the problems of "fixing one path and destroying another" or "interfering with adjacent path groups again after local correction" in traditional sequential single path correction, and improves the overall feasibility and result stability of water supply and drainage collaborative design in confined space and building-municipal connection scenarios.

[0018] Furthermore, this invention, through a unified semantic object model, corridor-level spatial constraint expression, group-level joint judgment, and a modified model write-back mechanism, enables object extraction, conflict localization, local correction, re-judgment, and result output to be based on consistent data, reducing the risk of information disconnect caused by repeated design adjustments and improving model reusability and subsequent detailed design efficiency. Attached Figure Description

[0019] Figure 1 A technical roadmap for existing underground 3D pipeline network modeling systems.

[0020] Figure 2This is a schematic diagram of a BIM-based water supply and drainage design method according to the present invention.

[0021] Figure 3 This is a schematic diagram of the pairing of occupied sections within the candidate installation corridor to form a coupled path group within the same corridor. Detailed Implementation

[0022] The technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0023] Example 1

[0024] A public building project has a domestic water pump room, a fire pump room, a sewage collection pit, and equipment pipe trenches on the first basement level. A municipal water supply access point and a sewage inspection well are located outside the west exterior wall of the underground parking garage. The domestic water supply main and the horizontal sewage main need to pass through the underground equipment area, cross the underground parking garage, and exit through the exterior wall, connecting to the outdoor water supply network and sewage inspection well respectively. This area has constraints such as shear walls, frame beams, equipment foundations, pump maintenance range, valve operating space, and reserved sleeves in the exterior wall. The water supply and drainage paths are mutually restrictive within the same access area. Therefore, the method of this invention is used for collaborative design, the process of which is as follows: Figure 2 As shown.

[0025] At the start of the design process, the boundaries of exterior walls, equipment rooms, underground parking garage ceiling areas, shaft boundaries, exit points, and equipment interfaces were extracted from the Building Information Model (BIM). Beam bottom elevations, slab bottom elevations, shear wall locations, structural obstacle zones, and reserved opening ranges were extracted from the Structural Information Model (SIM). Municipal water supply connection points, sewage inspection well locations, well bottom elevations, and connection directions were extracted from the building-municipal connection conditions. Simultaneously, the rule data for permitted crossing zones, maintenance operation zones, and equipment maintenance envelope zones already configured for this project were pre-loaded. This formed the basic set of objects for collaborative design.

[0026] The object set in this embodiment includes water supply points, drainage points, equipment interfaces, candidate access nodes, outlet sections, connection wells, structural obstacle zones, permitted crossing zones, maintenance operation zones, and equipment maintenance envelope zones.

[0027] To facilitate subsequent path generation, conflict localization, and model write-back, all objects are coded hierarchically using the format of "System Type—Region—Floor—Node or Pipe Segment Number." System types are categorized as water supply and drainage systems; regions are divided into pump room area, garage area, exit area, and connection area; floors are uniformly designated as B1; and nodes and pipe segments use three-digit serial numbers. The interface code for the main outlet pipe of the domestic water pump room is GS-PF-B1-N001; the code for the turning node of the underground garage sewage and wastewater horizontal main pipe is PS-CK-B1-N018; the code for the external wall water supply pipe segment is GS-CH-B1-P006; and the code for the western sewage inspection well is PS-JD-B1-N031. After coding, a topological association relationship is established between nodes and pipe segments, and object attributes, spatial boundaries, elevation information and connection relationships are uniformly written into the semantic object model. At the same time, a unique identifier mapping relationship is established between nodes or pipe segments in the semantic object model and corresponding component instances in the building information model, so that each candidate path can trace its starting point, ending point, system to which it belongs, area it passes through, adjacent components and connecting objects, and supports accurate writing back to the building information model of subsequent local correction results.

[0028] In this embodiment, the main input parameters and control thresholds for collaborative design are as follows: Domestic water supply starting pressure is 0.33 MPa; preset minimum residual pressure threshold is 0.18 MPa; drainage starting elevation is -2.080 m; elevation of the center of the external wall water supply outlet sleeve is -1.980 m; sewage inspection well bottom elevation is -2.450 m; minimum design slope for DN100 is 0.015; preset net distance threshold is 50 mm; maintenance operation net clearance threshold is 600 mm; preset lower limit of net clearance is 600 mm; allowable range of access node elevation is ±50 mm of the target access elevation; preset lower limit of pressure margin is 0 MPa; preset lower limit of elevation difference margin is 0 mm; effective overlap length threshold is 0.30 m; local elevation adjustment step size is 20 mm; local rerouting step size is 50 mm; preset maximum number of correction iterations is 6.

