CN109403367B - Assembled box transformer foundation and field construction method thereof - Google Patents

Abstract

The invention belongs to the field of box-type transformer substation foundations, and discloses an assembled box-type transformer substation foundation and a site construction method. The assembled box transformer substation foundation comprises a bottom plate, a column base, columns, connecting steel plates, connecting bolts and the like, and can be realized by the design of six modularized bottom plates after the modularized bottom plates are added or removed when the assembled box transformer substation foundation is required to be adapted to box substations with different sizes. When the box transformer substation foundation is required to be shifted, only foundation soil is needed to be excavated, welding parts of the box transformer substation foundation and the box transformer substation foundation are cut off, and then the box transformer substation foundation is integrally removed, so that the box transformer substation foundation can be put into the next engineering for use. The invention has the advantages of reasonable structure, clear force transmission path, simple assembly, short construction period, low cost, repeated use, suitability for box-type substations of various specifications, small disturbance to the environment and the like.

Description

A prefabricated box-type transformer foundation and on-site construction method thereof

Technical Field

The present invention belongs to the field of box-type transformer substation foundations, and more specifically, relates to an assembled box-type transformer substation foundation and an on-site construction method thereof.

Background technique

At present, most of the box-type substation foundations are constructed using cast-in-place construction methods. The cast-in-place box-type substation foundation has the following disadvantages:

1) Long construction period. The cast-in-place box-type transformer foundation requires on-site steel bar binding, on-site formwork, on-site concrete pouring, and later formwork removal, which takes a long construction period;

2) High cost, from foundation excavation, steel bar tying, mold making, concrete pouring, concrete curing, and formwork removal, it costs a lot of money;

3) It has a great impact on the environment. The foundation of the box-type transformer is often built in the city. The excavation of the foundation soil will inevitably affect the urban environment and the city's image. The construction period of the cast-in-place box-type transformer foundation often takes one month or more, which has a great impact on the urban environment and affects normal travel.

At present, there are few inventions for prefabricated box foundations. The existing prefabricated box transformer foundation structure design is unreasonable, the structural force transmission path is inappropriate, the integrity and stability are poor, and post-poured concrete is used in the assembly of the prefabricated box transformer foundation, resulting in the prefabricated box transformer foundation cannot be reused, long construction period, high cost, etc. These unfavorable factors have limited the application and promotion of prefabricated box transformer foundations.

Summary of the invention

In view of the above defects or improvement needs of the prior art, the present invention provides an assembled box-type transformer foundation and an on-site construction method, which obtains an assembled box-type transformer foundation with a reasonable structure and clear force transmission path through the design of the structure and arrangement of key components such as six basic base plates, column bases, columns and connecting steel plates. The foundation has the advantages of short construction period, low cost, easy manual assembly, reusability and small environmental disturbance.

To achieve the above object, according to one aspect of the present invention, there is provided an assembled box-type transformer foundation, comprising a bottom plate, a column base, a column and a connecting steel plate arranged in sequence from bottom to top, wherein:

The bottom plate is cast with reinforced concrete, on which bolts for connecting the column base are embedded. The side of the bottom plate is also provided with a convex shear key for resisting lateral shearing and a shear key groove slightly larger than the shear key; the shear key groove is used to form a concave-convex connection with the shear keys on other bottom plates to resist the lateral shear force transmitted from the upper column base;

The base plate is divided into six basic prefabricated base plates according to the position and arrangement of shear keys, shear key grooves and bolts, forming the basic array as follows: the first base plate is on the four corners; the second base plate is in the middle of the first column, and the third base plate is in the middle of the third column; the fourth base plate and the fifth base plate are at both ends of the second column, and the sixth base plate is in the middle; among them, the first base plate, the second base plate and the third base plate are of the same size and square cross-section, but the settings of the shear keys and shear key grooves on the sides of the base plates and the positions of the bolts embedded in the plate surface are different; the fourth base plate, the fifth base plate and the sixth base plate are all rectangular in cross-section, with equal transverse widths and set to five different specifications to be suitable for box-type transformer foundations of a full range of sizes, and the longitudinal widths of the fourth base plate, the fifth base plate and the sixth base plate are equal to the longitudinal width of the first base plate;

The first bottom plate, the second bottom plate and the third bottom plate are all provided with column bases, columns and connecting steel plates; the fourth bottom plate, the fifth bottom plate and the sixth bottom plate are used to expand the distance between two columns in the same row.

