Optimization design method for drainage gallery of shipping engineering power plant

Abstract

The invention discloses a drainage gallery optimization design method for a shipping engineering power plant, and relates to the technical field of shipping hub engineering, the drainage gallery optimization design method can optimize the structure of a drainage gallery, prevent the drainage gallery at a structural joint from leaking, and ensure the normal operation of the power plant; the drainage gallery optimization design method comprises the following steps: determining a material of a drainage pipe in combination with a main body structure, geological conditions, hydrological conditions and construction efficiency of a drainage gallery setting area; the damage risk of the drainage pipe embedded in the main body structure is analyzed; designing a compensation mechanism by combining the material property of the drain pipe and the damage risk faced by the drain pipe; combining with a compensation mechanism, designing a drainage gallery structure, performing finite element analysis on the drainage gallery structure, optimizing the drainage gallery structure and the like.

Description

Technical Field

[0001] The invention relates to the technical field of shipping hub engineering, and in particular to a drainage gallery optimization design method for a power plant of a shipping engineering. Background Art

[0002] In shipping hubs, dams have functions such as improving shipping conditions, flood control, regulating water flow, and storing water for power generation. The drainage corridors of dam power plants are mainly used to remove excess water generated by various factors (such as rainfall, seepage, etc.) inside and outside the dam and power plant, so as to ensure the stability of hydraulic structures, prevent safety hazards, and support power plant operations. The drainage corridors of power plants are usually concrete corridors, which are in the form of culverts. The following problems usually exist during construction and operation: During the construction process, it is usually necessary to erect scaffolding, set up formwork, pour concrete and maintain the work. The erection and dismantling of a large number of formworks are cumbersome and the amount of wet work on site is high. The construction efficiency is low and the project quality is difficult to guarantee.

[0003] During the operation process, due to the limitations of design and construction requirements, structural joints need to be set up in the foundation. Structural joints have inherent settlement and expansion and contraction deformation characteristics. The foundation may settle unevenly due to geological conditions or large differences in the weight of adjacent blocks, which will affect the service life of the concrete corridor. It will also affect the water-stopping equipment, causing cracks in the water-stopping parts, causing leakage in the structural joints, and affecting the normal operation of the power plant. Summary of the invention

[0004] At least one of the purposes of the present invention is to provide a drainage corridor optimization design method for a shipping engineering power plant in order to overcome the problems existing in the above-mentioned prior art, which can optimize the structure of the drainage corridor, prevent leakage of the drainage corridor at the structural joints, and ensure the normal operation of the power plant.

[0005] In order to achieve the above-mentioned purpose, the technical solution adopted by the present invention includes the following aspects.

[0006] A drainage gallery optimization design method for a power plant in a shipping engineering project comprises the following steps: Step S1, determining the material of the drainage pipe in combination with the main structure, geological conditions, hydrological conditions and construction efficiency of the drainage corridor setting area; Step S2, analyzing the damage risk faced by the drainage pipe buried in the main structure; Step S3, designing a compensation mechanism based on the material properties of the drainage pipe and the damage risk faced by the drainage pipe; Step S4, designing the drainage corridor structure in combination with the compensation mechanism; Step S5: Perform finite element analysis on the drainage corridor structure to optimize the drainage corridor structure.

[0007] Preferably, in step S2, the main structure is a large-volume concrete structure; the damage risks faced by the drainage pipe include: when the drainage pipe passes through the structural joint, the structural joint cracks or shrinks due to thermal expansion and contraction or geological effects, causing the drainage pipe to bear local deformation stress, threatening the structural integrity and functionality of the drainage pipe; and the structural joints at the junction of the main structure open or shrink to varying degrees, causing radial misalignment and deformation of the drainage pipe, affecting the continuity and stability of the drainage pipe, causing fatigue damage or even breakage of the drainage pipe.

[0008] Preferably, in step S3, the design compensation mechanism includes: considering the expansion compensation mechanism to ensure the safety and stability of the drainage corridor structure; considering the settlement compensation mechanism to reduce and adapt to the foundation settlement.

[0009] Preferably, in step S5, when performing finite element analysis on the drainage corridor structure, a pipeline model is established using solid units in the Ansys WorkbenchDM interface; when setting boundary conditions, an anisotropic hexahedral meshing method is used to divide the mesh, and the set boundary conditions include the size of the pipeline model and the type of applied load; The pipeline model dimensions include: pipeline outer diameter D O 、Wall thickness D t and the length of the pipe section, L; The applied load types include: applying a gravity load to the overall pipeline model to simulate the deadweight of the soil and the pipeline, applying a displacement load to the bottom of one end of the pipeline model to simulate the underground settlement effect, and using the side of the other end of the pipeline model as a fixed constraint to stabilize the foundation.

