Gravitational dam foundation intelligent excavation design method and system

Abstract

This invention relates to the field of water conservancy and hydropower engineering design technology, and provides an intelligent excavation design method and system for gravity dam foundations. The method includes steps S1, slope and platform excavation design within the dam body; step S2, upstream slope and platform excavation design, using the upstream excavation boundary line as a reference, independently designing the upstream slope and platform excavation for the left and right banks respectively; and step S3, downstream slope and platform excavation design, using the apron boundary line as a reference, independently designing the downstream slope and platform excavation for the left and right banks respectively. This intelligent excavation design method for gravity dam foundations achieves fully parametric design of dam foundation excavation, supports independent slope design for the left and right banks and automatic elimination of cross-intersections of walkways, and can automatically optimize the slope ratio based on the location of the weathered rock zone. It completes work that traditionally takes several days in just a few hours, directly outputting BIM data, effectively improving design efficiency, adaptability to complex terrain, and geological matching accuracy.

Description

Technical Field

[0001] This invention relates to the field of water conservancy and hydropower engineering design technology, specifically to an intelligent excavation design method and system for gravity dam foundations. Background Technology

[0002] Gravity dams are one of the main dam types in water conservancy and hydropower projects. Their foundation excavation design directly affects the dam's anti-sliding stability, stress distribution, and overall project safety. In traditional design methods, gravity dam foundation excavation is typically completed using a combination of manual calculations and two-dimensional CAD drawings. However, with the increasing scale of hydropower projects and the growing complexity of terrain and geological conditions, traditional methods are no longer sufficient to meet the demands of efficient, precise, and intelligent modern design. The main technical problems include: (1) Low design efficiency, difficulty in modifying parameters, and poor integration with BIM technology. In the traditional method, parameters such as the intersection of slopes at all levels and the location of the walkway need to be calculated manually at each level, and the design cycle is as long as several days. Once the scheme is adjusted, all related parameters need to be iterated again, which is a huge workload. At the same time, two-dimensional drawings are difficult to intuitively show the three-dimensional spatial relationship of the excavation body, and the results are difficult to seamlessly connect with the BIM system, which restricts the management of the entire life cycle of the project.

[0003] (2) Insufficient ability to handle geometric relationships under complex geological conditions. Existing methods and conventional software have weak ability to handle complex situations such as asymmetrical terrain on the left and right banks and differences in the elevation of the horse trail. The connection or termination of the same level of horse trail requires a lot of manual intervention. During the process of step-by-step slope, the horse trail lines often intersect due to geometric shortening. There is a lack of effective automatic repair methods, which leads to model generation failure or the need for manual cutting.

[0004] (3) The slope parameters are out of sync with the geological conditions and lack intelligent matching. The selection of the excavation slope ratio relies heavily on the experience of the designers and fails to establish an automatic mapping relationship with the weathering zones of the rock mass (fully weathered, strongly weathered, weakly weathered, and slightly weathered) obtained from the detailed exploration. This often leads to a conservative slope ratio (increasing the amount of excavation) or safety risks, making it difficult to achieve economical excavation while ensuring stability. Summary of the Invention

[0005] This invention provides an intelligent excavation design method for gravity dam foundations. Addressing issues in the prior art such as low design efficiency, difficulty in parameter modification, insufficient 3D rendering, poor integration with BIM, weak handling of left and right bank asymmetry and self-intersection of walkways under complex terrain conditions, and disconnection between slope parameters and geological weathering zones, this invention provides an intelligent excavation design method for gravity dam foundations. The aim is to achieve parameterization, automation, and intelligence in dam foundation excavation design, improve design efficiency, accuracy, and geological adaptability, and achieve seamless integration with BIM systems.