Further, the longitudinal expansion of the basic array is achieved by installing a second base plate between the first base plate and the second base plate, installing a third base plate between the first base plate and the third base plate, and installing a sixth base plate between the fourth base plate and/or the fifth base plate;

The horizontal expansion of the basic array is achieved by installing a fourth base plate of the same or different specifications between the first base plate and the fourth base plate, installing a fifth base plate of the same or different specifications between the first base plate and the fifth base plate, installing a sixth base plate of the same or different specifications between the second base plate and the sixth base plate, or replacing the fourth base plate of different specifications and the fifth base plate of the corresponding specifications between the first base plates in the same row, and replacing the sixth base plate of the corresponding specifications between the second base plate and the third base plate.

Furthermore, it also includes a connecting steel plate; the connecting steel plate is divided into a first connecting steel plate, a second connecting steel plate, and a third connecting steel plate, the first connecting steel plate is used to connect four bottom plates, the second connecting steel plate is used to connect two adjacent bottom plates, and the third connecting steel plate is used to connect the sides of two adjacent bottom plates;

The first to sixth base plates are all pre-embedded with first bolts facing upwards, the sides of the first to fifth base plates are all pre-embedded with second bolts facing sideways, and the middle parts of the first to third base plates are also pre-embedded with third bolts for connecting the column bases; the multiple first bolts are respectively used to cooperate with the first connecting steel plate to connect the upper surfaces of the four adjacent base plates and to cooperate with the second connecting steel plate to connect the upper surfaces of the two adjacent base plates, and the second bolts are used to cooperate with the third connecting steel plate to connect the sides of the two adjacent base plates.

Further, first bolts are pre-buried at three corners on the upper surface of the first bottom plate, and the three corners correspond to two side edges of the first bottom plate, one of which is provided with a shear key groove, and the other side is provided with a shear key; the first bottom plate is provided with a second bolt near the shear key at the side opposite to the shear key groove, and is also provided with a second bolt near the shear key groove at the opposite side of the shear key;

The first bolts are embedded in the four corners on the upper surface of the second bottom plate. The two opposite sides of the second bottom plate are used to connect with the two first bottom plates, and are respectively provided with a shear key and a shear key groove; two second bolts are embedded in the side of the second bottom plate located at the edge of the basic array, and a shear key groove is provided on the side of the second bottom plate connected with the sixth bottom plate;

The first bolts are embedded in the four corners on the upper surface of the third bottom plate. The two opposite sides of the third bottom plate are used to connect with the two first bottom plates, and are respectively provided with a shear key and a shear key groove; two second bolts are embedded in the side of the third bottom plate located at the edge of the basic array, and a shear key is provided on the side of the third bottom plate connected with the sixth bottom plate;

The fourth to sixth bottom plates are provided with corresponding shear keys and shear key grooves for docking with adjacent bottom plates according to their positions in the basic array.

Furthermore, the lateral widths of the fourth base plate, the fifth base plate, and the sixth base plate are all set to five different specifications: 30 cm, 50 cm, 70 cm, 90 cm, and 110 cm.

Furthermore, the column base is shaped like a quadrangular pyramid, and bolt holes are provided on the four sides of the column base for cooperating with the third bolt and fastening with nuts to connect and fix with the corresponding base plate; a fourth bolt is pre-embedded on the top surface of the column base to connect with the column.

The bottom end of the column is provided with a column bottom steel plate for connecting the column and the column base in conjunction with the fourth bolt; the top of the column is pre-embedded with a column top steel plate for connecting to the box transformer; the thickness of the column bottom steel plate is not less than 15mm, and the thickness of the column top steel plate is not less than 10mm.

Furthermore, the steel plate at the bottom of the column is welded to the inwardly bent steel bars at the bottom of the longitudinal reinforcement of the column, and the steel plate at the top of the column is welded to the inwardly bent steel bars at the top of the longitudinal reinforcement of the column, and then the formwork is supported and concrete is poured to form the column.

Furthermore, the six types of base plates, column bases, and columns are all provided with pull rings for transportation.

Furthermore, the base plate, column bases and columns are all prefabricated reinforced concrete components, which are cast in one go through a mold with tied steel bars and cured to reach a predetermined strength.

