Discussion on vertical transportation scheme of teaching building frame project?

Vertical transportation scheme of teaching building frame project

1, tower crane

Select 1. 1 tower crane.

(1) tower crane selection principle:

According to the plane size of the building, the weight of the hoisted object and the hoisting capacity of the tower crane, and combined with the on-site construction conditions and engineering characteristics, bulk materials shall be hoisted in place at one time as far as possible, and the tower crane shall cover the building completely as far as possible, leaving no blind spots.

(2) Review of crane lifting capacity:

Taking this project as an example, check the lifting capacity of tower crane:

In the construction stage of above-ground structure, the flowing water of frame column formwork is the key line of construction. The main task of tower crane is to hoist the formwork of frame column, and the auxiliary task is to hoist the roof, beam formwork and various steel bars. In addition, it is necessary to assist in lifting the distributor when pouring and lifting the column concrete.

The above-ground structure construction lasts for 7 days on average. According to the working hours of the tower crane from 7: 00 a.m. to 12: 00 a.m. and from 14: 00 a.m. to 22: 00 p.m., the total lifting capacity of the tower crane is 15 minutes.

According to the layout scheme of columns, roofs and beams in each area, there are 78 columns, and each column template is hoisted twice, with an average of 78×2 times = 196 times; Roof and beam formwork * * * is about 4038m2, which can be hoisted at one time 150m2. * * * Need to lift 27 times. The support system and bowl buckle frame are dismantled early, and they are handled manually, without tower crane hoisting;

All kinds of steel bars * * * are about 103 tons, and need to be hoisted 103/2.5=42 times.

Considering the need of sporadic hoisting times during column pouring, 16× 3 = 48 times.

Consider that the hoisting of sporadic materials such as electrical embedded pipes is 10 times.

The lifting capacity of * * * is:196+27+42+48+10 = 323 times < 364 times, and each area can meet the requirements with a tower crane, so each area is equipped with a tower crane.

In the foundation construction stage, materials can be transported to the working face with manual assistance.

(3) the basis of tower crane selection:

(1) Through the calculation of tower crane lifting capacity, each area 1 tower crane can meet the construction requirements.

(2) A 60-meter-long tower crane can cover most of the whole main project and underground structure, and can cover the stacking area of circulating materials. Small pieces of materials are transported by manual assistance.

(3) According to the situation of the construction site, the more tower cranes are selected, the worse the construction.

(4) There are no main components to be hoisted in this project, and there is no need for tower cranes with heavy lifting load.

After calculation and construction experience, combined with the company's existing machinery, two 60-meter-long TC6020 tower cranes are selected. See the construction layout for the layout of tower crane.

1.2 Layout of Tower Crane

(1) Layout of Tower Crane

The main factors that determine the layout of tower crane are:

(1) Utilization of available construction sites and material processing sites;

(2) Select the tower crane model;

(3) Considering the demolition of tower crane, it is necessary to combine the structural layout conditions;

(2) Tower crane construction schedule

① Construction time of tower crane foundation: Excavation of foundation pit of tower crane foundation will be carried out immediately after entering the site, with manual and mechanical cooperation. The reinforced concrete structure of tower crane foundation and the installation of tower crane should be completed and accepted in advance before the construction of well pile structure.

② Tower dismantling time: After the main structure is capped, the tower will be dismantled after the materials needed for roof construction are basically hoisted. The timetable is as follows:

On April 24, 2006, the structure was capped and the roofing materials were hoisted. It is planned to dismantle the tower crane on May 5, 2006.

1.3 tower crane foundation construction

(1) tower crane foundation design

According to the site geological conditions and tower crane models, the tower crane foundation form is selected from the random data of tower cranes.

The tower crane foundation adopts replacement foundation, and the replacement foundation adopts 600mm thick 3: 7 lime soil. Basic design requirements are as follows:

It is required that the concrete strength grade of the tower foundation is C30, and this project is poured according to C35 concrete, so as to meet the strength requirements of tower crane installation as soon as possible. The foundation reinforcement is increased to be Ф 25 @167 bidirectional for upper iron, Ф 25 @167 bidirectional for lower iron, and Ф18 @ 500 for Rachel reinforcement, so as to improve the strength and install tower cranes in advance to meet the acceptance and operation of tower cranes.

