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GY/T 328-2020

Chinese Standard: 'GY/T 328-2020'
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GY/T 328-2020EnglishRFQ ASK Days<=3 (Technical specification for operation and maintenance of radio and television steel tower mast) Valid GY/T 328-2020
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BASIC DATA
Standard ID GY/T 328-2020 (GY/T328-2020)
Description (Translated English) (Technical specification for operation and maintenance of radio and television steel tower mast)
Sector / Industry Radio, Film & TV Industry Standard (Recommended)
Date of Issue 2020-07-28
Date of Implementation 2020-07-28
Regulation (derived from) Broadcasting TV Announcement (2020) No. 52

GY/T 328-2020
Technical specification for operation and maintenance of radio and TV steel tower and mast
GY
The People's Republic of China Radio, Television and Network Audiovisual Industry Standards
Technical specification for operation and maintenance of radio and television steel tower mast
2020-07 -28 released
2020 -07 -28 implementation
Issued by the State Administration of Radio and Television
Table of contents
Foreword...III
1 Scope...1
2 Normative references...1
3 Terms and definitions...1
4 Basic regulations...3
5 Routine Inspection and Maintenance...4
5.1 Foundation...5
5.2 Superstructure...5
5.3 Containment system...6
5.4 Lightning protection grounding...6
5.5 Health Monitoring...7
6 Testing and Evaluation...7
6.1 General regulations...7
6.2 Foundation inspection...8
6.3 Superstructure inspection...8
6.4 Inspection of enclosure system...10
6.5 Lightning protection grounding detection...10
6.6 Safety assessment...11
7 Professional maintenance...11
7.1 General regulations...11
7.2 Foundation...11
7.3 Superstructure...12
7.4 Containment system...13
7.5 Lightning protection grounding...14
8 Reinforcement...15
8.1 General provisions...15
8.2 Materials...15
8.3 Loads and effects...15
8.4 Basic rules for structural analysis...15
8.5 Basic methods of reinforcement...16
9 Acceptance...17
10 Retirement...17
Appendix A (informative appendix) Daily inspection and maintenance record table...18
Appendix B (Normative Appendix) Testing and Evaluation Period and Table of Contents...22
Appendix C (Normative Appendix) Professional Maintenance Record Form...25
Appendix E (informative appendix) The main forms of increasing the section of a member...30
Appendix F (Informative Appendix) Acceptance Record Form...31
Preface
This standard was drafted in accordance with the rules given in GB/T 1.1-2009.
Please note that certain contents of this document may involve patents. The issuing agency of this document is not responsible for identifying these patents.
This standard is under the jurisdiction of the National Radio, Film and Television Standardization Technical Committee (SAC/TC 239).
Drafting organizations of this standard. China Broadcasting, Film and Television Design and Research Institute, National Radio and Television Administration Bureau, National Radio
General Administration of Television Supervision Center, China Guangjian (Beijing) Tower Safety Technology Co., Ltd., Tongji University Architectural Design and Research Institute (Group) Co., Ltd.
Division, Zhejiang Radio and Television Group, Guangxi Radio and Television Technology Center, Xinjiang Uygur Autonomous Region Radio and Television Bureau, Jiangsu Radio and Television Bureau,
Liaoning Provincial Press, Publication, Radio, Film and Television Development Research Center, Inner Mongolia Radio and Television Bureau, Shenzhen Radio and Television Transmission Center, Beijing Beiguang Technology
Co., Ltd., Xinzheng Hongda Communication Equipment Factory, Qingdao Zhongtian Strong Technology Co., Ltd., Hebei Zhihengda Tower Co., Ltd., Shanghai
Ruilaibai Structural Design Office, Qingdao Oriental Tower Co., Ltd., Jiangsu Guohua Tube Tower Manufacturing Co., Ltd.
The main drafters of this standard. Xia Daqiao, Tan Xiaozhi, Chen Yuxin, Gu Hongzhou, Ge Chaoqing, Wang Fanglin, Wang Hongru, Wang Qian, Zuo Linsheng,
Tian Shuguang, Liu Kuifu, Guan Xingyuan, Wu Jun, Gu Haifeng, Zhang Guangli, Zhang Yang, Zheng Chaohui, Zhao Hailong, Xu Tao, Guo Jianxin, Guo Luming,
Cao Xiangdong, Liang Feng, Han Baosheng, Han Yong, Hei Zhenyou, Xie Weichang.
Technical specification for operation and maintenance of radio and television steel tower mast
1 Scope
This standard specifies the daily inspection and maintenance, professional maintenance, reinforcement and transformation, and operation of radio and television steel tower mast ("steel tower mast").
Management requirements.
This standard applies to the operation and maintenance of radio and television steel tower masts, and other steel tower masts can be used as reference.
2 Normative references
The following documents are indispensable for the application of this document. For dated reference documents, only the dated version applies to this document.
For undated references, the latest version (including all amendments) applies to this document.
GB/T 11345-2013 Ultrasonic testing technology, testing level and assessment for non-destructive testing of welds (ISO 17640.2010, MOD)
GB 14907-2018 Steel structure fireproof coating
GB/T 21431-2015 Technical Specification for Building Lightning Protection Device Testing
GB/T 26952-2011 Weld non-destructive testing Weld magnetic particle testing acceptance level (ISO 23278.2006, MOD)
GB 50017-2017 Steel Structure Design Standard
GB 50135-2019 Design standard for high-rise structures
GB 50205-2001 Code for acceptance of construction quality of steel structure engineering
GB 50207-2012 Code for quality acceptance of roofing engineering
GB 50208-2011 Code for quality acceptance of underground waterproof engineering
GB 50210-2018 Building Decoration Engineering Quality Acceptance Standard
GB 50367-2013 Code for design of reinforcement of concrete structures
GB/T 50621-2010 Technical standards for on-site inspection of steel structures
GB 51203-2016 Code for acceptance of construction quality of high-rise structure engineering
GY/T 64 Radio and TV steel tower mast corrosion protection coating
GY/T 178-2001 Medium and short wave antenna feeder operation and maintenance regulations
GY/T 5034-2015 Design Specification for Medium and Short Wave Broadcast Transmitting Station
GY 5062-1998 TV and FM radio transmission (rebroadcast) station (station) design specification
GY 5077-2007 Specification for quality acceptance of radio and television microwave communication towers and masts
GY/T 5089-2014 Specification for Reliability Testing and Appraisal of Broadcasting and Communication Steel Tower Mast
JGJ 8-2016 Building Deformation Measurement Specification
JGJ 102-2003 Technical Code for Glass Curtain Wall Engineering
JGJ 123-2012 Technical Specification for Foundation Reinforcement of Existing Buildings
JGJ/T 139-2001 Glass curtain wall engineering quality inspection standard
JGJ/T 324-2014 Standard for testing method of building curtain wall engineering
3 Terms and definitions
The following terms and definitions apply to this document.
