With the development of China’s economy and the acceleration of highway and bridge construction, a series of quality accidents have also occurred in highway and bridge engineering, which is directly related to people’s property safety and has become the focus of attention. Highway and bridge construction units should attach great importance to this. The concealment of bridge pile foundation construction requires that in the construction of bridge pile foundation, we should not only rely on advanced science and technology, but also deal with the problems in the construction in time according to rich construction experience, so as to avoid the occurrence of engineering quality accidents. According to the specific geological conditions of the project, the pile foundation construction generally adopts the excavation pile construction. Bored cast-in-place pile shall be used for construction in geology that is not easy to excavate. As the bored cast-in-place pile in bridge engineering is a concealed project, most of the work is carried out underwater, and the construction quality inspection is difficult. Therefore, discussion on bored pile construction technology in bridge engineering is of great significance

• The pile foundation is composed of several piles and pile top bearing platform ? A common deep foundation. When the position of pier and abutment is weak ? When the overburden is thick and the bearing stratum is deep, the pile foundation can ? It passes through the weak layer and is supported on the supporting rock layer. Bridge pile ? Most foundations are reinforced concrete piles.

Lanzhou Zhongchuan International Airport Transportation Hub Project

By simply adjusting the relative position of the connector during connection, the track lines of the upper and lower threads of the butted reinforcement can be adjusted from non collinear to collinear

The strength of double screw sleeve is up to grade I, and the joint can be connected in the same plane. The reinforcement cage connection does not need to be staggered by 50%

Wulongxing double screw sleeve has the advantages of high strength, simple operation, fast construction speed and good mechanical properties

It has the characteristics of convenient, fast and simple connection, no power saving in construction, no obstruction in rain or wind, and all-weather construction

In the construction of road and bridge, high-speed railway station, nuclear power station, rail transit and other large projects, the traditional steel bar straight thread threading production line is used for steel bar processing, which often faces the following pain points:

• Insufficient efficiency of single machine
• Multiple machines cover a large area

In case of tight construction period and large amount of straight thread threading in large projects, the use of traditional straight thread threading production line for reinforcement processing will lead to a large amount of space occupied by the overall scheme and inconvenience in production and transportation.

Live shooting of products of Wulongxing production line

Wulongxing production line is widely praised in the use of the project

The intelligent rebar thread rolling automatic production line independently developed by Beijing Wulongxing is invested in the project. The comparison with the ordinary thread production line is as follows (hereinafter referred to as WL production line):

一、Wiring mode and floor area:

Full functions of reinforcement processing: the production line can integrate the two main functions of reinforcement sawing and thread processing on the same production line, while the conventional production line is arranged with the two lines of cutting production line and thread processing production line;

Small land occupation of the production line: the production line adopts high-speed milling processing technology, and the milling device is arranged in front of the thread processing device, eliminating the land occupation of the conventional shear production line;

二、WL high efficiency processing and reasons:

“Exquisite structure and easy transportation”. The intelligent steel bar thread rolling automatic production line has exquisite structural design. The whole production line occupies a small space (10m * 16m), has low requirements for site space, modular design, easy disassembly and convenient transportation transfer. Wiring can be produced even in the narrow construction area of the city, saving the cost of secondary material transfer;

三、Reasons for high quality of WL processing:

“High quality”. Due to the separate processing method of rib stripping and wire rolling of reinforcement, the rib stripping cutting can adopt alloy tool for high-speed cutting, with high surface finish and dimensional accuracy of reinforcement and excellent thread quality;

The thread accuracy can reach grade 6, and is not disturbed by any external conditions and personnel factors, with good consistency. The processing quality of steel wire head is good ? Intelligent dimension sensing identification system for rib stripping and wire rolling. The processing quality of wire head meets 100% of the specification requirements, completely solves the quality defects of reinforcement wire rolling, and “zero” rework;

Comparison of thread quality between Wulongxing production line and other production lines

In addition, the intelligent steel bar thread rolling automatic production line independently developed by Wulongxing has the following characteristics:

(1) “Exquisite structure and easy transportation”. The intelligent steel bar thread rolling automatic production line has exquisite structural design. The whole production line occupies a small space (10m * 16m), has low requirements for site space, modular design, easy disassembly and convenient transportation transfer. Wiring can be produced even in the narrow construction area of the city, saving the cost of secondary material transfer;

設(shè)備在工廠組裝后，經(jīng)過(guò)測(cè)試即將交付

(2) “Man machine dialogue”, no matter equipment failure, regular maintenance or regular tool replacement, it will alarm and prompt possible fault points and problem solutions; The steel bar blanking adopts double head simultaneous sawing and blanking setting, and the steel bar is cut to length with a length error of 1mm.

