CN115354882A - Method for dismantling ultra-large spanning old electric tower - Google Patents
Method for dismantling ultra-large spanning old electric tower Download PDFInfo
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- CN115354882A CN115354882A CN202210836206.2A CN202210836206A CN115354882A CN 115354882 A CN115354882 A CN 115354882A CN 202210836206 A CN202210836206 A CN 202210836206A CN 115354882 A CN115354882 A CN 115354882A
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- E—FIXED CONSTRUCTIONS
- E04—BUILDING
- E04G—SCAFFOLDING; FORMS; SHUTTERING; BUILDING IMPLEMENTS OR AIDS, OR THEIR USE; HANDLING BUILDING MATERIALS ON THE SITE; REPAIRING, BREAKING-UP OR OTHER WORK ON EXISTING BUILDINGS
- E04G23/00—Working measures on existing buildings
- E04G23/08—Wrecking of buildings
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- E—FIXED CONSTRUCTIONS
- E04—BUILDING
- E04H—BUILDINGS OR LIKE STRUCTURES FOR PARTICULAR PURPOSES; SWIMMING OR SPLASH BATHS OR POOLS; MASTS; FENCING; TENTS OR CANOPIES, IN GENERAL
- E04H12/00—Towers; Masts or poles; Chimney stacks; Water-towers; Methods of erecting such structures
- E04H12/02—Structures made of specified materials
- E04H12/08—Structures made of specified materials of metal
- E04H12/10—Truss-like structures
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- E—FIXED CONSTRUCTIONS
- E04—BUILDING
- E04H—BUILDINGS OR LIKE STRUCTURES FOR PARTICULAR PURPOSES; SWIMMING OR SPLASH BATHS OR POOLS; MASTS; FENCING; TENTS OR CANOPIES, IN GENERAL
- E04H12/00—Towers; Masts or poles; Chimney stacks; Water-towers; Methods of erecting such structures
- E04H12/24—Cross arms
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- G—PHYSICS
- G06—COMPUTING; CALCULATING OR COUNTING
- G06F—ELECTRIC DIGITAL DATA PROCESSING
- G06F30/00—Computer-aided design [CAD]
- G06F30/20—Design optimisation, verification or simulation
- G06F30/23—Design optimisation, verification or simulation using finite element methods [FEM] or finite difference methods [FDM]
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- G—PHYSICS
- G06—COMPUTING; CALCULATING OR COUNTING
- G06F—ELECTRIC DIGITAL DATA PROCESSING
- G06F2119/00—Details relating to the type or aim of the analysis or the optimisation
- G06F2119/14—Force analysis or force optimisation, e.g. static or dynamic forces
Abstract
The invention discloses a method for dismantling an ultra-large spanning old electric tower, which comprises the following steps: erecting a simple hoisting device on the ground wire support, and hoisting and dismantling two single section mineshafts at the uppermost part of the mineshafts by using the simple hoisting device; installing a traveling crane at the top of the tower body to remove the residual single section of shaft; after the shaft is dismantled, a double-horizontal-arm holding pole is built at the position of the original shaft, and two ground wire supports are hoisted and dismantled simultaneously by using two hoisting arms of the double-horizontal-arm holding pole; hoisting and dismantling two wire cross arms simultaneously by using two hoisting arms; and hoisting and dismantling the tower body by utilizing the double-flat-arm holding rod. The invention provides some key mechanical parameters and data for three key dismantling processes of shaft dismantling, ground wire bracket dismantling and lead cross arm dismantling by using a mechanical finite element method, thereby ensuring the high efficiency and safety of field construction and playing a certain role in guiding and promoting the aspects of improving the construction efficiency, standardizing the construction method, optimizing the construction process, improving the economic benefit and the like.
Description
Technical Field
The invention relates to the demolition of an ultra-large spanning old electric tower, in particular to a method for demolishing an ultra-large spanning old electric tower.
Background
In order to newly build a project of a white crane beach-Jiangsu +/-800 KV extra-high voltage direct current transmission line, the built +/-500 kV Long Zheng line needs to be dismantled from a spanning tower of a Yangtze river large spanning section. The long-span large-span tower of +/-500 kV Long Zheng line is built in 2000 years, and two base strain towers and two base straight-line span towers are adopted in the whole section, so that four base towers are used. Is positioned at the place of 300m far across the upstream of the Changjiang river of the 500kV Chuzhou transformation-Maanshan switching station double-circuit line. The north bank crossing tower is positioned on the north side of Zheng Pugang new area small Zhu Zhuangdong in Maanshan city, and the south bank crossing tower is positioned on the east side of Liang Sheou villages in economic development area of Wuhu lake city. The current situations of the south-north crossing tower and the anchor tower are farmlands, the topography is flat, and the south-north crossing tower and the anchor tower are parallel to the existing river-crossing power line. The crossing length Jiang Jiang is about 1430m wide and the embankment distance is about 1650m. The total length of the tension resistant section is 3050 meters, wherein the distance between the two spanning towers is 1910 meters. The normal water width at the crossing is about 1400 meters, and the maximum water width is about 1620 meters. And the single-loop power transmission is realized, and the positive and negative conductors are all split into four parts. The total height of the two-base strain tower is 40 meters, the root of the two-base strain tower spans the tower foundation by 46 meters, the total height of the iron tower is 216 meters, the total height is 229 meters, the cross section size of the tower top is 3 meters multiplied by 6 meters, the weight of a single base is 1020 tons (containing an elevator and a shaft), and the two-base strain tower is a steel pipe structure tower connected by bolts in a shape like a Chinese character 'gan'. Wherein the two-base spanning tower belongs to an ultra-large tower. The overall structural design of the old tower is shown in fig. 1, the structure is divided into 20 sections from top to bottom, and the shaft is positioned at the central position.