[0029] After completing the object modeling, candidate installation corridors are generated based on the beam bottom elevation, slab bottom elevation, wall boundaries, equipment maintenance envelope, reserved opening range, shaft boundaries, and building-municipal connection point elevation. Each candidate installation corridor is jointly characterized by the corridor centerline, the allowable horizontal width range, and the allowable vertical elevation range, used to define the spatial boundaries for the placement of water supply and drainage candidate paths. This embodiment forms three candidate installation corridors: a pump room corridor extending from the outside of the domestic water pump room and sewage collection pit to the garage, with a length of 5.8m; an exit corridor along the west exterior wall of the underground garage, with a length of 14.2m, which is the key corridor in this embodiment; and a connection corridor extending from the exit point on the exterior wall to the sewage inspection well and the municipal water supply connection point, with a length of 4.6m.

[0030] In this embodiment, the exit corridor is the key area for the candidate installation corridor. The exit corridor has a net width of 1.35m and a net height of 0.95m at the bottom of the slab. There is a 0.40m wide and 0.18m drooping frame beam in the middle. The east end is adjacent to the maintenance area of ​​the domestic pump group, and the west end is close to the area where the exit sleeve of the exterior wall connects to the sewage inspection well.

[0031] After candidate installation corridors are generated, they undergo continuous and effective space screening. Specifically, spatial difference operations are performed on the candidate installation corridors and structural obstacle areas such as frame beams, shear walls, and equipment foundations, as well as non-permitted crossing areas not included in the permitted crossing areas and pump unit maintenance envelope areas. If fixed maintenance restricted areas exist, the corresponding maintenance operation restricted areas are further eliminated. Subsequently, the remaining space is decomposed according to connectivity to form one or more continuous and effective layout space units.

[0032] After processing, the exit corridor is divided into two continuous effective layout space units. The first unit is 6.9m long, and the second unit is 4.8m long, with a 1.6m break in the middle formed by the influence zone of the frame beam. The continuous effective layout space units are used to define the effective layout sections of candidate paths. A single candidate path can be formed by splicing segmented paths from multiple continuous effective layout space units within the same candidate installation corridor. Adjacent segmented paths are only allowed to be connected through reserved openings, permitted crossing areas, corridor transition points, or connectable sections confirmed by rules.

[0033] It should be noted that the elimination of fixed maintenance restricted areas such as valve operation areas is a static space screening; the maintenance operation clearance check in the subsequent joint feasibility assessment is used to determine whether the relevant inspection ports, valves or equipment still retain dynamic clearance boundaries that meet the operation requirements after the candidate path is generated or locally modified.

[0034] Within a continuously and effectively deployed spatial unit, candidate paths for water supply and drainage are generated based on the water supply access direction, drainage access direction, candidate access node locations, connection well locations, and permitted crossing zone locations. Path generation follows the principles of length priority, number of turns priority, and legal crossing priority, while constraining a single candidate path to have no more than two horizontal turns within the same candidate installation corridor, prioritizing connections to corridor entrances, corridor turning points, and the center point of permitted crossing zones.

[0035] In this embodiment, two candidate paths, denoted as G1 and G2, are generated within the corridor leading to the domestic water supply. Two candidate paths, denoted as D1 and D2, are also generated within the same corridor for sewage and wastewater drainage. G1 originates from the main outlet pipe interface of the domestic water pump room, passes through the effective layout sections corresponding to the first and second continuous effective layout space units, and connects to the exterior wall outlet sleeve, with a total length of 12.6m and an initial pipe diameter of DN65. G2 is laid close to the wall side, turning early at the end of the first unit to connect to the outlet point via a shorter route, with a total length of 10.9m and an initial pipe diameter of DN65. D1 originates from the sewage and wastewater horizontal main pipe inlet point, passes through candidate inlet position R2, and connects to the outdoor fixed connection section, with a total length of 11.4m and a pipe diameter of DN100. D2 turns early at the end of the first unit, switches to candidate inlet position R3, and connects to the outdoor fixed connection section, with a total length of 10.2m and a pipe diameter of DN100. The effective deployment sections of the above candidate paths are all located within continuous effective deployment space units, and the entry and exit positions in the permitted crossing area are consistent with the reserved opening range.

