This project is a commercial and residential building project of Hongyang Garden in Tangshan City, located on the west side of Torch Road in Tangshan City. Prepared by Tangshan Hongyang Real Estate Development Company through bidding, Tangshan Guo Wang Construction and Installation Co., Ltd. won the bid. The construction period is 333 days, and it is required to start on June 1+00, and be completed and delivered on October 30, 2002. The project is designed by Tangshan Planning and Architectural Design and Research Institute, and the building plane is a 5-unit combined strip residential building. The building area is 16757.66M2 (including basement area of 23 10M2). The basement is one and a half floors, and the main body on the ground is six floors. The basement is 2.2M high, the first floor is 3.6M high, the second floor is 3.0M high, and the third to sixth floors are 2.9M high. Huxing combination is one staircase and two households, the first and second floors are commercial and the third to sixth floors are residential. The project is a frame structure. Scaffold erection scheme is based on Technical Specification for Safety of Fastening Steel Pipe Scaffolding in Building Construction (JGJ 130-200 1), Safety Inspection Standard for Building Construction (JGJ59-99), Detailed Rules for Implementation of Safety Inspection Standard for Building Construction in Hebei Province and drawings.

Second, the scaffold material requirements

1) All kinds of scaffolding bars are welded steel pipes of No.3 steel, with an outer diameter of 48mm and a wall thickness of 3.5 mm. The products qualified by the manufacturer are used and have certificates of approval, and their mechanical properties should comply with the provisions of Q235A steel in the current national standard "Carbon Structural Steel" GBT700. The length of steel pipes used for vertical rods, main rails and diagonal rods is 4-6m, and the length of small rails and Rachel rods is 2. 1.

2) Fasteners shall use the qualified products of the manufacturer and hold the product certificate. The technical performance of fastener forged cast iron meets the requirements of Steel Pipe Scaffolding GB15831-1995. All fasteners used shall be inspected, and there shall be no defects such as air holes, sand holes, cracks and slippery threads. The joint surface between fastener and steel pipe should be strictly shaped to ensure good contact with steel pipe fastener. When the fastener clamps the steel pipe, the minimum distance at the opening should not be less than 5mm, the movable parts of the fastener can rotate flexibly, the gap between the two rotating surfaces of the rotating fastener should be less than 65438±0mm, and the fastener should not be damaged when the tightening torque of the fastener bolt reaches 60n * m..

3) The scaffold board shall be made of larch, with a thickness of 50mm and a width of 300 mm, and it shall not be used if it is decayed, twisted, twisted, broken or has a large transverse scab. The scaffold board used is 8cm at both ends, and it is wrapped with No.8 lead wire hoop for 3 times.

Three, scaffolding technical measures

1, construction preparation

(1) Before the scaffold erection, the technical director of the construction site shall make a written technical disclosure to the professional team leader paragraph by paragraph according to the scaffold erection plan, and perform the disclosure signing procedures, with each party holding one copy and supervising each other. The professional team leader shall make technical disclosure to the operators before the shift, and make disclosure records.

(2) According to the requirements of various materials used in scaffolding, all materials used should be inspected and accepted before they can be used on site. After entering the site, it should be classified and neatly stacked, and used for listing.

(3) Scaffolding operators must be trained by the labor department and hold relevant certificates.

2, the basis of scaffolding

(1) Before scaffold erection, the foundation shall be leveled and compacted, and there shall be no water around the scaffold foundation. A drainage ditch shall be set at 0.5 meters outside the scaffold external pole. Set a puddle at the lowest point, water flows into the puddle, and the water is discharged by submersible pump. The slope of the drainage ditch is 3-5‰. In order to ensure the bearing capacity of the frame foundation, the backfill soil of the foundation groove must be compacted layer by layer before the scaffold foundation can be made.

(2) After the backfill soil is compacted, a 0.2×3m wooden scaffold board with a thickness of 50mm is laid on it, and then a steel base is placed on the wooden scaffold board, and a vertical rod is placed on the steel base. After that, pay-off positioning shall be carried out according to the designed vertical pole spacing, and the wooden scaffold board shall be laid smoothly and shall not be suspended.

3, scaffolding structure technical requirements

(1) According to the requirements of scaffold structure, this project is a frame structure with internal and external double bent frames. The inside of the scaffold is 200mm away from the wall, the column is 450mm below the cornice, the outside column is out of the wall 1.2m, the column row spacing 1.2m, the vertical distance of the column 1.8m, and the step distance of the main rail is 65438. The upright post and the main rail are connected by straight fasteners. During erection, the vertical pole should be erected on the outside of the main rail, and the joints of two adjacent rails should be staggered by one step, and not less than 500mm. The distance from the center of each joint to the main node should not be greater than 1/3 step. Erection of poling should be vertical and horizontal, the verticality of poling should be 1/400, the total height should not exceed 50mm, the main rail should be horizontal, the total horizontal difference should not exceed 20 mm, the vertical distance deviation of poling should not exceed 20 mm, the length of small rail extending laterally from the frame should be 140mm, and the distance between small rail and main node should not be greater than 65430 mm

(2) For Rachel of the frame and the building, the height of the frame should be tied with short steel pipes and building columns on each floor, and the scaffolding with Rachel poles inside and outside should be fastened with fasteners and vertical poles or main rails. The vertical height of the tensile joint is not more than 4m, the layer-by-layer tensile joint and the horizontal spacing are not more than 6m, and one tensile joint is set every other concrete column. When setting, it should be as close as possible to the master node, and the distance from the master node should not exceed 30cm. The layout form adopts flower rows.

