A steel structure assembled root key foundation for power transmission lines and construction method thereof

Abstract

The present invention discloses a steel structure assembled root key foundation and construction method for power transmission lines, wherein the foundation comprises a foundation base plate and a foundation support; the foundation base plate comprises a bottom steel section, a root key connection steel section, a middle steel section and a root key; a plurality of bottom steel sections are arranged at intervals, a plurality of middle steel sections are arranged at intervals and staggered and fixedly connected with the top of the dry bottom steel section; a plurality of root key connection steel sections are staggered and fixedly arranged up and down to form two layers, a plurality of root key connection steel sections on each layer are arranged at intervals, the root key connection steel sections on the lower layer are staggered and fixedly connected with the top of the middle steel section, and the root key connection steel sections on the upper layer are fixedly connected with the bottom of the foundation support; the ends of the root key connection steel sections on each layer are fixedly connected with the root keys, and the root keys extend into the original soil around the foundation pit. The foundation of the present invention is composed entirely of spliced ​​steel components, which are light in weight, easy to transport and install on site, and can achieve the purpose of fast, convenient and economical construction.

Description

Technical Field

[0001] The invention belongs to the field of assembled foundations for power transmission lines, and in particular relates to an assembled steel structure root key foundation for power transmission lines and a construction method thereof. Background Art

[0002] At present, the commonly used large excavation metal plate column prefabricated foundation is suitable for towers with gentle terrain. This type of foundation mainly uses the soil backfilled after excavation disturbance to bear the uplift load, which cannot fully utilize the strength of the original soil. In addition, due to its relatively complex structure, the backfill soil cannot be fully compacted, resulting in low foundation pull-out bearing capacity. In actual application, concrete pouring is added above the bottom plate to encapsulate the bottom plate, which increases the concrete operation process, construction difficulty and construction period. In addition, the existing foundation layout and force transmission form are relatively complex. When the foundation force is large, the number and weight of components increase with the increase of the foundation burial depth, which brings difficulties to transportation and on-site operations. For the excavated plate-column foundation, there is no foundation type that can fully utilize the original soil for uplift bearing on a large scale. In addition, the traditional plate-column foundation adopts a large excavation operation mode, which usually causes large-scale ecological damage when used in complex mountainous terrain. Especially for the foundation with large forces, this type of foundation is not suitable. The plate-column foundation that can fully utilize the original soil strength to resist pull-out and can be used for small-scale mountain excavation operations is still in a technical gap. In general, there are still many problems with the existing prefabricated excavated slab-column foundation, especially in the face of large forces, complex terrain, and fast and convenient construction requirements. There is still a certain gap between actual use and the goal of being light, fast, convenient, and adaptable to various terrains. Therefore, researching and developing a prefabricated foundation with strong pull-out bearing capacity, wide applicability, and easy construction is of great significance to the development of power transmission line repair foundation. Summary of the invention

[0003] The technical problem to be solved by the present invention is that the large-excavation metal plate column assembled foundation commonly used in the prior art cannot fully utilize the strength of the original soil, the backfill soil cannot be fully compacted, the earth excavation area is large, and it cannot be applied to mountainous terrain. The purpose is to propose a steel structure assembled root key foundation and construction method for power transmission lines. The foundation of the present invention is composed entirely of spliced ​​steel components, which are light in weight, easy to transport and install on site, and can achieve the purpose of fast, convenient and economical construction.

[0004] The present invention is achieved through the following technical solutions:

[0005] A steel structure assembled root key foundation for a power transmission line, comprising: a foundation bottom plate and a foundation bracket;

[0006] The foundation bottom plate includes bottom steel, root key connection steel, middle steel and root key; a plurality of bottom steels are arranged at intervals, a plurality of middle steels are arranged at intervals and staggered and fixedly connected with the top of the bottom steel; a plurality of root key connection steels are staggered and fixedly arranged up and down to form two layers, a plurality of root key connection steels on each layer are arranged at intervals, the root key connection steels of the lower layer are staggered and fixedly connected with the top of the middle steel, and the root key connection steels of the upper layer are fixedly connected with the bottom of the foundation bracket;

[0007] The ends of the root key connection steel sections on each layer are fixedly connected to the root keys, and the root keys extend into the original soil around the foundation pit.