[0006] A method for intelligent excavation design of gravity dam foundations includes the following steps: Step S1: Extract the bottom foundation surface from the three-dimensional solid model of the gravity dam, and extend the boundary line of the bottom foundation surface upstream by a first preset distance and downstream by a second preset distance to generate an excavation model within the dam body. The excavation model within the dam body has an upstream excavation edge line, a downstream excavation edge line, and a bottom foundation pit edge line; the excavation model within the dam body serves as the reference area for dam foundation excavation. Step S2: Using the upstream excavation boundary line of the dam body as a reference, set the slope height, slope ratio, and ramp width parameters, and design the independent single-sided upstream slope and platform excavation for the left and right banks respectively. Specifically, the design for the independent single-sided upstream slope and platform excavation of the left and right banks includes: S21. Taking the upstream excavation line of the dam body at the lowest elevation as the starting baseline, and the direction perpendicular to the upstream excavation line of the dam body as the slope direction, two horse trail lines of the first-level horse trail are generated according to the slope height, slope ratio, and horse trail width parameters, namely the upper horse trail line and the lower horse trail line that are horizontally parallel. Step S22: Extend the bottom foundation pit edge line generated in step S1 to intersect the two horse path lines of the first-level horse path, and obtain the two intersection points of the first-level slope. Step S23: Connect the two intersection points with the corresponding endpoints of the first-level wide ramp of the dam foundation to complete the first-level slope excavation; Step S24: Using the line connecting the two intersection points of the generated horse trail line and the first-level slope as the new baseline, repeat the above steps to generate the next level horse trail and perform the intersection and connection steps, and carry out subsequent slope excavation step by step upward until the dam crest elevation. Step S25: During the step-by-step upward excavation process, when the bridle path is excessively shortened, causing the line segment to extend in the opposite direction and resulting in self-intersection, the self-intersection is eliminated by skipping the failed line segment and directly taking the intersection point of the adjacent two line segments to reconstruct the inflection point. Step S3: Using the revetment boundary line as a reference, set the downstream slope height, slope ratio, and ramp width parameters, and design independent single-sided downstream slope and platform excavation for the left and right banks respectively. Specifically, the design for independent single-sided downstream slope and platform excavation on both the left and right banks includes: Step S31: Using the boundary line of the protective slope as the starting baseline and the direction perpendicular to the boundary line of the protective slope as the slope direction, generate two horse trail lines for the first-level horse trail downstream based on the downstream slope height, slope ratio, and horse trail width parameters. These are a longitudinally parallel horse trail line on the riverside and a horse trail line on the mountainside. Step S32: Extend the downstream excavation edge line generated in step S1 to intersect the two horse path lines of the downstream first-level horse path, and obtain two intersection points of the downstream first-level slope. Step S33: Connect the two intersection points with the corresponding endpoints of the first-level wide ramp of the dam foundation to complete the excavation of the downstream first-level slope; Step S34: Using the line connecting the two intersection points of the generated horse trail line and the downstream first-level slope as the new baseline, repeat the above steps to generate the next level horse trail and perform the intersection and connection steps, and carry out subsequent slope excavation step by step upward until the dam crest elevation. Step S35: During the step-by-step upward excavation process, when the path line is excessively shortened, causing the line segment to extend in the opposite direction and resulting in self-intersection, the self-intersection is eliminated by skipping the failed line segment and directly taking the intersection point of the adjacent two line segments to reconstruct the inflection point.

[0007] More preferably, the first preset distance is 1 meter and the second preset distance is 1.2 meters.

[0008] A further preferred embodiment is that, in step S2, when designing the excavation of the upstream slope and platform on both the left and right banks independently, if there is a difference in the elevation of the same-level horse trails on the left and right banks, the following processing is performed based on the positional relationship of the same-level horse trails on the left and right banks in the planar projection: If the left and right bank horse trails of the same level overlap or intersect in the plane projection, the offset is calculated based on the elevation difference between the two sides, the endpoint of the horse trail on the higher elevation side is shortened back, and a connecting line segment is generated to connect with the horse trail on the other side to form a longitudinal slope transition. If the same level horse trails on the left and right banks are completely offset and do not overlap in the planar projection, the horse trails on both sides will automatically extend to the opposite bank and terminate at the contour points of the opposite bank slope.

[0009] More preferably, step S2 further includes the following steps: automatically matching the optimal excavation slope within a preset slope ratio threshold range based on the weathering zone category of the stratum to which the dam foundation slope elevation belongs.

[0010] Further preferably, the weathering zone category includes fully weathered, strongly weathered, weakly weathered, and slightly weathered, with corresponding preset slope ratio ranges of: fully weathered 1:1.25~1:1.5, strongly weathered 1:1.00~1:1.25, weakly weathered 1:0.5~1:1.00, and slightly weathered 1:0.25~1:0.5; the slope ratio is preferably selected from a set of discrete standard slope ratios, including 1:0.3, 1:0.5, 1:0.75, 1:1, 1:1.25, and 1:1.5.

[0011] Further preferably, the optimization logic of the slope ratio is as follows: when the starting elevation is near the boundary between the two types of weathering layers, a steeper slope ratio connecting the two is selected; when the starting elevation is in the middle area of ​​any weathering layer, a typical value within that range is selected.

[0012] More preferably, in step S3, the downstream first-level walkway includes a walkway on the river side and a walkway on the mountain side. In step S32, the downstream excavation edge is extended to intersect with the walkway on the river side and the walkway on the mountain side, respectively, to obtain two intersection points of the downstream first-level slope.

[0013] A further preferred embodiment is to automatically generate a three-dimensional excavation model and an excavation quantity statistics table based on the design parameters, and output the data format for integration into the BIM system.

[0014] A gravity dam foundation intelligent excavation design system, applying any of the aforementioned intelligent gravity dam foundation excavation design methods, includes: The model extraction module extracts the bottom foundation surface from the 3D solid model of the gravity dam; The excavation module within the dam body extends the foundation surface edge line upstream by a first distance and downstream by a second distance to generate an excavation model within the dam body. The upstream slope and platform excavation module is configured to perform the single-sided design process of step S2 on the left and right banks respectively, including the self-intersection elimination submodule of the horse trail, the connection or pinch-out treatment submodule of the same level horse trail on the left and right banks, and the weathering zone adaptive slope ratio matching submodule. The downstream slope and platform excavation module executes the design process described in step S3 on the left and right banks respectively. The output module is configured to generate a 3D excavation model and a quantity statistics table.

[0015] More preferably, the upstream slope and platform excavation module further includes: a storage unit configured to store preset slope ratio discrete values, and a comparison unit configured to automatically match the slope ratio according to the location of the weathering zone to which the slope elevation belongs.

