Cantilever beam reinforced excavation foundation for power transmission line
By setting up a cantilever beam structure connected to the steel cage on the main column of the transmission line foundation, the pull-out resistance and overturning resistance of the foundation are enhanced, solving the problems of large material consumption and complex construction of conventional excavation foundations, and achieving more efficient and safer construction results.
Patent Information
- Authority / Receiving Office
- CN · China
- Patent Type
- Utility models(China)
- Current Assignee / Owner
- Filing Date
- 2025-04-21
- Publication Date
- 2026-04-07
Smart Images
Figure CN224092561U_ABST
Abstract
Description
TECHNICAL FIELD
[0001] The utility model relates to power transmission line tower foundation technical field especially a kind of cantilever beam reinforced type excavation foundation for power transmission line. BACKGROUND
[0002] When the ground of power transmission line belongs to the rock-soil without water, in order to protect the environment and the original landform, the design often adopts the type of excavation foundation. The type is a straight column with internal reinforcement, and the bottom is a circular truncated cone expansion head. The expansion part is plain concrete. When designing the foundation of power transmission line, the downward pressure, uplift force and horizontal force of the tower leg and other working conditions are considered, but the design parameters are often controlled by the uplift force and horizontal force of the tower leg. The characteristics of uplift and horizontal stress of the line foundation are that the bearing capacity is the largest within 3 meters near the ground surface, and the smaller the closer to the lower part of the foundation. The uplift force mainly depends on the side friction between the main column of the excavation foundation and the rock-soil and the embedding effect of the bottom circular truncated cone and the soil. The horizontal force condition, i.e. the anti-overturning condition, mainly depends on the resistance of the lateral soil at the upper part. The slope of the expansion head of the conventional design excavation foundation is not greater than 45 degrees, which can resist the uplift to a certain extent, but because the expansion part of the main column is not reinforced, the tensile property of the concrete expansion head is poor. Therefore, in the design of high-voltage or large-angle towers, or when the foundation outcrop is increased in mountainous and hilly terrain, the side friction and anti-overturning capacity of the conventional straight column excavation foundation are not enough due to the large uplift force and horizontal force, so the buried depth needs to be designed deeper, which requires the diameter of the main column to be increased accordingly, and the expansion head at the bottom also needs to be increased, which will lead to the following problems: 1. The amount of foundation material is increased, and the cost is increased; 2. The amount of excavated original soil is increased, which is difficult to handle and is not conducive to environmental protection; 3. A risk prevention plan for dangerous projects needs to be prepared, and even expert opinions need to be obtained; 4. The risk of workers' excavation work is increased during construction, and even ventilation equipment needs to be added. CONTENT OF THE UTILITY MODEL
[0003] The technical problem to be solved by the utility model is to provide a cantilever beam reinforced type excavation foundation for power transmission line in view of the above problems.
[0004] The technical scheme adopted by the utility model is: a cantilever beam reinforced type excavation foundation for power transmission line, comprising:
[0005] a foundation main column structure, which is internally provided with a steel reinforcement cage;
[0006] at least one set of upper cantilever beam structure, which is vertically arranged on the top outer wall of the foundation main column structure, the upper cantilever beam structure is symmetrically arranged about the axis of the foundation main column structure, and is internally provided with a supporting steel bar, which passes through the inside of the foundation main column structure and is connected with the steel reinforcement cage;
[0007] The bottom cantilever beam structure is vertically arranged on the bottom outer wall of the foundation main column structure, is symmetrically arranged about the axis of the foundation main column structure, and is internally provided with a supporting steel bar.
[0008] By adding the upper cantilever beam structure to the outer wall of the upper part of the foundation main column structure and symmetrically arranging the upper cantilever beam structure, the contact area between the upper cantilever beam structure and the surrounding rock and soil is increased, the overall lateral friction and overturning bending moment of the foundation are effectively improved, and the uplift force is more evenly distributed, thereby reducing the risk of foundation failure caused by local stress concentration. By adding the bottom cantilever beam structure to the outer wall of the bottom of the foundation main column structure, compared with the traditional circular truncated cone enlarged head structure, the uplift resistance is enhanced, the amount of soil and the amount of excavation work are reduced. Meanwhile, the upper and lower cantilever beam structures form a force composite body, which can reduce the amount of material compared with the traditional excavation foundation while ensuring the bearing effect, thereby saving the cost.