3.1
Steel tower and mast
Self-standing towers and guyed towers (masts) and their foundations with steel structure as the main stress structure.
3.2
Guyed steel tower (mast)
A high-rise steel structure composed of columns and cables.
3.3
Height of tower and mast
The vertical distance from the bottom surface of the tower foot bottom plate of the steel tower mast structure to the top surface of the tower top lightning rod installation location.
3.4
Check and measure
Check and measure the main technical requirements (including indicators and others) of the steel tower masts that have been completed and delivered.
3.5
Maintenance
Inspect the steel tower mast structure that has been completed and delivered, including daily inspection and maintenance, professional maintenance, and reinforcement and transformation.
3.6
Maintenance administrative unit
The main unit responsible for the normal operation of the steel tower mast structure.
3.7
Maintenance unit
The main unit with relevant qualifications to implement the operation and maintenance of the steel tower mast structure.
3.8
Routine inspect
Maintenance personnel conduct periodic routine inspections on steel tower masts.
3.9
Professional maintenance
The maintenance unit professionally handles unqualified items or problems in the steel tower mast structure.
3.10
Vertical deviation
The distance from the top of the steel tower mast from the center position/tower mast height.
3.11
External hangings
Except the antenna feeder, the objects hanging on the steel tower mast, such as lighting devices, warning signs, billboards, etc.
3.12
Enclosure system space enclosing
Non-load-bearing envelope structure and building function accessories.
3.13
Super structure
The main stress-bearing components and connections in the upper stress structure and the enclosure structure.
3.14
Lightning receptor
Metal objects designed to receive direct lightning strikes (lightning flashes).
4 Basic regulations
4.1 After the steel tower mast structure is accepted and put into use, it should be used according to the design requirements. Without design permission or technical review, no
Adding antennas and other facilities to the steel tower mast structure shall not change the original design function of the steel tower mast.
4.2 The operation and maintenance of the steel tower mast structure includes daily inspection and maintenance, inspection and evaluation, professional maintenance and reinforcement transformation.
4.3 Before testing, safety assessment and reinforcement, it should be based on the structural purpose, structural design service life, used life, and the structural service history.
History, current situation and future use requirements, comprehensive analysis and determination of testing, evaluation and reinforcement targets.
4.4 The daily inspection and maintenance of the steel tower mast structure can be undertaken by the maintenance personnel, mainly the routine inspection and maintenance of the steel tower mast structure.
4.5 Before the professional maintenance and reinforcement of the steel tower mast structure, a unit with corresponding qualifications should be entrusted to inspect and evaluate the steel tower mast structure.
Reinforcement design.
4.6 High-altitude operators should hold corresponding professional qualification certificates and perform construction within the approved scope.
4.7 The steel tower mast structure should be operated and maintained in accordance with the following regulations.
a) When the weather wind pressure reaches more than 60% of the design wind pressure, the seismic intensity is more than six degrees, thunderstorms, fires, etc., increase
A daily inspection and maintenance;
b) The steel tower mast structure should be inspected and evaluated before professional maintenance and reinforcement;
c) The maintenance management unit can appropriately increase the frequency of routine inspection and maintenance according to the environment and service life of the steel tower mast to ensure its safety
run;
d) Refer to Appendix A for daily inspection and maintenance items.
4.8 Safety protection requirements for operation and maintenance of steel tower mast structure.
a) The maintenance unit shall establish and improve a safety inspection system and take corrective measures for hidden safety hazards.
b) The maintenance unit shall compile targeted safety technology according to different site conditions, equipment conditions, maintenance personnel, maintenance construction season, etc.
Measures.
c) The maintenance unit should formulate corresponding emergency plans according to the project site conditions, prepare necessary emergency equipment, and conduct necessary emergency
Drills and training.
d) The maintenance unit shall establish a file for the safety technical data of the maintenance construction site, which shall be managed by a dedicated person. The safety technical data shall be authentic
Real, complete and complete.
e) Maintenance workers should wear safety helmets and non-slip shoes, fasten safety belts, and check whether the safety belts and hooks are correct before working on the tower.
Usually, the tower can only be operated after inspection and confirmation by safety personnel.
f) The accumulative time for tower operation during daytime temperature 37℃~40℃ shall not exceed 3h, and tower operation is prohibited when the temperature is higher than 40℃ and above.
g) Tower maintenance should not be carried out under the following environmental and climatic conditions.
1) In case of strong high frequency induction at the construction site, effective protective measures have not been taken;
2) The wind force is above level five (including level five);
3) Rain and snow or thunder and lightning near the site;
4) There is icing and frost on the tower;
5) Moments of poor visibility.
h) Maintenance of the construction site should be based on the tower type, topography and other environmental factors, determine and divide the construction hazard warning area, and enclose it,
A safety net or other safety protection facilities for preventing falling objects should be set up in the restricted area of the construction site.
i) During the maintenance and construction of the steel tower mast structure, it is strictly forbidden for operators on the tower to work on the same vertical plane at the same time. If vertical operation is required under special circumstances,
It shall be approved by the person in charge of safety, and special protective shelters or other isolation facilities shall be set up between the upper and lower floors as appropriate.
j) During the maintenance and construction process, the maintenance unit should pay attention to protecting the safety of all radio and television facilities such as antennas and feeders on the steel tower mast structure. Such as
In the event of damage to radio and television facilities, the maintenance unit shall promptly report to the maintenance management unit.
4.9 In the routine inspection and maintenance, it is found that the steel tower mast structure has potential safety hazards, which cannot be eliminated through the routine inspection and maintenance.
Correspondingly qualified testing agencies shall conduct testing and evaluation of the steel tower mast structure in accordance with the requirements in Appendix B.
4.10 After the professional maintenance work is completed, the inspection should be carried out in accordance with the work content in Appendix C, and the form C.1 or C.2.
4.11 The operation and maintenance of steel tower masts should be archived. The operation and maintenance data should be complete, continuous and accurate.
Establish a safety management system for steel tower mast operation and maintenance including health monitoring.
4.12 Long-term health monitoring should be carried out for steel tower masts under the following conditions.
a) When there are serious quality defects or serious corrosion, damage or deformation;
b) When it reaches the design service life and intends to continue to use it;
c) When you need to continue using it after suffering a serious disaster or accident;
d) When the geological conditions are special (such as subsidence area);
e) When there is a safety hazard during inspection;
f) After the repair and reinforcement work is completed.