[0008] As a further improvement of the present invention, the staggered arrangement is a vertical arrangement.

[0009] As a further improvement of the present invention, the root key end is arranged outside the end of the root key connection steel.

[0010] As a further improvement of the present invention, the lengths of the bottom steel section, the root key connection steel section and the middle steel section are equal to the length of the foundation pit in the corresponding installation direction.

[0011] As a further improvement of the present invention, the foundation pit is a square foundation pit, and the lengths of the bottom steel, the root key connection steel and the middle steel are all equal to the width of the foundation pit.

[0012] As a further improvement of the present invention, the basic support includes a main material, an oblique material and a top material. The bottoms of multiple main materials are fixed to the ends of the root key-connected steel sections, and the tops of multiple main materials are connected to the top material to form a quadrangular pyramid structure; adjacent main materials are directly fixed by oblique materials.

[0013] As a further improvement of the present invention, the top material is higher than the top plane of the foundation pit.

[0014] As a further improvement of the present invention, steel pads are arranged at the gaps of all fixed connections, and all connections are fixed with high-strength bolts; the strength of the high-strength bolts is not less than grade 8.8.

[0015] A construction method for a steel structure assembled root key foundation for a power transmission line comprises the following steps:

[0016] After the excavation of the foundation pit is completed, the bottom of the foundation pit is leveled, and the bottom steel and the middle steel are connected as a whole and lowered to the bottom of the foundation pit;

[0017] Determine the position of the first layer of root keys, push the root keys to the depth determined by theoretical calculation or finite element analysis in the early stage, and connect the root key connecting steel to the bottom steel through the middle steel. Connect the two webs facing the root key through two back-to-back channel steels and fix them; then connect the root key connecting steel to the middle steel;

[0018] Then determine the position of the second layer of root keys, push the root keys into the designed depth, connect the two webs facing the root keys through the root key connecting steel, and then effectively connect the second layer of root keys with the first layer of root keys to complete the splicing of the foundation slab;

[0019] After the foundation slab is spliced, lower the spliced ​​foundation bracket onto the foundation slab, adjust the position of the foundation bracket and fix it.

[0020] The foundation support is assembled in advance through main materials, oblique materials and top materials, and the assembled foundation support is directly connected to the foundation bottom plate during construction.

[0021] Compared with the prior art, the present invention has the following beneficial effects:

[0022] The present invention inserts root keys at the foundation bottom plate and effectively connects all the root keys. The technical solution of the present invention realizes the miniaturization, lightness, standardization, modularization, and batch processing and production of the assembled foundation. By inserting the root keys into the surrounding original soil at the foundation bottom plate, the bearing capacity of the original soil can be fully utilized, the foundation pull-out bearing capacity is increased, the foundation pit excavation area is small, and it can be used in complex mountainous terrain. At the same time, the foundation is entirely composed of spliced ​​steel components, which are light in weight, easy to transport and install on site, and can achieve the purpose of fast, convenient, and economical construction. It improves the pull-out bearing capacity of the transmission line tower foundation, reduces the foundation pit volume, saves foundation size, material quantity, and construction period, and can be used in complex mountainous terrain. Compared with conventional foundations, this foundation shortens the construction period by 1 / 3 and improves the bearing capacity by 50%. BRIEF DESCRIPTION OF THE DRAWINGS

[0023] The drawings described herein are for explanation purposes only and are not intended to limit the scope of the present invention in any way. In addition, the shapes and proportional dimensions of the components in the drawings are only for illustration purposes to help understand the present invention, and are not intended to specifically limit the shapes and proportional dimensions of the components of the present invention. In the drawings:

[0024] Figure 1 It is a side elevation view of a steel structure assembled root key foundation for a power transmission line according to the present invention.