[0009] In some embodiments, the upper cantilever beam structure and the bottom cantilever beam structure each include a plurality of cantilever beams vertically connected to the outer wall of the foundation main column structure, the plurality of cantilever beams are arranged in a ring shape and are spaced apart along the outer wall of the foundation main column structure, and the plurality of cantilever beams are symmetric to each other, and the supporting steel bar in the cantilever beam on the same axis is fixedly connected to the steel reinforcement cage.
[0010] In some embodiments, the cantilever beam is arranged in a cross shape or a rice character shape.
[0011] In some embodiments, the arrangement spacing of the upper cantilever beam structure to the top end of the foundation main column structure is 2m-4m.
[0012] In some embodiments, the cross section of the cantilever beam is in a rectangular structure.
[0013] In some embodiments, the upper cantilever beam structure, the bottom cantilever beam structure and the foundation main column structure are integrally formed by pouring concrete.
[0014] The beneficial effects of the utility model are as follows:
[0015] 1、By setting the steel-mix cantilever beam structure on the top outer wall of the foundation main column structure and symmetrically arranging these cantilever beam structures, the contact area between the foundation and the surrounding rock-soil can be significantly increased. Not only the overall side friction of the foundation is effectively improved, but also the uplift force is more evenly distributed, thereby reducing the risk of foundation failure caused by local stress concentration. Compared with the traditional methods of simply increasing the foundation burial depth, increasing the diameter of the main column or increasing the bottom enlarged head, the structural form of the foundation main column structure cooperating with the cantilever beam structure can achieve similar bearing effect without significantly increasing the amount of materials. Not only the cost is saved, but also the construction difficulty and risk are reduced.
[0016] 2、By setting the steel-mix cantilever beam structure at the bottom of the foundation main column structure, the tensile properties of the steel in the structure are fully utilized, the foundation's resistance to uplift and horizontal overturning is enhanced, the amount of concrete of the traditional round-tapered structure is greatly reduced, the foundation depth is reduced, the cost is saved, and the construction difficulty and risk are reduced.
[0017] 3、By connecting the supporting steel in the cantilever beam with the steel cage in the foundation main column structure, the integrity and stiffness of the entire foundation structure are enhanced, which helps to better resist uplift force and overturning load and improve the overall stability of the structure. At the same time, the arrangement structure of the cantilever beam is more adaptable. Combined with the feature that the uplift bearing capacity is maximum near the ground surface, the arrangement form of the cantilever beam can be adjusted in length and quantity to specifically strengthen the uplift performance of the top area of the foundation, making the arrangement of the cantilever beam more flexible and efficient. According to the calculation, compared with the traditional excavation foundation, the new type of foundation saves about 30% of the amount of concrete, about 8% of the amount of steel, and the foundation burial depth can be reduced by 20% to 30%. The effect is particularly obvious for the foundation of ultra-high voltage and above high voltage line engineering. BRIEF DESCRIPTION OF DRAWINGS
[0018] Figure 1 is a schematic diagram of a conventional excavation foundation structure.
[0019] Figure 2 is a schematic diagram of the side view structure of the present application.
[0020] Figure 3 is a schematic diagram of the overhead structure of the cross-shaped arrangement of the cantilever beam in the present application.
[0021] Figure 4 is a schematic diagram of the overhead structure of the rice-shaped arrangement of the cantilever beam in the present application
[0022] BRIEF DESCRIPTION OF DRAWINGS:
[0023] 1, foundation main column structure; 2, upper cantilever beam structure; 3, bottom cantilever beam structure.
[0024] This specification includes references to “one embodiment” or “an embodiment.” The appearance of the phrases “in one embodiment” or “in an embodiment” does not necessarily refer to the same embodiment. Particular features, structures, or characteristics can be combined in any suitable manner in one or more embodiments.
[0025] “includes”, this term is open. As used in the appended claims, this term does not exclude additional structures or steps. DETAILED DESCRIPTION
[0026] In order to make the person skilled in the art better understand the technical scheme of the utility model, the technical scheme of the utility model will be further explained in combination with specific embodiments below.
[0027] Embodiment one:
[0028] Figure 1 A conventional excavation foundation structure is shown, the upper part is a straight column with internal reinforcement, and the bottom is a circular truncated cone-shaped enlarged head, and the enlarged part is plain concrete.
