Drainage gallery structure of power plant building and construction method

Abstract

The application discloses a kind of power plant drainage gallery structure and construction method, can improve the construction quality and construction efficiency of drainage gallery, avoid the uneven settlement of foundation to cause the leakage of drainage gallery at structure joint, ensure the normal operation of power plant;The drainage gallery structure includes drainage pipe and compensator covered in main structure, compensator includes sleeve and elastic sealing structure, drainage pipe is connected with maintenance sump and infiltration sump, sleeve is sleeved on drainage pipe, is sealed by elastic sealing structure, structure joint is provided on main structure, sleeve is arranged at structure joint position and straddles structure joint;The construction method includes designing drainage gallery structure, carrying out finite element analysis to the drainage gallery at structure joint, setting drainage pipe at the preset construction position of drainage gallery, setting sleeve on drainage pipe corresponding to structure joint, repeating construction drainage pipe and sleeve, and pouring concrete to form main structure, so that main structure covers drainage pipe and sleeve and the like steps.

Description

TECHNICAL FIELD

[0001] The present application relates to the field of shipping hub engineering, and in particular to a drainage gallery structure of a power plant and a construction method thereof. BACKGROUND

[0002] In a shipping hub, a dam has the functions of improving shipping conditions, flood control, regulating water flow, water storage and power generation, etc. The drainage gallery of the dam power plant is mainly used to remove excess water caused by various factors (such as rainfall, seepage, etc.) inside and outside the dam and the power plant, so as to ensure the stability of the hydraulic structure, prevent safety hazards and support the operation of the power plant. The drainage gallery of the power plant usually adopts a concrete gallery, which is in the form of a culvert. During construction and operation, the following problems usually exist:

[0003] During construction, it is usually necessary to set up supports, set up forms, pour concrete and maintain. The setting up and removal of a large number of forms are complicated, and the amount of wet work on site is high. The construction efficiency is low, and the engineering quality is difficult to guarantee.

[0004] During operation, due to the limitations of design and construction requirements, the foundation needs to be provided with a structural joint. The structural joint has inherent settlement and expansion deformation characteristics. The foundation may not be uniformly settled due to geological conditions or large weight difference of adjacent blocks, which affects the service life of the concrete gallery, and also affects the water stop equipment, causing cracks in the water stop part, causing structural joint leakage, and affecting the normal operation of the power plant. SUMMARY

[0005] One of the purposes of the present application is at least to provide a drainage gallery structure of a power plant and a construction method thereof, which can improve the construction quality and efficiency of the drainage gallery, avoid the leakage of the drainage gallery at the structural joint caused by uneven settlement of the foundation, and ensure the normal operation of the power plant.

[0006] In order to achieve the above purpose, the technical solution adopted by the present application includes the following aspects.

[0007] A drainage gallery structure of a power plant, comprising: a drainage pipe and a compensator, the compensator comprising a sleeve and an elastic sealing structure, one end of the drainage pipe being communicated with a maintenance sump and the other end being communicated with a seepage sump, the sleeve being sleeved on the drainage pipe and being sealed by the elastic sealing structure, the drainage pipe and the sleeve being covered in a main body structure, the main body structure being provided with a structural joint, the drainage pipe penetrating the structural joint, and the sleeve being arranged at the position of the structural joint and spanning the structural joint.

[0008] Preferably, the elastic sealing structure comprises a first sealing layer, a second sealing layer and a third sealing layer, the first sealing layer is applied on the outer wall of the drain pipe to wrap the drain pipe, the first sealing layer partially extends into the sleeve and partially locates outside the sleeve; the second sealing layer is coated on the surface of the first sealing layer, and the third sealing layer is coated on the surface of the first sealing layer, and the third sealing layer is attached to the second sealing layer and located close to the pipe opening of the sleeve.

[0009] Preferably, the surface of the drain pipe is further coated with a fourth sealing layer, the fourth sealing layer covers the surface of the third sealing layer, and the fourth sealing layer extends away from the pipe opening of the sleeve.

[0010] Preferably, the first sealing layer is made of asphalt and oil felt, the second sealing layer is made of hemp rope, the third sealing layer is made of asphalt hemp sheet, and the fourth sealing layer is made of asphalt.

[0011] Preferably, the drain pipe is made of a steel pipe, and the sleeve is also made of a steel pipe; the outer wall of the steel pipe is coated with one or more layers of anti-rust paint, and the outer wall of the drain pipe is further coated with oil-resistant paint, which is coated on the surface of the anti-rust paint.