[0016] The beneficial effects of this invention are: (1) This invention directly extracts the foundation surface from the three-dimensional solid model of the gravity dam and automatically generates slopes and ramp lines of each level in a bottom-up, step-by-step manner. Designers only need to input a few parameters such as slope height, slope ratio, and ramp width to complete the design work that would normally take several days in just a few hours. When the scheme is adjusted, only the relevant parameters need to be modified, and the system automatically updates the entire excavation model, avoiding a lot of repetitive work. At the same time, the generated three-dimensional excavation model can be directly exported as BIM format data, supporting quantity surveying, construction simulation, and full life cycle management, solving the problems of insufficient visualization and poor integration with BIM in traditional two-dimensional drawings.

[0017] (2) This invention supports independent design of the left and right banks, and can automatically perform connection (forming a transition section) or pinch-out processing according to the elevation difference and planar projection position of the same level of horse trails on the left and right banks, without manual intervention. During the process of gradually sloping upwards, when the horse trail lines intersect due to geometric shortening, the system automatically eliminates the problem by "skipping the failed line segment and reconstructing the inflection point by taking the intersection point of the adjacent two line segments", ensuring the robustness of model generation and solving the problem of insufficient geometric relationship processing capability under complex geological conditions.

[0018] (3) This invention establishes a mapping relationship between the weathering zone of the rock mass (fully weathered, strongly weathered, weakly weathered, and slightly weathered) and the slope ratio threshold, and has a set of discrete standard slope ratios (1:0.3, 1:0.5, 1:0.75, 1:1, 1:1.25, and 1:1.5) built in. The system automatically selects the most suitable slope ratio based on the location of the weathering zone to which the dam foundation slope elevation belongs and its relative position in the weathering zone (near the boundary line or in the middle), avoiding the problem of being too conservative or too risky due to relying on the experience of designers, and achieving economical excavation while ensuring slope stability. Attached Figure Description

[0019] Figure 1 This is a flowchart of the method of the present invention; Figure 2 This is a schematic diagram of the slope and platform zoning of the present invention; Figure 3 This is a schematic diagram of the upstream and downstream slope excavation of the dam foundation; Figure 4 This is a schematic diagram of the self-intersection processing method for horse paths; Figure 5 A schematic diagram showing the left and right banks before the staggered bridle path treatment at the same level; Figure 6 Schematic diagram of the staggered bridle paths on the left and right banks after the treatment. Figure 7 A schematic diagram of the right bank bridleway decapitation treatment; Figure 8 This is a schematic diagram before processing of the overlapping bridle paths on the left and right banks at the same level; Figure 9 This is a schematic diagram showing the connection method of overlapping bridle paths on the left and right banks after processing. Detailed Implementation

[0020] 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.

[0021] Example 1 See also Figure 1 The present invention provides a flowchart of an intelligent excavation design method for gravity dam foundations, comprising the following steps: Step S1: Extract the bottom foundation surface from the 3D solid model of the gravity dam, and extend the boundary line of the bottom foundation surface upstream by a first preset distance and downstream by a second preset distance to generate an excavation model within the dam body. The excavation model within the dam body has an upstream excavation boundary line, a downstream excavation boundary line, and a bottom foundation pit boundary line; the excavation model within the dam body serves as the reference area for dam foundation excavation. The first preset distance is 1 meter, and the second preset distance is 1.2 meters.

[0022] Step S2: Using the upstream excavation line of the dam body as a reference, set the parameters of slope height, slope ratio, and ramp width, and design the excavation of the upstream slope and platform on both the left and right banks independently.

[0023] Specifically, the design for the independent single-sided upstream slope and platform excavation of the left and right banks includes: S21. Taking the upstream excavation line of the dam body at the lowest elevation as the starting baseline, and the direction perpendicular to the upstream excavation line of the dam body as the slope direction, two horse trail lines of the first-level horse trail are generated according to the slope height, slope ratio, and horse trail width parameters, namely the upper horse trail line and the lower horse trail line that are horizontally parallel. Step S22: Extend the bottom edge of the foundation pit generated in step S1 to intersect the two paths of the first-level walkway, thus obtaining the two intersection points of the first-level slope. Step S23: Connect the two intersection points with the corresponding endpoints of the first-level wide ramp of the dam foundation to complete the first-level slope excavation; Step S24: Using the line connecting the two intersection points of the generated horse trail line and the first-level slope as the new baseline, repeat the above steps to generate the next level horse trail and perform the intersection and connection steps, and carry out subsequent slope excavation step by step upward until the dam crest elevation. Step S25: During the step-by-step upward excavation process, when the path line is excessively shortened, causing the line segment to extend in the opposite direction and resulting in self-intersection, the self-intersection is eliminated by skipping the failed line segment and directly taking the intersection point of the adjacent two line segments to reconstruct the inflection point.

[0024] When designing independent single-sided upstream slopes and platform excavations for the left and right banks, if there is a difference in elevation between the left and right banks' equivalent ramps, the following treatment should be applied based on the positional relationship of the left and right banks' equivalent ramps in the planar projection: If the left and right bank horse trails of the same level overlap or intersect in the planar projection, the offset is calculated based on the elevation difference between the two sides, the endpoint of the horse trail on the higher elevation side is shortened back, and a connecting line segment is generated to connect with the horse trail on the other side to form a longitudinal slope transition.