4.13 The object of health monitoring for steel tower masts can be the entire tower, foundation or tower body, etc.; monitoring items can include foundation
Foundation monitoring, connecting bolt monitoring, tower monitoring; technical means include foundation settlement and displacement monitoring, deformation monitoring, strain monitoring, vibration monitoring
Wait.
4.14 The implementation plan and plan for online monitoring of steel tower masts shall be based on the use history, current use situation and future maintenance and use plans of the tower.
The client and the implementer are jointly determined.
4.15 Operation and maintenance of steel tower mast structure shall not only meet the requirements of this standard, but also comply with GB 51203-2016 and GY 5077-2007
Relevant provisions in
5 Routine inspection and maintenance
5.1 Foundation
5.1.1 Routine inspection and maintenance of the foundation of the steel tower mast structure shall include the following.
a) Check whether the anchor bolts are loose, missing, or less than 2 buckles exposed; if the nut is loose, tighten it; find that the nut and washer are missing
Use nuts and washers of the same specification to make up and tighten; if the exposed thread is less than 2 buckles, entrust a professional maintenance unit to repair it.
b) Check whether the second-stage concrete pouring is good. If the concrete is not poured or the pouring fails to meet the design requirements, a professional maintenance unit should be entrusted to handle the
Check it once or after the repair is good, keep a record, and perform inspection and maintenance according to the foundation stigma.
c) Check whether the foundation is sinking, uplifting, or slipping. If the above conditions are found, the inspection and evaluation unit should be entrusted to conduct a safety assessment.
d) Check the protection facilities around the steel tower mast structure and the stability of the slope. If it is found that the slope of the protection facility has landslide, collapse, collapse,
For slope instability such as staggering, scouring damage, etc., the inspection and evaluation unit should be entrusted to conduct safety assessment in time, and professional maintenance should be entrusted
The unit is repaired.
e) Check whether the soil around the foot of the steel tower mast structure has collapsed or bulged; if the ground has collapsed or bulged, if the foundation is not
If there is obvious sinking, uplifting, or slipping, the backfill can be compacted and the ground can be redone. If the foundation sinks, uplifted, or slipped significantly
If the situation is changed, a testing and evaluation unit should be entrusted to conduct a safety assessment.
f) Check whether there is water accumulation around the foundation of the steel tower mast structure; if there is water accumulation, construct drainage ditches and lay scattered water
Water surface and other measures to reduce the occurrence of water accumulation, such as the backfill soil elevation is not in place, sinking, etc., you need to fill the soil and compact it before doing a good job
Disperse water measures; if the daily inspection and maintenance unit finds more serious problems, they should report to the maintenance unit to entrust a professional maintenance unit to deal with it.
g) Check whether there are cracks in the exposed parts of the concrete structure of the steel tower mast structure, tower foot column head and other exposed parts.
Entrust professional maintenance unit to repair.
h) Check whether the drain hole between the flange chassis and the pile top is blocked. If the drain hole is blocked, it should be cleared in time.
5.1.2 The daily inspection and maintenance of the foundation of the steel tower mast structure built on the roof of the building should add the following contents.
a) Check whether the anchoring points of the roof cable towers are firm, and if the anchor points are loose, the inspection and evaluation unit should be entrusted to carry out
Safety assessment; check whether the cable is corroded, loose, the number of fixed rope clamps, spacing and tightening conditions. If you have any questions, press the relevant
Request for processing.
b) Check whether there are new obvious cracks in the roof beam or floor slab where the steel tower mast structure is located, or there is new water seepage phenomenon in the floor.
In the above cases, a testing and evaluation unit should be entrusted to conduct a safety assessment, and a professional maintenance unit should be entrusted to repair it.
c) Check whether the concrete structure of the exposed part of the tower foot, column head, back beam, etc. is cracked or exposed. If the above situation occurs, the inspection should be entrusted
The assessment unit conducts a safety assessment and commissions a professional maintenance unit to repair it.
5.1.3 Routine inspection and maintenance of ground anchors for steel tower mast structures shall include the following.
a) Check whether there is a gap between the anchor foundation of the guyed tower and the surrounding soil. When the gap is less than 10mm, the surrounding soil can be re-compacted.
When 10mm, the inspection and evaluation unit should be entrusted to conduct safety evaluation;
b) Check whether the ground bolt exposed to the ground is corroded, the corrosion area reaches more than 40% or the depth of the rust point reaches 1/5 of the diameter of the ground bolt
If it is on, a professional maintenance unit should be entrusted to replace it in time.
5.2 Superstructure
5.2.1 The daily inspection and maintenance of the upper structure of the steel tower mast shall include the following.
a) Regularly check the overall tilt. If the tilt exceeds the allowable deviation range specified in Table 10.5.4 of GY 5077-2007, the
Entrust the inspection and evaluation unit to conduct a safety assessment and entrust a professional maintenance unit to repair;
b) Inspect whether the components are cracked or obviously bent, twisted, deformed, or missing. In the event of the above, the inspection and evaluation should be commissioned in time.
The assessment unit conducts a safety assessment and commissions a professional maintenance unit to repair it;
c) Inspect whether the connecting welds of the components are cracked. If the above situations occur, the inspection and evaluation unit should be entrusted to conduct a safety assessment, and
Entrust professional maintenance unit to repair;
d) Check whether the component bolts and nuts are exposed to less than 2 buckles, broken, rusted, deformed, or lost. Bolts and nuts are found
If the bolts are lost, they shall be repaired and tightened in time. The bolts with less than 2 bolts exposed, broken, rusted and deformed shall be entrusted to a professional maintenance unit
Repair or replace;
e) Check whether the components are corroded. If the components are slightly corroded, they should be repaired. If the components are severely corroded or the corrosion area is large, they should be
Entrust professional maintenance unit to repair or replace;
f) Regularly check whether there is ice coating on the steel tower mast structure, and the thickness of the ice coating exceeds the 50-year maximum in GB 50135-2019.
When the ice thickness is large, a professional maintenance unit should be entrusted to handle it.
5.2.2 Routine inspection and maintenance of pull cords and accessories shall include the following.
a) Check the rust of the cable (wire rope);
b) Check whether the tension of the cable is normal, whether there is slack, whether the initial stress meets the design requirements, and whether the tightness of the cable is consistent;
c) Check the broken wire of the pull wire;
d) Check the corrosion of the turnbuckle screws, looped rope clips and connectors;
e) Check the condition of the insulation frame.
If an abnormal situation occurs, a professional maintenance unit should be entrusted to handle it.
