Assembly type foundation of power distribution comprehensive building of transformer substation and design method

Abstract

The invention discloses a transformer substation power distribution comprehensive building assembly type foundation and a design method, the assembly type foundation comprises a bottom plate, an upper module and a prefabricated foundation beam, the bottom plate comprises a first prefabricated module and a second prefabricated module which are matched in a mortise and tenon mode, the first prefabricated module and the second prefabricated module define an empty groove, and a connecting node is installed in the empty groove; the connecting node is connected with the first prefabricated module and the second prefabricated module, the upper module is connected with the bottom plate in a tenon-and-mortise fit mode, the upper end face of the bottom plate is connected with a plurality of tensile connecting pieces, a hole channel is formed in the lower side of the upper module, the prefabricated foundation beam is connected with the upper module, and the lower side of the prefabricated foundation beam abuts against the upper side of the bottom plate. The first prefabricated module and the second prefabricated module are connected through the connecting joints to form the bottom plate, and high overall strength and rigidity are achieved; the bottom plate and the upper module are connected in a tenon-and-mortise fit mode, and meanwhile, the tensile connecting pieces are matched with the hole channels, so that the bearing of the fabricated foundation under the tension and bending effects is guaranteed.

Description

Technical Field

[0001] The present invention relates to the technical field of power transmission and transformation engineering, and particularly to a prefabricated foundation and design method for a substation distribution complex building. Background Art

[0002] As one of the most important parts of the structure of a building (structure), the foundation generally adopts cast-in-place reinforced concrete foundation in substation engineering because it needs to meet the requirements of compressive and flexural bearing capacities at the same time. However, the cast-in-place reinforced concrete foundation also has problems such as long construction period, high labor cost, and inability to construct in rainy and winter seasons.

[0003] With the development of prefabrication in substation engineering, there has currently emerged a construction method using prefabricated foundations to replace cast-in-place reinforced concrete foundations. For example, a prefabricated foundation for a substation main transformer equipment and its construction method disclosed in Chinese Patent CN116607558A proposes to form a bottom plate by pouring concrete after overlapping reserved distribution steel bars of four prefabricated bottom plates, and connecting with prefabricated piers using connectors, thereby forming a complete prefabricated foundation for a substation main transformer equipment. However, it has deficiencies such as too long overlapping length of distribution steel bars, poor flexural bearing capacity in the direction perpendicular to the piers, and weak connection between the bottom plate and the piers, and cannot be directly used for building foundations. For example, a mortise and tenon structure prestressed prefabricated foundation structure and its construction method disclosed in Chinese Patent CN115680014A proposes a prefabricated foundation structure in which components such as prefabricated bottom plates and columns are linked by an anchoring mechanism, sleeve grouting, and a mortise and tenon structure. However, it has deficiencies such as difficult control of sleeve grouting accuracy, complex prestress application, and difficult anti-corrosion treatment. Summary of the Invention

[0004] The purpose of the present invention is to overcome the defects and problems of poor stability and complex construction in the existing prefabricated foundation structure, and provide a prefabricated foundation and design method for a substation distribution complex building with relatively high structural stability and simple construction.

[0005] To achieve the above purpose, the technical solution of the present invention is: A prefabricated foundation for a substation distribution complex building includes a bottom plate, an upper module, and a precast foundation beam. The bottom plate includes a first precast module and a second precast module with mortise and tenon cooperation. An empty slot is formed by surrounding the first precast module and the second precast module. A connection node is installed in the empty slot and is respectively connected to the first precast module and the second precast module. The upper module is connected to the first precast module and the second precast module by mortise and tenon cooperation. A plurality of tensile connectors are connected to the upper end surfaces of the first precast module and the second precast module. A plurality of channels matching the tensile connectors are opened on the lower side of the upper module. The precast foundation beam is connected to the upper module and its lower side abuts against the upper side of the first precast module or the second precast module.

[0006] Two first tenons are connected to the rear side of the first precast module. The rear side of the first tenon abuts against the front side of the second precast module. Two second tenons are connected to the front side of the second precast module. One side of each of the two second tenons abuts against the inner side of each of the two first tenons respectively. The front side of the second tenon abuts against the rear side of the first precast module. An empty groove is formed by enclosing the two second tenons, the first precast module, and the second precast module.