[0025] Figure 2 It is a front elevation view of a steel structure assembled root key foundation for a power transmission line according to the present invention.

[0026] Figure 3 The present invention is a top view of a steel structure assembled root key foundation base plate for a power transmission line.

[0027] Figure 4 The present invention is a vertical view of a steel structure assembled root key foundation base plate for a power transmission line.

[0028] In the figure, 1-bottom steel, 2-key connecting steel, 3-middle steel, 4-key, 5-main material, 6-oblique material, 7-top material, 8-high-strength bolts, 9-steel pads. DETAILED DESCRIPTION

[0029] In order to enable those skilled in the art to better understand the technical solutions in the present invention, the technical solutions in the embodiments of the present invention will be clearly and completely described below in conjunction with the drawings in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work should fall within the scope of protection of the present invention.

[0030] It should be noted that when an element is referred to as being "disposed on" another element, it may be directly on the other element or there may be a central element. When an element is considered to be "connected to" another element, it may be directly connected to the other element or there may be a central element at the same time. The terms "vertical", "horizontal", "left", "right" and similar expressions used herein are for illustrative purposes only and are not intended to be the only embodiment.

[0031] Unless otherwise defined, all technical and scientific terms used herein have the same meaning as those commonly understood by those skilled in the art to which the present invention belongs. The terms used herein in the specification of the present invention are only for the purpose of describing specific embodiments and are not intended to limit the present invention. The term "and / or" used herein includes any and all combinations of one or more of the related listed items.

[0032] like Figure 1-4 As shown, a steel structure assembled root key foundation for a power transmission line includes a foundation bottom plate and a foundation bracket;

[0033] The foundation bottom plate includes a bottom steel 1, a root key connection steel 2, a middle steel 3 and a root key 4; a plurality of bottom steels 1 are arranged at intervals, a plurality of middle steels 3 are arranged at intervals and staggered and fixedly connected to the top of the bottom steel 1; a plurality of root key connection steels 2 are staggered and fixedly arranged up and down to form two layers, a plurality of root key connection steels 2 on each layer are arranged at intervals, the root key connection steels 2 of the lower layer are staggered and fixedly connected to the top of the middle steel 3, and the root key connection steels 2 of the upper layer are fixedly connected to the bottom of the foundation bracket;

[0034] The ends of the root key connection steel sections 2 on each layer are fixedly connected to the root keys 4, and the root keys 4 extend into the original soil around the foundation pit.

[0035] The basic support includes a main material 5, an oblique material 6 and a top material 7. The bottoms of multiple main materials 5 are fixed to the ends of the root key connection steel 2, and the tops of multiple main materials 5 are connected to the top material 7 to form a quadrangular pyramid structure; adjacent main materials 5 are directly fixed by oblique materials 6.

[0036] As a preferred embodiment, the staggered arrangement is a vertical arrangement.

[0037] The end of the root key 4 is sleeved outside the end of the root key connection steel 2. The lengths of the bottom steel 1, the root key connection steel 2 and the middle steel 3 are equal to the length of the foundation pit corresponding to the installation direction.

[0038] The root key 4 has two layers, the first layer is the front and back sides, and the second layer is the left and right sides. Figure 3 The first and second root keys of Figure 3 The root keys for the left and right directions are on the top, and the root keys for the front and back directions are on the bottom.

[0039] The lengths of the bottom steel 1, the root key connection steel 2 and the middle steel 3 are all equal to the width of the foundation pit.

[0040] The top material 7 is higher than the top plane of the foundation pit. Steel pads 9 are arranged at the gaps of the fixed connections, and all the connections are fixed with high-strength bolts 8; the strength of the high-strength bolts is not less than grade 8.8.

[0041] The bottom steel 1, root key connection steel 2, middle steel 3, root key 4, main material 5, diagonal material 6, top material 7 and steel pad 9 should be reserved with holes required for connection with high-strength bolts 8 in advance. The diameter of the holes should be slightly larger than the diameter of the high-strength bolts 8 to facilitate later adjustments.