[0036] R2 and R3 are candidate access nodes for the drainage path, which in this embodiment are candidate access locations associated with the outdoor connection relationship; the fixed connection section between the candidate access location and the sewage inspection well is a known connection section and is not included in this round of coupling optimization; the corresponding allowable access elevation range is used to limit the allowable elevation window of the candidate access location.

[0037] After candidate paths are generated, the projected length segment of each path along the centerline of the candidate installation corridor within a continuous effective deployment space unit is defined as the occupied interval. Using the projected length segment instead of a three-dimensional outer envelope is to characterize the continuous occupancy relationship of the effective deployment space within the same candidate installation corridor.

[0038] In this embodiment, the occupied area of ​​G1 in the exit corridor is 2.1m to 10.8m, the occupied area of ​​G2 is 1.7m to 9.5m, the occupied area of ​​D1 is 3.4m to 12.2m, and the occupied area of ​​D2 is 2.8m to 8.9m. When the overlap length of the occupied areas of two paths is not less than 0.30m, they are considered to have formed an effective spatial competition relationship. Water supply candidate paths and drainage candidate paths with overlapping occupied areas are paired to form a corridor-coupled path group. Figure 3 The initial occupancy interval projection and pairing results of the candidate paths are shown.

[0039] For path pairs with overlapping relationships within the same candidate installation corridor, not all are treated as corridor-coupled path groups for subsequent processing. Instead, a pairing score is applied based on a combination of priority and weighted evaluation according to access node consistency, overlap length, and total path cost. First, access node consistency is compared; when access node consistency is the same, the overlap length of the occupied interval is compared; when the first two are the same or the differences are within a preset allowable range, the total path cost is compared. The total path cost considers at least one or more of the following: path length, number of turns, permitted crossings, local rerouting, and impact on maintenance operation space. Each corridor-coupled path group consists of one water supply candidate path and one drainage candidate path; multiple independent corridor-coupled path groups can be formed within the same candidate installation corridor. Therefore, G1 and D1 have a 7.4m effective overlap between 3.4m and 10.8m, and are designated as Group A; G2 and D2 have a 6.1m effective overlap between 2.8m and 8.9m, and are designated as Group B. Groups A and B serve as the basic units for subsequent joint feasibility assessment and local correction, respectively.

[0040] After groups A and B are determined, the pressure margin of the candidate water supply path and the elevation difference margin of the candidate drainage path are calculated respectively. The pressure margin of the candidate water supply path is determined by the following formula:

[0041]

[0042] Among them, M p As a pressure margin, P end For the end pressure of the candidate water supply path, P min A preset minimum residual pressure threshold is used. In this embodiment, the preset minimum residual pressure threshold is 0.18 MPa. The G1 path is 12.6 m long, with a pipe diameter of DN65 and a total elevation increase of 0.45 m. After considering the friction loss and the resistance of local components such as elbows and valves, its end pressure is calculated to be 0.206 MPa, with a pressure margin of 0.026 MPa. The G2 path is 10.9 m long, with an end pressure of 0.221 MPa and a pressure margin of 0.041 MPa.

[0043] The elevation margin of the drainage candidate path is determined by the following formula:

[0044]

[0045] Among them, M h For height difference margin, H avail For the available elevation difference, H reqThe required elevation difference is determined based on the path length and minimum design slope. Path D1 is 11.4m long with a pipe diameter of DN100, corresponding to a minimum design slope of 0.015, therefore the required elevation difference is 171mm. The starting elevation of D1 is -2.080m, and the endpoint at R2 is at an elevation of -2.220m, providing a usable elevation difference of 140mm. Therefore, the elevation difference margin is -31mm, creating a slope conflict. Path D2 is 10.2m long, requiring an elevation difference of 153mm. The starting elevation is also -2.080m, and the endpoint at R3 is at an elevation of -2.245m, providing a usable elevation difference of 165mm. Therefore, the elevation difference margin is 12mm. Regarding the access window, the allowable range of the access node elevation for R2 is -2.250m to -2.150m, and the allowable range of the access node elevation for R3 is -2.295m to -2.195m. Therefore, the endpoint elevations of D1 and D2 are both within the allowable range of the corresponding access node candidate positions, and do not currently constitute an access elevation conflict.