At present, the dismantling of the full-height 229 m ultra-large spanning old electric tower is not precedent at home and abroad. Aiming at the actual situation of the full-height 229 m ultra-large spanning old electric tower, how to provide technology and safety measures in the process of dismantling the old electric tower to ensure that the dismantling construction task of a large spanning tower with a +/-500 kV Long Zheng line length is completed safely, excellently and efficiently is a technical problem faced at present.
Disclosure of Invention
Aiming at the technical problem existing in the prior art of dismantling the ultra-large spanning old electric tower, the invention provides a method for dismantling the ultra-large spanning old electric tower, which can dismantle the ultra-large spanning old electric tower safely and efficiently.
The invention adopts the following technical scheme:
a method for dismantling an ultra-large crossing old electric tower comprises a tower body, wherein the left side and the right side of the top of the tower body are respectively provided with a wire cross arm, the top of the tower body is provided with two inclined ground wire supports, the center inside the tower body is provided with a shaft, and the shaft is formed by connecting a plurality of single shafts up and down;
the dismantling method comprises the following steps:
step 1: erecting a simple hoisting device on the ground wire support, and hoisting and dismantling two single section mineshafts at the uppermost part of the mineshafts by using the simple hoisting device;
and 2, step: installing a traveling crane at the top of the tower body to remove the residual single section of shaft;
and step 3: after the shaft is removed, a double-flat-arm holding pole is built at the position of the original shaft, the double-flat-arm holding pole comprises a holding pole main body, a left suspension arm and a right suspension arm are arranged at the upper part of the holding pole main body, and the two ground wire supports are simultaneously hoisted and removed by utilizing the two suspension arms;
and 4, step 4: hoisting and dismantling two wire cross arms simultaneously by using two hoisting arms;
and 5: and hoisting and dismantling the tower body by utilizing the double-flat-arm holding rod.
Preferably, step 1 specifically comprises:
step 1.1: after the simple hoisting device is erected, establishing a first calculation analysis model of the old electric tower by using finite element software;
step 1.2: selecting the heaviest parts in the two single-section mineshafts at the uppermost part of the mineshafts, calculating the value of the maximum stress sigma 1max in the tower body structure through a first calculation analysis model when the heaviest parts in the two single-section mineshafts are just lifted by the simple hoisting device, calculating the value of the maximum stress sigma 1max 'in the tower body structure when the heaviest parts in the two single-section mineshafts are just descended by the simple hoisting device, and comparing the values of the maximum stress sigma 1max and sigma 1max' with the yield limit sigma 1s of the old electric tower material;
step 1.3: if and only if the values of the maximum stresses σ 1max and σ 1max' are both less than the yield limit σ 1s of the old electric tower material, then it is safe to remove the two single sections of the uppermost wellbore, then step 1.6 is performed;
step 1.4: if the value of the maximum stress sigma 1max or sigma 1max' is larger than the yield limit sigma 1s of the old electric tower material, the two single sections of the uppermost part of the shaft are unsafe to be dismantled, and the included angle of the steel wire rope of the bearing section in the simple hoisting device needs to be readjusted to reduce the equivalent force of the hoisted part on the tower body structure;
step 1.5: re-establishing a new first calculation analysis model of the old electric tower, and repeating the steps 1.2 to 1.5;
step 1.6: and (4) performing field construction, and disassembling, hoisting and disassembling the two single-section mineshafts.
Preferably, step 2 specifically comprises:
step 2.1: after the travelling crane is installed, establishing a second calculation analysis model of the old electric tower, calculating the value of the maximum stress sigma 2max in the tower body structure when the travelling crane is just lifted to n single-section mineshafts by using the second calculation analysis model, calculating the value of the maximum stress sigma 2max 'in the tower body structure when the travelling crane is just descended to the n single-section mineshafts, and selecting the maximum value of the maximum stress sigma 2max and the maximum stress sigma 2max' to compare with the yield limit sigma 1s of the material of the old electric tower;
step 2.2: when the maximum value of the maximum stress sigma 2max and sigma 2max' is smaller than and close to the yield limit sigma 1s of the old electric tower material, the driving is proved to be theoretically safe for the simultaneous hoisting of n single-section wellshafts;
step 2.3: during on-site construction, the driving vehicle is used for simultaneously hoisting n-1 single-section mineshafts until the mineshafts are completely dismantled, and then the driving vehicle is dismantled.