[0029] In combination Figures 2 to 4 As shown in the figure, the embodiment is a cantilever beam reinforced excavation foundation for a power transmission line, which comprises a foundation main column structure 1, at least one set of upper cantilever beam structure 2 and bottom cantilever beam structure 3, the foundation main column structure 1 is internally provided with a steel cage (not shown in the figure), the upper cantilever beam structure 2 is vertically arranged on the top outer wall of the foundation main column structure 1, and the bottom cantilever beam structure 3 is vertically arranged on the bottom outer wall of the foundation main column structure 1, the upper cantilever beam structure 2 and the bottom cantilever beam structure 3 are symmetrically arranged about the axis of the foundation main column structure 1, and the inside of the upper cantilever beam structure 2 and the bottom cantilever beam structure 3 is provided with supporting steel bars (not shown in the figure), which pass through the inside of the foundation main column structure 1 and are connected with the steel cage.
[0030] Specifically, the foundation main column structure 1 in the embodiment comprises a column section, and a steel cage is arranged in the inside in the direction of its own axis.
[0031] In some embodiments, the upper cantilever beam structure 2 and the bottom cantilever beam structure 3 each comprise a plurality of cantilever beams, the plurality of cantilever beams are vertically connected to the outer wall of the foundation main column structure 1, the plurality of cantilever beams are arranged in a ring shape and at intervals along the outer wall of the foundation main column structure 1, and the plurality of cantilever beams are mutually symmetrical, and the supporting steel bars in the cantilever beams on the same axis are fixed by binding at the connection with the steel cage.
[0032] Further, the length and number of the cantilever beams in the embodiment can be adaptively adjusted, and the positional relationship of the upper cantilever beam structure 2 and the bottom cantilever beam structure 3 in the vertical direction can be flexibly adjusted to be corresponding or staggered, so as to specifically enhance the uplift performance of the top area of the foundation, and make the design scheme more flexible and efficient.
[0033] Further, the cross section of the cantilever beam is rectangular, and the cantilever beams are arranged in a cross shape or a rice character shape. Specifically, in the embodiment, the arrangement spacing of the upper cantilever beam structure 2 to the top end of the column section is 2m-4m. When the excavation foundation is constructed, a rectangular cavity is vertically excavated from the column section to a position 2m-4m below the top of the column section in each direction. For the cross shape, the cavity is excavated in four directions, and for the rice character shape, the cavity is excavated in eight directions. The width and length of the rectangular cavity are determined according to the characteristics of the rock and soil and the force required. Similarly, after the foundation main column structure 1 is excavated to the designed depth, a rectangular cavity is vertically excavated in each direction, and a cross shape is generally sufficient, forming the bottom cantilever beam structure 3. Then, a plurality of supporting steel bars are arranged inside the upper and bottom rectangular cavities to cross the steel cage inside the foundation main column structure 1, and the connecting part of the supporting steel bars and the steel cage is bound and fixed. Finally, the foundation main column structure 1 and the cantilever beam are integrally poured and formed by concrete, so that the upper cantilever beam structure 2 and the bottom cantilever beam structure 3 form a cross-shaped or rice character-shaped support, which can effectively resist the uplift force and overturning load of the tower leg.
[0034] The implementation principle of the embodiment of the cantilever beam reinforced excavation foundation for the power transmission line is as follows:
[0035] By arranging a plurality of cantilever beams along the outer wall of the foundation main column structure 1 in a ring direction, relying on the friction between the cantilever beams and the rock and soil, and the mutual symmetry of the cantilever beams, the uplift force and the downward pressure can be more evenly distributed, thereby significantly improving the overall bearing capacity and stability of the foundation. In the embodiment, a cross shape or a rice character shape is used, which can enhance the ability of the foundation to resist forces in different directions and improve the torsional resistance and overall stiffness of the excavation foundation structure.
[0036] The supporting steel bars in the cantilever beam are firmly connected with the steel cage inside the foundation main column structure 1, thereby enhancing the integrity of the entire structure and improving the overall stability and durability of the structure. The foundation main column structure 1, the upper cantilever beam structure 2, and the bottom cantilever beam structure 3 are integrally poured and formed by concrete, thereby reducing the construction joints and improving the integrity of the structure. The excavation foundation structure formed by the cooperation of the foundation main column structure 1, the upper cantilever beam structure 2, and the bottom cantilever beam structure 3 can reduce the foundation depth, the main column diameter, the amount of foundation material, the amount of soil excavation, and the risk of worker operation in deep foundation pits.