[0042] At the foundation bottom plate, a root key 4 is pushed into the surrounding original soil.

[0043] The root key 4 can also be replaced by a steel root key of a channel steel, an H-shaped steel or other types. The bottom plate profile adopts a bottom steel or an I-shaped steel, and the middle steel 3 can all be replaced by steel members of H-shaped, I-shaped or other types.

[0044] The bottom steel section 1 and the middle steel section 3, the main material 5, the diagonal material 6 and the top material 7 can be assembled in advance. During construction, the assembled basic support can be directly connected to the bottom plate to reduce assembly time.

[0045] The number of root keys 4 and the strength of high-strength bolts 8 can be determined through theoretical calculation or finite element analysis according to the different levels of power transmission lines and the different required pull-out bearing capacities.

[0046] The main base material is composed of four angle steels, which are tilted upward and intersect at the same point, at which the top material is arranged. The root key inside the bottom plate needs to be driven into the surrounding original soil by a jack. The channel steel and the root key inside the bottom plate, as well as the middle steel, the foundation bottom plate and the foundation support, the main material and the oblique material, and the main material and the top material are connected and fixed by high-strength bolts, and the strength of the high-strength bolts is not less than grade 8.8.

[0047] When all the components are processed in the factory, their surfaces need to be coated with a certain thickness of anti-corrosion material for corrosion protection, and different anti-corrosion thicknesses are used for components with different anti-corrosion years according to specification requirements.

[0048] When in use, all steel components are prefabricated according to the design specifications. When selecting the strength of the high-strength bolts 8, it is necessary to perform simulation analysis through theoretical calculation or finite element software to calculate the stress value at the bolt connection node, and select bolts of corresponding strength based on the calculated stress value.

[0049] At the construction site, the bottom steel section 1 can be connected to the middle steel section 3 in advance according to the designed spacing through high-strength bolts 8 to form a whole. At the same time, the diagonal material 6 and the top material 7 can be fixed to the main material 5 through high-strength bolts 8 in advance to form a basic support structure. When assembling the basic support structure, the theodolite and ruler should be continuously used for observation to discover the offset of the center point of the basic support as early as possible.

[0050] The present invention also provides a construction method for a steel structure assembled root key foundation for a power transmission line, comprising the following steps:

[0051] After the foundation pit is excavated, the bottom of the foundation pit is leveled, and the bottom steel 1 connected with the middle steel 3 is lowered to the bottom of the foundation pit;

[0052] Determine the position of the first layer of root key 4, push the root key 4 to the depth determined by theoretical calculation or finite element analysis in the early stage, fix the root key connection steel 2 with the bottom steel 1 through the middle steel 3, connect and fix the two webs facing the root key 4 through two back-to-back root key connection steels 2; then connect the root key connection steel 2 with the middle steel 3;

[0053] Then determine the position of the second layer root key 4, push the root key 4 to the designed depth, connect the two webs facing the root key 4 through the root key connecting steel 2, and then effectively connect the second layer root key 4 with the first layer root key 4 to complete the splicing of the foundation bottom plate;

[0054] After the foundation slab is spliced, lower the spliced ​​foundation bracket onto the foundation slab, adjust the position of the foundation bracket and fix it.

[0055] The foundation support is assembled in advance through the main material 5, the oblique material 6 and the top material 7, and the assembled foundation support is directly connected to the foundation bottom plate during construction.

[0056] The present invention is described in detail below with reference to specific embodiments.

[0057] Example

[0058] like Figure 1-4 As shown, a steel structure assembled root key foundation and construction method for a power transmission line include a steel structure assembled root key foundation and construction method for a power transmission line, including a foundation base plate and a foundation bracket, the foundation base plate is composed of a bottom channel steel, a root key connecting channel steel, an H-shaped steel, an I-beam root key 4, a high-strength bolt 8 and a steel pad 9, and the foundation bracket is composed of a main material 5, an oblique material 6, a top material 7 and a high-strength bolt 8.