[0010] Preferably, in step S5, in order to evaluate the influence of gravity on the drainage corridor structure and obtain the stress distribution at the settlement joints and the pipe connections, the initial amplitude of the displacement load is set to 50 mm, and then the displacement load is modified to a uniform increase of 10-50 mm to analyze the stress conditions at the pipe connections under different load conditions.

[0011] Preferably, in step S5, when optimizing the drainage corridor structure, stress data is extracted, stress changes at settlement joints and pipe connections are analyzed, stress intensity cloud maps and distribution curves are drawn, and stress change patterns at settlement joints and pipe connections are obtained, thereby providing data support for optimizing the drainage corridor structure.

[0012] Preferably, in step S4, the drainage corridor structure includes: a drainage pipe and a compensator, the compensator includes a casing and an elastic sealing structure, one end of the drainage pipe is connected to the maintenance water collection well, and the other end is connected to the infiltration water collection well, the casing is sleeved on the drainage pipe, and the casing is sealed by the elastic sealing structure, the drainage pipe and the casing are both covered in the main structure, a structural seam is provided on the main structure, the drainage pipe passes through the structural seam, and the casing is provided at the position of the structural seam and crosses the structural seam.

[0013] Preferably, the elastic sealing structure includes a first sealing layer, a second sealing layer and a third sealing layer. The first sealing layer is laid on the outer wall of the drain pipe to wrap the drain pipe. The first sealing layer partially extends into the casing and partially is located outside the casing. The second sealing layer is coated on the surface of the first sealing layer. The third sealing layer is coated on the surface of the first sealing layer. The third sealing layer adheres to the second sealing layer and is arranged close to the pipe mouth of the casing.

[0014] Preferably, a fourth sealing layer is further provided on the surface of the drain pipe, the fourth sealing layer covers the surface of the third sealing layer, and the fourth sealing layer extends from the pipe opening of the casing toward a direction away from the pipe opening of the casing.

[0015] Preferably, in step S5, when establishing the pipeline model, the first sealing layer, the second sealing layer, the third sealing layer and the fourth sealing layer are uniformly represented as an asphalt cushion layer, and the size of the pipeline model also includes the thickness t of the asphalt cushion layer.

[0016] In summary, due to the adoption of the above technical solution, the present invention has at least the following beneficial effects: The drainage corridor structure designed in the present invention optimizes the material of the drainage pipe and arranges a sleeve at the position where the drainage pipe passes through the structural joint, which can compensate for the settlement and shrinkage of the drainage pipe, significantly alleviate the stress and strain of the drainage pipe caused by load concentration and the expansion and contraction changes caused by the external environment, and make up for the potential defects in the drainage corridor structure; compared with the traditional concrete drainage corridor, the drainage corridor designed in the present invention has significant time limit and cost advantages while meeting the functional requirements. In the drainage corridor structure, the drainage pipe and the sleeve play a dual protection role. Even if the drainage pipe fails partially or under special working conditions, the concrete channel in the main structure can still maintain the function of the drainage corridor, ensure the stable operation of the drainage corridor, and avoid wider damage due to local problems.

[0017] The drainage corridor optimization design method of the present invention provides an economical and durable drainage corridor design by optimizing material selection and construction scheme, which effectively shortens the construction period, reduces the construction difficulty, and reduces the construction and maintenance costs. During construction, the prefabricated drainage pipes are used as the main structure, and a complete drainage channel is formed through on-site assembly and connection. This not only reduces the amount of wet work on site, avoids the tedious processes of formwork erection, concrete pouring and maintenance in traditional concrete construction, but also significantly improves the construction efficiency and project quality. BRIEF DESCRIPTION OF THE DRAWINGS

[0018] Figure 1 It is a flow chart of a drainage gallery optimization design method for a power plant in a shipping engineering according to an exemplary embodiment of the present invention.

[0019] Figure 2 It is a cross-sectional view of a drainage corridor structure according to an exemplary embodiment of the present invention.

[0020] Figure 3 It is a longitudinal cross-sectional view of the drainage corridor structure of an exemplary embodiment of the present invention.

