CN114809065A - A kind of transmission tower foundation structure and construction method - Google Patents

Abstract

The invention discloses a basic structure of a transmission tower, comprising: a raft plate, a force-bearing pile is arranged under the beam intersection point of the raft plate, a sand cushion is laid at the bottom, and ground connecting walls are arranged on four sides; the plate is provided with Reserved holes, which are provided with permeable nets; vertical drainage bodies, which are arranged under the raft and inserted into the sand cushion to improve the efficiency of drainage consolidation; settlement monitoring points, all The settlement monitoring point is set at the top of the ground connecting wall. The ground connection wall and raft foundation of the patent of the present invention greatly improve the integrity of the foundation, and restrain the horizontal displacement of the soil under the foundation, so that the soil drainage and consolidation can be effectively realized; the sand pile used in the patent of the present invention , which can greatly improve the drainage and consolidation efficiency of the foundation soil, shorten the construction period and improve the effective foundation bearing capacity.

Description

A kind of transmission tower foundation structure and construction method

technical field

The invention relates to a transmission tower foundation structure and a construction method, and belongs to the technical field of foundation foundation.

Background technique

In order to achieve the dual carbon goal as soon as possible, the State Grid plans to build "24-14-direct" UHV lines, involving more than 30,000 kilometers of transmission lines, and large-scale transmission of clean energy such as hydropower and wind power in the west to economically developed regions such as the Yangtze River Delta and the Pearl River Delta. . my country has a vast territory and many rivers, and it is inevitable to cross the Yangtze River and other natural moats during the construction of power transmission channels. With the increasing tension of transmission channels, the construction height of towers has gradually increased. At present, the height of the world's largest transmission line tower has reached 385m. For the middle and lower reaches of the Yangtze River, Qiantang River and other watersheds, the soil conditions in some areas along the line are poor, and the bearing layer is mainly composed of deep water-saturated soft clay layers. At present, super-long cast-in-place piles are mainly used for the design of super-large transmission towers. The cost of cast-in-place piles is high, the construction period is long, and the construction of foundation piles in soft soil areas has construction risks such as necking and broken piles, and it is difficult to guarantee the safety of the structure. Therefore, the present inventor proposes an extra-large transmission tower foundation type suitable for the deep water-saturated soft clay layer area.

SUMMARY OF THE INVENTION

The purpose of the present invention is to provide a transmission tower foundation structure and a construction method, so as to solve the defects of low bearing capacity of the existing building foundation in the deep soft clay area, and it is difficult to guarantee the safety and stability in the prior art.

A transmission tower infrastructure, characterized in that it includes:

A raft board, a stress pile is arranged under the beam intersection point of the raft board, a sand cushion layer is laid at the bottom, and ground connecting walls are arranged on the four sides;

The plate is provided with a reserved hole, and a water permeable net is arranged in the reserved hole;

a vertical drainage body, which is arranged under the raft and inserted into the sand cushion to improve the drainage consolidation efficiency;

The settlement monitoring point is set at the top of the ground connecting wall.

Further, at least eight settlement monitoring points are set, and at least two settlement monitoring points are set on each side of the ground connecting wall.

Further, the permeable net comprises a sleeve, a steel mesh is arranged in the sleeve, and a permeable geotextile interlayer is arranged in the middle of the steel mesh.

Further, the stressed pile is one of a screw pile, a cast-in-place pile or a prefabricated pile.

Further, the vertical drainage body is one of sand piles, sand wells or plastic drainage belts.

Further, the ground connecting wall is arranged under the raft in the form of a "field" or a "well".

A construction method for a transmission tower foundation structure, the method comprising the steps of:

S1: Arrange the bearing piles, vertical drainage bodies, sand cushions, ground connecting walls, rafts and permeable nets in sequence;

Carry out measurement and set-out, drive vertical drainage bodies, stress piles at designated positions, arrange ground connecting walls, lay sand cushion after completion, and reserve steel bars or steel joints for ground connecting walls and stress piles, and chisel the tops. The wool and the raft foundation are poured into a whole, and the permeable net is installed at the reserved holes;

S2: Directly carry out the construction of the superstructure on the raft and carry out static stacking at the same time, and arrange the settlement monitoring points on the raft foundation, and adjust the position of the upper load in real time according to the monitoring data until the final foundation settlement is stable.