[0007] A plurality of shear resistance grooves are formed in the upper sides of the first precast module and the second precast module. The shear resistance grooves are trapezoidal in reverse. A plurality of shear keys that are respectively matched with the shear resistance grooves are connected to the lower side of the upper module.

[0008] The tensile connection member includes a U-shaped embedded part and two embedded bolts. The U-shaped embedded part is connected to the interiors of the first precast module and the second precast module. The two embedded bolts are respectively vertically connected to the ends of the two side walls of the U-shaped embedded part and are located above the first precast module and the second precast module.

[0009] The upper module includes a foundation upper step and a short column. The cross-section of the foundation upper step is rectangular. The foundation upper step is connected to the first precast module and the second precast module by tenon and mortise fit. A plurality of channels that are matched with the plurality of embedded bolts are formed in the lower side of the foundation upper step. The short column is vertically arranged and connected to the upper side of the foundation upper step. A plurality of enlarged channels are formed in the upper end surface of the foundation upper step. The plurality of enlarged channels are in one-to-one correspondence and communication with the plurality of channels. High-strength nuts are arranged in the enlarged channels. The high-strength nuts are threadedly connected to the upper ends of the embedded bolts.

[0010] The precast foundation beam is in a stepped shape. The small end of the precast foundation beam is attached to the upper side of the foundation upper step. A foam rubber board is filled between the small end of the precast foundation beam and the side surface of the short column. The large end of the precast foundation beam is attached to the upper side of the first precast module or the second precast module. A foam rubber board is filled between the large end of the precast foundation beam and the side surface of the foundation upper step. A grouting hole is vertically formed in the small end of the precast foundation beam. Stirrups are connected to the interior of the foundation upper step. The stirrups are U-shaped. The two side walls of the stirrups pass through the upper side of the foundation upper step and are located in the grouting hole. The grouting hole is filled with grouting material.

[0011] The connection node includes a plurality of first steel bars, a plurality of second steel bars, a plurality of horizontal steel bars and concrete. The first steel bars and the second steel bars are both U-shaped. The plurality of first steel bars are arranged at intervals and both ends are connected to the rear side of the first precast module. The plurality of second steel bars are arranged at intervals and correspond to the plurality of first steel bars one by one. Both ends of the plurality of second steel bars are connected to the front side of the second precast module. The plurality of horizontal steel bars are arranged horizontally and are all located on the inner side walls of the first steel bars and the second steel bars. The concrete is filled in the empty groove.

[0012] A design method for an assembled foundation of a substation distribution comprehensive building. The design method is applied to an assembled foundation of a substation distribution comprehensive building. The design method includes the following steps:

[0013] Step 1: Obtain various data of the assembled foundation of the substation distribution comprehensive building and calculate the bending moment at the most unfavorable section of the connection node under the action of eccentric compressive load.

[0014] Step 2: Perform reinforcement calculation according to the bending moment at the most unfavorable section of the connection node to obtain the total area of the required horizontal steel bars, and determine the number and diameter of the horizontal steel bars according to the total area of the required horizontal steel bars.

[0015] Step 3: Apply an uplift force to the assembled foundation of the substation distribution comprehensive building, calculate the ultimate uplift bearing capacity of the tensile connector under the action of the uplift force, and determine the size and number of the tensile connectors according to the ultimate uplift bearing capacity.

[0016] The calculation formula for the total area of the required horizontal steel bars is as follows:

[0017]

[0018] Where, M 5，max is the bending moment at the most unfavorable section of the connection node, f y is the design value of the tensile strength of the horizontal steel bars, h0 is the effective thickness of the connection node, b is the side length of the bottom plate perpendicular to the connection node, l is the side length of the bottom plate parallel to the connection node 5, P max is the design value of the maximum foundation reaction force at the edge of the bottom plate, p is the design value of the foundation reaction force of the bottom plate at the center of the connection node, G is the self-weight of the assembled foundation of the substation distribution comprehensive building and the self-weight of the soil, and A is the bottom area of the bottom plate.

[0019] The calculation formula for the ultimate uplift bearing capacity is as follows:

[0020] F = W + F c ;

[0021] W = γV;

[0022] F c = nf bA eq ;

[0023] Wherein, F is the uplift force, F c is the ultimate uplift bearing capacity of the tensile connection member, W is the self-weight of the upper module, V is the volume of the upper module, γ is the unit weight of the material of the upper module, n is the number of tensile connection members, f b is the ultimate tensile strength value of the tensile connection member, A eq is the equivalent diameter of the tensile connection member.