[0046] After completing the above calculations, the access elevation condition, minimum clearance condition, crossing permission condition, and maintenance operation clearance condition are then superimposed for a joint feasibility assessment. This embodiment uses a corridor conflict determination matrix to record the comprehensive status of each set of coupled paths. The matrix's rows represent the coupled path groups, and the columns represent pressure status, elevation difference status, access elevation status, minimum clearance status, crossing permission status, and maintenance operation clearance status, respectively. Each column dimension uses a binary status representation, with a 1 for satisfying the condition and a 0 for not satisfying it. These six statuses together form a conflict status code. When all six statuses are 1, a no-conflict result is output; when only a single 0 exists, a single conflict type is output; when two or more 0s exist, a composite conflict type is output.

[0047] In Group A, the pressure margin of G1 is 0.026 MPa, and the pressure status is recorded as 1; the elevation margin of D1 is -31 mm, and the elevation status is recorded as 0; the endpoint elevation of D1 is within the allowable elevation range of the access node corresponding to R2, and the access elevation status is recorded as 1; the minimum clearance between the closest positions is 42 mm, which is less than the 50 mm threshold, and the minimum clearance status is recorded as 0; the crossing position is within the permitted crossing zone, and the crossing permission status is recorded as 1; the maintenance operation clearance is 680 mm, which is greater than the 600 mm threshold, and the maintenance operation clearance status is recorded as 1. Therefore, the conflict status code of Group A is 101011, corresponding to the composite conflict result of "slope conflict + clearance conflict".

[0048] In Group B, the pressure margin of G2 is 0.041 MPa, the elevation difference margin of D2 is 12 mm, the elevation of the endpoint of D2 is within the allowable range of the elevation of the access node corresponding to R3, the minimum clearance is 58 mm, and the crossing permission and maintenance operation clearance both meet the requirements. Therefore, the conflict status code of Group B is 111111, corresponding to a no-conflict result.

[0049] For Group A, local corrections are performed according to the preset correction order. The correction order is as follows: first, address slope conflicts and access elevation conflicts; then, address residual pressure conflicts; next, address clearance conflicts and crossing conflicts; and finally, address maintenance conflicts.

[0050] The primary issue for Group A was slope conflict, so D1 was corrected first. The first correction lowered the endpoint elevation of D1 by 20mm, increasing the available elevation difference from 140mm to 160mm and improving the elevation margin from -31mm to -11mm, but the slope conflict remained. The second correction, while maintaining the candidate installation corridor for Group A, switched D1 from candidate access node R2 to R3 and simultaneously reconstructed its latter half of the route, resulting in the corrected drainage path being designated D1'. Within the first continuous effective deployment space unit, D1' maintains the same initial route as D1, only switching to the latter connection path corresponding to R3 before entering the second continuous effective deployment space unit. After the correction, the endpoint elevation of D1' is -2.245m, the total path length is adjusted to 10.4m, the required elevation difference is 156mm, the available elevation difference is 165mm, the elevation margin becomes 9mm, and the slope conflict is eliminated.

[0051] It should be noted that D1' and D2 are not the same path. D1' is a modified path obtained by updating the original path D1 for group A, while D2 is a drainage candidate path generated independently in the candidate stage and used for group B. Although both are connected to R3, their front-end occupancy sections, turning positions, and pairing objects are different.

[0052] In this invention, the acceptance conditions for local correction include the following five items: First, the corrected path meets the corresponding requirements; second, another candidate path in the same group meets its boundary feasibility conditions; third, the entire corridor-coupled path group meets the boundary requirements for minimum clearance, crossing permission, and maintenance operation clearance; fourth, the corrected occupied area is still located within a continuous and effective deployment space unit; and fifth, no new non-permitted crossing conflicts are added after correction.

[0053] Therefore, after D1 was revised to D1', a boundary feasibility check was immediately performed, and the pressure status, minimum clearance status, crossing permission status, and maintenance operation clearance status of G1 in the same group that was not revised were rechecked. Since this revision only changed the access node and the occupancy method of the latter half of the drainage path, and the path length, local components, and elevation difference of G1 itself remained unchanged, the pressure margin of G1 remained at 0.026MPa, which is not less than the preset lower limit of pressure margin of 0MPa. At the same time, the minimum clearance between G1 and the revised D1' increased from 42mm to 54mm, which is not less than the preset clearance threshold of 50mm. The endpoint elevation of the revised D1' is within the allowable range of the access node elevation corresponding to R3, and the outdoor fixed connection section after the candidate access position has not changed, and no new unpermitted crossing conflicts have been added. Therefore, this drainage revision was accepted.