Compared with the prior art, the present invention has the following beneficial effects: the patented structure of the present invention is simple, reasonable in design, low in construction cost, short in construction period, environmentally friendly, and can effectively reduce the risk of overall collapse caused by foundation settlement and slip;

The ground connection wall and raft foundation of the patent of the present invention greatly improves the integrity of the foundation, and restrains the horizontal displacement of the soil under the foundation, so that the soil drainage and consolidation can be effectively realized;

The vertical drainage body adopted by the patent of the present invention can greatly improve the drainage and consolidation efficiency of the foundation soil, shorten the construction period and improve the effective foundation bearing capacity;

The patent of the invention controls the distribution and size of the applied load on the foundation through the monitoring results of the settlement monitoring points, which can effectively control the stability of the foundation settlement and the overall settlement difference of the foundation.

Description of drawings

Fig. 1 is the overall sectional view of the structure of the present invention;

Fig. 2 is the water permeable net sectional view of the present invention;

Fig. 3 is the construction method flow chart of the present invention;

In the picture: stress pile-1, vertical drainage body-2, ground connection wall-3, raft-4, permeable net-5, settlement monitoring point-6, sand cushion-7, permeable geotextile interlayer-8 , Sleeve-9, Wire mesh-10.

Detailed ways

In order to make the technical means, creative features, achievement goals and effects realized by the present invention easy to understand, the present invention will be further described below with reference to the specific embodiments.

As shown in Figures 1-3, a transmission tower infrastructure is characterized in that it includes:

The raft 4 is provided with a stress pile 1 under the beam intersection point of the raft 4, a sand cushion 7 is laid at the bottom, and ground connecting walls 3 are provided on the four sides;

The raft 4 is provided with a reserved hole, and a water permeable net 5 is arranged in the reserved hole;

The vertical drainage body 2, the vertical drainage body 2 is arranged under the raft 4 and inserted into the sand cushion layer 7 to improve the drainage consolidation efficiency;

The settlement monitoring point 6 is set on the top of the ground connecting wall 3 .

As a priority, the stressed pile 1 is arranged under the junction of the beams of the raft 4 according to the structural stress requirements. It is recommended to select a screw pile. If the soil layer conditions are good, a cast-in-place pile or a prefabricated pile can also be selected;

As a priority, the vertical drainage body 2: one of sand piles, sand wells or plastic drainage belts can be selected, which can be evenly distributed under the foundation of the raft 4 according to the drainage area, and the main function is to accelerate drainage and improve the bearing capacity of the foundation. ;

As a priority, the ground connecting wall 3: It is recommended to use the TRD construction method for construction, and if the foundation required for the building is large, the ground connecting wall can also be added under the raft 4 in the form of "field" or "well". The function is to constrain the soil under the raft 4 to prevent the soil under the raft 4 from having a large displacement to the outside under the load, so as to ensure the effective progress of the hydrostatic drainage consolidation in the later stage;

As a priority, the raft 4: select the beam-slab raft foundation, and reserve holes according to the drainage area, and connect it with the ground connecting wall to form a whole, so that the soil under the raft can only be deformed vertically. To ensure the effective progress of hydrostatic drainage consolidation in the later stage;

As a priority, the permeable net 5 is composed of two upper and lower layers of steel wire mesh and a layer of permeable geotextile in the middle, and is arranged at the reserved hole of the raft to ensure the smooth progress of drainage and effectively prevent the occurrence of piping;

As a priority, six of the settlement monitoring points are arranged on the top of the ground connecting wall, no less than eight, and at least two on each side;