故障燈快速示警

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(3) “Low cost of consumables” ?， Self developed special rib stripping and wire rolling tools for reinforcement, with super hard and super long service life, and the cost of a single reinforcement processing tool is less than 0.02 yuan; The super long durability can ensure that the tool does not need to be replaced for a month or even a few months;

(4) “Excellent workmanship” ?， The first-line brand suppliers are preferred to provide the installation of key parts, “Siemens motor”, “Youyan hydraulic valve”, “Taiwan oil pump motor and oil pump”, “Taiwan Shangyin guide rail”, “Mitsubishi PLC controller” and “France Schneider Electric”. The equipment has high durability, stable operation and low failure rate;

(5) “Wide application range”, ? One production line can simultaneously complete “single double head threading”, “single single head threading”, “two double heads threading with the same or different specifications”, “one positive wire and one reverse wire” and “ultra short steel bar specimen threading”

The intelligent steel bar thread rolling automatic production line can reduce the labor cost and optimize the processing process in an all-round way. Under the background of the government’s strong support for the development of prefabricated buildings, Wulongxing intelligent reinforcement thread rolling automatic production line, as an advanced productive force, conforms to the development trend of the industry. It is a revolution in the field of reinforcement engineering industrialization and has completed its mission of high efficiency, less manpower and less land occupation given by the times! It is also the only way for the digital upgrading of the reinforcement processing plant. Choosing Wulongxing intelligent reinforcement thread rolling automatic production line is a very valuable investment!

Applicable scenario: roads and bridges / large public buildings / nuclear power

Industry advantages:

① High efficiency: process a 12m steel bar in 12 seconds, complete 4000 wire heads in 8 hours, and break 100 tons of steel bar threading in a single day

② Small footprint: single machine integrated thread processing and reinforcement sawing

③ High precision: the thread precision can reach grade 6

Cooperation mode: equipment leasing / leasing for sale / whole machine sales / project contracting

Project：Xiamen North Railway Station

Cooperation mode: reinforcement processing contracting

Wulongxing production line has entered the equipment commissioning stage in Xiamen north railway station project and will be put into use soon

One 12m steel bar is processed in 12 seconds, and 4000 wire heads can be completed in 8 hours

Full functions of reinforcement processing: the production line can integrate the two main functions of reinforcement sawing and thread processing on the same production line, while the conventional production line is arranged with the two lines of cutting production line and thread processing production line;

Small land occupation of the production line: the production line adopts high-speed milling processing technology, and the milling device is arranged in front of the thread processing device, eliminating the land occupation of the conventional shear production line;

Manufacturing steps

Support the steel bar

In order to better bind the reinforcement cage, we need to find something to support the reinforcement first.

Put on stirrups according to design requirements

There are requirements for the number of stirrups on the design drawing. We will thread the corresponding number of stirrups into the reinforcement cage according to the design.

Fixed reinforcement and stirrup

Then we need to use tools to fix the reinforcement and stirrup with binding wires, so that it will not be easy to shake.

Uniform distribution

When fixing stirrups, we must distribute evenly, so that the stress will be uniform and the project will be more solid.

Multi person collaboration

If we make it alone, the speed will be very slow, so we need more than one person to make it at the same time, so we can improve the work efficiency.

Final effect

After the fabrication, we can see a very perfect reinforcement cage. Finally, we can place the reinforcement cage in the position required by the fixed project

When the concrete structure is a column or strip member, the central part does not need to be reinforced, and the reinforcement is only configured under the surface where the concrete member contacts the air. If the component is independent, we make the reinforcement around the component in advance, which is the reinforcement cage. Usually, we call the pre fabricated reinforcement structures such as bored pile, dug pile and column as reinforcement cage.

Effect:

The main function of the reinforcement cage is the same as that of the longitudinal reinforcement of the column. It mainly plays a tensile role. The compressive strength of the concrete is high, but the tensile strength is very low. It can restrain the concrete of pile body and make it bear certain axial tension.

During the construction of bridges and culverts or high-rise buildings, piling may be required for the foundation according to the requirements. The method is to use machine punching and water mill drilling, and the hole depth meets the design requirements, then lower the reinforcement cage to the pile hole, and then insert the conduit for concrete pouring.

Production control points:

Whether the raw materials of reinforcement have been submitted for inspection, whether the specifications of raw materials meet the design requirements of drawings, stirrup spacing, lap length of welding points, and welding rods shall be provided with quality assurance certificate.

The reinforcement cage shall be manufactured and processed in strict accordance with the design, and the equal distance shall be controlled by the reinforcement positioning support for the position of the main reinforcement. Thickness of reinforcement cover. Whether the butt joint of reinforcement is bent as required, and whether the weld thickness and weld length of the bent joint meet the quality requirements.