[0054] It should be further explained that when a local correction of a path group coupled with a corridor is accepted, not only are the pressure status, elevation difference status, access elevation status, minimum clearance status, crossing permission status, and maintenance operation clearance status of that group recalculated, but also the occupied intervals of other candidate paths within the same candidate installation corridor that have overlapping occupied intervals, changes in access node associations, or changes in independent pairing relationships with the corrected path are recalculated. Furthermore, a joint feasibility assessment is re-performed for other affected path groups coupled with the corridor. When the original path independence relationship no longer holds, pairing scoring is re-performed and the corresponding path groups coupled with the corridor are updated. Only after all affected path groups within the corridor meet the corresponding boundary feasibility conditions is this local correction output as a result.

[0055] In this embodiment, after reprojecting D1', the occupied intervals and pairing independence of G2 and D2 in group B remain unchanged, and group B remains in a conflict-free state. Therefore, the correction results of group A can be output.

[0056] Subsequently, Group A was reassessed. Group A's elevation difference, access elevation, minimum clearance, crossing permission, and maintenance operation clearance all met the requirements, so no further conflicts were processed.

[0057] To further illustrate the priority correction of the water supply path, another independent group of paths coupled to the same corridor, group D, is provided. In this group, the drainage path is denoted as D3, and the water supply path is denoted as G3. The drainage path D3 already meets the elevation margin requirement. D3 is 9.8m long, has a pipe diameter of DN100, requires an elevation difference of 147mm, has an actual usable elevation difference of 155mm, and an elevation margin of 8mm. The end elevation is within the allowable range of the corresponding access node elevation. The water supply path G3, due to its longer path and more bends, has an end pressure of only 0.166MPa, which is lower than the preset minimum residual pressure threshold of 0.18MPa, resulting in a pressure margin of -0.014MPa and causing a residual pressure conflict.

[0058] First, a partial correction was attempted on G3, shortening the path and increasing the pipe diameter from DN65 to DN80. After the correction, the terminal pressure of G3 increased to 0.189 MPa, with a pressure margin of 0.009 MPa, and the residual pressure conflict was eliminated. However, this correction also reduced the installation space of D3 within the same continuous effective installation space unit, causing the available elevation difference of D3 to decrease from 155 mm to 149 mm, while the required elevation difference of D3 remained at 147 mm. Although the elevation difference margin remained at 2 mm, the clearance in front of the original valve maintenance location decreased from 620 mm to 560 mm, which is lower than the preset lower clearance limit of 600 mm. Therefore, this water supply correction was not accepted.

[0059] Subsequently, the second water supply correction method was adopted, which maintained the original lateral occupancy of the path, switched the water supply access point, and reduced two local bends. After the correction, the end pressure of G3 increased to 0.191 MPa, with a pressure margin of 0.011 MPa. At the same time, the elevation difference margin of D3 remained at 8 mm, the endpoint elevation was still within the allowable range of the corresponding access node elevation, and the maintenance operation clearance was restored to 610 mm. Therefore, the second water supply correction method was accepted. This process shows that when performing local correction on the water supply candidate path, in addition to the path being corrected itself meeting the corresponding requirements, the elevation difference margin, endpoint elevation, minimum clearance within the group, crossing permission, and maintenance operation clearance boundary of the drainage candidate path should all be maintained. Otherwise, the water supply correction cannot be included in the result output. The results before and after correction for Group A and Group B are shown in Table 1.

[0060] Table 1 Comparison of the states of the same corridor coupling path group before and after correction

[0061] project Group A Group B Water supply route number G1 G2 Drainage path number D1→D1' D2 Pressure margin before correction / MPa 0.026 0.041 Pre-correction height difference margin / mm -31 12 Previous access elevation status satisfy satisfy Minimum clearance before correction / mm 42 58 Pre-correction maintenance clearance / mm 680 650 Results before correction Slope conflict + clearance conflict No conflict Correction action Lower the access elevation by 20mm, switch to R3 and reconstruct the second half of the path to form D1' none Corrected pressure margin / MPa 0.026 0.041 Corrected height difference margin / mm 9 12 After correction, the connection to the elevation status is established. satisfy satisfy Corrected minimum clearance / mm 54 58 Corrected maintenance clearance / mm 640 650 Corrected results Meets the requirements for joint feasibility assessment Meets the requirements for joint feasibility assessment

[0062] As shown in Table 1, after two local corrections in Group A, namely "lowering the access elevation by 20mm" and "switching to R3 and reconstructing the second half of the path to form D1'", the elevation margin increased from -31mm to 9mm, the minimum net distance increased from 42mm to 54mm, and the pressure margin of the water supply path G1 remained at 0.026MPa. The access elevation status continued to meet the requirements, indicating that the correction process can maintain the feasible conditions of the water supply path and the overall boundary within the group while eliminating drainage conflicts.