In addition, a construction method for the foundation of a power transmission tower in a deep water-rich saturated soft clay area is provided, and the steps are as follows:

S1: Arrange stress piles, vertical drainage bodies, sand cushions, ground connection walls, rafts, and permeable nets in sequence, measure and set out first, drive sand piles, stress piles, and arrange ground connection After the wall is completed, sand cushion is laid, and steel bar heads or steel bar joints are reserved on the ground connecting wall and stress pile. Settlement monitoring points shall be arranged on the raft foundation, and shall be arranged at the top of the ground connecting wall, no less than eight;

S2: After the foundation strength reaches the standard, the superstructure construction can be directly carried out on the raft and the static stacking can be carried out at the same time. The initial load is borne by the excess static pore water pressure, but with the structural construction, the load increases, and the pore water pressure gradually increases. Dissipate, consolidate the soil, increase the effective stress, and make the final load value 1.1-1.3 times the design load of the superstructure. While stacking, adjust the position of the upper load in real time according to the monitoring data until the final foundation settlement is stable.

The invention has the advantages of simple structure, reasonable design, environmental friendliness, low construction cost and time and labor saving. It can effectively resist the vertical and lateral deformation of the building infrastructure, and is suitable for building buildings in deep soft soil areas.

The above are only the preferred embodiments of the present invention. It should be pointed out that for those skilled in the art, without departing from the technical principle of the present invention, several improvements and modifications can also be made. These improvements and modifications It should also be regarded as the protection scope of the present invention.

Claims (7)

1. a transmission tower infrastructure, is characterized in that, comprises: A raft plate (4), a stress pile (1) is arranged under the beam intersection point of the raft plate (4), a ground connecting wall (3) is arranged on the four sides of the bottom, and a sand cushion layer (7) is laid at the bottom; The raft plate (4) is provided with a reserved hole, and a water permeable net (5) is arranged in the reserved hole; a vertical drainage body (2), the vertical drainage body (2) is arranged under the raft (4) and inserted into the sand cushion layer (7) for improving the drainage consolidation efficiency; A settlement monitoring point (6), the settlement monitoring point (6) is set on the top of the ground connecting wall (3). 2 . The transmission tower infrastructure structure according to claim 1 , wherein at least eight settlement monitoring points ( 6 ) are set, and at least two settlement monitoring points ( 6 ) are set on each side of the ground connecting wall ( 3 ). ). 3. The basic structure of the transmission tower according to claim 1, characterized in that the permeable net (5) comprises a sleeve (9), and a steel wire mesh (10) is arranged in the sleeve (9), and the A permeable geotextile interlayer (8) is arranged in the middle of the steel wire mesh (10). 4 . The transmission tower foundation structure according to claim 1 , wherein the stressed pile ( 1 ) is one of a screw pile, a cast-in-place pile or a prefabricated pile. 5 . 5 . The transmission tower infrastructure structure according to claim 1 , wherein the vertical drainage body ( 2 ) is one of sand piles, sand wells or plastic drainage belts. 6 . 6 . The basic structure of the transmission tower according to claim 1 , wherein the ground connecting wall ( 3 ) is arranged in the form of a “field” or a “well” below the raft ( 4 ). 7 . 7. A construction method for a transmission tower foundation structure, characterized in that the method comprises the steps: S1: Arrange the bearing piles, vertical drainage bodies, sand cushions, ground connecting walls, rafts and permeable nets in sequence; Carry out measurement and set-out, drive vertical drainage bodies, stress piles at designated positions, arrange ground connecting walls, lay sand cushion after completion, and reserve steel bars or steel joints for ground connecting walls and stress piles, and chisel the tops. The wool and the raft foundation are poured into a whole, the permeable net is installed at the reserved holes, and the settlement monitoring points are arranged on the raft foundation; S2: Directly carry out the construction of the superstructure on the raft and carry out static stacking at the same time, and arrange the settlement monitoring points on the raft foundation, and adjust the position of the upper load in real time according to the monitoring data until the final foundation settlement is stable.

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