[0024] Compared with the prior art, the beneficial effects of the present invention are as follows:

[0025] 1. In the prefabricated foundation and design method of the substation distribution comprehensive building of the present invention, the minimum disassembly principle and the modular principle are adopted, which only include three prefabricated modules, with a high degree of factoryization and simple on-site assembly. At the same time, there are no exposed steel members in each component, avoiding the anti-corrosion problem of steel member connection in the existing prefabricated foundation; the first prefabricated module and the second prefabricated module adopt a mortise and tenon joint connection form, which is convenient and fast to install. The first prefabricated module and the second prefabricated module form a bottom plate through the connection of the connection nodes, with high overall strength and stiffness; the bottom plate and the upper module also adopt a mortise and tenon joint connection form, and at the same time, through the cooperation of the tensile connection member and the duct, the bearing capacity of the prefabricated foundation under tensile and bending moments is ensured. Therefore, the structure of the present invention has high stability and is convenient for construction.

[0026] 2. In the prefabricated foundation and design method of the substation distribution comprehensive building of the present invention, the connection strength between the upper module and the first prefabricated module and the second prefabricated module can be improved through the cooperation of the shear groove and the shear key. By installing high-strength nuts in the enlarged duct to fix the ends of the embedded bolts, and then using grout to fill the enlarged duct, this process not only ensures tightness but also isolates the U-shaped embedded part from contact with air, significantly improving the anti-corrosion ability and extending the service life of the foundation. Therefore, the present invention has a long service life and high structural stability.

[0027] 3. In the prefabricated foundation and design method of the substation distribution comprehensive building of the present invention, grouting holes corresponding to the prefabricated foundation beam are reserved at the top of the upper stage of the foundation for achieving rebar connection. After grouting is completed, the rebar and the grout are integrally cured to form a firm connection. At the same time, a foam rubber board is filled in the gap between the prefabricated foundation beam and the upper module to absorb the micro-deformation of the beam body, further enhancing the flexibility and adaptability of the overall structure. Therefore, the structure of the present invention has high stability.

[0028] 4. In the prefabricated foundation and design method of a substation distribution comprehensive building of the present invention, the connection node adopts a combination of a first steel bar, a second steel bar, a horizontal steel bar and concrete to form a splicing node equivalent to cast-in-place, with a small node width, and the first steel bar and the second steel bar are staggered and lapped with the horizontal steel bar, having low requirements for installation accuracy; at the same time, the on-site construction of the connection node does not require formwork erection, simplifies the on-site construction process, and improves the construction efficiency. Therefore, the construction efficiency of the present invention is relatively high. BRIEF DESCRIPTION OF THE DRAWINGS

[0029] Figure 1 FIG. is a schematic structural diagram of a prefabricated foundation of a substation distribution comprehensive building in the present invention.

[0030] Figure 2 FIG. is a schematic structural diagram of the bottom plate in the present invention.

[0031] Figure 3 FIG. is a schematic structural diagram of the first prefabricated module in the present invention.

[0032] Figure 4 FIG. is a schematic structural diagram of the second prefabricated module in the present invention.

[0033] Figure 5 FIG. is a sectional view of the upper stage of the foundation and the first prefabricated module in the present invention.

[0034] Figure 6 FIG. is a sectional view of the upper stage of the foundation, the first prefabricated module and the tensile connection member in the present invention.

[0035] Figure 7 FIG. is a sectional view of the upper module and the prefabricated foundation beam in the present invention.

[0036] Figure 8 FIG. is a schematic structural diagram of the connection node in the present invention.

[0037] In the figure: bottom plate 1, first prefabricated module 11, second prefabricated module 12, empty groove 13, first tenon 14, second tenon 15, shear-resistant groove 2, upper module 3, upper stage of the foundation 31, short column 32, shear key 33, hole 34, enlarged hole 35, high-strength nut 36, inserted steel bar 37, prefabricated foundation beam 4, grouting hole 41, connection node 5, first steel bar 51, second steel bar 52, horizontal steel bar 53, concrete 54, tensile connection member 6, U-shaped embedded part 61, embedded bolt 62, foam rubber plate 7. DETAILED DESCRIPTION OF THE EMBODIMENTS

[0038] The present invention will be further described in detail below with reference to the drawings and specific embodiments.