[0025] If the same level horse trails on the left and right banks are completely offset and do not overlap in the planar projection, the horse trails on both sides will automatically extend to the opposite bank and terminate at the contour points of the opposite bank slope.

[0026] Step S2 further includes the following steps: Based on the weathering zone category of the dam foundation's initial elevation, automatically match the optimal excavation slope within a preset slope ratio threshold range. Weathering zone categories include fully weathered, strongly weathered, weakly weathered, and slightly weathered, with corresponding preset slope ratio ranges of: fully weathered 1:1.25–1:1.5, strongly weathered 1:1.00–1:1.25, weakly weathered 1:0.5–1:1.00, and slightly weathered 1:0.25–1:0.5. The slope ratio is selected from a set of discrete standard slope ratios, including 1:0.3, 1:0.5, 1:0.75, 1:1, 1:1.25, and 1:1.5. The optimization logic for the slope ratio is as follows: when the initial elevation is near the boundary between two weathering layers, select the steeper slope ratio connecting the two; when the initial elevation is in the middle region of any weathering layer, select a typical value within that range.

[0027] Step S3: Using the side line of the revetment as a reference, set the downstream slope height, slope ratio, and ramp width parameters, and design the excavation of the downstream slope and platform on both the left and right banks independently.

[0028] Specifically, the design for independent single-sided downstream slope and platform excavation on both the left and right banks includes: S31. Using the boundary line of the protective slope as the starting reference line and the direction perpendicular to the boundary line of the protective slope as the slope direction, generate two horse trail lines for the first-level horse trail downstream based on the downstream slope height, slope ratio, and horse trail width parameters. These lines are a longitudinally parallel horse trail line on the riverside and a horse trail line on the mountainside.

[0029] S32. Extend the downstream excavation edge line generated in step S1 to intersect the two horse path lines of the downstream first-level horse path, and obtain two intersection points of the downstream first-level slope.

[0030] S33. Connect the two intersection points with the corresponding endpoints of the first-level wide ramp of the dam foundation to complete the excavation of the downstream first-level slope.

[0031] S34. Using the line connecting the two intersection points of the generated ramp and the downstream first-level slope as the new baseline, repeat the above steps to generate the next level ramp and perform the intersection and connection steps, and excavate the subsequent slopes step by step upwards until the dam crest elevation.

[0032] S35. During the step-by-step upward excavation process, when the path is excessively shortened, causing the line segment to extend in the opposite direction and resulting in self-intersection, the self-intersection is eliminated by skipping the failed line segment and directly taking the intersection point of the adjacent two line segments to reconstruct the inflection point.

[0033] In step S3, the downstream first-level walkway includes the walkway on the river side and the walkway on the mountain side. In step S32, the downstream excavation edge is extended to intersect with the walkway on the river side and the walkway on the mountain side, respectively, to obtain two intersection points of the downstream first-level slope.

[0034] The intelligent excavation design method for gravity dam foundations in this embodiment also includes: automatically generating a three-dimensional excavation model and an excavation quantity statistics table based on design parameters, and outputting the data format for integration into the BIM system.

[0035] Example 2 This embodiment provides an intelligent excavation design method for gravity dam foundations. The example used is the excavation design of a concrete gravity dam foundation for the lower reservoir of a pumped storage power station. The dam has a maximum height of 93m and a crest length of 324m. The dam site has complex topography, asymmetrical left and right banks, and significant differences in the degree of rock weathering (including fully weathered, strongly weathered, weakly weathered, and slightly weathered rock). Traditional methods are insufficient for efficient and accurate dam foundation excavation design; therefore, the intelligent excavation design method for gravity dam foundations of this invention is adopted.

[0036] I. Design of slope and platform excavation within the dam body area See also Figure 2 The excavation design of this invention is divided into three main areas: the slope and platform within the dam body, the upstream slope and platform of the dam body, and the downstream slope and platform of the dam body. First, the bottom foundation surface is directly extracted from the established three-dimensional solid model of the gravity dam to obtain the initial foundation surface outline. Then, the foundation surface outline is extended 1m upstream and 1.2m downstream to generate the excavation model within the dam body. The excavation model within the dam body has an upstream excavation edge line U1, a downstream excavation edge line L1, and bottom foundation pit edges J1 and J2; the excavation model within the dam body serves as the reference area for dam foundation excavation. This extension distance can be adjusted according to the actual engineering situation. For example, in other embodiments, an upstream extension of 0.5–2.5m and a downstream extension of 0.6–3.0m are both within the scope of protection of this invention.

[0037] In this embodiment, extending 1m upstream and 1.2m downstream fully considers the working space required for dam concrete pouring and the foundation treatment requirements, ensuring a safe distance between the dam body and the excavation boundary.

[0038] II. Excavation Design of Upstream Slope and Platform of Dam See also Figure 3 This invention provides schematic diagrams of the upstream and downstream slope excavation of the dam foundation. Figure 3The design includes the location and connection relationships of each key point. Using the upstream excavation edges U1 and U2 as references, the left and right banks are designed independently. The left bank uses the ab segment of the upstream excavation edge U1 at the lowest elevation of the dam body as the starting reference line, and the right bank uses the ac segment of the upstream excavation edge U1 as the starting reference line. The design process for both is consistent.