[0059] Carry out foundation pit excavation. After the excavation is completed, level the bottom of the foundation pit, lower the whole connected with the bottom channel steel and H-shaped steel to the bottom of the foundation pit, and use the theodolite, ruler, etc. to position it to ensure that the error is small during placement, which can effectively reduce the workload of later adjustments.

[0060] The insertion and connection of the I-beam root key, determine the position of the first layer of I-beam root key 4, use a jack to push the I-beam root key 4 at this position to the depth determined in the early stage through theoretical calculation or finite element analysis, and correct the position of the I-beam root key 4, the first layer of root key 4 and the bottom channel steel are fixedly connected by high-strength bolts 8, and the two webs facing the I-beam root key 4 are connected by two back-to-back channel steels and fixed by high-strength bolts 8. Then, the root key connecting channel steel and the H-shaped steel are connected by high-strength bolts 8. Since the height of the connecting channel steel is lower than the I-beam root key 4, there is a certain gap between the connecting channel steel and the lower layer of H-shaped steel. In order to ensure the stability of the structure, a steel pad 9 of a certain size needs to be placed in the gap. Then, the position of the second layer of I-beam root key 4 is determined. At this position, the I-beam root key 4 is pushed into the designed depth with a jack. Similar to the construction method of the first layer of root key, the two webs facing the I-beam root key 4 are connected by the root key connecting channel steel. Then, the second layer of I-beam root key 4 is effectively connected to the first layer of I-beam root key 4. Steel pads 9 also need to be arranged at the gaps. All connections are fixed with high-strength bolts 8 to complete the splicing of the foundation slab.

[0061] Due to the compaction and stress diffusion effect of the jacking root key, the bearing potential of the soil around the foundation is fully mobilized, and the soil's grip and resistance to the root key are used to improve the bearing capacity. At present, the pull-out bearing of the power transmission line slab-column foundation is the main controlling condition. The present invention pushes a new structure - an I-beam root key 4 - into the original soil around the foundation, making full use of the characteristic that the original soil has better bearing capacity than compacted backfill soil, so that its pull-out bearing capacity is significantly higher than that of the traditional metal assembled foundation, changing the current situation where the assembled slab-column foundation can only use backfill soil for bearing.

[0062] Through finite element analysis, it is found that the pull-out bearing capacity of this foundation is more than 50% higher than that of the traditional metal prefabricated foundation when the base plate area and burial depth are the same. Since the pull-out bearing capacity of the foundation is mainly provided by the I-beam root key 4, when connecting the base plate I-beam root keys 4, it is necessary to ensure that the high-strength bolts 8 are tightened and installed firmly according to the connection verification calculation.

[0063] Installation of the foundation bracket: After the foundation base plate is spliced, the already spliced ​​foundation bracket is placed on the foundation base plate, the position of the foundation bracket is adjusted, the bolt holes reserved in the upper structure are aligned with the bolt holes reserved in the foundation base plate, and they are connected and fixed by high-strength bolts 8. Thus, the assembly of the entire steel structure assembled root key foundation is completed.

[0064] For other technologies, refer to the prior art.

[0065] It should be noted that, in the description of the present invention, the terms "first", "second", etc. are only used for descriptive purposes and to distinguish similar objects. There is no order of precedence between the two, and they cannot be understood as indicating or implying relative importance. In addition, in the description of the present invention, unless otherwise specified, "plurality" means two or more.

[0066] It should be understood that the above description is for illustration and not for limitation. Many embodiments and many applications beyond the examples provided will be apparent to those skilled in the art upon reading the above description. Therefore, the scope of the present teachings should not be determined with reference to the above description, but rather with reference to the foregoing claims and the full scope of equivalents to which such claims are entitled. For the purpose of comprehensiveness, all articles and references, including disclosures of patent applications and publications, are incorporated herein by reference. The omission of any aspect of the subject matter disclosed herein in the foregoing claims is not intended to be a waiver of such subject matter, nor should it be considered that the applicant has not considered such subject matter to be part of the disclosed inventive subject matter.