Preferably, step 3 specifically comprises: the pole body is fixedly connected with the tower body through a plurality of waist ring components, and each waist ring component comprises a waist ring and a waist ring stay wire;
step 3.1: establishing a third calculation analysis model of the electric tower with the double-flat-arm holding pole by using finite element software;
step 3.2: each suspension arm is connected with a sliding crane, each crane is connected with a ground wire support through a steel wire rope, and the ground wire support can be shaken instantly when being separated from the tower body during actual hoisting, so that the cranes have a pulling force of a pre-hoisting steel wire rope on the ground wire support through the steel wire rope, and the optimal value of the pulling force of the pre-hoisting steel wire rope is obtained through multiple calculations of a third calculation analysis model;
step 3.3: calculating to obtain the value of the maximum stress sigma 3max in the whole tower body when the suspension arm just lifts the ground wire support by utilizing a third calculation analysis model, and calculating the value of the maximum stress sigma 3max' in the whole tower body when the suspension arm just descends the ground wire support;
calculating to obtain a value of the maximum stress sigma 4max in the double-flat-arm holding pole when the suspension arm just lifts the ground wire support, and calculating to obtain a value of the maximum stress sigma 4max' in the double-flat-arm holding pole when the suspension arm just descends the ground wire support;
comparing the values of the maximum stresses σ 3max and σ 3max' with the yield limit σ 1s of the old electric tower material;
comparing the values of the maximum stress sigma 4max and sigma 4max' with the yield limit sigma 2s of the double-flat-arm holding pole material;
step 3.4: if the values of the maximum stress sigma 3max and sigma 3max 'are smaller than the yield limit sigma 1s of the old electric tower material, and the values of the maximum stress sigma 4max and sigma 4max' are smaller than the yield limit sigma 2s of the double-flat-arm holding pole material, the dismounting of the two ground wire brackets is proved to be safe, and the step 3.7 is executed;
step 3.5: if the value of the maximum stress sigma 3max or sigma 3max' is larger than the yield limit sigma 1s of the old electric tower material, the tower body structure is proved unsafe when the two ground wire supports are dismantled; a rod piece at the maximum stress position corresponding to the maximum stress value larger than the yield limit sigma 1s of the old electric tower material needs to be found, and the rod piece at the maximum stress position needs to be reinforced;
if the value of the maximum stress sigma 4max or sigma 4max' is larger than the yield limit sigma 2s of the double-flat-arm holding pole material, the fact that the double-flat-arm holding pole structure is unsafe when the two ground wire supports are dismantled proves that a pole piece at the maximum stress position corresponding to the maximum stress value larger than the yield limit sigma 2s of the double-flat-arm holding pole material needs to be found, and the pole piece at the maximum stress position needs to be reinforced;
step 3.6: re-establishing a third calculation analysis model of the modified electric tower with the double-flat-arm holding pole, and repeating the steps 3.2 to 3.6;
step 3.7: and (4) in site construction, the two ground wire supports are hoisted and dismounted simultaneously by utilizing the double-flat-arm holding pole.
Preferably, step 4 specifically includes:
step 4.1: establishing a fourth computational analysis model of the electric tower with the double-horizontal-arm holding pole by using finite element software;
and 4.2: during actual hoisting, the wire cross arm can be flashed at the moment of separating from the tower body, so that the crane has a tension of a pre-hoisting wire rope on the wire cross arm through the wire rope, and the optimal value of the tension of the pre-hoisting wire rope is obtained through multiple calculations by a fourth calculation analysis model;
step 4.3: calculating to obtain the value of the maximum stress sigma 5max in the whole tower body when the suspension arm just lifts the wire cross arm by utilizing a fourth calculation analysis model, and calculating the value of the maximum stress sigma 5max' in the whole tower body when the suspension arm just descends the wire cross arm;
calculating to obtain a value of the maximum stress sigma 6max in the double-flat-arm holding pole when the suspension arm just lifts the wire cross arm, and calculating to obtain a value of the maximum stress sigma 6max' in the double-flat-arm holding pole when the suspension arm just descends the wire cross arm;
comparing the values of the maximum stresses σ 5max and σ 5max' with the yield limit σ 1s of the used electric tower material;
comparing the values of the maximum stress sigma 6max and sigma 6max' with the yield limit sigma 2s of the double-flat-arm holding pole material;
step 4.4: if the values of the maximum stress sigma 5max and sigma 5max 'are smaller than the yield limit sigma 1s of the material of the old electric tower, and the values of the maximum stress sigma 6max and sigma 6max' are smaller than the yield limit sigma 2s of the material of the double-flat-arm holding pole, the dismounting of the two wire cross arms is proved to be safe, and the step 4.7 is executed;
step 4.5: if the value of the maximum stress sigma 5max or sigma 5max' is larger than the yield limit sigma 1s of the old electric tower material, the tower body structure is proved unsafe when the two lead cross arms are dismantled, a rod piece at the maximum stress position corresponding to the maximum stress value larger than the yield limit sigma 1s of the old electric tower material needs to be found, and the rod piece at the maximum stress position needs to be reinforced;
if the value of the maximum stress sigma 6max or sigma 6max' is larger than the yield limit sigma 2s of the double-flat-arm holding pole material, the double-flat-arm holding pole structure is proved to be unsafe when the two lead cross arms are dismantled, a rod piece at the maximum stress position corresponding to the maximum stress value larger than the yield limit sigma 2s of the double-flat-arm holding pole material needs to be found, and the rod piece at the maximum stress position needs to be reinforced;
step 4.6: re-establishing a fourth calculation analysis model of the electric tower containing the double-flat-arm holding pole after correction, and repeating the steps from 4.2 to 4.6;
step 4.7: and in site construction, the two wire cross arms are hoisted and removed simultaneously by utilizing the double-flat-arm holding rod.
The invention has the beneficial effects that:
according to the method for dismantling the ultra-large spanning old electric tower, the shaft is dismantled firstly, then the double-flat-arm holding rod is built at the shaft position to dismantle the ground wire support, the wire cross arm and the tower body, and in the process, a mechanical finite element method is used for providing key mechanical parameters and data for three key dismantling processes of shaft dismantling, ground wire support dismantling and wire cross arm dismantling, so that the method can ensure the high efficiency and safety of field construction, and plays a certain guiding and promoting role in improving the construction efficiency, standardizing the construction method, optimizing the construction process, improving the economic benefit and the like.
Drawings
Fig. 1 is a general structural view of a used electric tower.
Figure 2 is a schematic illustration of the uppermost two individual well bores removed.
FIG. 3 is a diagram of a first computational analysis model.
Figure 4 is a schematic view of a lumbar ring assembly.
FIG. 5 is a diagram of a third computational analysis model.
Fig. 6 is a schematic diagram of a hoisting ground wire bracket.
Fig. 7 is a schematic view of a hoisting wire cross arm.