[0039] Example 1:

[0040] See Figures 1 to 7, An assembled foundation for a substation distribution comprehensive building, comprising a bottom plate 1, an upper module 3 and a plurality of precast foundation beams 4. The bottom plate 1 includes a first precast module 11 and a second precast module 12 that are mortise-and-tenon fitted. The first precast module 11 and the second precast module 12 enclose an empty slot 13. A connection node 5 is installed in the empty slot 13. The connection node 5 is respectively connected to the first precast module 11 and the second precast module 12. The upper module 3 is mortise-and-tenon fitted and connected to the first precast module 11 and the second precast module 12. A plurality of tensile connectors 6 are connected to the upper end surfaces of the first precast module 11 and the second precast module 12. A plurality of holes 34 matching the tensile connectors 6 are provided on the lower side of the upper module 3. The plurality of precast foundation beams 4 are connected to the upper module 3 and the lower sides thereof abut against the upper sides of the first precast module 11 and the second precast module 12;

[0041] Two first tenons 14 are connected to the rear side of the first precast module 11. The rear sides of the first tenons 14 abut against the front side of the second precast module 12. Two second tenons 15 are connected to the front side of the second precast module 12. One sides of the two second tenons 15 respectively abut against the inner sides of the two first tenons 14. The front sides of the second tenons 15 abut against the rear side of the first precast module 11. The two second tenons 15, the first precast module 11 and the second precast module 12 enclose the empty slot 13.

[0042] In this embodiment, the first precast module 11 and the second precast module 12 have basically the same shape. The dimensions of the first tenon 14 and the second tenon 15 are 100 mm in width and 300 mm in length, and can be accurately embedded into adjacent precast modules to achieve a tight connection. During installation, first place the first precast module 11 at the designed position and fix it. Then dock the second precast module 12 to the first precast module 11. During the docking process, embed the second tenon 15 of the second precast module 12 into the gap of the first tenon 14 of the first precast module 11. The empty slot 13 between the first precast module 11 and the second precast module 12 is the filling area for the connection node 5. The filling material is selected as high-strength non-shrinkage grouting material. At the node, since the steel bars are relatively dense, a vibrating device needs to be used to vibrate it after grouting to ensure that the grouting material is fully compacted, thereby enhancing the node strength. The first precast module 11 and the second precast module 12 form the bottom plate 1 through the connection of the connection node 5, and have relatively high overall strength and stiffness;

[0043] After the bottom slab 1 is completed, the upper module 3 is installed on top of the first precast module 11 and the second precast module 12, with the tensile connector 6 positioned within the duct 34. Then, the precast foundation beam 4 is connected to the upper module 3. After the overall installation is completed, the foundation trench can be backfilled and cured for 28 days. After the high-strength non-shrinkage grouting material is fully cured and the joint strength reaches the design requirements, the installation of the upper structure can be carried out.

[0044] Through the combination of modular prefabrication and on-site assembly, the construction efficiency is significantly improved, while ensuring the shear resistance, uplift resistance and overall bearing capacity of the foundation structure. The first precast module 11 and the second precast module 12 form a high-strength base structure through the connection joint 5, and the anti-uplift connection design between the upper module 3 and the bottom slab 1 further enhances the horizontal bearing capacity and vertical uplift resistance of the foundation.

[0045] Example 2:

[0046] The basic content is equivalent to that of Example 1, except that:

[0047] A plurality of shear grooves 2 are provided on the upper sides of the first precast module 11 and the second precast module 12. The shear grooves 2 are trapezoidal in reverse, and a plurality of shear keys 33 that are respectively matched with the shear grooves 2 are connected to the lower side of the upper module 3.

[0048] The tensile connector 6 includes a U-shaped embedded part 61 and two embedded bolts 62. The U-shaped embedded part 61 is connected to the interiors of the first precast module 11 and the second precast module 12, and the two embedded bolts 62 are respectively vertically connected to the ends of the two side walls of the U-shaped embedded part 61 and are located above the first precast module 11 and the second precast module 12.