5.2.3 Routine inspection and maintenance of insulators shall include the following.
a) Check the cable insulators for cracks, chipping, and outer wall contamination;
b) Check the base insulator for cracks, oil leakage, and outer wall contamination.
c) If the base insulator has cracks, sparks, oil leakage, etc., it should be replaced, and the discharge ball gap should be adjusted or repaired every month.
Check it once. The replacement of the base insulator shall be implemented in accordance with the relevant regulations of GY/T 178-2001.
5.2.4 Check whether the platforms, ladders, ladders, and external hanging objects are corroded, firm, or deformed. If abnormal conditions occur, they should be entrusted with maintenance management.
Processing unit.
5.2.5 Timely clean up the bird's nest, honeycomb, garbage, tools, waste materials and other attachments on the upper structure of the steel tower mast.
5.3 Containment system
5.3.1 The daily inspection and maintenance of the roof system on the steel tower mast shall include the following.
a) Check whether the roof structure is damaged;
b) Check whether the waterproof layer is aging, bubbling, cracked or damaged;
c) Check whether the drainage device is blocked or leaking.
If an abnormal situation occurs, a professional maintenance unit should be entrusted to handle it.
5.3.2 Peripheral protection and daily inspection and maintenance of doors and windows shall include the following.
a) Check whether the curtain wall glass is broken;
b) Check whether the structural glue has hardened and fallen off;
c) Check whether there are cracks, holes or fragments in the curtain wall panels;
d) Check whether there is water leakage on the curtain wall. If there is water leakage, take pictures and record the location of the water leakage in time;
e) Check whether the doors, windows or connecting parts are damaged.
If an abnormal situation occurs, a professional maintenance unit should be entrusted to handle it.
5.3.3 The daily inspection and maintenance of other protective facilities should check whether the aviation obstruction lights are working properly, and if they are damaged, they should be replaced or repaired in time.
A professional maintenance unit should be entrusted to repair it.
5.4 Lightning protection grounding
Check whether the lightning protection down conductor of the steel tower mast structure is smooth and well fixed; if it is found that the lightning protection down conductor is not firmly fixed, the down conductor should be removed
The offline is fixed on the tower.
5.5 Health monitoring
When there is an early warning on the steel tower mast health monitoring platform, attention should be paid to the risk trend; when there is a potential safety hazard, the inspection and evaluation should be immediately commissioned.
The assessment unit conducts a safety assessment.
6 Testing and evaluation
6.1 General provisions
6.1.1 When professional maintenance is required, the inspection and evaluation cycle and content in Appendix B shall be entrusted with inspection and inspection materials for steel tower mast structures.
The quality unit undertakes the inspection and safety assessment of the steel tower mast structure project.
6.1.2 The sampling plan for the inspection of the existing steel tower mast structure can be selected according to the following principles according to the characteristics of the test items.
a) The detection of external defects, the scope of inspection is small or the number of components is small, the quality of components is very different, after the disaster occurs, the matching
The identification of damage to the structure and the requirements of the entrusting party, etc., should use a full detection plan;
b) In the inspection of structural connection structure, sampling should be carried out on parts that have a large impact on structural safety;
c) The items tested according to the test batch shall be randomly sampled, and the minimum sample size shall meet the requirements of 6.1.4.
6.1.3 For sampling inspection, components of the same type and same specification are used as an inspection lot.
6.1.4 Existing steel tower mast structural members sampling test requirements, the minimum sample size of each inspection lot sampling test should not be less than the limit of Table 1.
Value.
Note 2.Unless otherwise specified, the sample is a component.
6.1.5 Sampling inspection requirements for foundations.
a) For basic concrete material performance testing, non-destructive testing methods should be adopted, and no less than 3 testing areas should be measured for each typical part;
b) For basic internal defect detection, non-destructive testing methods such as ultrasonic method should be adopted, and no less than 3 samples can be taken.
Measurement;
c) For foundation steel bar testing, sampling should be the main stressed steel bar parts of important foundations and the parts requiring testing, and each foundation tested
There are no less than 3 parts of the same type.
6.1.6 Anti-corrosion testing requirements.
a) The overall structure shall be inspected for the appearance quality of the steel structure anticorrosive coating;
b) Conduct thickness inspection on representative parts;
c) Thickness detection can determine the number of measuring points for each part according to the actual measured coating thickness uniformity, and the actual thickness of each measuring point can be taken
Use the average of no less than 3 measurements.
6.2 Foundation inspection
6.2.1 Basic testing includes material performance, size, deformation, and damage testing.
6.2.2 When in doubt about the performance of the basic material, the material performance of the basic concrete, steel bar, foundation anchor, skeleton and other components should be improved.
Line testing.
6.2.3 The appearance quality of concrete includes appearance defects and appearance defects such as exposed tendons, honeycombs, holes, slag inclusions, looseness, and cracks.
6.2.4 The basic inspection should carry out structural crack inspection, and observe the following regulations.
a) The test items should include the location, length, width, depth, shape and number of cracks;
b) The crack depth can be detected by ultrasonic method, and core samples can be drilled for verification if necessary.
6.2.5 The detection of steel bar configuration can be divided into items such as steel bar position, protective layer thickness, diameter, and quantity.
6.2.6 When the appearance quality of steel bars needs to be inspected, according to the drawings and site conditions, the parts that may be severely corroded should be checked.
Excavate.
6.2.7 The appearance size and corrosion of ground anchor rods should be tested.
6.2.8 The content of foundation deformation detection is the deformation value of each foundation of the steel tower mast structure, including foundation settlement, horizontal displacement and deflection.
6.2.9 For the steel tower mast structure with perfect settlement observation reference points in the construction phase and the use phase, the foundation settlement and change shall be required.
For steel tower mast structures without reference points for settlement observation, the relative settlement and center horizontal displacement of each foundation should be measured.
And keep the observation point of this measurement.
6.2.10 When the quality of the foundation is questioned, the foundation can be excavated, and the size and depth of each part buried in the foundation below the ground
Perform testing.
6.3 Superstructure inspection
6.3.1 Components
6.3.1.1 For the inspection of the geometric dimensions of the components, when the drawings and documents are complete and complete, on-site sampling inspection can be carried out; when the drawings and documents are incomplete
When there are no drawings or materials, detailed site surveys should be conducted through the analysis of the structural layout, and the layout of the structural components should be drawn after site surveys
Figure, as the basic data for structural accounting.
6.3.1.2 The thickness of steel should be measured with an ultrasonic thickness gauge, the finish layer should be removed before testing, and the thickness of the galvanized layer should be deducted for galvanized components.
6.3.1.3 The inspection items, inspection methods and allowable deviations of the geometric dimensions of the components shall be implemented in accordance with GY 5077-2007.