In order to achieve the above object, according to another aspect of the present invention, a method for on-site construction of a prefabricated box-type transformer foundation is provided, comprising the following steps:

S1: Measure and lay out, excavate the foundation soil to the specified elevation;

S2: transport the pre-prepared reinforced concrete base plate to the designated location and assemble it;

S3: Use connecting steel plates to connect the spliced bottom plates and tighten them with nuts;

S4: Move the pre-prepared reinforced concrete base to the bolt holes reserved on the base plate for assembly and fasten with nuts;

S5: The pre-prepared columns are then moved to the bolt holes reserved on the column base for assembly and fastened with nuts;

S6: Use PVC pipes to cover the wires connected to the box-type substation, and make good interface treatment with the underground power pipe group at the line inlet to prevent groundwater leakage;

S7: Place the box-type substation on the pillar, do grounding, install the wires connected to the box-type substation, and finally backfill the foundation soil.

In general, the above technical solutions conceived by the present invention can achieve the following beneficial effects compared with the prior art.

1. The present invention can greatly shorten the construction time of the box-type substation foundation by assembling fewer assembly parts, reduce the impact on the environment when prefabricating cable working wells in urban construction, and reduce the project cost.

2. The present invention adopts the design of six universal modules of the bottom plate, and only needs to use the universal modules in combination with each other to make the present invention applicable to almost all specifications of box-type substations, which greatly expands the scope of application of the present invention.

3. The present invention is easy to assemble. The entire assembled box-type transformer foundation only involves the physical connection of bolt connection, shear key and shear key groove. The connection method is simple, the disassembly is convenient, the construction period is short, and it is conducive to the promotion of assembled box-type transformer foundation.

4. The present invention breaks down the original large components into small parts through modularization, and the mass of a single concrete component can be greatly reduced. Therefore, no machinery is needed during construction, and only manual handling, assembly and connection are required to complete the construction of the entire box-type transformer foundation. Since no large-scale construction machinery is required, especially no on-site pouring and maintenance are required, the scope of application of the assembled box-type transformer foundation is greatly expanded, so that the present invention can be widely used in the construction of box-type transformer substations in remote areas and the construction of emergency box-type transformer substations.

5. The assembled box-type transformer foundation of the present invention can be reused. After the construction of a project is completed, the connection between the box-type transformer foundation and the substation can be cut off, and then the assembled box-type transformer foundation can be disassembled into basic prefabricated blocks, and then transported to the next project for continued use, which greatly reduces the waste of resources.

6. The present invention has a clear force transmission path and a reasonable structural design. The column transmits the constant load of the box-type substation to the column base, and the column base transmits the load to the bottom plate, and the bottom plate finally transmits the load to the foundation soil. Due to the large area of the bottom plate, the load transmitted from the upper part can be evenly and dispersedly transmitted downward, which can not only reduce the settlement of the foundation soil, but also reduce the differential settlement of the prefabricated box-type transformer foundation, and the settlement of the entire foundation is uniform.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG1 is a three-dimensional axonometric schematic diagram of the assembled box-type transformer foundation of the present invention;

FIG2 is a top view of the relative positions and assembly methods of the six base plates of the present invention;

FIG3 is a diagram showing the position distribution of the bottom plate pull ring when the present invention is placed in the position shown in FIG2 ;

Figure 4 (a) to (f) are respectively the distribution diagrams of six basic base plates and embedded bolt parts of the present invention;

Figure 5 (a) and (b) are two side views of the first base plate of the present invention;

Figure 6 (a) to (c) are three views of the column base of the present invention;

Figure 7 (a) to (c) are three views of the column of the present invention;

FIG8 (a) to (c) are top views of three types of connected steel plates according to the present invention.

Detailed ways

In order to make the purpose, technical solutions and advantages of the present invention more clearly understood, the present invention is further described in detail below in conjunction with the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are only used to explain the present invention and are not intended to limit the present invention. In addition, the technical features involved in the various embodiments of the present invention described below can be combined with each other as long as they do not conflict with each other.