[0039] Figure 3 In the middle: line segments ab and ac are the upstream excavation edge lines U1 of the left and right banks, respectively; Line segments de and fg are the revetment boundary lines of the right bank and left bank, respectively, also known as the revetment side lines, which serve as the starting baseline for downstream slope excavation. The boundary of the area enclosed by points K3-K4-K6-K7 is the boundary line of the first-level wide horse path of the dam foundation; In the first-level slope of the upstream section, the line segment passing through intersection point K1 and parallel to the dam axis is the lower horse trail line, and the corresponding line segment passing through intersection point K2 is the upper horse trail line. In the first-level slope of the downstream section, the line segment passing through intersection point K8 is the downstream horse trail line on the river side, and the line segment passing through intersection point K9 is the downstream horse trail line on the mountain side. The downstream excavation boundary L1 is located at the downstream side boundary of the excavation model within the dam body area; The other levels of bridle paths and their intersections can be deduced similarly and will not be marked individually. The following is a detailed explanation using the left bank as an example.

[0040] (I) Design of the upstream slope of the left bank 1. Generation of the first-level slope Using ab as the baseline and the direction perpendicular to the baseline as the slope direction, input a slope height of 14m, a slope ratio of 1:0.5, and a walkway width of 2m. The system will automatically generate two walkway lines for the first level slope (i.e., the upper walkway line and the lower walkway line).

[0041] 2. Find intersections and connections Extend the left bank dam foundation pit boundary line (i.e., the boundary line of the excavation model within the dam body generated in step S1) to intersect with the two ramp lines of the first-level slope, obtaining intersection points K1 and K2. Define the riverside endpoint of the ramp line at the upper end of the first-level slope as K5. Then connect K1 to the riverside endpoint K3 of the first-level wide ramp line of the dam foundation, and connect K2 to the mountainside endpoint K4 of the first-level wide ramp line of the dam foundation, completing the excavation of the first-level slope.

[0042] 3. Parameter adjustability During the design process of this embodiment, the designers discovered that the position of point K1 was biased upstream, resulting in an excessive excavation volume for the first-stage slope. At this point, simply adjusting the slope height from 14m to 12m and the slope ratio from 1:0.5 to 1:0.3 was sufficient. The system automatically recalculated the position of the walkway and the intersection points K1 and K2, and updated the relevant connecting lines. The entire adjustment process was completed within minutes, whereas traditional manual drawing methods require recalculating all associated parameters, taking several hours.

[0043] 4. Gradual slope Using the line connecting K5K2 and K2K4 as the new baseline, input the second-level slope height of 16m, slope ratio of 1:0.5, and ramp width of 2m. The system repeats the above steps of slope setting, intersection finding, and connection to generate the second-level slope. Repeat this process until all 6 levels of slope excavation are completed to the dam crest elevation.

[0044] 5. Intelligent processing of self-intersection of bridle paths During the gradual upward slope, as the slope becomes steeper, the length of the intermediate section of the walkway shortens with increasing elevation. In this embodiment, when the slope reaches level 4, the system detects that a certain section of the walkway has excessively shortened, resulting in a reverse extension and self-intersection of the path. The system automatically eliminates the self-intersection by skipping the failed segment and directly reconstructing the inflection point from the intersection of adjacent segments (e.g., ...). Figure 4 The diagram shows the self-intersection processing method for the horse track. Figure 4 The image on the right shows the processed result. This process requires no manual intervention, ensuring the robustness of the generated model.

[0045] (II) Design of the upstream slope on the right bank and intelligent treatment of the same level of horse trails on both banks The right bank is based on the ac line of the upstream excavation edge U1 of the dam body. Due to the relatively steep terrain on the right bank, the first-level slope height is set at 5m (lower than the 14m on the left bank).

[0046] 1. Intelligent identification of elevation differences The system automatically identified a discrepancy in the elevation of the first-level bridle paths on the left and right banks (the left bank bridle path elevation is lower than the right bank bridle path elevation). Based on the positional relationship of the bridle paths of the same level on the planar projection, the system determined that they were completely offset and did not overlap, therefore automatically performing "tapering out": extending both bridle paths towards the opposite bank and tapering them out at equal elevation points on the opposite bank slope (e.g., ...). Figure 5 , Figure 6 The images shown are schematic diagrams of the left and right banks before and after the staggered exit design at the same level. Figure 7 (Schematic diagram of the right bank bridleway decapitation treatment).

[0047] 2. Subsequent slope design The subsequent slope excavation parameters were set (slope heights of 8m, 10m, 12m, 14m, and 16m, with a slope ratio of 1:0.5 and a walkway width of 2m), and the excavation method was consistent with that of the left bank. The system automatically handled asymmetry and completed the excavation of seven slope levels on the right bank to the dam crest elevation.