Detailed Description
The following description of the embodiments of the present invention will be made with reference to the accompanying drawings:
example 1
With reference to fig. 1 to 7, a method for dismantling an ultra-large type crossing old electric tower comprises a tower body, wherein the left side and the right side of the top of the tower body are respectively provided with a wire cross arm, the top of the tower body is provided with two inclined ground wire supports, the center inside the tower body is provided with a shaft, and the shaft is formed by connecting a plurality of single shafts up and down.
Referring to fig. 1, in this embodiment, the ultra-large spanning power tower is divided into 20 segments from top to bottom, the (1) th segment is a ground wire support, the (2) th segment is a wire cross arm, and the (3) th to (3) th segments
The section is a towerAnd (4) self-cleaning.
The well bore is composed of 42 single well bores which are connected up and down. The length of a single section of the shaft is 3.5-10 meters, the weight of the single section is 1.4-5.9 tons, the sizes of 1-41 sections from bottom to top are all phi 1700X 8 steel pipes, the 42 th section consists of phi 1700X 8 and phi 2500X 8 steel pipes, and the shaft is erected at the center of the tower.
The dismantling method comprises the following steps:
because the space position of the top end of the tower is smaller, the shaft does not have enough space position to fall down after being lifted, the 42 th shaft and the 41 th shaft at the uppermost end are firstly disassembled and disassembled, namely the 42 th shaft and the 41 th shaft are disassembled into parts and then are disassembled, and enough space is reserved for installing a travelling crane at the top end of the tower body in the section (3) to disassemble the residual shaft and the auxiliary device.
Step 1: and erecting a simple hoisting device on the ground wire support, and hoisting and dismantling the 42 th section and the 41 th section of the shaft on the uppermost part by using the simple hoisting device.
Simple and easy hoisting accessory is like figure 2, and simple and easy hoisting accessory's arrangement and structure belong to prior art, and the site operation personnel can arrange according to actual conditions, do not have too much explanation here.
The method specifically comprises the following steps:
step 1.1: after the simple hoisting device is erected, establishing a first calculation analysis model of the old electric tower by using finite element software;
step 1.2: selecting the heaviest parts in the 42 th and 41 th pitshafts, calculating the value of the maximum stress sigma 1max in the tower body structure through a first calculation analysis model when the heaviest parts in the two single pitshafts are just lifted by the simple hoisting device, calculating the value of the maximum stress sigma 1max 'in the tower body structure when the heaviest parts in the two single pitshafts are just driven by the simple hoisting device to descend, and comparing the values of the maximum stress sigma 1max and sigma 1max' with the yield limit sigma 1s of the old electric tower material;
step 1.3: if and only if the values of the maximum stresses σ 1max and σ 1max' are both less than the yield limit σ 1s of the old electric tower material, then it is safe to dismantle the 42 th and 41 th wellbore, then step 1.6 is performed;
step 1.4: if the value of the maximum stress sigma 1max or sigma 1max' is larger than the yield limit sigma 1s of the old electric tower material, the dismounting of the 42 th and 41 th sections of the shaft is unsafe, and the included angle of the steel wire rope of the bearing section in the simple hoisting device needs to be readjusted to reduce the force which is equivalently applied to the tower body structure by the hoisted part;
step 1.5: re-establishing a new first calculation analysis model of the old electric tower, and repeating the steps 1.2 to 1.5;
step 1.6: and (4) performing site construction, and performing disassembly, hoisting and dismantling of the 42 th and 41 th shaft.
Wherein the calculation of the values of the maximum stresses σ 1max and σ 1max' is within the reach of a person skilled in the art from data and analytical models of the actual electric power tower.
Step 2: and installing a traveling crane at the top of the tower body to remove the residual single section of the shaft.
And (4) after the 42 th section and the 41 th section of the shaft are dismantled, installing a travelling crane at the top end of the tower body section (3) to dismantle the rest shaft.
The method specifically comprises the following steps:
step 2.1: after the travelling crane is installed, establishing a second calculation analysis model of the old electric tower, calculating the value of the maximum stress sigma 2max in the tower body structure when the travelling crane is just lifted to n single-section mineshafts by using the second calculation analysis model, calculating the value of the maximum stress sigma 2max 'in the tower body structure when the travelling crane is just descended to the n single-section mineshafts, and selecting the maximum value of the maximum stress sigma 2max and the maximum stress sigma 2max' to compare with the yield limit sigma 1s of the material of the old electric tower;
step 2.2: when the maximum value of the maximum stress sigma 2max and sigma 2max' is smaller than and close to the yield limit sigma 1s of the material of the old electric tower, the driving is proved to be theoretically safe for the simultaneous hoisting of the n single-section mineshafts;
step 2.3: during on-site construction, the driving vehicle is used for simultaneously hoisting n-1 single-section mineshafts until the mineshafts are completely dismantled, and then the driving vehicle is dismantled.
In this embodiment, through calculation, when it is found that 35 single-section mineshafts are hoisted by a traveling crane, the maximum value of the maximum stresses σ 2max and σ 2max' is smaller than and close to the yield limit σ 1s of the old electric tower material, and then during construction, 34 single-section mineshafts can be hoisted by the traveling crane at the same time, so that compared with sequential hoisting and dismounting of the single-section mineshafts, the efficiency is greatly improved.
Certainly, during actual construction, hoisting needs to be carried out according to actual conditions, and due to the limitation of the bottom space of the electric tower, hoisting of 34 single-section shafts is not in accordance with actual conditions. Multiple individual well bores can be hoisted, for example, 5 or 10 individual well bores at a time, depending on the bottom space of the electric tower and the actual operability.
And step 3: after the shaft is dismantled, a double-flat-arm holding pole is built at the position of the original shaft, the double-flat-arm holding pole comprises a holding pole main body, a left suspension arm and a right suspension arm are arranged on the upper portion of the holding pole main body, and the two ground wire supports are hoisted and dismantled simultaneously by the aid of the two suspension arms.