[0021] Figure 4 is an oblique cross-sectional view of a finite element pipeline model of an exemplary embodiment of the present invention.

[0022] Figure 5 It is the stress cloud diagram of settlement joints in concrete drainage corridor.

[0023] Figure 6 It is the stress cloud diagram of settlement joints in casing drainage gallery.

[0024] Figure 7 It is the strain cloud diagram of settlement joints in concrete drainage corridor.

[0025] Figure 8 It is the strain cloud diagram of settlement joints in casing drainage gallery.

[0026] Fig. 9 It is the stress curve of settlement joints of concrete drainage gallery and casing drainage gallery.

[0027] Fig.10 It is the strain curve of settlement joints of concrete drainage gallery and casing drainage gallery.

[0028] Fig.11 It is the stress cloud diagram at the center of the casing.

[0029] Fig.12 It is the stress curve at the center of the steel pipe under different vertical displacement loads.

[0030] Fig.13 It is the stress curve at the center of the casing under different vertical displacement loads.

[0031] Markings in the figure: 1-drainage pipe, 2-casing, 3-elastic sealing structure, 31-first sealing layer, 32-second sealing layer, 33-third sealing layer, 34-fourth sealing layer, 4-main structure, 5-structural joint. DETAILED DESCRIPTION

[0032] The present invention is further described in detail below in conjunction with the accompanying drawings and embodiments to make the purpose, technical solutions and advantages of the present invention more clearly understood. It should be understood that the specific embodiments described herein are only used to explain the present invention and are not intended to limit the present invention.

[0033] refer to Figure 1 The drainage corridor optimization design method for a power plant in a shipping engineering according to an exemplary embodiment of the present invention comprises the following steps: Step S1, determining the material of the drainage pipe in combination with the main structure, geological conditions, hydrological conditions and construction efficiency of the drainage corridor setting area.

[0034] Step S2: Analyze the damage risk faced by the drainage pipes buried in the main structure based on the rigor and logic of engineering practice.

[0035] In the power plant of shipping engineering, the main structure of the drainage corridor is usually a large-volume concrete structure. In the process of constructing the main structure on the surface of the drainage pipe, in order to avoid cracks or crushing of the concrete of the main structure due to volume shrinkage or changes in ambient temperature during the hardening process, it is usually necessary to set structural joints to control cracks and maintain the integrity of the main structure. When the structural joint passes through the buried drainage pipe, the structural joint may crack or shrink due to thermal expansion and contraction or geological effects, causing the drainage pipe to bear local deformation stress, threatening the structural integrity and functionality of the drainage pipe; the structural joint may also open or shrink to varying degrees due to geological conditions, construction errors or long-term environmental effects, causing radial dislocation deformation of the drainage pipe, which not only affects the continuity and stability of the drainage pipe, but also easily causes fatigue damage or even breakage of the drainage pipe.

[0036] Step S3: design a compensation mechanism based on the material properties of the drainage pipe and the damage risk faced by the drainage pipe.

[0037] When steel pipes are used for drainage pipes, they have the characteristics of thermal expansion and contraction. The external environment (such as temperature changes) has a significant impact on the drainage pipes. Considering the expansion compensation mechanism during design can effectively ensure the safety and stability of the drainage corridor structure. When designing the expansion compensation mechanism, you can consider setting expansion joints, using flexible connectors, optimizing the layout of drainage pipes, etc. to improve the adaptability of drainage pipes to temperature changes and reduce the risk of damage to drainage pipes, thereby ensuring the stable operation of the drainage corridor and the safe transportation of water resources.

[0038] During the operation of the drainage corridor, due to the influence of geological effects, construction factors and long-term loads, the foundation soil is gradually compressed, causing the foundation of the drainage corridor to settle. The settlement compensation mechanism considered in the design can reduce and adapt to the foundation settlement, ensuring that the safety and functionality of the drainage corridor are not affected during use; when designing the settlement compensation mechanism, settlement joints (a type of structural joints) are set at key locations of the drainage corridor (such as the junction of different geological conditions or structural transitions) or at a certain interval to allow the drainage corridor structure to move relatively during settlement to prevent stress concentration; when setting settlement joints, ensure that the settlement joints are well sealed to prevent moisture or other media from penetrating into the settlement joints.

[0039] Step S4: design the drainage corridor structure in combination with the compensation mechanism.