[0048] 3. Alternative scenarios for connection processing In other embodiments of the present invention, if the left and right bank bridleways of the same class overlap or intersect in the planar projection and cannot be staggered, such as Figure 8 As shown, the system calculates the offset based on the elevation difference between the two sides, shortens the endpoint of the path on the higher elevation side, and generates a connecting line segment to connect with the path on the other side, forming a 1:1 longitudinal slope transition (e.g., Figure 9 The diagram shows the connection method after processing of overlapping bridle paths at the same level on the left and right banks.

[0049] (III) Automatic matching of slope parameters based on geological weathering zone In this embodiment, the system automatically matches the optimal excavation slope based on the weathering zone category of the strata to which the dam foundation's slope elevation belongs. The mapping relationship between preset strata and slope ranges is shown in the table below:

[0050] The slope value is selected from a set of discrete standard slope ratios (1:0.3, 1:0.5, 1:0.75, 1:1, 1:1.25, 1:1.5). The selection logic is as follows: When the starting elevation is near the boundary between two types of weathering layers, a steeper slope ratio connecting the two is selected. For example, in this embodiment, the starting elevation of the left bank is located near the boundary between weak and slight weathering, and the system automatically selects 1:0.5 (a steeper value).

[0051] When the starting elevation is located in the middle region of a weathered layer, a typical value within that range is selected. For example, if the starting elevation of the first-level slope on the right bank is located in the middle of a weakly weathered layer, the system automatically selects 1:0.75.

[0052] III. Excavation Design of Downstream Slope and Platform of Dam First, input the extent of the revetment (22m long, 50m wide) and its elevation (302.0m). Considering the inconsistent elevations of the ramps on the left and right banks, the downstream slope is also designed separately for the left and right banks. The left bank uses the revetment boundary line (side line) fg as the starting baseline, and the right bank uses the revetment boundary line (side line) de as the starting baseline. The following explanation uses the left bank as an example.

[0053] (I) Design of the downstream slope of the left bank 1. Generation of the first-level slope Using the boundary line fg of the protective embankment as the starting baseline, slope the path perpendicular to the direction of water flow. Input a slope height of 12m, a slope ratio of 1:0.5, and a bridle path width of 2m, and the system will generate the first-level bridle path line.

[0054] 2. Find intersections and connections Calculate point K8, the intersection of the river-side path of the first-level downstream ramp and the downstream excavation edge U1 of the dam body; calculate point K9, the intersection of the mountain-side path of the first-level downstream ramp and the downstream excavation edge U1 of the dam body. Connect K8 to the endpoint K6 of the river-side path of the first-level wide ramp of the dam foundation, and connect K9 to the endpoint K7 of the mountain-side path of the first-level wide ramp of the dam foundation, thus completing the first-level slope excavation.

[0055] 3. Parameter Adjustment Based on the site topography, the designers found that point K9 was positioned upstream and needed to be adjusted 3 meters downstream to avoid conflict with existing geological tunnels. At this point, simply changing the position parameter of point K9 to "offset 3 meters downstream" automatically updated the coordinates of point K9 and regenerated the relevant connecting lines and subsequent slopes.

[0056] 4. Gradual slope Using K7, K9, K9, and K10 as the starting lines for excavation, repeat the above steps of slope setting, intersection finding, and connection. Input the parameters for the second and subsequent slopes (slope heights of 14m, 16m, and 18m, slope ratios of 1:0.5, and walkway width of 2m) until the excavation of the left bank's 6-level slope to the dam crest elevation is completed.

[0057] (II) Design of the downstream slope of the right bank The right bank adopted the same design process as the left bank, but adjusted the elevation and slope ratio parameters of each level of the ramps according to the topographical characteristics of the right bank: the first level slope height was 10m (2m lower than the left bank), the second level slope height was 12m, the third level slope height was 14m, the fourth level slope height was 16m, the fifth level slope height was 18m, the sixth level slope height was 16m, the seventh level slope height was 14m, and the eighth level slope height was 10m, with a slope ratio of 1:0.5 for all levels and a ramp width of 2m for all levels. The system automatically handled the asymmetry between the left and right banks, completing the excavation of 8 levels of slopes on the right bank to the dam crest elevation. During the step-by-step slope excavation process, the downstream slope also applied the ramp self-intersection elimination algorithm to ensure the geometric validity of the model.

[0058] IV. Design Deliverables and Outputs After completing all excavation designs, the system automatically generates the following results: 3D excavation model: Fully displays the excavation shape and spatial relationship of the upstream and downstream slopes within the dam body, and can be directly rotated, sectioned, and measured in the 3D environment.

[0059] Excavation volume statistics table: including the excavation area of ​​each level of slope, the area of ​​the access road, and the total excavation volume. In this example, the total excavation volume is 856,200 m³.

[0060] Analysis by overlay with geological model: The excavation model is overlaid with the geological exploration model to verify whether the excavation boundary exceeds the weathering zone range allowed by the design. The results meet the design specifications.

[0061] BIM Data Export: Export common BIM formats such as DGN, IFC, DWG, and DXF for progress simulation, resource allocation, and quality traceability during the construction phase.