The ground wire bracket is positioned at the topmost end of the tower body and is the component with the largest weight and the largest volume in the old electric tower, so the removal of the ground wire bracket is the key removal.
The method specifically comprises the following steps:
embrace pole main part through a plurality of waist ring subassemblies and body of the tower fixed connection, waist ring subassembly includes waist ring and waist ring stay wire.
In this embodiment, the number of the lumbar ring assemblies is 16 from bottom to top, the specific structure of the lumbar ring assemblies is shown in fig. 4, and the structure of the lumbar ring assemblies is the prior art and is not described herein again.
Step 3.1: establishing a third calculation analysis model of the electric tower with the double-flat-arm holding pole by using finite element software;
step 3.2: each suspension arm is connected with a sliding crane, each crane is connected with a ground wire support through a steel wire rope, and the ground wire support can be shaken instantly when being separated from the tower body during actual hoisting, so that the cranes have a pulling force of a pre-hoisting steel wire rope on the ground wire support through the steel wire rope, and the optimal value of the pulling force of the pre-hoisting steel wire rope is obtained through multiple calculations of a third calculation analysis model;
step 3.3: calculating to obtain the value of the maximum stress sigma 3max in the whole tower body when the suspension arm just lifts the ground wire support by utilizing a third calculation analysis model, and calculating the value of the maximum stress sigma 3max' in the whole tower body when the suspension arm just descends the ground wire support;
calculating to obtain the value of the maximum stress sigma 4max in the double-flat-arm holding rod when the suspension arm just lifts the ground wire support, and calculating to obtain the value of the maximum stress sigma 4max' in the double-flat-arm holding rod when the suspension arm just descends the ground wire support;
comparing the values of the maximum stresses σ 3max and σ 3max' with the yield limit σ 1s of the old electric tower material;
comparing the values of the maximum stress sigma 4max and sigma 4max' with the yield limit sigma 2s of the double-flat-arm holding pole material;
step 3.4: if the values of the maximum stress sigma 3max and sigma 3max 'are smaller than the yield limit sigma 1s of the old electric tower material, and the values of the maximum stress sigma 4max and sigma 4max' are smaller than the yield limit sigma 2s of the double-flat-arm holding pole material, the dismounting of the two ground wire brackets is proved to be safe, and the step 3.7 is executed;
step 3.5: if the value of the maximum stress sigma 3max or sigma 3max' is larger than the yield limit sigma 1s of the old electric tower material, the tower body structure is proved unsafe when the two ground wire supports are dismantled; it is necessary to find the rod at the maximum stress corresponding to the maximum stress value larger than the yield limit σ 1s of the material of the old electric tower and perform reinforcement processing on the rod at the maximum stress.
Specifically, if the value of the maximum stress σ 3max is greater than the yield limit σ 1s of the material of the old electric tower, a rod piece at the maximum stress position corresponding to the maximum stress σ 3max is found, and several auxiliary support steel pipes are welded around the rod piece, so that the value of the maximum stress can be effectively reduced.
If the value of the maximum stress sigma 3max 'is larger than the yield limit sigma 1s of the material of the old electric tower, a rod piece at the maximum stress position corresponding to the maximum stress sigma 3max' is found, and a plurality of auxiliary supporting steel pipes are welded around the rod piece, so that the value of the maximum stress can be effectively reduced.
If the value of the maximum stress sigma 4max or sigma 4max' is larger than the yield limit sigma 2s of the double-flat-arm holding pole material, the double-flat-arm holding pole structure is proved to be unsafe when the two ground wire supports are dismantled, a rod piece at the maximum stress position corresponding to the maximum stress value larger than the yield limit sigma 2s of the double-flat-arm holding pole material needs to be found, and the rod piece at the maximum stress position needs to be reinforced;
specifically, if the value of the maximum stress σ 4max is greater than the yield limit σ 2s of the double-flat-arm holding pole material, the pole piece at the maximum stress position corresponding to the maximum stress σ 4max is found, and several auxiliary supporting steel pipes are welded around the pole piece, so that the value of the maximum stress can be effectively reduced.
If the value of the maximum stress sigma 4max 'is larger than the yield limit sigma 2s of the double-flat-arm holding rod material, a rod piece at the maximum stress position corresponding to the maximum stress sigma 4max' is found, and a plurality of auxiliary supporting steel pipes are welded around the rod piece, so that the value of the maximum stress can be effectively reduced.
Step 3.6: re-establishing a third calculation analysis model of the tower body or the processed double-flat-arm holding pole, and repeating the steps 3.2 to 3.6;
step 3.7: and (3) performing field construction, namely hoisting and dismounting the two ground wire supports simultaneously by using the double-flat-arm holding pole, as shown in figure 6.
It should be noted that when the double-flat-arm holding pole is used for dismounting the ground wire bracket, the hoisting should be balanced as much as possible.
And 4, step 4: hoisting and dismantling two wire cross arms simultaneously by using two hoisting arms;
the weight and the volume of the wire cross arm are only second to those of the ground wire bracket, so that the removal of the wire cross arm is also key removal.