6.3.1.4 The cross-sectional dimensions of the components shall be tested at three or more locations that have a greater impact on the safety of the tested components. When the component is strong
For degree control, the minimum cross-section is taken as the representative value; when the component is stable and the slenderness ratio is controlled, the average cross-section is taken as the representative value.
6.3.1.5 The inspection items for component cracks, including the location, length, width, shape and quantity of cracks, should be recorded in tables.
Grid or graphic form.
6.3.1.6 The steel sampled for inspection shall be subject to mechanical performance inspection, and chemical composition analysis may be conducted when necessary.
6.3.1.7 For the inspection of the mechanical properties of materials, samples can be taken from the components. When it is not suitable or impossible to take samples from the components, the hard surface can be used.
Degree method to estimate the strength of steel.
6.3.1.8 If local damage occurs, samples shall be taken for testing of the mechanical properties of the steel. Test content includes tensile strength, elongation and yield
The strength and fatigue of welded structural steel should be tested for impact toughness and its chemical composition should be analyzed.
6.3.2 Connection
6.3.2.1 The test of connection quality and performance can be divided into items such as bolt connection, welding connection and cable connection.
6.3.2.2 The fastening standard parts for the connection of the steel tower mast structure may include high-strength bolts, ordinary bolts, anchor bolts (including mechanical and chemical
(Study grout anchor type) and other standard fasteners, nuts and washers.
6.3.2.3 When the ordinary bolt connection is damaged, the minimum tensile load of the bolt and the load of the bolt wedge shall be rechecked.
6.3.2.4 When the high-strength bolt connection is damaged, the bolt wedge load, nut guaranteed load, nut and washer hardness test shall be carried out.
6.3.2.5 When the appearance of the anchor bolt is abnormal, the mechanical performance test of its material shall be carried out. The direct tension method may be used to stretch the anchor bolt to
Observe whether the anchor bolt is pulled out, deformed, broken, etc. under the internal force under the load design value.
6.3.2.6 When the hot-dip galvanized high-strength bolts of 10.9 and above are damaged, the bolted joints of the suspected parts can be sampled for magnetic
Powder inspection or penetrant inspection.
6.3.2.7 When the wire clamps, basket bolts, wire rods, etc. used for the mast are damaged, the material properties shall be tested in accordance with the corresponding product standards.
6.3.2.8 When there are doubts about the cable material, the test piece can be cut from the original cable tail rope to conduct the cable material performance test.
6.3.2.9 Use visual inspection to check all the anti-loosening measures, strength grades and geometric parameters of the bolt connection. The geometric parameters include specifications and numbers.
Quantity and arrangement, etc.
6.3.2.10 For the connection quality of torsion shear type high-strength bolts, you can check whether the torx heads at the ends of the bolts have been screwed off.
Except for those who use a special wrench to unscrew the torx head, the number of bolts that have not been unscrewed in the final tightening shall not exceed 5% of the number of bolts at the node.
6.3.2.11 The quality of high-strength bolt connection can be inspected for exposed threaded fasteners. The exposed threaded fasteners should be 2 to 3 fasteners, allowing 10%
1 or 4 buckles are exposed on the bolt threads.
6.3.2.12 Looseness or breakage of bolts can be detected by observation, hammering or torque wrench methods.
6.3.2.13 The appearance quality inspection of bolted connection includes bolt fracture, looseness, falling off, screw bending, flatness of gusset plate, etc.
6.3.2.14 The inspection items, inspection methods and allowable deviations of welds shall be implemented in accordance with GY 5077-2007.
6.3.2.15 The first and second level welds with full penetration can be detected by ultrasonic flaw detection. The weld defects shall be classified according to GB/T 11345
-2013 confirmed. Important three-level welds can be detected by magnetic particle inspection, and weld defects should be classified according to GB/T 26952-2011.
set.
6.3.2.16 All welds of the superstructure shall be visually inspected. The external dimension and appearance defect detection method and evaluation standard of weld
It should be determined according to GY 5077-2007.
6.3.2.17 The raw materials used in the steel strands, clamps, basket bolts, and wire rods used for the mast, and their varieties, specifications, and performance should meet
Current national product standards and design requirements.
6.3.2.18 For the steel strands and wire ropes of the existing masts, the instantaneous tension can be measured by means of tension meter, etc., and its value should conform to the current national
Standards and design requirements.
6.3.2.19 The base insulators and pull-wire insulators should be checked for cracks.
6.3.3 Deformation
6.3.3.1 The deformation test of components includes the bending deformation, mid-span deflection, uneven deformation of the plate, twisting deformation and other items.
6.3.3.2 Before testing the deformation of the component, the finish layer should be removed; when the thickness of the finish layer at each test point of the component is close, and not obvious
Affect the evaluation result, the finishing layer may not be removed.
6.3.3.3 The deformation of the component can be detected by observation or measurement with a ruler and a wire drawing method to measure the degree of deformation.
6.3.3.4 The verticality of the steel tower mast structure includes the overall verticality detection of the structure and the verticality detection between sections.
6.3.3.5 The inspection of the overall deformation of the steel tower mast structure shall be carried out when the wind is less than level 2, cloudy or sunlight has not been irradiated on the structure for a long time.
6.3.3.6 For the verticality test of the steel tower mast structure, an observation point should be set at a certain distance outside the tower, and theodolite or total station should be used to measure
The horizontal displacement of the tower at different heights.
6.3.3.7 For a symmetrical steel tower mast structure, the observation line of sight shall be on the line connecting the vertical line of the tower center and on a symmetry axis.
6.3.3.8 Observations shall measure the verticality of the steel tower mast structure at no less than two measuring points at an angle to each other, and calculate the vector sum as the steel tower
The actual vertical deviation value of the mast structure.
6.3.3.9 For high-rise steel structures with cantilevered towers, the level of the cantilevered structure shall be measured.
6.3.3.10 The overall deformation deviation of the steel tower mast structure shall be implemented in accordance with GY 5077-2007.
6.3.3.11 The flange deformation test includes flange flatness and flange flat clearance. The test method and evaluation standard should be in accordance with GY 5077
-2007 implementation.
6.3.3.12 The deformation of the gusset plate shall be tested for the fit between the gusset plate and the member.
6.3.4 Anticorrosion
6.3.4.1 The inspection of the anti-corrosion layer includes the appearance of the anti-corrosion layer, the thickness of the coating, and the adhesion.
6.3.4.2 The inspection of anti-corrosion layer shall be carried out in accordance with GY/T 64.
6.4 Inspection of enclosure system
6.4.1 The inspection of the enclosure system includes the inspection of the roofing system, outer protection, doors and windows, and the thickness of the fireproof coating.