[0049] In this embodiment, the shear grooves 2 and the embedded bolts 62 are respectively used to provide shear resistance and uplift resistance at the connection. The embedded bolts 62 protrude 290 mm from the upper surfaces of the first precast module 11 and the second precast module 12, providing a reliable tensile connection for the subsequent installation of the upper part 3. The shear grooves 2 are designed as trapezoidal in reverse, with a bottom cross-sectional dimension of 300 mm × 300 mm and an upper cross-sectional dimension of 350 mm × 350 mm. The shear keys 33 on the lower surface of the upper module 3 are rectangular, with a bottom cross-sectional dimension of 300 mm × 300 mm and an upper cross-sectional dimension of 300 mm × 300 mm. The shear keys 33 are integrally formed with the upper module 3. When the shear keys 33 are embedded in the shear grooves 2 of the first precast module 11 and the second precast module 12, they jointly resist the horizontal load and uplift load with the tensile connector 6, improving the shear and uplift resistance performance of the foundation.

[0050] Example 3:

[0051] The basic content is the same as that of Embodiment 2, except that:

[0052] See Figure 5 and Figure 6 , the upper module 3 includes a basic upper step 31 and a short column 32. The cross-section of the basic upper step 31 is rectangular. The basic upper step 31 is connected to the first precast module 11 and the second precast module 12 by mortise and tenon joints. A plurality of holes 34 matching the embedded bolts 62 are formed in the lower side of the basic upper step 31. The short column 32 is vertically arranged and connected to the upper side of the basic upper step 31. A plurality of enlarged holes 35 are formed in the upper end surface of the basic upper step 31. The plurality of enlarged holes 35 are in one-to-one correspondence and communication with the plurality of holes 34. High-strength nuts 36 are arranged in the enlarged holes 35. The high-strength nuts 36 are threadedly connected to the upper ends of the embedded bolts 62. The enlarged holes 35 are filled with grouting material.

[0053] In this embodiment, the 8 ends of the embedded bolts 62 of the first precast module 11 and the second precast module 12 pass through the holes 34 of the upper module 3 and extend into the enlarged holes 35 on the upper surface of the upper module 3. High-strength nuts 36 are installed in the enlarged holes 35 to fix the ends of the embedded bolts 62, and then high-strength non-shrink grouting material is used to fill the enlarged holes 35. This process not only ensures the tightness of the joint connection, but also isolates the enlarged holes 35 from contact with air, significantly improving the corrosion resistance and extending the service life of the foundation.

[0054] Embodiment 4:

[0055] The basic content is the same as that of Embodiment 1, except that:

[0056] See Figure 7 , the number of the precast foundation beams 4 is two. The precast foundation beams 4 are in a stepped shape. The small ends of the precast foundation beams 4 are attached to the upper side of the basic upper step 31. Foam rubber plates 7 are filled between the small ends of the precast foundation beams 4 and the sides of the short columns 32. The large ends of the two precast foundation beams 4 are respectively attached to the upper sides of the first precast module 11 and the second precast module 12. Foam rubber plates 7 are filled between the large ends of the precast foundation beams 4 and the sides of the basic upper step 31. Grouting holes 41 are formed vertically in the small ends of the precast foundation beams 4. Inserted bars 37 are connected inside the basic upper step 31. The inserted bars 37 are in a U shape. The two side walls of the inserted bars 37 pass through the upper side of the basic upper step 31 and are located in the grouting holes 41. The grouting holes 41 are filled with grouting material.

[0057] In this embodiment, 4 grouting holes 41 are provided at the connection between the basic integral body and the precast foundation beam 4, and the connection is achieved through the inserted steel bars 37 and the high-strength non-shrinking grouting material. The use of the grouting material not only fills the voids in the grouting holes 41, but also isolates the inserted steel bars 37 from contact with air, thereby effectively preventing the oxidation and corrosion of the inserted steel bars 37. The connection between the beam end and the upper module 3 uses a foam rubber sheet 7 to fill the gap to absorb minor deformations and relieve local stress concentration;

[0058] Grouting holes 41 corresponding to the precast foundation beam 4 are reserved at the top of the upper module 3 for realizing the connection of the inserted steel bars. During the installation process, first place the precast foundation beam 4 at the corresponding position of the upper module 3, align the grouting holes 41 at the beam end with the reserved high-strength inserted steel bars 37 on the module 3, insert the high-strength inserted steel bars 37 into the grouting holes 41, and ensure that the upper end of the inserted steel bars 37 is located 40 mm below the grouting holes 41, so as to avoid contact between the inserted steel bars 37 and the outside air. After the grouting is completed, the inserted steel bars 37 and the high-strength non-shrinking grouting material are integrally cured to form a firm connection. In addition, a foam rubber sheet 7 is filled in the gap between the beam end and the upper module 3 to absorb the minor deformation of the beam body and further enhance the flexibility and adaptability of the overall structure.