[0012] The application also provides a construction method of a drainage gallery structure of a power plant building, comprising the following steps:

[0013] Step S1, designing a drainage gallery structure of a power plant building, wherein the drainage gallery structure is the drainage gallery structure described above;

[0014] Step S2, establishing a drainage gallery model at a structural joint in finite element software, performing finite element analysis on the drainage gallery at the structural joint, and ensuring that the drainage gallery structure meets the construction requirements;

[0015] Step S3, setting a drain pipe at a predetermined construction position of the drainage gallery;

[0016] Step S4, setting a sleeve on the drain pipe at a position corresponding to a predetermined structural joint;

[0017] Step S5, repeating steps S3 and S4 to connect the drain pipe to the maintenance sump and the infiltration sump;

[0018] Step S6, pouring concrete to form a main structure, so that the main structure wraps the drain pipe and the sleeve to form a drainage gallery.

[0019] Preferably, in step S1, the process of designing a drainage gallery structure of a power plant building comprises:

[0020] Determine the material of the drain pipe in combination with the main structure, geological conditions, hydrological conditions and construction efficiency of the drainage gallery setting area;

[0021] According to the strictness and logic of engineering practice, the damage risk of the drainage pipe buried in the main structure is analyzed;

[0022] Combined with the material properties of the drainage pipe and the damage risk of the drainage pipe, a compensation mechanism is designed;

[0023] Combined with the compensation mechanism, the drainage gallery structure is designed.

[0024] Preferably, when the drainage gallery at the structural joint is analyzed by finite element analysis, a pipe model is established by using a solid element in the Ansys Workbench DM interface; when the boundary conditions are set, an anisotropic hexahedral mesh division method is used to divide the mesh, and the set boundary conditions include the pipe model size and the load type;

[0025] The pipe model size includes the pipe outer diameter D O , wall thickness D t and pipe segment length L;

[0026] The load type includes applying a gravity load to the overall pipe model to simulate the soil and the self-weight of the pipe, applying a displacement load to the bottom of one end of the pipe model to simulate the underground settlement effect, and taking the side of the other end of the pipe model as a fixed constraint to stabilize the foundation.

[0027] Preferably, in step S4, when the drainage pipe is connected to the structural joint position, an elastic sealing structure is arranged at the connection position of the drainage pipe and the sleeve, the sleeve and the drainage pipe are connected through the elastic sealing structure, and after the connection, heated asphalt is laid on the elastic sealing structures at both ends of the sleeve to form a fourth sealing layer, the fourth sealing layer is arranged on the surface of the drainage pipe, extends away from the pipe opening of the sleeve, and the laying length of the fourth sealing layer is 2-3 m.

[0028] Preferably, on the drainage pipe, the elastic sealing structure is symmetrically arranged relative to the structural joint, when the elastic sealing structure is arranged, heated asphalt is laid on the surface of the drainage pipe at the preset connection position of the drainage pipe and the sleeve, the asphalt is wrapped around the drainage pipe, and then one or more layers of linoleum are pasted on the surface of the asphalt to completely wrap the asphalt to form a first sealing layer; after the first sealing layer is arranged, a jute rope is embedded on the surface of the first sealing layer, the jute rope forms a cross or net structure on the surface of the first sealing layer, thereby forming a second sealing layer; then, asphalt mat is wrapped on the surface of the first sealing layer to form a third sealing layer, the asphalt mat is arranged on the end surface of the second sealing layer and is arranged towards the direction of the pipe opening of the sleeve, and the wrapping thickness of the asphalt mat is the same as the thickness of the second sealing layer.

[0029] As described above, by using the technical solutions described above, the present application has at least the following beneficial effects:

[0030] The drainage gallery structure of the present application can compensate the settlement and shrinkage of the drainage pipe by setting the sleeve at the position where the drainage pipe crosses the settlement joint, significantly alleviates the stress and strain of the drainage pipe caused by the load concentration and the expansion and contraction caused by the external environment, makes up the potential defects in the drainage gallery structure, effectively avoids the leakage of the drainage pipe at the structure joint, and has the double protection effect of the drainage pipe and the sleeve, that is, even if the drainage pipe is locally failed or in special working conditions, the concrete channel in the main structure can still maintain the function of the drainage gallery, ensures the stable operation of the drainage gallery, and avoids the larger range of damage caused by local problems.

[0031] The steel pipe is used as the drainage pipe, which can be quickly connected on the construction site, and compared with the traditional concrete drainage gallery construction, the construction method of the present application not only reduces the amount of wet work on site, avoids the complicated procedures such as formwork erection, concrete pouring and curing in the traditional concrete construction, but also significantly improves the construction efficiency and engineering quality, and reduces the construction and maintenance cost; before the drainage pipe is installed, the finite element analysis is performed on the drainage gallery structure, so that the drainage gallery structure can be optimized according to the specific construction condition, and the drainage gallery structure can meet the construction requirements. BRIEF DESCRIPTION OF DRAWINGS

[0032] Figure 1 is the longitudinal section view of the drainage gallery structure of the power plant room of the exemplary embodiment of the present application.