The method specifically comprises the following steps:
step 4.1: establishing a fourth computational analysis model of the electric tower with the double-horizontal-arm holding pole by using finite element software;
and 4.2: during actual hoisting, the wire cross arm can be flashed at the moment of separating from the tower body, so that the crane has a tension of a pre-hoisting wire rope on the wire cross arm through the wire rope, and the optimal value of the tension of the pre-hoisting wire rope is obtained through multiple calculations by a fourth calculation analysis model;
step 4.3: calculating to obtain the value of the maximum stress sigma 5max in the whole tower body when the suspension arm just lifts the wire cross arm by utilizing a fourth calculation analysis model, and calculating the value of the maximum stress sigma 5max' in the whole tower body when the suspension arm just descends the wire cross arm;
calculating to obtain the value of the maximum stress sigma 6max in the double-flat-arm holding pole when the suspension arm just lifts the wire cross arm, and calculating to obtain the value of the maximum stress sigma 6max' in the double-flat-arm holding pole when the suspension arm just descends the wire cross arm;
comparing the values of the maximum stresses σ 5max and σ 5max' with the yield limit σ 1s of the old electric tower material;
comparing the values of the maximum stress sigma 6max and sigma 6max' with the yield limit sigma 2s of the double-flat-arm holding pole material;
step 4.4: if the values of the maximum stress sigma 5max and sigma 5max 'are smaller than the yield limit sigma 1s of the material of the old electric tower, and the values of the maximum stress sigma 6max and sigma 6max' are smaller than the yield limit sigma 2s of the material of the double-flat-arm holding pole, the dismounting of the two wire cross arms is proved to be safe, and the step 4.7 is executed;
step 4.5: if the value of the maximum stress sigma 5max or sigma 5max' is larger than the yield limit sigma 1s of the old electric tower material, the tower body structure is proved unsafe when the two lead cross arms are dismantled, a rod piece at the maximum stress position corresponding to the maximum stress value larger than the yield limit sigma 1s of the old electric tower material needs to be found, and the rod piece at the maximum stress position needs to be reinforced;
specifically, if the maximum stress σ 5max is greater than the yield limit σ 1s of the material of the electric power tower, a rod at the maximum stress position corresponding to the maximum stress σ 5max is found, and several auxiliary support steel pipes are welded around the rod, so that the value of the maximum stress can be effectively reduced.
If the value of the maximum stress sigma 5max 'is larger than the yield limit sigma 1s of the material of the old electric tower, a rod piece at the maximum stress position corresponding to the maximum stress sigma 5max' is found, and a plurality of auxiliary supporting steel pipes are welded around the rod piece, so that the value of the maximum stress can be effectively reduced.
If the value of the maximum stress sigma 6max or sigma 6max' is larger than the yield limit sigma 2s of the double-flat-arm holding pole material, the double-flat-arm holding pole structure is proved to be unsafe when the two lead cross arms are dismantled, a rod piece at the maximum stress position corresponding to the maximum stress value larger than the yield limit sigma 2s of the double-flat-arm holding pole material needs to be found, and the rod piece at the maximum stress position needs to be reinforced;
specifically, if the value of the maximum stress σ 6max is greater than the yield limit σ 2s of the double-flat-arm holding pole material, the pole piece at the maximum stress position corresponding to the maximum stress σ 6max is found, and several auxiliary supporting steel pipes are welded around the pole piece, so that the value of the maximum stress can be effectively reduced.
If the value of the maximum stress sigma 6max 'is larger than the yield limit sigma 2s of the double-flat-arm holding rod material, a rod piece at the maximum stress position corresponding to the maximum stress sigma 6max' is found, and a plurality of auxiliary supporting steel pipes are welded around the rod piece, so that the value of the maximum stress can be effectively reduced.
Step 4.6: re-establishing a fourth computational analysis model of the tower body or the double-horizontal-arm holding pole after treatment, and repeating the steps from 4.2 to 4.6;
step 4.7: and (4) performing field construction, namely hoisting and dismounting two wire cross arms simultaneously by using the double-flat-arm holding pole, as shown in figure 7.
It should be noted that when the double-flat-arm holding pole is used for dismounting the wire cross arm, the hoisting should be balanced as much as possible.
And 5: and hoisting and dismantling the tower body by utilizing the double-flat-arm holding rod.
The weight of the components of the tower body is far lighter than that of the ground wire support and the wire cross arm, and after the double-flat-arm holding pole meets the hoisting and dismantling requirements of the ground wire support and the wire cross arm, the double-flat-arm holding pole is easy to dismantle the tower body, and the description is omitted.
It is to be understood that the above description is not intended to limit the present invention, and the present invention is not limited to the above examples, and those skilled in the art may make modifications, alterations, additions or substitutions within the spirit and scope of the present invention.
Claims (5)
1. A method for dismantling an ultra-large spanning old electric tower is characterized in that the ultra-large spanning old electric tower comprises a tower body, wherein the left side and the right side of the top of the tower body are respectively provided with a wire cross arm, the top of the tower body is provided with two inclined ground wire supports, the center inside the tower body is provided with a shaft, and the shaft is formed by connecting a plurality of single shafts up and down;
the dismantling method comprises the following steps:
step 1: erecting a simple hoisting device on the ground wire support, and hoisting and dismantling two single-section wellshafts at the uppermost part of the wellshaft by using the simple hoisting device;
and 2, step: installing a traveling crane at the top of the tower body to remove the residual single section of shaft;
and 3, step 3: after the shaft is removed, a double-flat-arm holding pole is built at the position of the original shaft, the double-flat-arm holding pole comprises a holding pole main body, a left suspension arm and a right suspension arm are arranged at the upper part of the holding pole main body, and the two ground wire supports are simultaneously hoisted and removed by utilizing the two suspension arms;
and 4, step 4: hoisting and dismantling two wire cross arms simultaneously by using two hoisting arms;
and 5: and hoisting and dismantling the tower body by utilizing the double-flat-arm holding rod.