[0062] (1) This invention directly extracts the foundation surface from the three-dimensional solid model of the gravity dam and automatically generates slopes and ramp lines of each level in a bottom-up, step-by-step manner. Designers only need to input a few parameters such as slope height, slope ratio, and ramp width to complete the design work that would normally take several days in just a few hours. When the scheme is adjusted, only the relevant parameters need to be modified, and the system automatically updates the entire excavation model, avoiding a lot of repetitive work. At the same time, the generated three-dimensional excavation model can be directly exported as BIM format data, supporting quantity surveying, construction simulation, and full life cycle management, solving the problems of insufficient visualization and poor integration with BIM in traditional two-dimensional drawings.

[0063] (2) This invention supports independent design of the left and right banks, and can automatically perform connection (forming a transition section) or pinch-out processing according to the elevation difference and planar projection position of the same level of horse trails on the left and right banks, without manual intervention. During the process of gradually sloping upwards, when the horse trail lines intersect due to geometric shortening, the system automatically eliminates the problem by "skipping the failed line segment and reconstructing the inflection point by taking the intersection point of the adjacent two line segments", ensuring the robustness of model generation and solving the problem of insufficient geometric relationship processing capability under complex geological conditions.

[0064] (3) This invention establishes a mapping relationship between the weathering zone of the rock mass (fully weathered, strongly weathered, weakly weathered, and slightly weathered) and the slope ratio threshold, and has a set of discrete standard slope ratios (1:0.3, 1:0.5, 1:0.75, 1:1, 1:1.25, and 1:1.5) built in. The system automatically selects the most suitable slope ratio based on the location of the weathering zone to which the dam foundation slope elevation belongs and its relative position in the weathering zone (near the boundary line or in the middle), avoiding the problem of being too conservative or too risky due to relying on the experience of designers, and achieving economical excavation while ensuring slope stability.

[0065] Example 3 This embodiment provides an intelligent excavation design system for gravity dam foundations, applying the aforementioned intelligent excavation design method for gravity dam foundations, including: The model extraction module extracts the bottom foundation surface from the 3D solid model of the gravity dam.

[0066] The excavation module within the dam body extends the foundation surface edge upstream by a first distance and downstream by a second distance to generate an excavation model within the dam body.

[0067] The upstream slope and platform excavation module is configured to execute the single-sided design process of step S2 on both the left and right banks, including a self-intersection elimination submodule for the walkway, a connection or pinch-out treatment submodule for walkways of the same level on the left and right banks, and an adaptive slope ratio matching submodule for the weathered zone. The upstream slope and platform excavation module also includes: a storage unit configured to store preset discrete slope ratio values, and a comparison unit configured to automatically match the slope ratio based on the location of the weathered zone to which the slope elevation belongs.

[0068] The downstream slope and platform excavation module executes the design process described in step S3 on the left and right banks respectively. The output module is configured to generate a 3D excavation model and a quantity statistics table.

[0069] The above description, in conjunction with specific preferred embodiments, provides a further detailed explanation of the present invention. It should not be construed that the specific implementation of the present invention is limited to these descriptions. For those skilled in the art, various simple deductions or substitutions can be made without departing from the concept of the present invention, and all such modifications and substitutions should be considered within the scope of protection of the present invention.

Claims

1. A method for intelligent excavation design of gravity dam foundations, characterized in that, Includes the following steps: Step S1: Extract the bottom foundation surface from the three-dimensional solid model of the gravity dam, and extend the boundary line of the bottom foundation surface upstream by a first preset distance and downstream by a second preset distance to generate an excavation model within the dam body. The excavation model within the dam body has an upstream excavation edge line, a downstream excavation edge line, and a bottom foundation pit edge line; the excavation model within the dam body serves as the reference area for dam foundation excavation. Step S2: Using the upstream excavation boundary line of the dam body as a reference, set the slope height, slope ratio, and ramp width parameters, and design the independent single-sided upstream slope and platform excavation for the left and right banks respectively. Specifically, the design for the independent single-sided upstream slope and platform excavation of the left and right banks includes: S21. Taking the upstream excavation line of the dam body at the lowest elevation as the starting baseline, and the direction perpendicular to the upstream excavation line of the dam body as the slope direction, two horse trail lines of the first-level horse trail are generated according to the slope height, slope ratio, and horse trail width parameters, namely the upper horse trail line and the lower horse trail line that are horizontally parallel. Step S22: Extend the bottom foundation pit edge line generated in step S1 to intersect the two horse path lines of the first-level horse path, and obtain the two intersection points of the first-level slope. Step S23: Connect the two intersection points with the corresponding endpoints of the first-level wide ramp of the dam foundation to complete the first-level slope excavation; Step S24: Using the line connecting the two intersection points of the generated horse trail line and the first-level slope as the new baseline, repeat the above steps to generate the next level horse trail and perform the intersection and connection steps, and carry out subsequent slope excavation step by step upward until the dam crest elevation. Step S25: During the step-by-step upward excavation process, when the bridle path is excessively shortened, causing the line segment to extend in the opposite direction and resulting in self-intersection, the self-intersection is eliminated by skipping the failed line segment and directly taking the intersection point of the adjacent two line segments to reconstruct the inflection point. Step S3: Using the revetment boundary line as a reference, set the downstream slope height, slope ratio, and ramp width parameters, and design independent single-sided downstream slope and platform excavation for the left and right banks respectively. Specifically, the design for independent single-sided downstream slope and platform excavation on both the left and right banks includes: Step S31: Using the boundary line of the protective slope as the starting baseline and the direction perpendicular to the boundary line of the protective slope as the slope direction, generate two horse trail lines for the first-level horse trail downstream based on the downstream slope height, slope ratio, and horse trail width parameters. These are a longitudinally parallel horse trail line on the riverside and a horse trail line on the mountainside. Step S32: Extend the downstream excavation edge line generated in step S1 to intersect the two horse path lines of the downstream first-level horse path, and obtain two intersection points of the downstream first-level slope. Step S33: Connect the two intersection points with the corresponding endpoints of the first-level wide ramp of the dam foundation to complete the excavation of the downstream first-level slope; Step S34: Using the line connecting the two intersection points of the generated horse trail line and the downstream first-level slope as the new baseline, repeat the above steps to generate the next level horse trail and perform the intersection and connection steps, and carry out subsequent slope excavation step by step upward until the dam crest elevation. Step S35: During the step-by-step upward excavation process, when the path line is excessively shortened, causing the line segment to extend in the opposite direction and resulting in self-intersection, the self-intersection is eliminated by skipping the failed line segment and directly taking the intersection point of the adjacent two line segments to reconstruct the inflection point.