The exposure draft points out that by 2022, Beijing will realize that prefabricated buildings will account for more than 40% of the new building area, and by 2025, prefabricated buildings will account for 55% of the new buildings.

The draft also pointed out that affordable housing and commercial housing development projects with state-owned land use rights obtained by bidding, auction and listing should meet the standard of assembly rate of no less than 60%; The newly approved new buildings invested by the government, new public buildings, industrial buildings and other buildings within the scope of implementation shall meet the standard that the assembly rate shall not be less than 50%.

In terms of key work, the draft also gives relevant guidance and suggestions: give play to centralized scientific and technological support, strengthen systematic integrated design, improve standardized production level, promote lean construction, implement full decoration finished product delivery, improve information application level, innovate project organization and management mode, carry out evaluation demonstration and reward, and cultivate professional talent team.

The draft mentioned that it is necessary to support the R & D of prefabricated buildings and strengthen the R & D and application of new structural system, standardized design, quality inspection and efficient connection technology of prefabricated buildings. A database of major scientific and technological achievements of prefabricated buildings has been preliminarily established. Further improve the technical standard system, evaluation system and pricing basis of prefabricated buildings.

In addition, new buildings should implement the delivery of fully decorated finished products, gradually improve the application proportion of prefabricated decoration in indemnificatory housing, commercial housing and public buildings, and encourage the decoration and transformation of existing buildings to adopt prefabricated decoration.

Vigorously promote the application of building information model (BIM) technology in the whole life cycle of design, production, construction, operation and maintenance. The prefabricated construction projects invested by the government and public rental housing should apply BIM Technology in the whole life cycle, and other types of prefabricated construction projects are encouraged to apply BIM Technology in the whole life cycle.

Explore the establishment of an Internet platform for the construction industry, carry out intelligent upgrading of production equipment and construction equipment, encourage the application of intelligent equipment such as construction robots, industrial robots and intelligent mobile terminals, and promote intelligent office and building automation systems. Promote the integrated application of big data technology, 5g, radio frequency identification (RFID) and two-dimensional code identification in the construction and management of prefabricated buildings.

In the process of developing prefabricated buildings, on the one hand, real estate enterprises are actively layout. Vanke began to develop prefabricated buildings in 2003 and established Vanke Industrialization Center, which is committed to the research of prefabricated system. Since 2007, it has gradually promoted prefabricated buildings throughout the country and established Vanke prefabricated system.

At present, country garden has established a highly standardized parts library, house type library and building type library to open up the data flow of the whole industrial chain such as R & D, design, production, transportation and construction with the help of BIM Technology. Mass customization of PC components is realized through the automatic production line, and construction robots and intelligent construction equipment are applied on the construction site to reduce the waste of construction materials, improve the construction quality, and achieve green consumption reduction in the whole construction process.

In addition, real estate enterprises regard prefabricated construction as the key business of enterprise development in the future. Meihao real estate officially entered the field of prefabricated buildings in 2017 and announced the transformation from traditional real estate development to intelligent building integration business of integrated prefabricated buildings. According to the annual report, in terms of prefabricated construction business, Meihao real estate put into operation two factories in Wuhan Jiangxia factory and Qingdao Jimo factory in 2018, five factories in Henan Xinxiang, Hubei Jingzhou, Hefei Feidong, Chongqing Jiangjin and Changsha Miluo in 2019, and two factories in Chengdu Jintang and Jiangsu Yizheng in 2020. In 2020, the fabricated construction business of Meimei real estate involved a total amount of 4.765 billion yuan.

Capital is also laying out prefabricated construction innovation companies. On July 28, the digital technology integration platform company of prefabricated buildings, Dale decoration, announced the completion of strategic financing, and achieved component standardization based on AI prefabricated building design, so as to reduce costs and improve efficiency for customers and suppliers. Investors include star institutions such as Tencent and China Merchants.

On August 10, the assembly interior decoration company Weishi housing workers announced that it had completed a new round of financing of tens of millions of yuan, with the exclusive strategic investment of Panasonic electric.

Information shows that since 2014, China has successively issued a number of important policy documents to promote the development of prefabricated buildings. Among them, the action plan for prefabricated buildings in the 13th five year plan: by 2020, the proportion of prefabricated buildings in new buildings will reach more than 15%, of which the key promotion areas, active promotion areas and encouraged promotion areas will be more than 20%, 15% and 10% respectively; The opinions on promoting the sustainable and healthy development of the construction industry issued by the State Council office requires that by 2025, the proportion of prefabricated buildings in new buildings should reach 30%.

According to the data of prospective industry research institute, in 2020, the proportion of prefabricated buildings in the new construction area will reach 15%, 30% in 2025, and about 14% in 2018, so it will increase by an average of 2 percentage points per year in the future.