[0059] Embodiment 5:

[0060] The basic content is equivalent to that of Embodiment 1, and the differences are as follows:

[0061] See Figure 8 , the connection node 5 includes a plurality of first steel bars 51, a plurality of second steel bars 52, a plurality of horizontal steel bars 53 and concrete 54. The first steel bars 51 and the second steel bars 52 are both U-shaped. The plurality of first steel bars 51 are arranged at intervals and both ends are connected to the rear side of the first precast module 11. The plurality of second steel bars 52 are arranged at intervals and correspond to the plurality of first steel bars 51 one by one. Both ends of the plurality of second steel bars 52 are connected to the front side of the second precast module 12. The plurality of horizontal steel bars 53 are arranged horizontally and are all located on the inner side walls of the first steel bars 51 and the second steel bars 52. The concrete 54 is filled in the empty groove 13.

[0062] In this embodiment, when fabricating the steel bar meshes of the first precast module 11 and the second precast module 12 in the factory, the first steel bar 51 and the second steel bar 52 are placed horizontally and vertically, and the first steel bars 51 and the second steel bars 52 protruding from the first precast module 11 and the second precast module 12 are offset by 2-5 times the diameter of the steel bar; the lengths of the upper ends of the first steel bar 51 and the second steel bar 52 embedded in the first precast module 11 and the second precast module 12 are 35 times the diameter of the steel bar, and the lower ends utilize the base slab reinforcement of the foundation; the spacing between the first precast module 11 and the second precast module 12 is the same as the spacing of the base slab steel bars of the foundation, and the length of the protruding concrete is 16 times the diameter of the steel bar, and the horizontal steel bar 53 is connected to the first steel bar 51 and the second steel bar 52 by binding.

[0063] Embodiment 6:

[0064] A design method for an assembled foundation of a substation distribution complex building, the design method is applied to an assembled foundation of a substation distribution complex building described in Embodiment 5, and the design method includes the following steps:

[0065] Step 1, obtain various data of the assembled foundation of the substation distribution complex building and calculate the bending moment at the most unfavorable section of the connection node 5 under the action of eccentric compressive load;

[0066] Step 2, perform reinforcement calculation according to the bending moment at the most unfavorable section of the connection node 5 to obtain the total area of the required horizontal steel bars 53, and determine the quantity and diameter of the horizontal steel bars 53 according to the total area of the required horizontal steel bars 53;

[0067] Step 3, apply an uplift force to the assembled foundation of the substation distribution complex building, calculate the ultimate uplift bearing capacity of the tensile connector 6 under the action of the uplift force, and determine the size and quantity of the tensile connector 6 according to the ultimate uplift bearing capacity.

[0068] The calculation formula for the total area of the required horizontal steel bars 53 is as follows:

[0069]

[0070] where M 5，max is the bending moment at the most unfavorable section of the connection node 5, f y is the design value of the tensile strength of the horizontal steel bar 53, h0 is the effective thickness of the connection node 5, b is the side length of the base slab 1 perpendicular to the connection node 5, l is the side length of the base slab 1 parallel to the connection node 5, P max is the design value of the maximum foundation reaction force at the edge of the base slab 1, p is the design value of the foundation reaction force of the base slab 1 at the center of the connection node 5, G is the self-weight of the assembled foundation of the substation distribution complex building and the self-weight of the soil, and A is the bottom area of the base slab 1.

[0071] The calculation formula for the ultimate uplift bearing capacity is as follows:

[0072] F = W + F c ;

[0073] W = γV;

[0074] F c = nf b A eq ;

[0075] Among them, F is the uplift force, F c is the ultimate uplift bearing capacity of the tensile connection member 6, W is the self-weight of the upper module 3, V is the volume of the upper module 3, γ is the unit weight of the material of the upper module 3, n is the number of tensile connection members 6, f b is the ultimate value of the tensile strength of the tensile connection member 6, and A eq is the equivalent diameter of the tensile connection member 6.