[0063] To further verify the technical effectiveness of this collaborative design process, it is compared with the sequential single-path correction method. The sequential single-path correction method only corrects the slope conflict of D1, without setting boundary feasibility conditions for the pressure margin and minimum clearance of the water supply path G1 in the same group. This method compensates for the height difference by locally pressing down D1 and shifting it towards the wall within the second continuous effective layout space unit. After the drainage slope is restored, the occupied G1 is passively bypassed, thus forming a traditional serial adjustment process of "first repairing drainage, then allowing water supply". The comparison results are shown in Table 2.

[0064] Table 2 Comparison of Results between the Method of the Present Invention and the Sequential Single-Path Correction Method

[0065] Handling method Has the drainage slope conflict been eliminated? Water supply pressure status Minimum clearance state Should new conflicts be introduced? Is it ultimately output? Sequential single-path correction method yes Not satisfied Not satisfied yes no Method of the present invention yes satisfy satisfy no yes

[0066] Table 2 shows that, under the same scenario, although the sequential single-path correction method can eliminate drainage slope conflicts, the pressure margin and spatial boundaries of the same group of water supply paths are not controlled synchronously during the correction process. Therefore, the corrected water supply pressure state and minimum clearance state do not meet the requirements, and it cannot be output as an feasible result. This embodiment focuses on joint feasibility assessment and local correction constrained by boundary feasibility conditions for the same corridor coupled path group. While eliminating drainage slope conflicts, it maintains that the water supply pressure state, minimum clearance state, and maintenance operation clearance all meet the requirements, ultimately obtaining a design result that meets all joint feasibility assessment requirements.

[0067] The final design results output in this embodiment are as follows: In Group A, the water supply path adopts G1, the pipe diameter remains DN65, the elevation of the end node of the outlet section is -1.980m, and the end pressure is 0.206MPa; the drainage path is modified from D1 to D1', D1' connects to the outdoor fixed connection section via the candidate access node R3, the end elevation of the candidate access position is -2.245m, and the final elevation difference margin is 9mm; the bottom elevation of the connection well J1 remains -2.450m, and the connection direction remains from east to west. Group B retains the original design state. After the modified results are written back to the building information model, the corresponding pipe section parameters, node elevations, and connection node parameters can be directly output for subsequent detailed design and model reuse.

[0068] Example 2

[0069] In a public building, the ceiling area between the equipment room and the shaft contains branch pipes for domestic water supply, sewage drainage, and fire hydrants. The domestic water supply and sewage drainage branch pipes must pass through a partition wall between the equipment room and the shaft before connecting to the water supply and drainage risers in the shaft, respectively. This ceiling area has a net width of 0.95m and a net height of 0.72m. Two through-wall openings are provided in the wall; the opening closer to the top is within the permitted through-wall area, while the opening closer to the bottom is not. A valve assembly is also located below the ceiling. The operating clearance in front of the valves is affected by the position of the equipment room door frame. In the design, a shorter through-wall path may be chosen to reduce water supply path loss, but the through-wall location may not meet the permitted conditions, or the through-wall location may meet the permitted conditions but result in insufficient clearance for valve maintenance.

[0070] In this scenario, objects are first extracted and coded in the same manner as in Example 1, forming object models such as water supply points, drainage points, equipment interfaces, access node candidate positions, permitted crossing areas, maintenance operation areas, and equipment maintenance envelope areas. Specifically, in this example, the access node candidate positions are water supply riser candidate positions and drainage riser candidate positions. Then, candidate installation corridors between the equipment room and the shaft are generated based on the slab bottom elevation, wall boundaries, equipment maintenance envelope, and reserved opening range. After removing the door frame obstruction area and the equipment maintenance envelope area, a continuous effective installation space unit with a length of 4.3m is formed. The water supply candidate path G4 and the drainage candidate path D4 occupy intervals of 0.8m to 3.6m and 1.1m to 3.4m respectively within this continuous effective installation space unit, with an overlap length of 2.3m, thus forming a corridor-coupled path group C.