[0040] Considering the need to perform expansion and contraction compensation and settlement compensation at the same time, the compensator structure designed in the present invention includes a casing and an elastic plugging structure. Figure 2 , Figure 3 The designed drainage gallery structure includes: a drainage pipe 1 and a compensator. One end of the drainage pipe 1 is connected to the maintenance water collection well, and the other end is connected to the infiltration water collection well. The compensator includes a casing 2 and an elastic sealing structure 3. The casing 2 is sleeved on the drainage pipe 1, and the casing 2 is sealed by the elastic sealing structure 3. The drainage pipe 1 and the casing 2 are both covered in the main structure 4. A structural seam 5 is provided on the main structure 4. The drainage pipe 1 passes through the structural seam 5. The casing 2 is arranged at the position of the structural seam 5 and crosses the structural seam 5.

[0041] By arranging a casing 2 on the drainage pipe 1 and making the casing 2 cross the structural joint 5, the drainage pipe 1 can be prevented from being deformed due to geological settlement during the settlement of the structural joint 5, and leakage of the drainage pipe 1 at the structural joint 5 can be avoided, thereby improving the structural safety and operating stability of the drainage corridor of the power plant.

[0042] There is a certain gap (8~12mm) between the inner wall of the casing 2 and the outer wall of the drainage pipe 1. During the foundation settlement process, the gap between the inner wall of the casing 2 and the outer wall of the drainage pipe 1 can absorb the cracks caused by the foundation settlement and reduce the risk of structural joint penetration. The casing 2 can also optimize the interaction between the drainage pipe 1 and the surrounding medium, and enhance the adaptability of the drainage pipe 1 to external environmental changes (such as soil movement, concrete shrinkage or expansion caused by temperature changes, etc.). Under the action of the casing 2, the axial, lateral and angular displacements caused by thermal expansion and contraction, foundation settlement and other factors can be absorbed.

[0043] The elastic sealing structure 3 includes a first sealing layer 31, a second sealing layer 32 and a third sealing layer 33. The first sealing layer 31 is laid on the outer wall of the drain pipe 1 to wrap the drain pipe 1. The first sealing layer partially extends into the casing 2 and partially is located outside the casing 2. The second sealing layer 32 is coated on the surface of the first sealing layer 31 to seal both ends of the casing 2. The third sealing layer 33 is coated on the surface of the first sealing layer 31. The third sealing layer 33 fits the second sealing layer 32 and is arranged close to the pipe mouth of the casing 2. During the foundation settlement process, the elastic sealing structure 3 can make the casing 2 move axially a certain distance relative to the drain pipe 1, reduce the influence of the foundation misalignment on both sides of the structural seam 5 on the drain pipe, and absorb the axial deformation of the drain pipe 1.

[0044] During the setting process of the sleeve 2, a fourth sealing layer 34 can also be set on the surface of the drain pipe 1. The fourth sealing layer 34 covers the surface of the third sealing layer 33. The fourth sealing layer 34 extends from the pipe mouth of the sleeve 2 in a direction away from the pipe mouth of the sleeve 2. The fourth sealing layer 34 completely covers and compacts the third sealing layer 33, and is tightly combined with the third sealing layer 33 to form a solid sealing structure.

[0045] The first sealing layer 31 is made of asphalt and asphalt felt. When the casing 2 and the drain pipe 1 are connected by the elastic sealing structure 3, heated asphalt is laid on the surface of the drain pipe at the preset connection position between the drain pipe 1 and the casing 2. After the asphalt wraps the drain pipe 1, one or more layers of asphalt felt are pasted on the surface of the asphalt to completely wrap the asphalt to form the first sealing layer 31. After the asphalt felt wraps the asphalt, it can prevent cement slurry from penetrating into the first sealing layer 31 during the subsequent construction of the main structure, thereby preventing the first sealing layer 31 from losing its elasticity. The second sealing layer 32 is made of hemp rope. After the first sealing layer 31 is set, the hemp rope is embedded in the surface of the first sealing layer 31, and the hemp rope forms a cross on the surface of the first sealing layer 31. A fork or mesh structure is formed to form a second sealing layer 32, and the thickness of the second sealing layer 32 is 8-12 mm (preferably 10 mm); when setting the hemp rope, the hemp rope is tightly and evenly arranged on the surface of the first sealing layer 31 to enhance the strength and toughness of the elastic sealing structure 3; the third sealing layer 33 is made of asphalt hemp sheets. After the second sealing layer 32 is set, the asphalt hemp sheets are wrapped on the surface of the first sealing layer 31 to form the third sealing layer 33. The asphalt hemp sheets are arranged in contact with the end face of the second sealing layer 32 and are arranged toward the pipe mouth of the casing 2. The wrapping thickness of the asphalt hemp sheets is the same as the thickness of the second sealing layer 32. The third sealing layer 33 can further improve the sealing effect on the casing. After the first sealing layer 31, the second sealing layer 32 and the third sealing layer 33 form an elastic sealing structure 3, the sleeve 2 is passed through the elastic sealing structure, so that the sleeve 2 is sealed by the elastic sealing structure 3. After sealing, the fourth sealing layer 34 is respectively arranged at the elastic sealing structure 3 at both ends of the sleeve 2. The fourth sealing layer 34 is made of asphalt. The fourth sealing layer 34 is laid on the surface of the drainage pipe 1, extending from the pipe mouth of the sleeve 2 to the direction away from the pipe mouth of the sleeve 2. The fourth sealing layer 34 completely covers and compacts the third sealing layer 33, so as to form a solid sealing structure; the laying length of the fourth sealing layer 34 is 2~3m, and the laying thickness is not greater than the thickness of the second sealing layer 32. In the length direction of the fourth sealing layer 34, the thickness of the fourth sealing layer 34 near the pipe mouth of the sleeve 2 is thicker than the thickness of other parts, so as to ensure the sealing of the connection between the sleeve 2 and the drainage pipe 1.