[0033] Figure 2 is the transverse section view of the drainage gallery structure of the power plant room of the exemplary embodiment of the present application.

[0034] Figure 3 is the construction method flowchart of the drainage gallery structure of the power plant room of the exemplary embodiment of the present application.

[0035] Figure 4 is the oblique section view of the finite element pipe model of the exemplary embodiment of the present application.

[0036] Figure 5 is the stress nephogram of the settlement joint of the concrete drainage gallery.

[0037] Figure 6 is the stress nephogram of the settlement joint of the sleeve type drainage gallery.

[0038] Figure 7 is the strain nephogram of the settlement joint of the concrete drainage gallery.

[0039] Figure 8 is the strain nephogram of the settlement joint of the sleeve type drainage gallery.

[0040] Figure 9 is the stress curve diagram of the settlement joint of the concrete drainage gallery and the sleeve type drainage gallery.

[0041] Figure 10 is a settlement joint strain curve diagram of a concrete drainage gallery and a casing drainage gallery.

[0042] Figure 11 is a stress cloud diagram at the center of the casing.

[0043] Figure 12 is a stress curve diagram at the center of the steel pipe under different vertical displacement loads.

[0044] Figure 13 is a stress curve diagram at the center of the casing under different vertical displacement loads.

[0045] Identified 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

[0046] The present application will be further described below in conjunction with the drawings and examples, so that the purpose, technical scheme and advantages of the present application are more clear and explicit. It should be understood that the specific examples described herein are only used to explain the present application, and are not used to limit the present application.

[0047] Reference Figure 1 , Figure 2 The drainage gallery of the power plant house of the exemplary embodiment of the present application comprises a drainage pipe 1 and a compensator, one end of the drainage pipe 1 is communicated with a maintenance sump, the other end is communicated with a permeation sump, the compensator comprises a casing 2 and an elastic sealing structure 3, the casing 2 is sleeved on the drainage pipe 1, the casing 2 is blocked by the elastic sealing structure 3, the drainage pipe 1 and the casing 2 are both coated in a main structure 4, the main structure 4 is provided with a structural joint 5, the drainage pipe 1 penetrates through the structural joint 5, and the casing 2 is arranged at the position of the structural joint 5 and spans the structural joint 5.

[0048] By arranging the casing 2 on the drainage pipe 1 and making the casing 2 span the structural joint 5, in the process of gap settlement of the structural joint 5, the deformation of the drainage pipe 1 due to geological settlement can be prevented, the leakage of the drainage pipe 1 at the structural joint 5 can be avoided, and the structural safety and operation stability of the drainage gallery of the power plant are improved.

[0049] There is a certain gap (8-12 mm) between the inner wall of the casing 2 and the outer wall of the drainage pipe 1, in the process of foundation settlement, the gap between the inner wall of the casing 2 and the outer wall of the drainage pipe 1 can absorb the cracks generated by the foundation settlement, reduce the risk of structural joint permeation, the casing 2 can also optimize the interaction between the drainage pipe 1 and the surrounding medium, improve the adaptability of the drainage pipe 1 to external environmental changes (such as soil movement, temperature change caused concrete shrinkage or expansion, etc.), under the action of the casing 2, axial, lateral and angular displacement caused by factors such as thermal expansion and cold contraction, foundation settlement, etc. can be absorbed.

[0050] The elastic sealing structure 3 comprises a first sealing layer 31, a second sealing layer 32 and a third sealing layer 33. The first sealing layer 31 is applied on the outer wall of the drainage pipe 1 to wrap the drainage pipe 1, and partially extends into the sleeve pipe 2 and partially locates outside the sleeve pipe 2. The second sealing layer 32 is coated on the surface of the first sealing layer 31 to seal the two ends of the sleeve pipe 2. The third sealing layer 33 is coated on the surface of the first sealing layer 31, and is close to the pipe opening of the sleeve pipe 2. During the process of foundation settlement, the elastic sealing structure 3 can make the sleeve pipe 2 axially move a certain distance relative to the drainage pipe 1, reduce the influence of the foundation dislocation on both sides of the structural joint 5 on the drainage pipe, and absorb the axial deformation of the drainage pipe 1.

[0051] During the setting process of the sleeve pipe 2, a fourth sealing layer 34 can also be arranged on the surface of the drainage pipe 1. The fourth sealing layer 34 is coated on the surface of the third sealing layer 33, and extends away from the pipe opening of the sleeve pipe 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 firm sealing structure.

[0052] The first sealing layer 31 is preferably made of asphalt and oil felt. The second sealing layer 32 is preferably made of brown rope. The third sealing layer 33 is preferably made of asphalt and hemp sheet. The fourth sealing layer 34 is preferably made of asphalt. The laying length of the fourth sealing layer 34 is 2-3 m, 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 at the position close to the pipe opening of the sleeve pipe 2 is thicker than that at other positions, so as to ensure the sealing performance of the connection part between the sleeve pipe 2 and the drainage pipe 1.