As shown in Figure 1, an assembled box-type transformer foundation provided by an embodiment of the present invention includes a column 3, a column base 2, a bottom plate 1, and a connecting steel plate 4 arranged in sequence from bottom to top, wherein the bottom plate 1 is cast from reinforced concrete as a raft for dispersing the upper load. There are six basic prefabricated modules for the bottom plate 1. Through this modular expansion, the present invention can be applied to almost all specifications of box-type transformer substations. After the modules of the bottom plate 1 are spliced, they are bolted together by the connecting steel plate 4, wherein the thickness of the connecting steel plate 4 is not less than 15 mm, and the size of the bolt hole 9 opened on the connecting steel plate 4 is slightly larger than the bolt 5 embedded in the bottom plate for installation. Bolt holes are opened at the corresponding positions of the base and the bottom plate of the column base 2. During assembly, the column base is directly moved to the designated position and fastened with bolts. After the column base is installed, the column is moved to the position corresponding to the bolt hole on the column base and fastened with bolts. After assembly, the box-type substation is hoisted to the top steel plate of the column, welded and connected on site, and finally the foundation soil is backfilled.

As shown in Figures 1, 2 and 3, the base plate 1 has a total of 6 basic modules, each of which is provided with a shear key 6 and a shear key groove 7 for preliminary splicing, wherein the first base plate 1-1, the second base plate 1-2, and the third base plate 1-3 have a square cross-section, and the side lengths of the first base plate 1-1, the second base plate 1-2, and the third base plate 1-3 are all 1000mm, and they are all cast by reinforced concrete, and the thickness of the base plate is not less than 200mm and not more than 300mm. The first base plate 1-1, the second base plate 1-2, and the third base plate 1-3 are pre-embedded with a first bolt 5-1, a second bolt 5-2 for connecting the base plate surface and the side, and a third bolt 5-3 at a position corresponding to the column base 2. In addition, the first bottom plate 1-1, the second bottom plate 1-2, and the third bottom plate 1-3 are also provided with pull rings 8 for manual transportation. Workers use the pull rings 8 to carry the bottom plate 1 to the designated position at the bottom of the foundation pit for preliminary assembly; the fourth bottom plate 1-4, the fifth bottom plate 1-5, and the sixth bottom plate 1-6 have rectangular cross-sections and are all cast with reinforced concrete. The thickness of the bottom plate is not less than 200mm and not more than 300mm. Its long side is equal to the side length of the first bottom plate 1-1, the second bottom plate 1-2, and the third bottom plate 1-3, and the short side is set to five specifications of 300mm, 500mm, 700mm, 900mm, and 1100mm. The horizontal distance between the columns can be adjusted to adapt to the width of box-type substations of all specifications by adding a fourth bottom plate 1-4 of the same or different specifications between the first bottom plates 1-1 and 1-4, adding a fifth bottom plate 1-5 of the same or different specifications between the first bottom plates 1-1 and 1-5, adding a sixth bottom plate 1-6 of the same or different specifications between the second bottom plates 1-2 and 1-6, or replacing a fourth bottom plate 1-4 and a fifth bottom plate 1-5 of different specifications between two first bottom plates 1-1 in the same row, and replacing a sixth bottom plate 1-6 of different specifications between the second bottom plate 1-2 and the third bottom plate 1-3. The longitudinal length of the box-type substation foundation can be adjusted to adapt to the length of box-type substations of all specifications by adding one or more second bottom plates 1-2 and third bottom plates 1-3 between the first bottom plate 1-1 and the second bottom plate 1-2, and between the first bottom plate 1-1 and the third bottom plate 1-3. Through the combination of these six basic modules, an assembled foundation suitable for box-type substations of almost all specifications can be made.

As shown in Figures 4 and 5, a third bolt 5-3 corresponding to the position of the column base 2 is pre-buried in the middle of the six basic modular base plates. The height of the bolt exposed from the base plate surface is 100mm, and the diameter of the bolt is not less than 20mm. The column base 2 is connected to the base plate 1 through the bolt hole, and is fastened by nuts after connection. Figure 5 is a three-view diagram of the first base plate 1-1, in which the shear key 6 and the shear key groove 7 are both arranged in the middle part of the side of the base plate. The height of the shear key 6 is 100mm, and its plane size is 800mm×150mm. The height of the shear key groove is 110m m, and its plane size is 960mm×160mm. The distribution positions of the shear keys 6 and shear key grooves 7 of other base plates are shown in Figure 4. When the base plates are initially assembled, the shear keys 6 of each base plate are inserted into the shear key grooves 7. When the base plates are subjected to upper loads, the coordinated use of the shear keys 6 and the shear key grooves 7 can enable the base plates to resist the effect of lateral shear force and enhance the integrity of the base plates. After the initial assembly of the base plates is completed, the first connecting steel plate 4-1, the second connecting steel plate 4-2, and the third connecting steel plate 4-3 are further connected to enhance the integrity and shear resistance of the base plates.