2. The intelligent excavation design method for gravity dam foundations according to claim 1, characterized in that, The first preset distance is 1 meter, and the second preset distance is 1.2 meters.

3. The intelligent excavation design method for gravity dam foundations according to claim 1, characterized in that, In step S2, when designing the excavation of the upstream slope and platform on both the left and right banks independently, if there is a difference in the elevation of the same-level horse trails on the left and right banks, the following processing is performed based on the positional relationship of the same-level horse trails on the left and right banks in the planar projection: If the left and right bank horse trails of the same level overlap or intersect in the plane projection, the offset is calculated based on the elevation difference between the two sides, the endpoint of the horse trail on the higher elevation side is shortened back, and a connecting line segment is generated to connect with the horse trail on the other side to form a longitudinal slope transition. If the same level horse trails on the left and right banks are completely offset and do not overlap in the planar projection, the horse trails on both sides will automatically extend to the opposite bank and terminate at the contour points of the opposite bank slope.

4. The intelligent excavation design method for gravity dam foundations according to claim 1, characterized in that, Step S2 also includes the following steps: automatically matching the optimal excavation slope within a preset slope ratio threshold range based on the weathering zone category of the strata to which the dam foundation slope elevation belongs.

5. The intelligent excavation design method for gravity dam foundations according to claim 4, characterized in that, The weathering zone categories include fully weathered, strongly weathered, weakly weathered, and slightly weathered, with corresponding preset slope ratio ranges of 1:1.25 to 1:1.5 for fully weathered, 1:1.00 to 1:1.25 for strongly weathered, 1:0.5 to 1:1.00 for weakly weathered, and 1:0.25 to 1:0.5 for slightly weathered. The slope ratio is selected from a set of discrete standard slope ratios, including 1:0.3, 1:0.5, 1:0.75, 1:1, 1:1.25, and 1:1.

5.

6. The intelligent excavation design method for gravity dam foundations according to claim 5, characterized in that, The optimal slope ratio is as follows: when the starting elevation is near the boundary between the two types of weathering layers, a steeper slope ratio connecting the two is selected; when the starting elevation is in the middle area of ​​either weathering layer, a typical value within that range is selected.

7. The intelligent excavation design method for gravity dam foundations according to claim 1, characterized in that, In step S3, the trail line of the downstream first-level trail includes the trail line on the river side and the trail line on the mountain side. In step S32, the downstream excavation edge line is extended to intersect with the trail line on the river side and the trail line on the mountain side, respectively, to obtain two intersection points of the downstream first-level slope.

8. The intelligent excavation design method for gravity dam foundations according to claim 1, characterized in that, Also includes: The system automatically generates a 3D excavation model and an excavation quantity statistics table based on design parameters, and outputs the data in a format suitable for integration with the BIM system.

9. An intelligent excavation design system for gravity dam foundations, employing the intelligent excavation design method for gravity dam foundations as described in any one of claims 1 to 8, characterized in that, include: The model extraction module extracts the bottom foundation surface from the 3D solid model of the gravity dam; The excavation module within the dam body extends the foundation surface edge line upstream by a first distance and downstream by a second distance to generate an excavation model within the dam body. The upstream slope and platform excavation module is configured to perform the single-sided design process of step S2 in claim 1 on the left bank and the right bank respectively, including the self-intersection elimination submodule of the horse trail, the connection or pinch-out treatment submodule of the same level horse trail on the left and right banks, and the weathering zone adaptive slope ratio matching submodule. The downstream slope and platform excavation module performs the design process of step S3 in claim 1 on the left bank and the right bank, respectively. The output module is configured to generate a 3D excavation model and a quantity statistics table.

10. The intelligent excavation design system for gravity dam foundations according to claim 9, characterized in that, The upstream slope and platform excavation module also includes: a storage unit configured to store preset slope ratio discrete values, and a comparison unit configured to automatically match the slope ratio based on the location of the weathering zone to which the slope elevation belongs.

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