[0071] In its initial state, G4 enters the shaft via a permissible access point above the crossing zone, with a path length of 5.1m, a pipe diameter of DN50, an end pressure of 0.171MPa, and a pressure margin of -0.009MPa, resulting in a residual pressure conflict. D4 has a path length of 4.8m, a pipe diameter of DN75, a corresponding minimum design slope of 0.020, a required elevation difference of 96mm, an actual usable elevation difference of 108mm, and a elevation difference margin of 12mm. The endpoint elevation is within the allowable range of the corresponding access node elevation. The minimum clearance for Group C is 52mm, and the maintenance clearance is 610mm; currently, there are no clearance or maintenance conflicts.

[0072] The first step is to correct the conflict regarding the residual pressure in the water supply. The first correction method is to change G4 to pass through the lower orifice to shorten the path and reduce one bend. After the correction, the pressure at the end of G4 increases to 0.185 MPa, and the pressure margin becomes 0.005 MPa. However, since the lower orifice is not within the permitted crossing zone, the joint feasibility assessment outputs a crossing conflict, therefore this correction is not accepted. The second correction method keeps G4 passing through the upper permitted crossing zone, while adjusting the valve assembly orientation and shortening the local connection section. After the correction, the pressure at the end of G4 increases to 0.183 MPa, and the pressure margin is 0.003 MPa, meeting the crossing permission requirement. However, the operating clearance in front of the valve is 570 mm, which is below the 600 mm threshold. Therefore, the joint feasibility assessment outputs a maintenance conflict, and this correction is also not accepted. The third correction method maintains that G4 passes through the permitted crossing area above, keeps the valve assembly orientation unchanged, and reduces local resistance only by reducing one local bend and increasing the pipe diameter from DN50 to DN65. After the correction, the pressure at the end of G4 increases to 0.188MPa, with a pressure margin of 0.008MPa. At the same time, the elevation difference margin of D4 remains at 12mm, the end elevation is still within the allowable range of the corresponding access node elevation, the minimum clearance is 51mm, and the maintenance clearance is maintained at 610mm. Therefore, this correction is accepted.

[0073] In this embodiment, the same corridor coupled path group C only includes one set of main paired path pairs that have the highest score after pairing and are mutually exclusive. Other path pairs that are partially overlapping but do not meet the main pairing conditions are not included in this round of joint feasibility determination.

[0074] This embodiment demonstrates that in scenarios where both ceiling penetration through walls and maintenance space are simultaneously limited, even if the water supply path only has residual pressure conflict, it must simultaneously meet the permissible penetration conditions, maintain the elevation difference margin and allowable range of the access node elevation for drainage paths within the same group, and meet the clearance requirements for maintenance operations within the group. Only after these corrections can the final output be obtained. Therefore, this invention is applicable not only to exterior wall corridors but also to ceiling-restricted spaces between equipment rooms and shafts.

[0075] In conclusion, the above description is only a preferred embodiment of the present invention and is not intended to limit the present invention. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of the present invention should be included within the protection scope of the present invention.