[0053] The drainage pipe 1 and the sleeve pipe 2 are preferably made of steel pipes. The steel pipes can be efficiently assembled and connected on the construction site, significantly reducing the amount of wet work on site. Compared with the construction of a concrete gallery, the complex steps of formwork erection and removal are avoided, and the construction efficiency and engineering quality are significantly improved. In addition, the steel pipe material has excellent impermeability, durability and high bearing capacity, which can 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 gallery. In the application process, the drainage pipe 1 can also be made of other materials with similar or better performance than the steel pipe. One or more layers of anti-rust paint are coated on the outer walls of the drainage pipe 1 and the sleeve pipe 2. An oil-resistant paint is also coated on the outer walls of the drainage pipe 1 and the sleeve pipe 2. The oil-resistant paint is coated on the surface of the anti-rust paint to improve the anti-corrosion and high-temperature performance of the drainage pipe 1 and the sleeve pipe 2, and ensure the reliability of the drainage gallery.

[0054] A structural joint 5 is arranged on the main structure 4 around the drain pipe 1 every 20-25 m along the length direction of the drain pipe 1, and the structural joint 5 on the main structure 4 and the structural joint on the foundation are arranged correspondingly when the drain pipe 1 is arranged on the foundation, so as to prevent the settlement and shrinkage of the main structure 4 on the drain pipe 1 during the water storage operation. The structural joint 5 has a width of 20-25 mm, and is filled with a polyethylene closed-cell foam board, so as to prevent water or other media from penetrating into the structural joint 5, to make the drain gallery better adapt to the deformation of the surrounding rock, and to prevent the stress concentration phenomenon. At the structural joint 5, the length of the sleeve pipe is 5-8 m, and the wall thickness is 12 mm, so as to improve the adaptability of the drain pipe 1 to the temperature change, reduce the risk of structural damage of the drain pipe 1, and thus ensure the stable operation of the drain gallery and the safe transportation of water resources; when the structural joint 5 is arranged, the structural joint 5 is preferably arranged at the center of the sleeve pipe 2 to better disperse the stress.

[0055] Reference Figure 3 The construction method of the drain gallery structure of the power plant room of the exemplary embodiment of the present application includes the following steps:

[0056] Step S1, designing the drain gallery structure of the power plant room. The process of designing the drain gallery structure of the power plant room specifically includes:

[0057] The material of the drain pipe is determined in combination with the main structure of the drain gallery setting area, the geological conditions, the hydrological conditions, and the construction efficiency, etc.

[0058] According to the rigor and logic of engineering practice, the damage risk of the drain pipe buried in the main structure is analyzed; the main structure of the drain gallery is usually a mass concrete structure, and in the process of constructing the main structure on the surface of the drain pipe, in order to avoid the cracks or crushing phenomenon of the concrete of the main structure in the hardening process due to volume shrinkage or environmental temperature change, a structural joint is usually arranged to control the cracks and maintain the integrity of the main structure. When the structural joint passes through the buried drain pipe, under the effects of thermal expansion and contraction or geology, the structural joint may crack or shrink, causing the drain pipe to bear local deformation stress, threatening the structural integrity and functionality of the drain pipe; the structural joint may also be opened or contracted to different degrees due to factors such as geological conditions, construction errors, or long-term environmental effects, causing the drain pipe to occur radial misplacement deformation, not only affecting the continuity and stability of the drain pipe, but also easily causing fatigue damage or even rupture of the drain pipe.

[0059] The compensation mechanism is designed in combination with the material properties of the drainage pipe and the damage risks faced by the drainage pipe; when the drainage pipe is made of steel pipe, the steel pipe has the characteristics of thermal expansion and cold contraction, and the external environment (such as temperature change) has a significant impact on the drainage pipe, and the expansion and contraction compensation mechanism is considered in the design to effectively guarantee the safety and stability of the drainage gallery structure; when designing the expansion and contraction compensation mechanism, the expansion joint, the flexible connecting piece, and the optimization of the drainage pipe layout can be considered to improve the adaptability of the drainage pipe to temperature changes and reduce the risk of damage to the drainage pipe, thereby ensuring the stable operation of the drainage gallery and the safe transportation of water resources.

[0060] In the operation process of the drainage gallery, due to the influence of geological action, construction factors and long-term load and other factors, the foundation soil gradually compresses, causing the foundation of the drainage gallery to settle, and considering the settlement compensation mechanism in the design can reduce and adapt to the foundation settlement, ensuring the safety and functionality of the drainage gallery in the use process are not affected; when designing the settlement compensation mechanism, settlement joints (one of the structure joints) are set at key positions of the drainage gallery (such as the junction of different geological conditions or structure conversion positions) or at certain intervals, allowing the drainage gallery structure to relatively displace when settling to prevent stress concentration; when setting the settlement joint, ensure that the settlement joint is well sealed to prevent water or other media from entering the settlement joint.