[0076] In this embodiment, for the precast foundation of the substation distribution comprehensive building, when it is under the action of eccentric compressive load, the most unfavorable section is the sectional moment at the center of the connection node 5, and the moment of this most unfavorable section is used for the design of reinforcement.

[0077] At a distance x from the center section of the connection node 5, the net foundation reaction force at the base is:

[0078]

[0079] Using the integral formula:

[0080]

[0081] Substitute and sort it out, and the moment M at the most unfavorable section of the precast foundation of the substation distribution comprehensive building under the action of eccentric compressive load can be obtained 5，max ,

[0082] Among them, the distance from the middle section of the post-cast strip of the bottom plate 1 to the edge of the precast foundation is p jx is the foundation pressure value at the base at a distance x from the center section of the connection node 5, p j max is the design value of the maximum net foundation reaction force at the edge of the bottom plate 1, and p j is the net foundation reaction force at the base at the post-cast strip section of the bottom plate 1.

Claims

1. An assembled foundation for a power distribution complex building of a substation, characterized by: The invention comprises a base plate (1), an upper module (3) and a plurality of prefabricated foundation beams (4); the base plate (1) comprises a first prefabricated module (11) and a second prefabricated module (12) which are matched with mortise and tenon joints; the first prefabricated module (11) and the second prefabricated module (12) are combined to form an empty groove (13); a connecting node (5) is installed in the empty groove (13); the connecting node (5) is connected to the first prefabricated module (11) and the second prefabricated module (12) respectively; the upper module (3) The first prefabricated module (11) and the second prefabricated module (12) are connected by mortise and tenon joints, the upper end surfaces of the first prefabricated module (11) and the second prefabricated module (12) are connected with a plurality of tensile connectors (6), the lower side of the upper module (3) is provided with a channel (34) matching the plurality of tensile connectors (6), and the plurality of prefabricated foundation beams (4) are connected to the upper module (3) and the lower side abuts against the upper side of the first prefabricated module (11) and the second prefabricated module (12).

2. The assembled foundation of a power distribution complex building of a substation according to claim 1, characterized in that: The rear side of the first prefabricated module (11) is connected to two first tenons (14), the rear side of the first tenons (14) abuts against the front side of the second prefabricated module (12), the front side of the second prefabricated module (12) is connected to two second tenons (15), one side of the two second tenons (15) abuts against the inner sides of the two first tenons (14), the front side of the second tenons (15) abuts against the rear side of the first prefabricated module (11), and the two second tenons (15), the first prefabricated module (11) and the second prefabricated module (12) together form the empty groove (13).

3. The assembled foundation of a power distribution complex building of a substation according to claim 1 is characterized by: The upper sides of the first prefabricated module (11) and the second prefabricated module (12) are provided with a plurality of shear-resistant grooves (2), the shear-resistant grooves (2) being in an inverted trapezoidal shape, and the lower side of the upper module (3) is connected with a plurality of shear keys (33) which are matched one by one with the shear-resistant grooves (2).

4. The assembled foundation of a power distribution complex building of a substation according to claim 1, characterized in that: The tensile connector (6) comprises a U-shaped embedded component (61) and two embedded bolts (62); the U-shaped embedded component (61) is connected to the inside of the first prefabricated module (11) and the second prefabricated module (12); the two embedded bolts (62) are respectively vertically connected to the ends of the two side walls of the U-shaped embedded component (61) and are located on the upper side of the first prefabricated module (11) and the second prefabricated module (12).

5. The assembled foundation of a power distribution complex building of a substation according to claim 4 is characterized by: The upper module (3) comprises a foundation step (31) and a short column (32). The cross-section of the foundation step (31) is rectangular. The foundation step (31) is connected to the first prefabricated module (11) and the second prefabricated module (12) by mortise and tenon joints. A hole (34) matching with a plurality of embedded bolts (62) is provided on the lower side of the foundation step (31). The short column (32) is vertically arranged and connected to the upper side of the foundation step (31). A plurality of enlarged holes (35) are provided on the upper end surface of the foundation step (31). The plurality of enlarged holes (35) are connected to the plurality of holes (34) in a one-to-one correspondence. A high-strength nut (36) is arranged in the enlarged hole (35). The high-strength nut (36) is threadedly connected to the upper end of the embedded bolt (62). The enlarged hole (35) is filled with grouting material.