(2) Tower crane foundation construction preparation

The positions of the two tower cranes in this project are all within the engineering ring, and the embedded parts of the tower crane foundation can be hoisted in place by the pit. When positioning embedded parts, surveyors must cooperate to measure their position and elevation correctly, and then check them after fixing them.

(3) Tower crane foundation construction

(1) The foundation pit of tower crane is excavated mechanically. After mechanical excavation, manually clean up the remaining 300mm soil, replace the tower foundation with 600mm thick 3: 7 lime soil, and then pour the cushion. Cushion thickness is 100, and concrete grade is C20. After the cushion strength reaches the master level, the surveyors will release the center line of the tower crane and the surrounding line of the tower foundation. The tire mold is built with shale bricks around the tower foundation, and the inside is plastered with cement mortar for calendering. The overbreak part of the tower foundation slope behind the waterproof guide wall is backfilled in layers by graded sand, with the thickness of each layer of 25cm and the compaction coefficient of 0.95.

(2) Binding of tower foundation reinforcement: After lofting, the foreman can bind the tower crane foundation reinforcement. The lower iron reinforcement pad is made of high-strength marble chips with a thickness of 25MM, and the upper iron is made of plastic pads with a spacing of1m.. When the steel bar is bound, it must be operated in strict accordance with the corresponding construction specifications. At the same time, the fixed leg of tower crane should be embedded. When the leg is buried, a steel pipe rack shall be erected, and the locating joint shall be supported by a U-shape, and a scaffold board with a length of 50cm and a width of 30cm shall be laid under the steel pipe under the U-shape to ensure that the elevation of the leg can be leveled at any time during concrete pouring.

(3) Concrete pouring: steel bars are concealed and inspected. After the embedded dimensions of the fixed legs of the tower crane are strictly checked, concrete pouring of the tower foundation can be carried out.

(4) In the process of concrete pouring of tower foundation, the elevation of the four corners of the built-in parts shall be measured with a level at any time to keep consistent. After the completion of concrete pouring, it is necessary to ensure that the inspection is correct.

1.4 tower crane accessories

Tower crane installation should be carried out by a professional tower crane installation team. 2cm thick steel plate is embedded in the frame column, and the attachment arm of the tower crane is welded with the steel plate. The reinforcement on the frame column needs to be further negotiated and calculated with the structural designer.

According to tower crane data, the free height of TC6020 tower crane can reach 50m. The calculated depth of the tower in the basement is 10m. When the tower is erected, first, let the first area jack up to the ultimate free height at one time, that is, let the first area tower than.

The tower height in Zone II must be at least three standard knots (8.4m) higher. The tower in the second area must be at least three standard sections (8.4m) higher than the working face to ensure safe operation.

1.5 tower crane demolition

According to the construction schedule, the tower crane demolition should be carried out after the completion of the main structure construction, so as to ensure that all the heavy materials that need to go upstairs in various professions are transported to the roof by the tower crane before the tower crane demolition.

When the tower is dismantled, the boom of the tower crane turns to the east-west direction to ensure that the boom is not hindered by buildings when it descends. First of all, the tower crane lowered the standard section by itself. When there are still four sections from the ground, with the help of the truck crane, the crane boom descends. After the rest standard sections and foundation sections are manually lowered, they are hoisted out by truck.

After the tower crane is dismantled, backfill and tamp the tower crane foundation pit with 2: 8 lime soil layer by layer.

1.6 tower crane installation and operation management safety protection measures:

(1) During the construction of tower crane foundation, it must be operated in strict accordance with the requirements of concrete structure construction specifications.

(2) The four fixed legs of the tower crane are 150+5 mm higher than the concrete base surface, and the center lines of pin holes of the four legs should be in the same plane, and the allowable tolerance is ≤0. 1%, that is, the absolute tolerance is ≤2mm, and the sealing verticality error is ≤0. 1%. The flatness error of the base surface shall not exceed 2mm. At the same time, the surface of tower crane foundation should be well drained.

(3) When attaching, check the verticality of the tower with theodolite and adjust the verticality with strut. The verticality deviation shall not exceed 0.2%.

(4) Synchronous grounding with grounding resistance ≤ 4Ω.