[0046] When designing the drainage corridor structure, the drainage pipe 1 and the casing 2 are preferably made of steel pipes. The steel pipes can be efficiently assembled and connected at the construction site, significantly reducing the amount of wet work on site. Compared with the construction of concrete corridors, the complex steps of template erection and removal are avoided, and the construction efficiency and project quality are significantly improved. In addition, the steel pipe material has excellent impermeability, durability and high bearing capacity, which enables it to effectively cope with the variable environmental conditions and load requirements in water conservancy projects, and provide strong support for the long-term stable operation of the drainage corridor. The outer walls of the drainage pipe 1 and the casing 2 are coated with one or more layers of anti-rust paint, and the outer walls of the drainage pipe 1 and the casing 2 are also coated with resistant paint, which is applied on the surface of the anti-rust paint to improve the corrosion resistance and high temperature resistance of the drainage pipe 1 and the casing 2, and ensure the reliability of the drainage corridor.

[0047] Along the length direction of the drainage pipe 1, a structural seam 5 is set on the main structure 4 around the drainage pipe 1 every 20~25m. When the drainage pipe 1 is set on the foundation, the structural seam 5 on the main structure 4 and the structural seam on the foundation are set correspondingly to prevent the main structure 4 from affecting the settlement and shrinkage of the drainage pipe 1 during the water storage operation. The width of the structural seam 5 is 20~25mm. The structural seam 5 is filled with a polyethylene closed-cell foam board to prevent moisture or other media from penetrating into the structural seam 5, so that the drainage corridor can better adapt to the deformation of the surrounding rock and prevent the occurrence of stress concentration. At the structural seam 5, the length of the casing is 5~8m and the wall thickness is 12mm to improve the adaptability of the drainage pipe 1 to temperature changes and reduce the risk of structural damage to the drainage pipe 1, thereby ensuring the stable operation of the drainage corridor and the safe transportation of water resources; when setting the structural seam 5, it is preferred to set the structural seam 5 at the center of the casing 2 to better disperse the stress.

[0048] Step S5: Perform finite element analysis on the drainage corridor structure to optimize the drainage corridor structure.

[0049] To facilitate finite element analysis, solid units were used for modeling in the Ansys Workbench DM interface. To simplify the pipeline model, the first sealing layer, the second sealing layer, the third sealing layer and the fourth sealing layer were uniformly represented as asphalt cushion layers. The established model is shown in the figure below. Figure 4 During the finite element analysis, the material parameters defined are shown in Table 1: Table 1 Material parameters name Tensile strength / MPa Shear modulus / GPa Poisson's ratio <![CDATA[Coefficient of linear expansion / 10 -6 *K -1 > Yield strength / MPa Young's modulus / Gpa Steel 375 76.9 0.3 12 235 200 Polyethylene closed cell foam board / 0.39 0.42 / / 1.1 Concrete 2.01 12.71 0.18 10 / 30 When setting the boundary conditions, in order to simplify the meshing process, the anisotropic hexahedral meshing method is used. The specific boundary conditions are set as follows: the outer diameter of the pipe D O 1200mm, wall thickness D t 12mm, pipe length L is 5m, asphalt cushion thickness t is 10mm (when it is a concrete pipe, D O, D t Respectively represent the outer diameter and thickness of the concrete pipe; when it is a sleeve pipe, D O , D t Respectively represent the outer diameter and thickness of the drainage pipe. The thickness of the casing is consistent with the thickness of the drainage pipe. The inner diameter of the casing is the sum of the outer diameter of the drainage pipe and the thickness of the asphalt cushion layer); when applying the load, a gravity load is applied to the overall pipeline model to simulate the deadweight of the soil and the pipeline. A displacement load is applied to the bottom of one end of the pipeline model to simulate the underground settlement effect. The side of the other end of the pipeline model is used as a fixed constraint to stabilize the foundation. By setting the aforementioned boundary conditions, the mechanical behavior and structural response of underground pipelines in complex geological environments can be more realistically simulated, providing reliable theoretical support for the design and construction of underground structures.