[0061] In combination with the compensation mechanism, the drainage gallery structure is designed; the designed drainage gallery structure adopts the drainage gallery structure of the power plant building as described above.

[0062] Step S2, a drainage gallery model at the structure joint is established in the finite element software, and finite element analysis is performed on the drainage gallery at the structure joint to ensure that the drainage gallery structure meets the construction requirements.

[0063] For the convenience of finite element analysis, entity elements are used for modeling in the Ansys Workbench DM interface, and the first sealing layer, the second sealing layer, the third sealing layer and the fourth sealing layer are uniformly represented as asphalt cushion layer to simplify the pipeline model, and the established model is as shown in Figure 4 The defined material parameters in the finite element analysis process are shown in Table 1:

[0064] Table 1 Material parameter table

[0065] Name Tensile strength / MPa Shear modulus / GPa Poisson's ratio Linear expansion coefficient / 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

[0066] When setting the boundary conditions, for the convenience of meshing, an anisotropic hexahedral meshing method is used, and the specific boundary condition setting is: the outer diameter D O of the pipeline is 1200mm, the wall thickness D t is 12mm, the length L of the pipe section is 5m, and the thickness t of the asphalt cushion layer is 10mm (when it is a concrete pipeline, D O , D tD, D respectively represent the outer diameter and thickness of the concrete pipe; when it is a casing pipe, D O , D t respectively represent the outer diameter and thickness of the drainage pipe, the thickness of the casing pipe is consistent with the thickness of the drainage pipe, and the inner diameter of the casing pipe is the sum of the outer diameter of the drainage pipe and the thickness of the asphalt cushion); when the load is applied, a gravity load is applied to the overall pipe model to simulate the soil and the self-weight of the pipe, a displacement load is applied to the bottom of one end of the pipe model to simulate the underground settlement effect, and the side surface of the other end of the pipe model is fixed as a constraint to stabilize the foundation; through the setting of the foregoing boundary conditions, the mechanical behavior and structural response of the underground pipe in the complex geological environment can be more truly simulated, and reliable theoretical support can be provided for the design and construction of the underground structure.

[0067] In the pipe model, one end of the pipe model is used to simulate the underground settlement effect, and the simulation condition of the other end as a fixed end is a rigid constraint or a displacement limited boundary. In this working condition, gravity as the main continuous external force has a significant influence on the mechanical properties of the structure: gravity not only causes the sinking trend of the structure in the vertical direction, increases the tensile stress, but also causes stress concentration in the weak areas in the structure (such as the settlement joint and the pipe connection). Due to the differences in material strength, geometric characteristics and construction quality, these weak areas are prone to become the key areas of stress concentration and become potential damage risks.

[0068] To evaluate the influence of gravity on the structure of the drainage gallery, especially the stress distribution at the settlement joint and the pipe connection, a vertical displacement load is introduced to simulate the deformation and stress response caused by ground settlement or external load. The initial amplitude of the vertical displacement load is set to 50 mm, and then 10-50 mm is used to analyze the stress conditions of the pipe connection under different load working conditions. By extracting stress data, the stress changes at the settlement joint and the pipe connection are analyzed, and stress intensity nephograms and distribution curve graphs are drawn, so that the stress change law of the settlement joint and the pipe connection can be determined, and reliable data support can be provided for optimizing the structure of the drainage gallery.

[0069] The concrete drainage gallery and the casing pipe drainage gallery of the present application are analyzed by finite element analysis respectively, and the advantages of the casing pipe drainage gallery are illustrated.

[0070] After establishing the finite element model of the concrete drainage gallery in the same way as step S5, the same boundary conditions and loads are set for the concrete drainage gallery and the casing pipe drainage gallery, and the stress nephograms and strain nephograms of the settlement joint of the concrete drainage gallery (as shown in Figure 5 , Figure 7 ), the stress nephograms and strain nephograms of the settlement joint of the casing pipe drainage gallery (as shown in Figure 6 , Figure 8 ), and the stress curve graphs and strain curve graphs of the settlement joint of the concrete drainage gallery and the casing pipe drainage gallery (as shown in Figure 9 ,Figure 10