Claims

1. A BIM-based water supply and drainage design method, characterized in that, include: Extract water supply and drainage design objects from building information model, structural information model and building-municipal connection conditions, and construct a unified semantic object model; Candidate installation corridors are generated in the connection area and confined space area, and continuous and effective spatial units are determined through spatial screening; Within the same candidate installation corridor, water supply candidate paths and drainage candidate paths with overlapping occupied areas are paired to form a corridor-coupled path group. Using the same corridor coupled path group as the processing unit, a joint feasibility determination is made by combining the pressure margin of the water supply candidate path, the elevation difference margin of the drainage candidate path, as well as the access elevation condition, minimum clearance condition, crossing permission condition and maintenance operation clearance condition. Based on the judgment results, perform local corrections, and after the local corrections, re-perform joint feasibility judgments or re-pair the affected path groups within the same candidate installation corridor; When the correction results meet the preset boundary feasibility conditions, the correction results are written back to the building information model and the water supply and drainage design results are output. The unified semantic object model identifies water supply and drainage design objects using hierarchical coding. The hierarchical coding includes at least system type, region, floor, and node or pipe segment number, and establishes node-pipe segment topological associations based on the hierarchical coding. The water supply and drainage design objects include at least water supply points, drainage points, equipment interfaces, candidate access nodes, structural obstacle zones, permitted crossing zones, maintenance and operation zones, and equipment maintenance envelope zones. A unique identifier mapping relationship is established between nodes or pipe segments in the unified semantic object model and component instances in the building information model. The method for constructing the same corridor coupled path group is as follows: within the same candidate installation corridor, water supply candidate paths and drainage candidate paths are generated according to the water supply access direction, drainage access direction, and access node candidate positions; the projection length segment of each candidate path along the center line of the candidate installation corridor within the continuous effective deployment space unit is determined as the occupied interval; for water supply candidate paths and drainage candidate paths with overlapping occupied intervals, they are paired and scored according to access node consistency, overlap length, and total path cost, and the path pairs with higher scores and mutual independence are selected to form the same corridor coupled path group, wherein each same corridor coupled path group consists of one water supply candidate path and one drainage candidate path; The mutual independence means that different path pairs do not share the same water supply candidate path or the same drainage candidate path. The joint feasibility determination is achieved by constructing a corridor conflict determination matrix. The corridor conflict determination matrix takes the same corridor coupled path group as the row object and pressure status, elevation difference status, access elevation status, minimum clearance status, crossing permission status and maintenance operation clearance status as column dimensions. Based on the combination status of each column dimension, it outputs a no-conflict result, a single conflict type or a compound conflict type. The conflict types include residual pressure conflict, slope conflict, access elevation conflict, clearance conflict, crossing conflict, and maintenance conflict.

2. The BIM-based water supply and drainage design method according to claim 1, characterized in that, The candidate installation corridor is generated based on one or more of the following: beam bottom elevation, slab bottom elevation, wall boundary, equipment maintenance envelope, reserved opening range, shaft boundary, and building-municipal connection point elevation. It is jointly characterized by the corridor centerline, the allowable horizontal width range, and the allowable vertical elevation range. The continuous and effective deployment space unit is a continuous deployable subspace formed after removing structural obstacle areas, unauthorized crossing areas, equipment maintenance envelope areas, and fixed maintenance restricted areas from the candidate installation corridor.

3. The BIM-based water supply and drainage design method according to claim 1, characterized in that, The pressure margin of the water supply candidate path is determined based on the starting pressure, path length, pipe diameter, friction loss, local resistance and path elevation difference of the water supply candidate path. When the pressure at the end of the water supply candidate path is lower than the preset minimum residual pressure threshold, it is determined to be a residual pressure conflict. The elevation margin of the drainage candidate path is determined based on the starting elevation, ending elevation, path length, and minimum design slope of the corresponding pipe diameter. When the available elevation difference of the drainage candidate path is less than the required elevation difference, it is determined to be a slope conflict. When the elevation of the endpoint of a drainage candidate path exceeds the allowable range of the access elevation corresponding to the candidate access node, it is determined to be an access elevation conflict.

4. The BIM-based water supply and drainage design method according to claim 1, characterized in that, The local correction includes one or more of the following: adjusting the access elevation, switching the candidate access node position, local rerouting, adjusting the pipe diameter, switching the water supply access point, adjusting the inspection port, and adjusting the orientation of valves or equipment. The preset boundary feasible conditions include at least the following: the lower limit of pressure margin corresponding to the water supply candidate path, the lower limit of elevation difference margin corresponding to the drainage candidate path, the allowable range of access elevation corresponding to the access node candidate position, the minimum clearance threshold, the maintenance operation clearance threshold, the crossing permission status, and the spatial boundary conditions that the occupied section is located within a continuous and effective deployment space unit. Any local modification is accepted only if all of the above boundary conditions remain valid.

5. The BIM-based water supply and drainage design method according to claim 1, characterized in that, When a local correction causes changes in the occupied range, access node candidate position, or path independence relationship of candidate paths within the same candidate installation corridor, the pairing scoring is re-executed for the affected candidate paths, and the path group coupled with the corridor is updated. The water supply and drainage design results include at least the modified building information model and one or more of the following: pipe segment parameters, node elevations, or connection node parameters corresponding to the local modification; The termination condition for the local correction is any one of the following: all paths coupled to the same corridor meet the joint feasibility determination requirements; the preset maximum number of correction iterations is reached; or a residual conflict list is output after the preset maximum number of correction iterations is reached.

Images