As shown in Figure 6, the column base 2 has a bolt hole 9 at a position corresponding to the third bolt 5-3 in the middle of the bottom plate, and is provided with a pull ring 8 for manual handling. The upper surface size of the column base 2 is 300mm×300mm, and the lower surface size is 800mm×800mm. The height of the column base 2 is 250mm. The top of the column base 2 is pre-embedded with a fourth bolt 5-4 at a position corresponding to the bolt hole 9 of the column 3. The fourth bolt 5-4 is 100mm higher than the top surface of the column base 2, and the diameter of the fourth bolt 5-4 is not less than 20mm. After the worker carries the column base 2 to the base, it is tightened with a nut to complete the connection between the column base and the bottom plate.

As shown in Figure 7, a column bottom steel plate 10 is provided at the bottom of the column 3, and the bottom steel plate 10 is obtained by welding the inner bent end of the bottom of the longitudinal reinforcement of the column 3 and the steel plate. A column top steel plate 11 is provided at the top, and the column top steel plate 11 is obtained by welding the inner bent top of the longitudinal reinforcement of the column 3 and the steel plate. Bolt holes 9 are provided on the column bottom steel plate 10 at positions corresponding to the embedded bolts on the upper surface of the column base 2. The column 3 is manually transported to the corresponding position of the column base 2 through the pull ring 8 on the column 3 and fastened with nuts.

As shown in Figure 8, the connecting steel plate 4 is divided into a first connecting steel plate 4-1 connecting the surface of the bottom plate, a second connecting steel plate 4-2 and a third connecting steel plate 4-3 connecting the side of the bottom plate, wherein the first connecting steel plate 4-1 has a plane size of 250mm×250mm and a thickness of not less than 20mm, the second connecting steel plate 4-2 has a plane size of 250mm×120mm and a thickness of not less than 20mm, and the third connecting steel plate 4-3 has a plane size of 250mm×100mm and a thickness of not less than 20mm. After the preliminary assembly of the bottom plate is completed, the connecting steel plates are connected according to the positions shown in Figure 1 to enhance the integrity of the bottom plate and resist lateral shear force.

The assembled box-type transformer foundation of the present invention is specifically constructed on site by the following steps:

S1: Preparation before construction: measurement and layout, excavation of foundation soil to the predetermined elevation, compaction of foundation soil, application of a sand cushion layer, and leveling;

S2: Move the base plate required for the project to the bottom of the foundation pit and assemble the base plate preliminarily according to the project drawings;

S3: After the assembly is completed, the bottom plate is connected to the steel plate at the corresponding position with the connecting steel plate and fastened with nuts;

S4: Move the column base to a position corresponding to the base plate, insert the column base into a designated position of the base plate, and fasten the column base with nuts;

S5: Move the column to a position corresponding to the column base plate, insert the column into the designated position of the column base, and tighten the column with a nut;

S6: Transport the box-type substation to the column, and weld the box-type substation and the steel plate on the top of the column on site;

S7: Use PVC pipe to cover the cable entering the box-type substation, and do a good job of fastening and waterproofing the cable outlet, and fastening and waterproofing the cable at the box-type substation. After completion, backfill the foundation soil to the original foundation pit position, so as to complete the entire construction of a box-type substation foundation;

When the box-type transformer foundation needs to be moved, it is only necessary to dismantle the assembled box-type transformer foundation and transport it to the designated location and reinstall it according to the above steps.

The present invention gives full play to the advantages of the prefabricated structure, such as short construction period, low cost, small environmental disturbance, reusability, simple construction (no need for mechanized construction), reasonable structure, and clear force transmission, and can be widely promoted and applied.

It will be easily understood by those skilled in the art that the above description is only a preferred embodiment of the present invention and is not intended to limit the present invention. Any modifications, equivalent substitutions and improvements made within the spirit and principles of the present invention should be included in the protection scope of the present invention.