[0071] From the stress and strain curves, it can be seen that the stress and strain in the upper region of the pipeline centerline are lower than those in the lower region, indicating that there is a significant difference in the mechanical response of the force acting on different positions of the pipeline under the same displacement load. Under the same displacement load, the stress and strain of the casing 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 types of 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, the stress difference gradually decreases in the 2600-4000 mm interval, with a maximum difference of about 30 MPa, reflecting that the mechanical response difference between the two types of drainage galleries is most obvious in this middle height section. Near the bottom, the stress of the two galleries reaches the maximum value, with the stress of the concrete drainage gallery being 124.1 MPa and the stress of the casing drainage gallery being 118.5 MPa, and the stress difference between the two is reduced to 6 MPa. Therefore, under the action of displacement load, although there is a difference in the stress distribution of the concrete drainage gallery and the casing drainage gallery, the stress tends to be consistent in the bottom region. In the upper part of the casing drainage gallery pipeline, there is a sharp drop in stress. This phenomenon is mainly caused by the discontinuity of the material. In this region, the material transitions from polyethylene closed-cell foam board to steel structure, resulting in a dramatic change in material properties, which leads to uneven stress distribution. This structural transition causes the transfer of stress concentration areas and leads to a rapid decrease in local stress.

[0072] The trend of strain change with displacement is similar to that of stress change. 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.

[0073] The displacement load of the boundary condition is modified to 10-50 mm uniformly increasing (such as increasing by 10 mm each time), and the stress curve of the top of the steel pipe with the vertical displacement load change (such as Figure 12 ) and the stress curve of the casing center with the vertical displacement load change (such as Figure 13 ) are obtained. Under the condition of vertical displacement load of 50 mm, the non-settlement section (the path of the centerline of the steel pipe from the settlement section to the non-settlement section is as Figure 11 ​The maximum stress value is 248.12 MPa, the maximum stress value of the settlement section is 234.64 MPa, and the minimum value is at the center (structure joint) 8.8 MPa; the overall stress distribution trend shows that in the 0-300 mm section, there is an asphalt pad contact between the steel pipe and the sleeve, and under the action of load, the stress slowly rises; when it transitions to the 300-800 mm interval, due to the gap between the steel pipe and the sleeve, the steel pipe is not in direct contact with the sleeve, in this area, the steel pipe only bears axial stress, and the stress concentration phenomenon in other directions is reduced, resulting in a relatively low stress value; to the 800-1000 mm section, the stress value starts to drop sharply, the steel pipe in this area may be affected by the bending effect, the stress concentration of the steel pipe in the non-axial direction is released, further causing the stress value to drop sharply; When the displacement load is less than 30 mm, the stress difference between the settlement section and the non-settlement section is small, when the displacement load reaches 30 mm and above, the average stress of the settlement section starts 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 the significant stress concentration phenomenon of the settlement area under high displacement load.

[0074] Reference Figure 13 Under each displacement load, the stress difference of the settlement section is not large, however, in the 400-600 mm interval, a small amplitude stress drop occurs, followed by a sharp rise and then a drop again. This phenomenon is due to the gap between the sleeve and the steel pipe, which causes the steel pipe to not fully contact the sleeve in this section, reducing stress concentration. In the 600-1000 mm interval, it experienced a slow rise and sharp drop in stress. This change is due to the slight tilting of the steel pipe under the settlement load, and the non-settlement section becomes the main stress area. When the tilt reaches a certain degree, the stress of the structure begins to release due to the lack of external force compensation, resulting in a decrease in stress value. This stress change characteristic illustrates the difference in stress mode between the settlement section and the non-settlement section, providing a basis for optimizing the design.

[0075] The stress intensity of the settlement joint and the central region of the steel pipe is evaluated, and the results show that the stress and strain amplitude of the sleeve type concrete drainage gallery at the settlement joint is not much different from that of the concrete drainage gallery, and even slightly lower by 10%. This shows that the use of steel pipes instead of concrete drainage galleries has a certain strengthening effect on the durability of the settlement joint, and the use of the sleeve also has the advantage of preventing permeation; the stress in the center of the sleeve is high, indicating that this area bears a large load, however, due to the presence of the sleeve, not only does it provide the necessary structural support, but it also effectively compensates for the settlement; the sleeve forms a gap during load transfer, helping to disperse stress and alleviate local stress concentration, thus 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 sleeve allows the pipe to undergo small displacement during settlement, thus preventing rigid damage caused by local settlement; the sleeve not only improves the mechanical properties of the steel pipe in the stress concentration area, but also enhances the stability and anti-settlement capacity of the overall structure. Therefore, the drainage gallery structure designed meets the construction requirements.

[0076] Step S3, setting a drainage pipe at the preset construction position of the drainage gallery.