6. The assembled foundation of a power distribution complex building of a substation according to claim 5, characterized in that: The number of the prefabricated foundation beams (4) is two. The prefabricated foundation beams (4) are in a stepped shape. The small end of the prefabricated foundation beam (4) fits with the upper side of the foundation step (31). The small end of the prefabricated foundation beam (4) and the side of the short column (32) are filled with a foam rubber plate (7). The large ends of the two prefabricated foundation beams (4) fit with the upper sides of the first prefabricated module (11) and the second prefabricated module (12) respectively. The large ends of the prefabricated foundation beams (4) and the side of the foundation step (31) are filled with a foam rubber plate (7). The small end of the prefabricated foundation beam (4) is vertically provided with a grouting hole (41). The foundation step (31) is internally connected with a dowel bar (37). The dowel bar (37) is U-shaped. The two side walls of the dowel bar (37) pass through the upper side of the foundation step (31) and are located in the grouting hole (41). The grouting hole (41) is filled with grouting material.

7. The assembled foundation of a power distribution complex building of a substation according to claim 1, characterized in that: The connection node (5) comprises a plurality of first steel bars (51), a plurality of second steel bars (52), a plurality of horizontal steel bars (53) and concrete (54); the first steel bars (51) and the second steel bars (52) are both U-shaped; the plurality of first steel bars (51) are arranged at intervals and both ends are connected to the rear side of the first prefabricated module (11); the plurality of second steel bars (52) are arranged at intervals and correspond one-to-one to the plurality of first steel bars (51); both ends of the plurality of second steel bars (52) are connected to the front side of the second prefabricated module (12); the plurality of horizontal steel bars (53) are arranged transversely and are all located on the inner side walls of the first steel bars (51) and the second steel bars (52); and the concrete (54) is filled in the empty groove (13).

8. A design method for the assembled foundation of a power distribution complex building of a substation, characterized by: The design method is applied to the assembled foundation of a substation power distribution complex building as described in claim 7, and the design method comprises the following steps: Step 1: Obtain various data of the assembled foundation of the power distribution complex building of the substation and calculate the bending moment at the most unfavorable section of the connection node (5) under the action of eccentric compressive load; Step 2: Calculate the reinforcement according to the bending moment at the most unfavorable cross section of the connection node (5), obtain the total area of ​​the required horizontal steel bars (53), and determine the number and diameter of the horizontal steel bars (53) according to the total area of ​​the required horizontal steel bars (53); Step 3: Apply a pull-out force to the assembled foundation of the power distribution complex building of the substation, calculate the ultimate pull-out bearing capacity of the tensile connector (6) under the action of the pull-out force, and determine the size and quantity of the tensile connector (6) according to the ultimate pull-out bearing capacity.

9. The design method of the assembled foundation of the power distribution complex building of a substation according to claim 8 is characterized by: The calculation formula for the total area of ​​the required horizontal steel bars (53) is as follows: Among them, M 5,max is the bending moment at the most unfavorable section of the connection node (5), f y is the design value of the tensile strength of the horizontal reinforcement (53), h0 is the effective thickness of the connection node (5), b is the length of the side of the bottom plate (1) perpendicular to the connection node (5), l is the length of the side of the bottom plate (1) parallel to the connection node (5), P max is the maximum foundation reaction design value at the edge of the bottom plate (1), p is the foundation reaction design value of the bottom plate (1) at the center of the connection node (5), G is the self-weight of the assembled foundation of the substation power distribution complex building and the self-weight of the soil, and A is the bottom area of ​​the bottom plate (1).

10. The design method of the assembled foundation of the power distribution complex building of a substation according to claim 8, characterized in that: The calculation formula of the ultimate pull-out bearing capacity is as follows: F=W+F c ; W = γV; F c =nf b A eq ; Where, F is the upward pull force, F c is the ultimate pull-out bearing capacity of the tensile connector (6), W is the deadweight of the upper module (3), V is the volume of the upper module (3), γ is the weight of the material of the upper module (3), n is the number of the tensile connector (6), and f b A is the tensile strength limit value of the tensile connector (6), eq is the equivalent diameter of the tensile connector (6).

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