[0050] In the pipeline model, one end of the pipeline model is used to simulate the underground settlement effect, and the simulation condition of the other end as the fixed end is a rigid constraint or a displacement-restricted boundary. Under this working condition, gravity, as the main continuous external force, will have a significant impact on the mechanical properties of the structure: gravity not only causes the structure to sink vertically and increases the tensile stress, but also causes stress concentration in weak areas of the structure (such as settlement joints and pipeline connections). These weak areas are prone to become key areas of stress concentration due to differences in material strength, geometric properties and construction quality, and become potential damage risks.

[0051] In order to evaluate the influence of gravity on the drainage corridor structure, especially the stress distribution at the settlement joints and pipe connections, a vertical displacement load was introduced to simulate the deformation and stress response caused by ground settlement or external loads. The initial amplitude of the vertical displacement load was set to 50 mm, and then 10-50 mm was used to analyze the stress conditions at the pipe connections under different load conditions. By extracting stress data, analyzing the stress changes at the settlement joints and pipe connections, and drawing stress intensity cloud maps and distribution curves, the stress change laws at the settlement joints and pipe connections can be clarified, providing reliable data support for optimizing the drainage corridor structure.

[0052] Finite element analysis is performed on the concrete drainage gallery and the sleeve-type drainage gallery of the present invention respectively below to illustrate the advantages of the sleeve-type drainage gallery.

[0053] After establishing the finite element model of the concrete drainage corridor in the same manner as step S5, the same boundary conditions are set for the concrete drainage corridor and the casing drainage corridor, and the same load is applied, to obtain the stress cloud map and strain cloud map of the settlement joint of the concrete drainage corridor (such as Figure 5 , Figure 7 As shown in the figure), stress cloud diagram and strain cloud diagram of the settlement joint of the casing drainage gallery (as shown in the figure), Figure 6 , Figure 8As shown in the figure), stress curve and strain curve at the settlement joint of concrete drainage gallery and casing drainage gallery (as shown in the figure Fig. 9 , Fig.10 as shown).

[0054] From the stress curve and strain curve, it can be seen that the stress and strain in the upper area of ​​the pipeline centerline are lower than those in the lower area, indicating that there are significant differences in the mechanical response of displacement loads at different positions of the pipeline. Under the same displacement load, the stress and strain of the sleeve drainage gallery at the same position are smaller than those of the concrete drainage gallery, showing better anti-deformation performance. In the 0-1400 mm height range of the path channel, the stress difference between the two drainage galleries is about 10 MPa, indicating that the mechanical properties of the two materials in this section are relatively close; with the increase of height, in the range of 2600-4000 mm, the stress difference gradually decreases from large to small, and the maximum difference is close to 30 MPa, reflecting that in this middle height section, the mechanical response difference between the two drainage galleries is most obvious; near the bottom, the stress of both galleries reaches the maximum value, the stress of the concrete drainage gallery is 124.1 MPa, and the stress of the sleeve drainage gallery is 118.5 MPa, and the stress difference between the two is reduced to 6 MPa. It can be seen that under the action of displacement load, although there are differences in stress distribution between concrete drainage gallery and sleeve drainage gallery, the stress in the bottom area tends to be consistent. In the upper part of the pipe of the sleeve drainage gallery, there is a steep drop in stress. This phenomenon is mainly caused by the discontinuity of the material. In this area, the material transitions from polyethylene closed-cell foam board to steel structure, resulting in a drastic change in material properties, which leads to uneven stress distribution. This structural transition causes the transfer of stress concentration areas and causes a rapid drop in local stress.

