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On the quality control of mine project

Author: YeMing TaoXiaoLan WuFangHua From: www.yourpaper.net Posted: 2010-06-24 16:39:43 Read:
Abstract: in this paper, through the analysis of the reasons influencing project construction phase quality, puts forward some ways and methods of strict quality control during the construction period, construction, site inspectors should strengthen the new technology of lightning protection of learning to master, familiar with the standard of lightning protection, unreasonable or lack of lightning protection design to put forward their own proposals, at the same time pay attention to process control, ensure the lightning protection engineering construction quality.
Keywords: lightning protection; construction; quality control of
1, the
Lightning protection engineering project in the construction engineering, welding including pile foundation, the pole rib downlead full-length welding, equalizing ring, lightning, lightning and lightning arrester installation, has been accompanied by the whole process of construction.A lot of factors to ensure construction quality of lightning protection engineering project, such as design, material, machinery, topography, geology, hydrology, weather, construction technology, operation method, technical measures, management system, construction of all aspects of the construction process to strictly control, are fully implemented.
2 basic methods of lightning, lightning protection, the principle of
The 2.1 principle of lightning stroke
Lightning is occurring in the atmosphere of sound, light, electric physical phenomenon, the discharge current of up to tens of amperes, or even hundreds of thousands of amperes.Discharge at the moment, the destructive force and electromagnetic interference is very strong lightning current, caused by the disaster is one of the ten major disasters in nature.
The construction of preventing thunder and lightning protection engineering in construction project refers to.Lightning is a lightning strike directly in the building lightning protection device, the earth, or other object, generate electricity effect, thermal and mechanical stress.Electrostatic and electromagnetic induction appeared around the conductor lightning induction lightning discharge,, it can induct electric charge and a charge opposite in buildings and overhead lines in the clouds, to other places after discharge, the electric field between the cloud and the earth suddenly disappeared, charge can not but gathered at the top of a building or overhead lines on very fast all leaked into the earth, a large amount of charge remaining, and generate a powerful energy make buildings shatter or residual high potential charge formation can be mutually exclusive, breakdown electrical insulation layer caused by wire, metal pipes and metal large discharge, cause fire, explosion.
2.2 basic methods of lightning protection of
Preventing thunder is to guide the discharge between lightning and lightning arrester, the lightning current quickly dispersed into the earth to go, so as to protect buildings from lightning.The grounding device and the earth to make a reliable connection lightning induction device, through building internal pipelines, steel window frame, metal, charge of the lightning discharge in building residue on the rapid introduction of the earth.The commonly used building lightning protection measures of a lightning arrester, wire, grounding, lightning arrester, pressure ring and a metal conductor and equipotential connection setup.
The construction process, often appear 3 lightning protection engineering problems of
(1), lightning downlead, grounding, equalizing ring lap connection length is not enough, not full welding, welding slag, slag, weld, bite of meat and stomata, not knocked off the welding slag and other defects.
(2) the ground connection point reinforced network fault, leakage solder; as the external grounding connection or detection of leakage point embedded parts.Especially in the building structure conversion layer, because of structural column (wall) main steel bars to adjust, lightning protection downlead reinforced the wrong welding happens.
(3) with structural steel instead of lightning rod (net) and wire, welding damage of galvanized layer is not brushed with antirust paint; or a bolt connecting piece connected to the untreated, and contact is not tight.
(4) the distance is too large, downlead across the deformation joints without a compensator, without the protection of pipe wear wall.Grounding installation depth is not enough or not embalmed pinout.
(5) the roof metal objects, such as pipes, ladders, poles and equipment housing, not connected with the lightning protection system on the roof, or equipotential bonding jumper wire diameter insufficient.
(6) electrical equipment grounding (earthing) branch line, not connected with the earthing line, the series connection.Using TN - S system of multi-storey residential, into the line in the total meter box office did not repeat grounding, not according to the requirements of MEB in power distribution room. 4, main measures of lightning protection engineering project construction quality control of the
4.1 strictly review the design drawings.
4.1.1 not only to be familiar with the electrical diagram, on the structure, equipment in architectural design layout should also have the preliminary understanding, understanding of the design, for some special construction project system, such as the intelligent weak current system engineering, the information communication, computer, monitor, because these locations and settings in the design plan in general are not clearly marked, is the specification for construction standards for embedded reserved, to control code for acceptance of construction mandatory standards, construction notice.Such as is found not to conform to the current construction specifications or practice requirements properly, the lightning protection and grounding materials is not the time, should be promptly determine the negotiation and design units, the formation of design documents, in order to comply with and for the record.
4.1.2 is a construction project, the relevant professional design drawings more, audit lightning drawings, to control construction diagram, structure diagram, foundation drawing.The cohesion complex, easily lead to erroneous construction.If the construction experience, because of work (sequence) mismatch errors caused by the construction.For the problems easily overlooked and particularly important construction should be written opinions, to remind the construction units for the implementation of.
4.2 strict control of material quality control.A is three test materials, the two is to look at the material specifications, three is to check whether the galvanized material used in the construction design and specification.In the construction supervision and inspection process, workers often take common structure steel do help welding, or plain steel instead of the galvanized material, or in the cold galvanized material instead of hot dip galvanized material, it shall promptly correct.
4.3 mine construction is the main welding, welding quality determines the quality of the project.Due to the use of welding technology does not pass the personnel of the lightning protection and grounding, lightning protection engineering failure cases have occurred, should be strictly audit professional lightning protection construction team and construction personnel qualification certificate.
4.4 to strengthen the quality control of
key position for lightning protection engineering and process
According to the construction of several links appear quality problems, formulate on-site detection of pre-control measures, so that prevention, dynamic tracking, ensure the construction quality of the lightning protection engineering.
The 4.4.1 Foundation Grounding welding is connected to the first link in construction.For the basis of girth welding or pile foundation reinforcement and foundation reinforcement welding, welding steel bar and column reinforcement, must strictly according to the drawings and grounding inspection is performed, especially for the expansion joints of foundation reinforced or across connected to confirm.When the grounding grid after welding is complete, grounding resistance measurement immediately, to confirm whether meet the design requirements.When the resistance value can not meet the design requirements, again welding quality inspection or artificial grounding device according to the requirement of design complement.
The 4.4.2 for column bars for lifting the grounding grid, construction personnel use SD position and reinforced each post weld root number per layer construction according to the axis, to prevent leakage of welding or welding position, welding length and quality does not meet the design requirements and specifications.To guide and span steel welding quality check carefully, and requirements for location identification of welding arc line, to prevent the upward welding wrong main reinforcement caused by grounding interrupt error.Especially for the conversion layer of the structure, as the pole rib adjustment, lightning protection downlead welding arc welding, weld easy wrong by column internal main reinforcement, to be repeated to verify.
4.4.3 for equipotential welding, repeat the grounding part, such as the equipment room, power distribution room, fire control room, air-conditioning, elevator machine room, water supply pipe, cooling tower, fan and other parts of the grounding welding to indicate the reference, the verification in construction diary.
The above 4.4.4 high-rise building height of 45 meters, each up to three layers in the structure of beam inner laying flat in a 25mm * 4mm and the lead wire welded into a circular horizontal lightning with or with less than two beam main reinforcement welding pressure ring.Metal pipes and metal building horizontal laying and lightning protection grounding welding, vertical metal pipe laying, at the bottom and the top should be and lightning protection grounding welding.
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