Claims (9)

1. The utility model provides an assembled case becomes basis, its characterized in that includes bottom plate (1), stand base (2), stand (3) and connecting steel sheet (4) that follow supreme setting gradually down, wherein:

the base plate (1) is formed by pouring reinforced concrete, bolts (5) for connecting the upright post bases (2) are pre-buried on the base plate, and the side surface of the base plate (1) is also provided with convex shear keys (6) for resisting transverse shearing and shear key grooves (7) with the sizes slightly larger than those of the shear keys (6); the shear key grooves (7) are used for forming concave-convex connection with the shear keys (6) on other bottom plates (1) together to resist the transverse shear force transmitted by the upper upright post base (2);

the base plate (1) is divided into six basic prefabricated base plates according to the positions and arrangement differences of shear keys (6), shear key grooves (7) and bolts (5), and a basic array is formed as follows: the four corners are provided with first bottom plates (1-1); the middle position of the first column is a second bottom plate (1-2), and the middle position of the third column is a third bottom plate (1-3); the two ends of the second row are respectively provided with a fourth bottom plate (1-4) and a fifth bottom plate (1-5), and the middle position is provided with a sixth bottom plate (1-6); the first bottom plate (1-1), the second bottom plate (1-2) and the third bottom plate (1-3) are identical in size, the cross sections are square, but the positions of the shear keys (6) and the shear key grooves (7) on the side surfaces of the bottom plates and the positions of the bolts (5) embedded in the plate surfaces are different; the cross sections of the fourth bottom plate (1-4), the fifth bottom plate (1-5) and the sixth bottom plate (1-6) are rectangular, the transverse widths are equal and are set to five different specifications so as to be suitable for a box transformer foundation in a full-size range, and the longitudinal widths of the fourth bottom plate (1-4), the fifth bottom plate (1-5) and the sixth bottom plate (1-6) are equal to the side length of the first bottom plate (1-1);

the first bottom plate (1-1), the second bottom plate (1-2) and the third bottom plate (1-3) are connected with a column base (2), and the column base (2) is connected with a column (3); the fourth bottom plate (1-4), the fifth bottom plate (1-5) and the sixth bottom plate (1-6) are used for expanding the distance between two upright posts (3) in the same row;

the longitudinal expansion of the basic array is realized by adding a second bottom plate (1-2) between a first bottom plate (1-1) and a second bottom plate (1-2), adding a third bottom plate (1-3) between the first bottom plate (1-1) and a third bottom plate (1-3), and adding a sixth bottom plate (1-6) between a fourth bottom plate (1-4) and/or a fifth bottom plate (1-5);

the transverse expansion of the basic array is realized by adding fourth bottom plates (1-4) with the same specification or different specifications between a first bottom plate (1-1) and the fourth bottom plate (1-4), adding fifth bottom plates (1-5) with the same specification or different specifications between the first bottom plate (1-1) and the fifth bottom plate (1-5), adding sixth bottom plates (1-6) with the same specification or different specifications between a second bottom plate (1-2) and a sixth bottom plate (1-6), or replacing fourth bottom plates (1-4) with different specifications and fifth bottom plates (1-5) with corresponding specifications between the first bottom plates (1-1) of the same row, and replacing sixth bottom plates (1-6) with corresponding specifications between the second bottom plates (1-2) and the third bottom plates (1-3).

2. The modular tank foundation according to claim 1, further comprising a connecting steel plate (4); the connecting steel plates (4) are divided into a first connecting steel plate (4-1), a second connecting steel plate (4-2) and a third connecting steel plate (4-3), wherein the first connecting steel plate (4-1) is used for connecting four bottom plates (1), the second connecting steel plate (4-2) is used for connecting the connection between two adjacent bottom plates (1), and the third connecting steel plate (4-3) is used for connecting the side surfaces of the two adjacent bottom plates (1);

the first bolts (5-1) facing upwards are embedded in the first bottom plate, the second bolts (5-2) facing sideways are embedded in the side edges of the first bottom plate, and the third bolts (5-3) used for connecting the upright post bases (2) are embedded in the middle of the first bottom plate; the first bolts (5-1) are respectively used for being matched with the first connecting steel plate (4-1) to connect the upper surfaces of the adjacent four bottom plates and the second connecting steel plate (4-2) to connect the upper surfaces of the adjacent two bottom plates, and the second bolts (5-2) are used for being matched with the third connecting steel plate (4-3) to connect the side surfaces of the adjacent two bottom plates (1).