The data also shows that according to the reference basis of prefabricated construction cost issued by the Ministry of housing and urban rural development, based on 2230 yuan / m2 (considering the different effects of rising technology level and rising prices on the price level, assuming that the cost will remain unchanged in the next few years), the area of new real estate buildings will replace the area of new urban buildings, By 2024, the scale of China’s prefabricated construction market will reach more than 120 billion yuan.

At present, according to the guidance issued by Beijing, the development requirements and speed of prefabricated buildings are improving rapidly, and the trillion market may come quickly in the future.

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1. Generally, the reinforcement processing shed is within the lifting range of the tower crane. Otherwise, it is inconvenient to lift the reinforcement. 
2. There are two layers on the top of the protective shed. The formwork is laid on the uppermost compartment and two layers of bamboo sheets are laid on the lower layer. The spacing between the two floors is 500 mm. There is a 500 high enclosure on the top surface. It is erected with double steel pipes as columns. 
3. There are fire extinguishers, reinforcement processing equipment and lighting system inside. 
4. There are name plates at the door and operating procedures and precautions next to the machinery.

（一）Steel bar rust removal

Generally, the rust removal of reinforcement can be achieved through the following two ways: first, the rust removal can be solved simultaneously through other processes of reinforcement processing, such as the rust removal in the process of cold drawing of reinforcement or straightening of steel wire, which is the most reasonable and economical method; The second is through mechanical derusting, of which the more common is to use electric derusting machine for derusting. The diameter of the disc wire brush of the commonly used electric derusting machine is 20 ~ 30cm, the thickness is 5 ~ 15mm, the rotating speed is about 1000r / min, and the motor power is 1.0 ~ 1.5KW. In order to reduce dust flying during rust removal, dust hood and dust pipe shall be installed.

In addition, manual rust removal (with steel wire brush and grinding wheel), pickling rust removal, sand blasting rust removal, etc. can also be used.

(二)Reinforcement straightening

The coiled reinforcement must be placed and straightened before use, and the thick reinforcement supplied with straight bars must also be straightened once before use, so as to meet the provisions of “reinforcement shall be straight without local twists and turns” required by the specification.

The steel bar straightening machine can complete three processes of rust removal, straightening and cutting at the same time. There are five straightening blocks in the straightening cylinder of the straightening machine. They do not rotate on the same center line. The offset value shall be adjusted according to the nature of the reinforcement and the wear degree of the straightening block, so that the reinforcement can get the best straightening effect. The two straightening blocks at the inlet and outlet ends of the straightening cylinder must be adjusted to the straightening position.

When the cold drawing method (such as winch) is used to straighten the reinforcement, the cold drawing rate of grade I reinforcement shall not be greater than 4%; The cold drawing rate of grade II and III reinforcement shall not be greater than 1%. If it is used for general tensile reinforcement, the strength after tension is not used, and the cold drawing rate during cold drawing and straightening can be appropriately improved, but the grade I reinforcement shall not exceed 6%, and the grade II and III reinforcement shall not exceed 2%; For structures that are not allowed to use cold drawn reinforcement, the straightening and cold drawing rate of reinforcement shall not be greater than 1%.

(三)Reinforcement cutting

1: The reinforcement shall be cut off according to the calculated blanking length. Reinforcement cutting machine or manual cutter can be used for reinforcement cutting. The manual cutter is only used to cut the reinforcement with diameter less than 16mm, and the reinforcement cutter can cut 40mm reinforcement. When the diameter of reinforcement is greater than 40mm, it shall be cut with oxygen acetylene flame or grinder.

2: In the construction of large and medium-sized construction projects, the reinforcement cutter is advocated. It not only has high production efficiency and convenient operation, but also ensures that the end face of the reinforcement is perpendicular to the reinforcement axis without horseshoe shape or warpage, which is convenient for welding or mechanical connection of the reinforcement. The blanking length of reinforcement shall be accurate, and the allowable deviation shall be ± 10mm.

(四)Reinforcement bending forming

1: After the reinforcement is cut according to the material length, it shall be scribed according to the characteristics of bending equipment, reinforcement diameter and bending angle, so as to bend into the designed size and shape. If both sides of the bent reinforcement are symmetrical, the marking work should start from the center line of the reinforcement to both sides; When bending the reinforcement with complex shape, the real sample (full-scale setting out) can be set out first, and then bending can be carried out.

2: Steel bar bending machine or steel bar hoop bending machine should be used for steel bar bending; When the diameter of reinforcement is less than 25mm, a small amount of reinforcement (or stirrup) can be bent, or it can also be bent by manual pulling hook.

The article comes from the Internet