6.4.2 The inspection of roof system shall be carried out in accordance with GB 50207-2012; the inspection of peripheral protection and doors and windows shall be carried out in accordance with JGJ/T 324-2014,
GB 50210-2018, JGJ/T 139-2001, JGJ 102-2003 are implemented; the thickness of fireproof coating shall be tested according to GB/T 50621
-2010, GB 50205-2001 implementation.
6.5 Lightning protection grounding detection
6.5.1 The detection of lightning protection grounding resistance value shall be implemented in accordance with GB/T 21431-2015.
6.5.2 The grounding resistance value requirements shall be implemented in accordance with GY 5062-1998 and GY/T 5034-2015.
6.5.3 The tower and the foundation lightning protection grounding grid should be reliably welded, and the cross-sectional area of the weld should not be less than the design requirements.
The cross-section of the grounded flat steel, the welding length shall not be less than 10cm, and the welding seam shall be treated with corrosion protection.
6.6 Safety assessment
6.6.1 After the steel tower mast is tested by a professional organization, the safety assessment shall be carried out in accordance with GY/T 5089-2014.
6.6.2 The safety assessment shall be based on the test results of the defects and damage conditions of the structure, components and connection nodes and their safety, applicability,
The durability evaluation conclusion, and suggestions for maintenance, reinforcement, transformation, and scrapping are put forward.
7 Professional maintenance
7.1 General provisions
7.1.1 The professional maintenance of steel tower mast should check all items of daily inspection and maintenance, and maintain existing problems.
7.1.2 The professional maintenance of steel tower mast shall include the following.
a) Problems that cannot be solved in daily inspection and maintenance;
b) Regular maintenance items such as the verticality, settlement and resistance of the steel tower mast structure required in this standard;
c) Problems found in the inspection and evaluation that the maintenance management unit cannot solve;
d) Other content that requires professional maintenance.
7.1.3 The steel tower mast structure should be professionally maintained on schedule. The maintenance period is shown in Table 2.
7.1.4 The number of settlement observations depends on the construction age of the steel tower mast. The newly-built steel tower mast structure can be observed not less than once every quarter in the first year.
Observation shall be no less than once every six months in the second year, and no less than once a year after three years; sudden increase and decrease of ground load near the foundation, four weeks after the foundation
In the case of a large amount of stagnant water and long-term continuous rainfall, the number of observations should be increased in time.
7.2 Foundation
7.2.1 The corrosion of anchor bolts should be manually derusted, and the oxide scale and rust on the surface of the anchor bolts should be cleaned up, and the rust removal level should reach St2.
Apply butter or epoxy.
7.2.2 When double nuts are not used for anchor bolts, one of the following methods should be used for treatment.
a) Add nuts;
b) For a single nut and the number of exposed threads is less than 2 buckles, the nut and screw can be welded around, and the welding seam requirements should meet the requirements of GB 50017-2017
related terms.
7.2.3 When the second-stage concrete is not poured, corresponding holes should be reserved according to the requirements, and the anchor nuts should be adjusted to make the verticality of the steel tower mast structure reach GY
Within the allowable range of 5077-2007, use fine stone concrete or grouting material for pouring.
7.2.4 The repair of concrete cracks in exposed parts such as tower foot column head and ground anchor foundation shall be carried out in accordance with the surface sealing method in GB 50367-2013.
Repair by injection method, pressure grouting method, filling and sealing method, etc.
7.2.5 If the protective layer of the foundation concrete falls off, the steel bar is exposed, corroded and broken, etc., weld the steel bar at the fractured place and prevent the exposed steel bar.
Corrosion treatment, repair with concrete.
7.2.6 The settlement and collapse of the soil around the foundation anchor shall be backfilled and compacted to disperse the water.
7.2.7 The observation of foundation settlement and displacement shall be carried out in accordance with the requirements of JGJ 8-2016, and the observation data shall be recorded. No observation point
Permanent observation points should be added. If abnormal conditions are found, a professional inspection and evaluation unit shall be entrusted for identification.
7.2.8 Various ground anchors shall be sampled and inspected every 5 to 10 years according to local corrosion types, and the sampling rate shall not be less than the total amount.
10%, a full inspection should be carried out if necessary. If the ground anchor rod is found to be rusted, thoroughly remove the rust and brush the asphalt, wrap it with linen cloth or plastic film. Ground
The surface of the anchor rod is rusted up to 40%, or the depth of the rusted point is more than 1/5 of the diameter, and it should be replaced.
7.2.9 The encapsulation of the tower foot foundation should be disassembled and inspected. If the anchor bolts are not equipped with double nuts and cannot be increased, they should be treated with corrosion protection.
The foundation should not be re-encapsulated or covered up by decoration, and the nuts should be checked for looseness during routine inspection and maintenance.
7.3 Superstructure
7.3.1 Connection
7.3.1.1 When bolts are broken, damaged, deformed, exposed to fewer than 2 buckles and gaskets are missing, the bolts should be replaced or reinstalled, and
Meet the following requirements.
a) When there is data, replace or reinstall according to the specifications in the data;
b) When there is no information, use high-strength bolts suitable for the original bolt hole diameter to replace or reinstall;
c) When the bolt bearing capacity calculation fails to meet the requirements, it shall be dealt with according to the appraisal results and recommendations;
d) After replacement, the exposed threads of the bolts shall not be less than 2 threads.
7.3.1.2 The bolts that are loose, under-tightened or miss-tightened shall be tightened, and the number of exposed bolt threads shall not be less than 2 buckles. The tightening torque should meet
7.3.1.3 When the bolt hole is displaced and the bolt cannot pass through, the diameter of the bolt hole can be enlarged under the premise of meeting the structural requirements, and mechanical
Expand the drill hole and reinstall suitable bolts; or use welding for local reinforcement to ensure that the connection strength should not be lower than the original design strength.
7.3.1.4 If the weld is cracked, the welded part needs to be partially reinforced or replaced. The quality of the weld meets the relevant requirements of GB 50017-2017
Regulations.
7.3.1.5 The initial stress of the cable should be determined after comprehensively considering the deformation and stability of the mast, and should be selected within the range of 150N/mm2~250N/mm2
And ensure that the verticality of the mast meets the requirements of GY 5077-2007.
7.3.2 Defects and Damage
7.3.2.1 If the component is broken, the component needs to be strengthened or replaced by local welding. The welding seam should meet the relevant regulations of GB 50017-2017
set.
7.3.2.2 The replacement of the insulating base shall be carried out in accordance with the relevant regulations of GY/T 178-2001.