[0077] The drainage gallery can be set on the foundation, or the drainage gallery can be constructed on the main structure after the construction of the main structure, and the specific position is determined according to the design and construction requirements; according to the construction requirements, structural joints (settlement joints) are respectively arranged on the foundation and the main structure, and when the settlement joint is arranged on the foundation, the settlement joint on the foundation is aligned with the settlement joint on the main structure. The drainage pipe is a prefabricated steel pipe, and after the drainage pipe is transported to the preset construction position, the multiple drainage pipes are connected in sequence according to the design line of the drainage gallery, ensuring the sealing of the connection part of adjacent drainage pipes to prevent pipe leakage; before setting the drainage pipe, supports are uniformly arranged at the bottom of the drainage pipe along the direction of the design line of the drainage gallery to avoid contact between the surface of the drainage pipe and the surface of the foundation or the main structure, and the concrete of the main structure can completely cover the drainage pipe during the later pouring of the main structure; when setting the supports, the positions of the supports are adjusted at the design positions of the structural joints to facilitate the construction of the sleeve.

[0078] Step S4, setting a sleeve on the drainage pipe corresponding to the preset structural joint position.

[0079] When the drain pipe is connected to the structural joint position, an elastic sealing structure is arranged at the connection position of the drain pipe and the sleeve, then the sleeve is passed through the drain pipe, and the sleeve is pushed into the elastic sealing structure to block the two ends of the sleeve respectively; during the arrangement, the sleeve can also be arranged on the drain pipe first, and after the elastic sealing structure is arranged on the drain pipe, the sleeve is pushed into the elastic sealing structure to block the two ends of the sleeve respectively; or the sleeve can be passed through the drain pipe, and then an elastic sealing structure is arranged on the drain pipe at one side of the structural joint, after one end of the sleeve is pushed into the elastic sealing structure, the end of the sleeve is separated from the end of the elastic sealing structure by a certain distance, the sleeve spans the structural joint, and then another elastic sealing structure is arranged on the drain pipe at the other side of the structural joint, and the other end of the sleeve is pushed into the corresponding elastic sealing structure, so as to connect the sleeve and the drain pipe.

[0080] On the drain pipe, the elastic sealing structure is symmetrically arranged relative to the structural joint, and when the elastic sealing structure is arranged, heated asphalt is applied on the surface of the drain pipe at the preset connection position of the drain pipe and the sleeve, the asphalt is wrapped on the drain pipe, and then one or more layers of oil felt are pasted on the surface of the asphalt to completely wrap the asphalt to form a first sealing layer, so that the cement slurry can be prevented from penetrating into the first sealing layer during the subsequent construction of the main structure, and the elasticity of the first sealing layer is avoided; after the first sealing layer is arranged, a jute rope is embedded on the surface of the first sealing layer, and the jute rope forms a cross or mesh structure on the surface of the first sealing layer, thereby forming a second sealing layer, and the thickness of the second sealing layer is 8-12 mm (preferably 10 mm); when the jute rope is arranged, the jute rope is arranged on the surface of the first sealing layer in a tight and uniform manner to enhance the strength and toughness of the elastic sealing structure; after the second sealing layer is arranged, asphalt mat is wrapped on the surface of the first sealing layer to form a third sealing layer, the end surface of the asphalt mat is arranged in abutment with the second sealing layer and is arranged in the direction of the sleeve opening, the wrapping thickness of the asphalt mat is the same as the thickness of the second sealing layer, and the third sealing layer can further improve the sealing effect of the sleeve.

[0081] After the sleeve and the drain pipe are connected by the elastic sealing structure, heated asphalt is applied on the elastic sealing structures at both ends of the sleeve to form a fourth sealing layer, and the asphalt is applied on the surface of the drain pipe and extends away from the sleeve opening in the direction away from the sleeve opening, and the length of the asphalt is 2-3 m.

[0082] Step S5, repeat steps S3 and S4 to connect the drain pipe to the inspection and collection well and the infiltration and collection well.

[0083] Step S6, pouring concrete to form the main body structure, so that the main body structure covers the drain pipe and the sleeve to form the drain gallery. During the pouring of the concrete, since the main body structure is a mass concrete structure, the concrete is poured in a layered pouring manner, a structural joint is arranged every 20-25 m along the direction of the drain pipe, and a polyethylene closed-cell foam board is filled in the structural joint to prevent uneven settlement of the foundation from causing damage to the main body structure.

[0084] The above is only a detailed description of the specific embodiments of the present application, not a limitation of the present application. Various substitutions, modifications and improvements made by those skilled in the related art without departing from the principles and scope of the present application shall be included in the protection scope of the present application.

Claims

1. A drainage corridor structure for a power plant building, characterized in that, include: The drain pipe and the compensator, wherein the compensator includes a sleeve and an elastic sealing structure, one end of the drain pipe is connected to a maintenance collection well and the other end is connected to a seepage collection well, the sleeve is sleeved on the drain pipe and sealed by the elastic sealing structure, both the drain pipe and the sleeve are enclosed in the main structure, the main structure is provided with a structural joint, the drain pipe passes through the structural joint, the sleeve is set at the location of the structural joint and spans the structural joint, and there is a gap of 8~12mm between the inner wall of the sleeve and the outer wall of the drain pipe; 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. Part of the first sealing layer extends into the sleeve and part is located outside the sleeve. The second sealing layer covers the surface of the first sealing layer, and the third sealing layer covers the surface of the first sealing layer. The third sealing layer is attached to the second sealing layer and is located near the pipe opening of the sleeve.