[0055] The variation trend of strain with displacement is similar to that of stress. By comparing and analyzing the strain performance of the casing drainage gallery and the concrete drainage gallery under the same displacement load, it is found that the maximum strain values ​​of the two are slightly different. Specifically, the maximum strain of the casing drainage gallery is 0.108 mm, while the maximum strain of the concrete drainage gallery is 0.113 mm.

[0056] Modify the displacement load of the boundary condition to a uniform increase of 10-50mm (e.g., 10mm each time), and obtain a curve of the stress at the top of the steel pipe versus the vertical displacement load (e.g., Fig.12 ) and the curve of the stress at the center of the casing changing with the vertical displacement load (as shown in Fig.13 As shown in the figure), when the vertical displacement load is 50 mm, the non-settlement section (the path of the center line of the steel pipe from the settlement section to the non-settlement section is as shown in the figure) Fig.11The maximum stress value in the settlement section is 248.12MPa, the maximum stress value in the settlement section is 234.64MPa, and the minimum stress value in the center (structural joint) is 8.8MPa; the overall stress distribution trend shows that in the 0-300mm section, there is asphalt cushion contact between the steel pipe and the casing, and the stress rises slowly under the load; when transitioning to the 300-800mm section, there is a gap between the steel pipe and the casing, and the steel pipe is not in direct contact with the casing. In this area, the steel pipe only bears axial force, and the stress concentration phenomenon in other directions is reduced, leading to The stress value is relatively low; in the 800-1000mm section, the stress value begins to drop sharply. The steel pipe may be affected by the bending effect in this area, and the stress concentration of the steel pipe in the non-axial direction is released, further leading to a steep drop in the stress value; when the displacement load is less than 30mm, the stress difference between the settlement section and the non-settlement section is small. When the displacement load reaches 30mm or above, the mean stress of the settlement section begins to be lower than that of the non-settlement section, but the maximum stress of the settlement section is still higher than that of the non-settlement section, showing a significant stress concentration phenomenon in the settlement area under high displacement load.

[0057] refer to Fig.13 , under each displacement load, the stress difference in the settlement section is not large. However, in the 400-600mm range, there is a small stress drop, followed by a sharp rise and drop again. This phenomenon is due to the gap between the casing and the steel pipe, which causes the steel pipe to not completely contact the casing in this section, reducing stress concentration. In the 600-1000mm range, the stress experienced a slow rise and a sharp drop. This change is due to the slight tilt of the steel pipe under the action of the settlement load, and the non-settlement section becomes the main stress area. When the tilt reaches a certain degree, due to the lack of external force compensation, the stress of the structure begins to release, resulting in a decrease in the stress value. This stress change characteristic explains the difference in stress mode between the settlement section and the non-settlement section, and provides a basis for optimal design.

[0058] The stress intensity of the settlement joint and the center area of ​​the steel pipe was evaluated. The results showed that the stress-strain amplitude of the casing concrete drainage corridor at the settlement joint was not much different from that of the concrete drainage corridor, and was even slightly lower by 10%. This shows that the use of steel pipes instead of concrete drainage corridors has a certain effect on enhancing the durability of settlement joints, and the use of casing also has the advantage of anti-seepage; the stress in the center of the casing is higher, indicating that this area is under a large load. However, due to the existence of the casing, it not only provides the necessary structural support, but also effectively compensates for settlement; the casing forms a gap during the load transfer process, which helps to disperse stress and alleviate local stress concentration, thereby making up for the shortcomings of the steel pipe structure; the setting of this gap effectively reduces the deformation of the steel pipe in the high stress area. At the same time, the casing allows the pipeline to make a small displacement during the settlement process, thereby preventing rigid damage caused by local settlement; the casing not only improves the mechanical properties of the steel pipe in the stress concentration area, but also improves the stability and anti-settlement ability of the overall structure.

[0059] The above is only a detailed description of the specific implementation of the present invention, rather than a limitation of the present invention. Various substitutions, modifications and improvements made by those skilled in the relevant art without departing from the principle and scope of the present invention should be included in the protection scope of the present invention.