7.3.3 Deformation
7.3.3.1 For bent, twisted and deformed components, a professional maintenance unit shall be entrusted to correct or replace them. Component curvature sagittal after correction or replacement
The high allowable deviation should meet the requirements of GY 5077-2007.
7.3.3.2 When the flange gap exceeds the requirements of GY 5077-2007, round gaskets or wedge-shaped gaskets can be used for processing.
The blue plate is effectively connected.
7.3.4 Anticorrosion
7.3.4.1 The components found to be rusty after routine inspection and maintenance or professional inspection shall be implemented in accordance with the following regulations.
a) Components with a corrosion area less than 40% of the component area should be partially derusted and coated with anti-corrosion treatment;
b) For components with a corrosion area exceeding 40% of the component area, the entire component should be derusted and coated with anti-corrosion treatment;
c) For steel tower mast structures where the number of rusty components exceeds 50% of the total number of tower components, the entire tower should be derusted and coated with anticorrosion
Rationale
d) Connecting bolts, turnbuckles, pull-wire insulation frames, pins, rope clamps, and discharge balls have surface corrosion of up to 40% or a certain depth of corrosion
If it is more than 1/5 of the original diameter, it should be replaced; if it does not need to be replaced, it should be coated with anti-corrosion treatment;
e) The rusted spots of the pull wire are common or the black rust and peeling reaches 40% of the surface area within one lay length; the mast pull wire is within one lay length
5% of the total number of broken wires or one strand must be replaced immediately; those with sparking traces and broken wires of 3 to 7 wires must be reinforced; no need
For reinforcement or replacement, rust removal and anti-corrosion treatment should be performed.
7.3.4.2 The rust removal and coating of the steel tower mast structure shall meet the following requirements.
a) Derusting quality should meet the requirements of St2 level.
b) The ambient temperature during coating construction should be between 10℃~30℃, and the relative humidity should not exceed 85%. When the environmental conditions do not meet this requirement
When required, adequate preventive measures should be taken to ensure quality.
c) The dry film thickness of the coating should not be less than 150µm, and the allowable deviation is ±25µm.
7.3.4.3 For components subjected to partial or overall anti-corrosion treatment, corresponding treatment should be taken according to the corroded location, degree of corrosion, coating method, etc.
Measures, surface anti-corrosion coating matching should be implemented in accordance with the requirements in Appendix D.
7.3.4.4 When the weld is rusted, the oxide scale and rust on the surface of the weld should be cleaned up, and the matching primer, intermediate and top paint should be painted.
7.3.5 Pull line and accessory components
Connecting bolts, turnbuckle screws, cable insulation frames, pins, rope clamps and other components on the cable that are corroded and do not need to be replaced shall be
Remove the surface oil stains, scales and rust from the rusted parts and polish them clean, and do coating anticorrosion treatment.
7.4 Containment system
7.4.1 Maintenance of roof system.
a) If the roof structure is damaged, it should be repaired or modified, and its quality should meet the technical requirements of GB 50207-2012;
b) If the waterproof layer has problems such as aging, bubbling, cracking or damage, it should be repaired in time, and its quality should meet GB 50207-
Technical requirements for.2012.
7.4.2 Peripheral protection and maintenance of doors and windows.
a) If the outer protective plate and glass are broken, damaged or cracked, they should be replaced or repaired in time, and the construction quality should meet JGJ/T
139-2001 technical requirements;
b) If the structural adhesive has hardened or fallen off, it needs to be repaired, and the construction quality should meet the technical requirements of JGJ/T 139-2001.
7.4.3 Maintenance of underground waterproofing.
If there is leakage in the underground space, a professional maintenance unit should be entrusted to repair it, and the construction quality should meet the technical requirements of GB 50208-2011.
Technical requirements.
7.4.4 Maintenance of other protective facilities.
a) Check the integrity and thickness of the fire retardant coating. If the fire retardant coating falls off or the thickness does not meet the standard, a professional maintenance unit should be entrusted to repair it.
The quality of work should meet the technical requirements of GB 14907-2018;
b) When other protective facilities that are not mentioned in this standard but actually appear need to be repaired by a professional maintenance unit, the relevant construction quality must be satisfied
Meet the technical requirements of relevant specifications.
7.5 Lightning protection grounding
7.5.1 Check whether the lightning protection down-conductor or tower foot bolts are effectively connected to the ground network, if the connection is found to fail to meet the technical requirements, it should be reconnected;
Check whether the lightning protection down conductor is smooth and well fixed. If it is found that the lightning protection down conductor is not firmly fixed, the down conductor should be effectively fixed to the tower body;
If the connection between the lightning rod and the lightning protection downconductor is rusty and disconnected, it should be dealt with in time.
7.5.2 When the grounding resistance does not meet the requirements of GY 5062-1998 and GY/T 5034-2015, excavation should be used to check the connection of the grounding body.
It can be used to repair the ground network, increase the area of the ground network, dope the soil around the grounding body with good conductive substances or resistance reducing agents, and increase the grounding
Extreme methods make it meet the technical requirements.
7.5.3 Maintenance of air-termination system.
a) Check the structural integrity of the air-termination system and the reliability of the connecting parts, and deal with any problems in time;
b) Check the corrosion of the connection between the air-termination base and the tower mast to avoid poor contact due to corrosion and affect the effective discharge of lightning current.
7.5.4 Use a shaker or other instruments to test the resistance value of the insulator, and replace it if it fails to meet the requirements.
7.5.5 Lightning arresters with broken wires and discharge umbrellas with sparking traces should be repaired or replaced.
7.5.6 Refer to Table 4 for the treatment methods of lightning protection devices and other common faults.
8 Reinforcement
8.1 General provisions
8.1.1 When the steel tower mast structure needs to be reinforced due to the following conditions, the reinforcement transformation plan shall be designed by a unit with the qualification of steel tower mast structure design
Or confirm that the professional maintenance unit will carry out structural reinforcement and reconstruction construction.
a) Found in daily inspection and maintenance;
b) What cannot be solved by professional maintenance;
c) The test and evaluation report mentions reinforcement;
d) Other needs to be reinforced.
8.1.2 Before the reinforcement and reconstruction construction, site survey and measurement shall be carried out, combined with the appraisal report, to determine the reinforcement and reconstruction plan.
8.1.3 The content and scope of the reinforcement and reconstruction shall be determined according to the test and evaluation conclusions and the use requirements after the reinforcement and reconstruction.
8.1.4 The reinforcement and reconstruction plan should be combined with actual construction methods, and effective measures should be taken to ensure that the new sections, components and components are in line with the original structure.
Structures are reliably connected to form a community.
8.1.5 The reinforcement and reconstruction plan should comprehensively consider structural safety, economy and construction period to reduce the impact on normal use.