3. The assembled box transformer substation foundation according to claim 2, characterized in that the first bolts (5-1) are pre-embedded at three corners of the upper surface of the first base plate (1-1), the three corners correspond to two sides of the first base plate (1-1), one side is provided with a shear key groove (7), and the other side is provided with a shear key (6); the first bottom plate (1-1) is provided with a second bolt (5-2) close to the shear key (6) on the opposite side of the side where the shear key groove (7) is located, and is also provided with a second bolt (5-2) close to the shear key groove (7) on the opposite side of the side where the shear key (6) is located;

the four corners of the upper surface of the second bottom plate (1-2) are respectively embedded with first bolts (5-1), and two opposite sides of the second bottom plate (1-2) are used for being in butt joint with the two first bottom plates (1) and are respectively provided with a shear key (6) and a shear key groove (7); the second bottom plate (1-2) is positioned on the side edge of the basic array, two second bolts (5-2) are pre-buried, and a shear key groove (7) is formed in the side edge of the butt joint of the second bottom plate (1-2) and the sixth bottom plate (1-6);

the four corners of the upper surface of the third bottom plate (1-3) are pre-embedded with first bolts (5-1), and two opposite sides of the third bottom plate (1-3) are used for being in butt joint with the two first bottom plates (1) and are respectively provided with a shear key (6) and a shear key groove (7); two second bolts (5-2) are pre-buried on the side edge of the foundation array of the third bottom plate (1-3), and a shear key (6) is arranged on the side edge of the butt joint of the third bottom plate (1-3) and the sixth bottom plate (1-6);

the fourth to sixth bottom plates are provided with corresponding shear keys (6) and shear key grooves (7) for mutually butting with adjacent bottom plates according to the positions of the fourth to sixth bottom plates in the foundation array.

4. A modular tank foundation according to any one of claims 1-3, characterized in that the fourth base plate (1-4), the fifth base plate (1-5) and the sixth base plate (1-6) are provided with five different specifications of 30cm, 50cm, 70cm, 90cm and 110cm in transverse width.

5. The assembled box transformer substation foundation according to any one of claims 1-3, characterized in that the upright post base (2) is in a quadrangular frustum, and four side surfaces of the upright post base (2) are provided with bolt holes (9) for being matched with third bolts (5-3) and fastened by nuts so as to be connected and fixed with corresponding bottom plates; a fourth bolt (5-4) is pre-embedded on the top surface of the upright post base (2) so as to be connected with the upright post (3);

the bottom end of the upright post (3) is provided with an upright post bottom steel plate (10) which is used for connecting the upright post (3) with the upright post base (2) by matching with a fourth bolt (5-4); the top of the upright post (3) is pre-embedded with an upright post top steel plate (11) for connecting with the box transformer; the thickness of the steel plate (10) at the bottom of the upright post is not less than 15mm, and the thickness of the steel plate (11) at the top of the upright post is not less than 10mm.

6. The assembled box transformer substation foundation according to claim 5, characterized in that the steel plates (10) at the bottom of the upright post and the steel bars bent inwards at the bottom of the longitudinal ribs of the upright post (3) are welded together, the steel plates (11) at the top of the upright post and the steel bars bent inwards at the top of the longitudinal ribs of the upright post (3) are welded together, and then the upright post (3) is formed by formwork casting concrete.

7. An assembled box transformer substation foundation according to any one of claims 1-3, characterized in that six base plates, column bases (2) and columns (3) are provided with pull rings (8) for carrying.

8. The assembled box transformer substation foundation according to any one of claims 1-3, wherein the base plate (1), the upright post base (2) and the upright post (3) are all prefabricated reinforced concrete members, and the bound steel bars are formed by casting through a die at one time and maintained to reach preset strength.

9. The field construction method of the assembled box transformer substation foundation according to any one of claims 1 to 8, comprising the following steps:

s1: measuring and paying off, excavating foundation soil to a specified elevation;

s2: carrying a pre-prepared reinforced concrete bottom plate (1) to a designated position and splicing the reinforced concrete bottom plate;

s3: connecting the spliced bottom plates (1) by using a connecting steel plate (4), and fastening by using nuts;

s4: carrying a pre-prepared reinforced concrete base (2) to a reserved bolt hole (9) of a bottom plate (1) for assembly, and fastening by using a nut;

s5: then carrying the pre-prepared upright post (3) to a reserved bolt hole (9) of the upright post base (2) for assembly, and fastening by using a nut;

s6: sleeving an electric wire connected into a box-type transformer substation by using a PVC pipeline, and performing interface treatment with an underground electric power pipe group at a wire inlet to prevent underground water leakage;

s7: and placing the box-type transformer substation on the upright post (3), performing grounding treatment, installing the electric wire connected into the box-type transformer substation, and backfilling foundation soil.