Claims

1. A drainage gallery optimization design method for a power plant in a shipping engineering project, characterized in that: The following steps are involved: Step S1, determining the material of the drainage pipe in combination with the main structure, geological conditions, hydrological conditions and construction efficiency of the drainage corridor setting area; Step S2, analyzing the damage risk faced by the drainage pipe buried in the main structure; Step S3, designing a compensation mechanism based on the material properties of the drainage pipe and the damage risk faced by the drainage pipe; Step S4, designing the drainage corridor structure in combination with the compensation mechanism; Step S5: Perform finite element analysis on the drainage corridor structure to optimize the drainage corridor structure.

2. The drainage corridor optimization design method according to claim 1, characterized in that: In step S2, the main structure is a large-volume concrete structure; the damage risks faced by the drainage pipe include: when the drainage pipe passes through the structural joint, the structural joint cracks or shrinks due to thermal expansion and contraction or geological effects, causing the drainage pipe to bear local deformation stress, threatening the structural integrity and functionality of the drainage pipe; and the structural joints at the junction of the main structure open or shrink to varying degrees, causing the drainage pipe to undergo radial misalignment and deformation, affecting the continuity and stability of the drainage pipe, causing fatigue damage or even breakage of the drainage pipe.

3. The drainage corridor optimization design method according to claim 1, characterized in that: In step S3, the design compensation mechanism includes: considering the expansion compensation mechanism to ensure the safety and stability of the drainage corridor structure; considering the settlement compensation mechanism to reduce and adapt to the foundation settlement.

4. The drainage corridor optimization design method according to claim 1, characterized in that: In the step S5, when performing finite element analysis on the drainage corridor structure, a pipeline model is established in the Ansys Workbench DM interface using solid units; when setting boundary conditions, an anisotropic hexahedral meshing method is used to divide the mesh, and the set boundary conditions include the size of the pipeline model and the type of applied load; The pipeline model dimensions include: pipeline outer diameter D O 、Wall thickness D t and the length of the pipe section, L; The applied load types include: applying a gravity load to the overall pipeline model to simulate the deadweight of the soil and the pipeline, applying a displacement load to the bottom of one end of the pipeline model to simulate the underground settlement effect, and using the side of the other end of the pipeline model as a fixed constraint to stabilize the foundation.

5. The drainage corridor optimization design method according to claim 4, characterized in that: In step S5, in order to evaluate the influence of gravity on the drainage gallery structure, the stress distribution at the settlement joints and the pipe connections is obtained, the initial amplitude of the displacement load is set to 50 mm, and then the displacement load is modified to a uniform increase of 10-50 mm to analyze the stress conditions at the pipe connections under different load conditions.

6. The drainage corridor optimization design method according to claim 5, characterized in that: In step S5, when optimizing the drainage corridor structure, stress data is extracted, stress changes at settlement joints and pipe connections are analyzed, stress intensity cloud maps and distribution curves are drawn, and stress change patterns at settlement joints and pipe connections are obtained, providing data support for optimizing the drainage corridor structure.

7. The drainage corridor optimization design method according to claim 4, characterized in that: In step S4, the drainage gallery structure includes: a drainage pipe and a compensator, the compensator includes a casing and an elastic sealing structure, one end of the drainage pipe is connected to the maintenance water collection well, and the other end is connected to the infiltration water collection well, the casing is sleeved on the drainage pipe, and the casing is sealed by the elastic sealing structure, the drainage pipe and the casing are both covered in the main structure, the main structure is provided with a structural seam, the drainage pipe passes through the structural seam, and the casing is arranged at the position of the structural seam and crosses the structural seam.

8. The drainage corridor optimization design method according to claim 7, characterized in that: The elastic sealing structure includes a first sealing layer, a second sealing layer and a third sealing layer. The first sealing layer is laid on the outer wall of the drain pipe to wrap the drain pipe. The first sealing layer partially extends into the casing and partially is located outside the casing. The second sealing layer is coated on the surface of the first sealing layer. The third sealing layer is coated on the surface of the first sealing layer. The third sealing layer adheres to the second sealing layer and is arranged close to the pipe mouth of the casing.

9. The drainage corridor optimization design method according to claim 8, characterized in that: A fourth sealing layer is also provided on the surface of the drain pipe. The fourth sealing layer covers the surface of the third sealing layer. The fourth sealing layer extends from the pipe opening of the sleeve toward a direction away from the pipe opening of the sleeve.

10. The drainage corridor optimization design method according to claim 9, characterized in that: In the step S5, when establishing the pipeline model, the first sealing layer, the second sealing layer, the third sealing layer and the fourth sealing layer are uniformly represented as an asphalt cushion layer, and the size of the pipeline model also includes the thickness t of the asphalt cushion layer.

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