2. The drainage gallery structure according to claim 1, characterized in that, The surface of the drain pipe is also covered with a fourth sealing layer, which covers the surface of the third sealing layer and extends from the pipe opening of the sleeve away from the pipe opening.

3. The drainage gallery structure according to claim 2, characterized in that, The first sealing layer is made of asphalt and tar paper, the second sealing layer is made of hemp rope, the third sealing layer is made of asphalt hemp sheet, and the fourth sealing layer is made of asphalt.

4. The drainage gallery structure according to any one of claims 1 to 3, characterized in that, The drain pipe is made of steel, and the sleeve is made of steel; the outer wall of the steel pipe is coated with one or more layers of anti-rust paint, and the outer wall of the drain pipe is also coated with paint-resistant paint, which is applied on the surface of the anti-rust paint.

5. A construction method for a drainage corridor structure in a power plant, characterized in that, Includes the following steps: Step S1: Design the drainage corridor structure of the power plant building, wherein the drainage corridor structure adopts the drainage corridor structure as described in any one of claims 1 to 4; Step S2: Establish a drainage gallery model at the structural joint in the finite element software, perform finite element analysis on the drainage gallery at the structural joint, and ensure that the drainage gallery structure meets the construction requirements. Step S3: Install drainage pipes at the predetermined construction location of the drainage corridor; Step S4: Install a sleeve on the drainage pipe at the position corresponding to the preset structural joint. Step S5: Repeat steps S3 and S4 to connect the drain pipe to the maintenance collection well and the seepage collection well. Step S6: Pour concrete to form the main structure, and let the main structure cover the drainage pipe and sleeve to form a drainage corridor.

6. The construction method according to claim 5, characterized in that, In step S1, the process of designing the drainage corridor structure of the power plant includes: The material for the drainage pipes is determined by considering the main structure, geological conditions, hydrological conditions, and construction efficiency of the area where the drainage corridor is located. Based on the rigor and logic of engineering practice, the damage risks faced by drainage pipes buried in the main structure are analyzed; Design a compensation mechanism based on the material properties of the drainage pipe and the risk of damage to it; The drainage corridor structure is designed in conjunction with a compensation mechanism.

7. The construction method according to claim 5, characterized in that, In step S2, when performing finite element analysis on the drainage corridor at the structural joint, a pipe model is established using solid elements in the Ansys Workbench DM interface; when setting boundary conditions, an anisotropic hexahedral meshing method is used to divide the mesh, and the set boundary conditions include the pipe model size and the type of applied load. The dimensions of the pipe model include: pipe outer diameter D. O Wall thickness D t and pipe section length L; The types of applied loads include: applying a gravity load to the overall pipeline model to simulate the weight of the soil and the pipeline itself; applying a displacement load to the bottom of one end of the pipeline model to simulate the underground settlement effect; and using the other side of the pipeline model as a fixed constraint to stabilize the foundation.

8. The construction method according to any one of claims 5 to 7, characterized in that, In step S4, when the drain pipe is connected to the structural joint, an elastic sealing structure is set at the connection between the drain pipe and the sleeve. The sleeve and the drain pipe are connected by the elastic sealing structure. After connection, heated asphalt is applied to the elastic sealing structures at both ends of the sleeve to form a fourth sealing layer. The fourth sealing layer is set on the surface of the drain pipe and extends from the opening of the sleeve away from the opening of the sleeve. The length of the fourth sealing layer is 2~3m.

9. The construction method according to claim 8, characterized in that, On the drain pipe, the elastic sealing structure is symmetrically arranged relative to the structural seam. When setting the elastic sealing structure, at the preset connection position between the drain pipe and the sleeve, heated asphalt is applied to the surface of the drain pipe. After the asphalt wraps the drain pipe, one or more layers of asphalt felt are pasted on the surface of the asphalt to completely wrap the asphalt and form a first sealing layer. After the first sealing layer is set, hemp rope is embedded in the surface of the first sealing layer. The hemp rope forms a cross or mesh structure on the surface of the first sealing layer to form a second sealing layer. Then, asphalt hemp sheet is wrapped on the surface of the first sealing layer to form a third sealing layer. The asphalt hemp sheet is set to fit the end face of the second sealing layer and is set towards the direction of the sleeve opening. The wrapping thickness of the asphalt hemp sheet is the same as the thickness of the second sealing layer.

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