2. The method for dismantling ultra-large spanning old electric towers according to claim 1, wherein the step 1 specifically comprises:
step 1.1: after the simple hoisting device is erected, establishing a first calculation analysis model of the old electric tower by using finite element software;
step 1.2: selecting the heaviest parts in the two single-section mineshafts at the uppermost part of the mineshafts, calculating the value of the maximum stress sigma 1max in the tower body structure through a first calculation analysis model when the heaviest parts in the two single-section mineshafts are just lifted by the simple hoisting device, calculating the value of the maximum stress sigma 1max 'in the tower body structure when the heaviest parts in the two single-section mineshafts are just descended by the simple hoisting device, and comparing the values of the maximum stress sigma 1max and sigma 1max' with the yield limit sigma 1s of the old electric tower material;
step 1.3: if and only if the values of the maximum stresses σ 1max and σ 1max' are both less than the yield limit σ 1s of the old electric tower material, then it is safe to remove the two single sections of the uppermost wellbore, then step 1.6 is performed;
step 1.4: if the value of the maximum stress sigma 1max or sigma 1max' is larger than the yield limit sigma 1s of the old electric tower material, the two single sections of the uppermost part of the shaft are unsafe to be dismantled, and the included angle of the steel wire rope of the bearing section in the simple hoisting device needs to be readjusted to reduce the equivalent force of the hoisted part on the tower body structure;
step 1.5: then a new first calculation analysis model of the old electric tower is established again, and the steps 1.2 to 1.5 are repeated;
step 1.6: and (4) performing on-site construction, and disassembling, hoisting and dismantling the two single-section mineshafts.
3. The method for dismantling the ultra-large spanning old electric tower according to claim 1, wherein the step 2 specifically comprises:
step 2.1: after the travelling crane is installed, establishing a second calculation analysis model of the old electric tower, calculating the value of the maximum stress sigma 2max in the tower body structure when the travelling crane is just lifted to n single-section mineshafts by using the second calculation analysis model, calculating the value of the maximum stress sigma 2max 'in the tower body structure when the travelling crane is just descended to the n single-section mineshafts, and selecting the maximum value of the maximum stress sigma 2max and the maximum stress sigma 2max' to compare with the yield limit sigma 1s of the material of the old electric tower;
step 2.2: when the maximum value of the maximum stress sigma 2max and sigma 2max' is smaller than and close to the yield limit sigma 1s of the material of the old electric tower, the driving is proved to be theoretically safe for the simultaneous hoisting of the n single-section mineshafts;
step 2.3: during on-site construction, the driving vehicle is used for simultaneously hoisting n-1 single-section mineshafts until the mineshafts are completely dismantled, and then the driving vehicle is dismantled.
4. The method for dismantling the ultra-large spanning old electric tower according to claim 1, wherein the step 3 specifically comprises: the holding pole main body is fixedly connected with the tower body through a plurality of waist ring components, and each waist ring component comprises a waist ring and a waist ring stay wire;
step 3.1: establishing a third calculation analysis model of the electric tower with the double-flat-arm holding pole by using finite element software;
step 3.2: each suspension arm is connected with a sliding crane, each crane is connected with a ground wire support through a steel wire rope, and the ground wire support can be flashed when being separated from the tower body during actual hoisting, so that the cranes have a pulling force of a pre-hoisting steel wire rope on the ground wire support through the steel wire rope, and the optimal value of the pulling force of the pre-hoisting steel wire rope is obtained through multiple calculations by a third calculation analysis model;
step 3.3: calculating to obtain the value of the maximum stress sigma 3max in the whole tower body when the suspension arm just lifts the ground wire support by utilizing a third calculation analysis model, and calculating the value of the maximum stress sigma 3max' in the whole tower body when the suspension arm just descends the ground wire support;
calculating to obtain the value of the maximum stress sigma 4max in the double-flat-arm holding rod when the suspension arm just lifts the ground wire support, and calculating to obtain the value of the maximum stress sigma 4max' in the double-flat-arm holding rod when the suspension arm just descends the ground wire support;
comparing the values of the maximum stresses σ 3max and σ 3max' with the yield limit σ 1s of the old electric tower material;
comparing the values of the maximum stress sigma 4max and sigma 4max' with the yield limit sigma 2s of the double-flat-arm holding pole material;
step 3.4: if the values of the maximum stress sigma 3max and sigma 3max 'are smaller than the yield limit sigma 1s of the old electric tower material, and the values of the maximum stress sigma 4max and sigma 4max' are smaller than the yield limit sigma 2s of the double-flat-arm holding pole material, the dismounting of the two ground wire brackets is proved to be safe, and the step 3.7 is executed;
step 3.5: if the value of the maximum stress sigma 3max or sigma 3max' is larger than the yield limit sigma 1s of the old electric tower material, the tower body structure is proved unsafe when the two ground wire supports are dismantled; a rod piece at the maximum stress position corresponding to the maximum stress value larger than the yield limit sigma 1s of the old electric tower material needs to be found, and the rod piece at the maximum stress position is reinforced;
if the value of the maximum stress sigma 4max or sigma 4max' is larger than the yield limit sigma 2s of the double-flat-arm holding pole material, the double-flat-arm holding pole structure is proved to be unsafe when the two ground wire supports are dismantled, a rod piece at the maximum stress position corresponding to the maximum stress value larger than the yield limit sigma 2s of the double-flat-arm holding pole material needs to be found, and the rod piece at the maximum stress position needs to be reinforced;
step 3.6: re-establishing a third calculation analysis model of the modified electric tower with the double-flat-arm holding pole, and repeating the steps 3.2 to 3.6;
step 3.7: and (4) in site construction, the two ground wire supports are hoisted and dismounted simultaneously by utilizing the double-flat-arm holding pole.