[0037] Embodiment two:
[0038] The embodiment is a construction method of a cantilever beam reinforced excavation foundation for a power transmission line, which comprises the following steps:
[0039] S1, preliminary preparation
[0040] Carrying out site investigation and geological exploration to determine the specific location, depth and size of the excavation foundation, and developing detailed construction plans and safety measures.
[0041] S2, manual excavation to the depth of the cantilever beam structure 2
[0042] The excavation work is started manually until the depth of the upper cantilever beam structure 2 required by the design is reached. During the construction process, attention should be paid to maintaining the stability of the pit wall to avoid collapse.
[0043] S3, forming treatment and continuous excavation
[0044] After reaching the depth of the upper cantilever beam structure 2, the excavated space is subjected to necessary forming treatment to ensure the accuracy of the space for placing the reinforcement cage, and then the excavation is continued downward to the predetermined depth of the foundation bottom.
[0045] S4, after the main column is excavated to the predetermined depth, excavate horizontally according to the width and height of the designed bottom cantilever beam structure 3 to reach the predetermined length.
[0046] S5, steel bar arrangement and fixation
[0047] First, place the reinforcement cage of the foundation main column; then, arrange the steel bars of the upper cantilever beam structure 2 and the bottom cantilever beam structure 3 at the predetermined position, and firmly connect the supporting steel bars of the upper cantilever beam structure 2 and the bottom cantilever beam structure 3 with the reinforcement cage of the foundation main column structure 1 through binding to form an integral steel frame.
[0048] S6, one-time pouring of concrete
[0049] After completing the steel bar arrangement and checking for no errors, one-time pouring and forming of concrete is carried out. During the pouring process, ensure uniform distribution and sufficient vibration of the concrete to ensure the integrity and strength of the foundation.
[0050] The above are preferred embodiments of the present utility model, which do not limit the protection scope of the present utility model, therefore: any equivalent changes made according to the structure, shape, principle of the present utility model should be covered within the protection scope of the present utility model.
Claims
1. A cantilever beam reinforced cut-and-cover foundation for power transmission lines, characterized in that, include: The main column structure (1) has a steel cage inside; At least one set of upper cantilever beam structure (2) is vertically set on the top outer wall of the foundation main column structure (1). The upper cantilever beam structure (2) is symmetrically arranged about the axis of the foundation main column structure (1). It is equipped with supporting steel bars inside. The supporting steel bars pass through the interior of the foundation main column structure (1) and are connected to the steel cage. The bottom cantilever beam structure (3) is vertically set on the bottom outer wall of the foundation main column structure (1). The bottom cantilever beam structure (3) is symmetrically arranged about the axis of the foundation main column structure (1). The bottom cantilever beam structure (3) is equipped with supporting steel bars inside. The supporting steel bars pass through the interior of the foundation main column structure (1) and are connected to the steel cage.
2. The cantilever beam reinforced cut-and-cover foundation for transmission lines according to claim 1, characterized in that: Both the upper cantilever beam structure (2) and the bottom cantilever beam structure (3) include multiple cantilever beams. The multiple cantilever beams are vertically connected to the outer wall of the foundation main column structure (1). The multiple cantilever beams are arranged circumferentially and spaced apart along the outer wall of the foundation main column structure (1). The multiple cantilever beams are symmetrical to each other. The supporting steel bars in the cantilever beams on the same axis are tied and fixed at the connection between the steel cage and the steel cage.
3. A cantilever beam reinforced cut-and-cover foundation for transmission lines according to claim 2, characterized in that: The cantilever beams are arranged in a cross or star shape.
4. A cantilever beam reinforced cut-and-cover foundation for transmission lines according to claim 2, characterized in that: The spacing between the upper cantilever beam structure (2) and the top of the foundation main column structure (1) is 2m to 4m.
5. A cantilever beam reinforced cut-and-cover foundation for transmission lines according to claim 2, characterized in that: The cantilever beam has a rectangular cross-section.
6. A cantilever beam reinforced cut-and-cover foundation for transmission lines according to claim 1, characterized in that: The upper cantilever beam structure (2) and the bottom cantilever beam structure (3) are both integrally cast with the foundation main column structure (1) using concrete.