Claims

1. A construction method for a steel structure assembled root key foundation for a power transmission line, characterized in that: The steel structure assembled root key foundation comprises: a foundation base plate and a foundation bracket; The foundation bottom plate comprises a bottom steel section (1), a root key connection steel section (2), a middle steel section (3) and a root key (4); a plurality of bottom steel sections (1) are arranged at intervals, a plurality of middle steel sections (3) are arranged at intervals and are staggered and fixedly connected to the top of the bottom steel section (1); a plurality of root key connection steel sections (2) are staggered and fixedly arranged up and down to form two layers, a plurality of root key connection steel sections (2) on each layer are arranged at intervals, the root key connection steel sections (2) of the lower layer are staggered and fixedly connected to the top of the middle steel sections (3), and the root key connection steel sections (2) of the upper layer are fixedly connected to the bottom of the foundation support; The ends of the root key connection steel (2) on each layer are fixedly connected to the root key (4), and the root key (4) extends into the original soil around the foundation pit; The construction method comprises the following steps: After the excavation of the foundation pit is completed, the bottom of the foundation pit is leveled, and the bottom steel section (1) connected with the middle steel section (3) is lowered to the bottom of the foundation pit; The position of the first layer root key (4) is determined, and the root key (4) is pushed in to the depth determined in the previous stage. The root key connecting steel (2) is fixedly connected to the bottom steel (1) through the middle steel (3), and the two webs facing the root key (4) are connected and fixed through two root key connecting steels (2) arranged in a back-to-back manner; then, the root key connecting steel (2) is connected to the middle steel (3); Then, the position of the second layer root key (4) is determined, the root key (4) is pushed in to the designed depth, the two webs facing the root key (4) are connected through the root key connecting steel (2), and then the second layer root key (4) is effectively connected to the first layer root key (4), thereby completing the splicing of the foundation bottom plate; After the foundation slab is spliced, lower the spliced ​​foundation bracket onto the foundation slab, adjust the position of the foundation bracket and fix it.

2. The construction method of a steel structure assembled root key foundation for a power transmission line according to claim 1, characterized in that: The staggered arrangement is a vertical arrangement.

3. The construction method of a steel structure assembled root key foundation for a power transmission line according to claim 1, characterized in that: The end of the root key (4) is arranged outside the end of the root key connection steel (2).

4. The construction method of a steel structure assembled root key foundation for a power transmission line according to claim 1, characterized in that: The lengths of the bottom steel section (1), the root key connection steel section (2) and the middle steel section (3) are equal to the length of the foundation pit in the corresponding installation direction.

5. The construction method of a steel structure assembled root key foundation for a power transmission line according to claim 1, characterized in that: The foundation pit is a square foundation pit, and the lengths of the bottom steel (1), the root key connection steel (2) and the middle steel (3) are all equal to the width of the foundation pit.

6. A construction method for a steel structure assembled root key foundation for a power transmission line according to any one of claims 1 to 5, characterized in that: The basic support comprises a main material (5), an oblique material (6) and a top material (7); the bottoms of a plurality of main materials (5) are fixed to the ends of the root key connection steel (2); the tops of a plurality of main materials (5) are connected to the top material (7) to form a quadrangular pyramid structure; adjacent main materials (5) are directly fixed by oblique tension through the oblique materials (6).

7. A construction method for a steel structure assembled root key foundation for a power transmission line according to claim 6, characterized in that: The top material (7) is higher than the top plane of the foundation pit.

8. The construction method of a steel structure assembled root key foundation for a power transmission line according to claim 6, characterized in that: Steel pads (9) are arranged at the gaps of all fixed connections, and all connections are fixed with high-strength bolts (8); the strength of the high-strength bolts is not less than grade 8.

8.

9. The construction method of a steel structure assembled root key foundation for a power transmission line according to claim 1, characterized in that: The foundation support is assembled in advance by means of a main material (5), an oblique material (6) and a top material (7), and during construction, the assembled foundation support is directly connected to the foundation bottom plate.

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