(5) Control the height and position of embedded parts in strict accordance with the disclosure size, observe the top elevation of embedded parts at any time during concrete pouring, and adjust the U-shaped bracket to make the top elevation of embedded parts consistent. Only when the concrete strength reaches more than 70% can the tower crane be installed. Attachment construction, the structural strength reached 70% before installation.

(6) When installing tower crane and its accessories, the construction must be carried out in strict accordance with the tower crane accessories, jacking and installation operation procedures.

(7) When the tower crane is installed, the technical personnel and safety management personnel of the installation unit must follow the classes to coordinate and solve the technical problems in the construction and control the safety.

(8) After the tower crane is installed in place, it must be accepted by professional and technical personnel, and it can only be put into use after it is qualified.

At the initial stage of installation, the project department must strengthen the observation of the settlement and inclination of the tower crane, which must be measured once a day at the beginning and twice a week after stabilization. After heavy rain and windy days, it is necessary to observe and notify the project department immediately if any abnormality is found.

(9) During the installation, dismantling and jacking of tower crane, the two sides of tower crane boom 15m are temporarily enclosed by shelf tube, and no personnel can enter or leave within this range. At the same time, the upper operators must coordinate with the following commanders. In the meantime, the project safety officer must be responsible for on-site safety supervision and safety coordination. In case of rain and windy weather above level 4, tower crane installation, dismantling and jacking operation shall not be carried out.

(10) For the first time, the height of the vertical tower must be controlled according to the jack-up requirements, and the tower crane that does not reach the designated position shall not be hoisted. Maintain the height difference between towers in the process of secondary jacking.

(1 1) Control the swing area of the boom, prohibit the load from rotating 360 degrees, prevent the boom from rotating over off-road and buildings, and specify the range where the hook load cannot cross the site.

(12) Use walkie-talkies instead of whistles for command, and use different frequencies to distinguish signals.

(13) Before the tower crane is used, a two-level acceptance system must be implemented. According to the relevant regulations of XX city and the company, after the acceptance of the project department, it should be reported to the equipment safety department of the company for review, signed step by step, and the responsibility should be implemented to the people. All materials shall be filed for future reference as required.

(14) Before the installation of tower crane, all professional installation units should instruct special personnel to conduct a comprehensive inspection of tower crane, and put forward written inspection materials and inspection and evaluation opinions. The defective parts should be replaced in time or other reliable guarantee measures should be taken. Only after all parts have passed the inspection can the tower be erected.

(15) During the use of tower cranes, regular and irregular safety inspections and maintenance shall be conducted, and written safety inspection records shall be formed. It is forbidden to carry out "sick" operation on tower crane and its accessories.

(16) When the safety devices such as lifting weight, lifting height and luffing display or are close to the critical alarm value, the driver must closely monitor it, and it is forbidden to work by force.

(17) Establish a system of related certificates, set up full-time drivers for tower cranes, and take turns to work. Fatigue operation is strictly prohibited. Operators must hold special trade licenses, and all tower crane commanders must be trained in advance and hold relevant certificates. During operation, the tower crane driver works closely with the hoisting command, and it is forbidden to command and operate illegally. It is forbidden to operate the tower crane without orders.

(18) Before tower crane operation in each shift, the tower crane driver must carry out trial hoisting. Only when the brake is sensitive and reliable and other instruments are free from hidden dangers can the operation be carried out. The commander is responsible for checking slings and spreaders every day and replacing damaged parts in time.

(19) Before lifting the goods, the commander must check the lifted goods to ensure that there is no danger of falling.

(20) In case of power failure or voltage drop during operation, immediately set the controller to zero and cut off the power supply.

If lifting a heavy object, use the brake loosely and tightly repeatedly, so that the heavy object can slowly descend to a safe place.

(2 1) In case of gale of magnitude 6 or above during operation, the operation shall be stopped immediately and measures shall be taken. There must be enough lighting for night work.

In the construction stage, the tower crane safety work instruction is compiled separately, and the tower crane is operated in strict accordance with the operating procedures and work instructions.

2, lifting frame

When the project construction reaches about four floors, insert the secondary structure and fine decoration project; The lifting frame should be installed before the masonry of more than two layers of infilled walls.

2. 1 lifting frame layout

Use five lifting frames, two in the north, one in the east and two in the south.

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