5. The method for dismantling the ultra-large spanning old electric tower according to claim 1, wherein the step 4 specifically comprises:
step 4.1: establishing a fourth calculation analysis model of the electric tower with the double-horizontal-arm holding pole by using finite element software;
step 4.2: during actual hoisting, the wire cross arm can be flashed at the moment of separating from the tower body, so that the crane has a tension of a pre-hoisting wire rope on the wire cross arm through the wire rope, and the optimal value of the tension of the pre-hoisting wire rope is obtained through multiple calculations by a fourth calculation analysis model;
step 4.3: calculating to obtain the value of the maximum stress sigma 5max in the whole tower body when the suspension arm just lifts the wire cross arm by using a fourth calculation analysis model, and calculating the value of the maximum stress sigma 5max' in the whole tower body when the suspension arm just descends the wire cross arm;
calculating to obtain a value of the maximum stress sigma 6max in the double-flat-arm holding pole when the suspension arm just lifts the wire cross arm, and calculating to obtain a value of the maximum stress sigma 6max' in the double-flat-arm holding pole when the suspension arm just descends the wire cross arm;
comparing the values of the maximum stresses σ 5max and σ 5max' with the yield limit σ 1s of the old electric tower material;
comparing the values of the maximum stress sigma 6max and sigma 6max' with the yield limit sigma 2s of the double-flat-arm holding pole material;
step 4.4: if the values of the maximum stress sigma 5max and sigma 5max 'are smaller than the yield limit sigma 1s of the old electric tower material, and the values of the maximum stress sigma 6max and sigma 6max' are smaller than the yield limit sigma 2s of the double-flat-arm holding pole material, the dismantling of the two wire cross arms is proved to be safe, and the step 4.7 is executed;
step 4.5: if the value of the maximum stress sigma 5max or sigma 5max' is larger than the yield limit sigma 1s of the old electric tower material, the tower body structure is proved unsafe when the two lead cross arms are dismantled, a rod piece at the maximum stress position corresponding to the maximum stress value larger than the yield limit sigma 1s of the old electric tower material needs to be found, and the rod piece at the maximum stress position needs to be reinforced;
if the value of the maximum stress sigma 6max or sigma 6max' is larger than the yield limit sigma 2s of the double-flat-arm holding pole material, the double-flat-arm holding pole structure is proved to be unsafe when the two lead cross arms are dismantled, a rod piece at the maximum stress position corresponding to the maximum stress value larger than the yield limit sigma 2s of the double-flat-arm holding pole material needs to be found, and the rod piece at the maximum stress position needs to be reinforced;
step 4.6: re-establishing a fourth calculation analysis model of the electric tower containing the double-flat-arm holding pole after correction, and repeating the steps from 4.2 to 4.6;
step 4.7: and in site construction, the two wire cross arms are hoisted and removed simultaneously by utilizing the double-flat-arm holding rod.
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Citations (9)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JP2009133139A (en) * | 2007-11-30 | 2009-06-18 | Tlc:Kk | Steel tower assembling/disassembling derrick, and method of removing the same |
| CN101958519A (en) * | 2010-09-27 | 2011-01-26 | 上海电力带电作业技术开发有限公司 | Method for transforming tangent tower of double-circuit double-bundle transmission lines by lifting in electrified mode in another place |
| CN102359302A (en) * | 2011-10-31 | 2012-02-22 | 湖北省输变电工程公司 | Extra-high voltage large-span iron tower assembling method |
| CN203903844U (en) * | 2014-06-13 | 2014-10-29 | 国家电网公司 | Floor double flat arm holding rod applied to mountainous landscape extra-high voltage cup type tower assemblage |
| CN204310727U (en) * | 2014-12-08 | 2015-05-06 | 刘建国 | The machine of tearing open built by high-rise structures |
| CN106786157A (en) * | 2016-12-31 | 2017-05-31 | 浙江省送变电工程公司 | Transmission line of electricity Great span above the navigation water surface tears aging method open |
| JP2018168601A (en) * | 2017-03-30 | 2018-11-01 | 太平電業株式会社 | Dismantling method of chimney supported with steel tower |
| CN109236012A (en) * | 2018-11-05 | 2019-01-18 | 中国电建集团山东电力建设第工程有限公司 | A kind of dry font Guywire tower hanging method of transmission line of electricity |
| CN112227814A (en) * | 2020-09-29 | 2021-01-15 | 中国化学工程第六建设有限公司 | Method for dismantling straight-barrel type concrete tower body |
-
2022
- 2022-07-15 CN CN202210836206.2A patent/CN115354882B/en active Active
Patent Citations (9)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JP2009133139A (en) * | 2007-11-30 | 2009-06-18 | Tlc:Kk | Steel tower assembling/disassembling derrick, and method of removing the same |
| CN101958519A (en) * | 2010-09-27 | 2011-01-26 | 上海电力带电作业技术开发有限公司 | Method for transforming tangent tower of double-circuit double-bundle transmission lines by lifting in electrified mode in another place |
| CN102359302A (en) * | 2011-10-31 | 2012-02-22 | 湖北省输变电工程公司 | Extra-high voltage large-span iron tower assembling method |
| CN203903844U (en) * | 2014-06-13 | 2014-10-29 | 国家电网公司 | Floor double flat arm holding rod applied to mountainous landscape extra-high voltage cup type tower assemblage |
| CN204310727U (en) * | 2014-12-08 | 2015-05-06 | 刘建国 | The machine of tearing open built by high-rise structures |
| CN106786157A (en) * | 2016-12-31 | 2017-05-31 | 浙江省送变电工程公司 | Transmission line of electricity Great span above the navigation water surface tears aging method open |
| JP2018168601A (en) * | 2017-03-30 | 2018-11-01 | 太平電業株式会社 | Dismantling method of chimney supported with steel tower |
| CN109236012A (en) * | 2018-11-05 | 2019-01-18 | 中国电建集团山东电力建设第工程有限公司 | A kind of dry font Guywire tower hanging method of transmission line of electricity |
| CN112227814A (en) * | 2020-09-29 | 2021-01-15 | 中国化学工程第六建设有限公司 | Method for dismantling straight-barrel type concrete tower body |
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