8.1.6 The welding reinforcement of the steel tower mast structure shall be welded by welders with corresponding welding qualifications, and a good welding environment shall be ensured. occur
Welding is not allowed in one of the following situations and without effective protective measures.
a) The wind speed is greater than 10m/s;
b) It rains or snows;
c) Relative humidity is greater than 90%;
d) The ambient temperature is lower than 0°C (Q235 steel) or lower than 5°C (Q345 steel, Q355 steel).
8.1.7 For steel tower mast structures that may have unsafe conditions such as inclination, instability or collapse during reinforcement and transformation, corresponding measures shall be taken before construction.
Temporary safety measures; force analysis or deformation monitoring of sensitive parts.
8.2 Materials
The reinforcement materials should comply with the current relevant national standards.
8.3 Loads and effects
8.3.1 When checking and calculating the bearing capacity of the original structure and performing reinforcement calculations, the load and effect shall be re-determined according to the actual situation.
8.3.2 During the reinforcement calculation, the load and action shall be adopted in accordance with the provisions of GB 50135-2019.When reliable actual measurement data is available,
Reasonably adjust according to the actual situation.
8.4 Basic rules for structural analysis
8.4.1 Structural analysis should be carried out according to the actual situation of the structure and the loads and effects it bears.
8.4.2 Before reinforcement, the original structure shall be checked according to the ultimate state of bearing capacity and the limit state of normal use.
8.4.3 The reinforcement calculation shall be carried out in two stages during the reinforcement process and after reinforcement, according to the limit state of the bearing capacity and the limit state of normal use
Check calculations.
a) The structural calculation during the reinforcement process should consider the changes in the original structure state such as the removal of the original parts and the addition of bolt holes during the reinforcement process.
At this time, only the loads and effects of the reinforcement process are considered;
b) In the calculation of the reinforced structure, the load and action during the expected service period after the reinforced structure should be considered, as well as the reinforced part and the original structure
Coordination work;
c) The calculated cross-sections of components shall be corresponding actual effective cross-sections respectively.
8.5 Basic methods of reinforcement
8.5.1 The reinforcement of the foundation shall be implemented in accordance with relevant standards such as GB 50367-2013 and JGJ 123-2012.
8.5.2 According to different reinforcement content, reinforcement methods such as changing the structural system, replacing components, increasing the cross-section of components, and strengthening connections can be adopted.
When mature experience is available, other reinforcement methods can also be used.
8.5.3 Change the structural system.
a) It can be used to change the load distribution, force transmission path, node properties and boundary conditions, add additional rods and supports, apply prestress, etc.
Measures
b) The changed structural system should be calculated according to the structural bearing capacity limit state and the normal service limit state, and the construction should be considered
The influence of the process on the carrying capacity and use function of related structural members.
8.5.4 Replacement components.
a) The original components that cannot meet the requirements for continued use can be removed and replaced with new ones;
b) The structural system after the removal of the original component and before the replacement of the new component shall be inspected in accordance with the ultimate state of bearing capacity and the limit state of normal serviceability.
Count
c) Practical and feasible temporary measures should be taken to ensure the safety of the original structure.
8.5.5 Increase the cross-section of the member.
a) The stress condition and existing defects of the components should be considered, and the most effective enlargement section should be selected under the premise of convenient construction and reliable connection.
Face form. Refer to Appendix E for the enlarged cross-sectional form of commonly used steel tower mast structural members.
b) Calculate the bearing capacity according to the enlarged section. The design value of steel strength should consider the reduction factor k, generally k=0.8.
c) When reinforcing the axially stressed member, the effect of the eccentricity of the member section should be considered.
d) When calculating flexural members and eccentrically stressed members after reinforcement, the plastic development of the section should not be considered.
e) For the stability check calculation of the reinforced member, the stability factor should be taken according to the reinforced section, and the steel strength reduction factor should be considered.
f) The reinforcement and the reinforcement can work together reliably, the cross-section is not deformed and the board is stable, and the connection points are not less than two.
And the distance between the connecting points should not be greater than 80i for tension members and 40i for compression members, where i is the single-limb cross-section rotation
The radius should be selected in accordance with 7.2.6 of the steel structure design standard GB 50017-2017.
8.5.6 Connection reinforcement.
a) The connection reinforcement method can be welding, ordinary bolt connection or high strength bolt connection.
b) When the newly added connection is stressed separately, it shall be calculated according to the current specification; when it is connected with the original structure, it shall be calculated according to the original connection and the new
The actual transmission state of the connection is calculated.
c) For the reinforcement of the original welded connection, increase the length of the weld, increase the effective thickness of the weld, or increase the independent new weld, and do a good job
Anti-corrosion treatment in the weld area. The new technical requirements for welds shall comply with the relevant regulations of GB 50017-2017.
d) The strength of the right-angle fillet weld after reinforcement should consider the joint force of the new weld and the original weld, and appropriately reduce the design strength of the fillet weld.
The calculation is multiplied by a reduction factor of 0.85.
e) When bolts are used to strengthen the connection, the bearing capacity and structure of the connected nodes after the reinforcement should meet the requirements of GB 50017-
2017 regulations.
f) Adopt the method of enlarging the member section, and when the reinforcing member and the member to be reinforced are connected by bolts, bolts with smaller diameter and higher strength should be used.
9 Acceptance
9.1 In addition to the requirements of this standard, the acceptance shall also meet the relevant requirements of Chapter 11 in GY 5077-2007.
9.2 For acceptance, the following documents shall be provided for inspection and filing.
a) Entrusted tasks and related agreement documents;
b) Test report and related documents;
c) Construction organization design or construction technical plan, technical disclosure records, etc.;
d) The quality certification documents of the steel materials used in the newly added components and parts, the connecting materials (welding materials and fasteners), and the coating materials or
experiment report;
e) Factory certificate of newly added components;
f) Acceptance record form, please refer to Appendix F;
g) Completion acceptance report;
h) Other relevant information.
10 Scrap
Any steel tower mast structure that meets one of the following conditions shall apply for scrapping.
a) After the design service life is reached, a professional testing and evaluation agency should conduct a safety assessment, and it can be scrapped according to the assessment conclusion;
b) Although it can be used, the cost of reinforcement and maintenance exceeds its survival value;
c) Severely damaged, does not meet the conditions for use, and has no repair value;
d) In other cases, it needs to be scrapped after being appraised by a professional testing unit.
Appendix A
(Informative appendix)
Daily inspection and maintenance record table
The daily inspection and maintenance work content and cycle of steel tower masts are shown in Table A.1 and Table A.2.
Related standard: GY/T 329-2020    GY/T 330-2020