(3) The bracing is set with 6m steel pipes, with 7 uprights and 7 crossbars as a set of bracing, and every 6 sets of bracing at a 45-degree angle with the ground. The corners at both ends of the scaffold are set on both sides, and each set of bracing should be set continuously from top to bottom. In addition to fastening both ends of the diagonal bar with rotating fasteners, two fasteners should be added in the middle, and the distance between the fasteners at both ends of the diagonal bar and the vertical railing node should not be greater than 150. At the bottom of the diagonal and vertical rod connection point distance is not more than 200mm, bridging lap length is 1000mm, with three fasteners, fasteners at the end of the steel pipe is not less than 10cm. The lower end of the scissors must touch the ground.

(4) The scaffold of the construction operation layer must be paved, stable and strict, and the distance from the wall shall not be greater than 200mm. Scaffolding boards shall be laid between the upright post and the wall surface, and there shall be no gaps and head control panels. Only one operation layer is considered in the top-down construction of this project. For scaffolding laid by opponents, two small bars must be set below the joint, and the plate end is at the corner from the small bar150 mm.

(5) In order to protect the operation floor and the access opening, two protective railings are set at the height of 1.2m of the operation floor, but a licensed dense mesh erection net should be hung, and the side ropes of the erection net should be tied tightly with the main rail, and the skirting board with the height of 180mm should be replaced with wooden feet. Set a layer of pocket net at a distance of 3m from the ground, and set a safe passage at the south side of the building, with a length of 3m and a height of 3m, which is the same as the width of the hole. The upper layer is paved with a layer of 50mm wooden scaffolding, and signs are hung.

(6) Sealing method between scaffold and building: the federated eye network is vertically closed, and the quality requirements of federated eye network: ① The federated eye network should have four certificates and be flame retardant, and its continuous burning and smoldering time should not exceed 4 seconds. Comply with GB 16909. ② There are more than 2,000 meshes per10cm×10cm =100cm2. Permeability test of dense mesh net: When conducting the permeability test, lay the net flat at an angle of 30 degrees with the ground, and 3 meters above its center, use a 5KG steel pipe (pipe diameter 48-5 1mm) to freely fall vertically. If it does not penetrate, it will be a qualified product. Binding method of dense mesh wind: use 14# lead wire to bind the dense mesh net on the column or main rail to make the net firmly connected with the frame. The material of the fly should comply with GB 16909. Bag net sealing: use big eye safety net (flat net) to seal scaffolding and buildings, and set flat net on the second floor, once every10m.

(7) Scaffolding passage: Scaffolding body shall be provided with safety rails: ① The rail width shall not be less than 1m, and the slope shall be 1: 3 (height: length). (2). The spacing between the vertical pole and the horizontal pole should be suitable for scaffolding, the foundation should be treated according to the requirements of scaffolding, and the facade should be set with scissors. (3) The spacing between the small bars on the pedestrian ramp should not exceed1.5m. (4) When scaffolding is spread, anti-skid strips should be nailed on the board, and the anti-skid strips should not be greater than 300 mm..⑤ (5) A guardrail should be set, with the upper protective railing 1.2m and the lower protective railing 0.6m away from the scaffold board, and the width of 180mm should be set at the same time.

(8) scaffold unloading platform: the unloading platform shall be marked with the control load; Construction should be carried out in strict accordance with the erection plan.

Design and calculation of unloading platform

The transverse distance of the vertical pole is b = 1m, the longitudinal distance of the vertical pole is l = 1.5m, and the step distance is h =1.5m..

Scissors are arranged continuously, and the width of the discharging platform is c = 2m.

(1) strength calculation

Mmax=q 12/8

q= 1.2(GK。 c+GH)+ 1.4 qqk . c

GK- scaffold board weight GK=0.3KN/M2

C- width of discharging platform C=2M.

GK- unit length of steel pipe GK = 38n/m

Kq- construction live load KQ= 1.2N/M2.

Qk- standard value of construction load QK=2000N/M2.

q = 1.2 *(300 * 1.0+38)+ 1.4 * 1.2 * 2000 * 1 = 405.6+3360 = 3765.6n/M

mmax =(3765.6 * 12)/8 = 470.7n . m

Check bending strength

s = Mmax/W = 470.7/5078 = 92.7n/MM2 & lt； 205 North /MM2

Therefore, the safety meets the design requirements.

(2) Calculation of deformation

Look-up table φ48*3.5 steel pipe parameters.

E=2.06* 105N/MM2 (elastic modulus of steel pipe)

I= 12 190mm (moment of inertia of steel pipe section) w/b = 5ql3/384ei = (5 * 3765.6 *10003)/(384 * 2.06 *105).

= 0.19% =1/5261150 meets the requirements.

Structural calculation meets the requirements of strength, stiffness and stability.

(9) Erection sequence of external scaffold

Scaffolding of this project will be erected from bottom to top. After the vertical pole mat is laid, let out a ruler from one side of the building and draw the vertical pole axis with chalk on the mat. Then put the standard base and sweeping bar on the pad-> vertical bar (and then fasten the vertical bar and sweeping bar with right-angle fastener)-> install sweeping bar-> install the first step ledger-> install the first step ledger-> correct the vertical bar-> set the first row of pull nodes-> Ann.

Four, scaffolding inspection and acceptance

During installation, disclosure shall be made according to the construction progress; During inspection and acceptance, installation and acceptance shall be carried out in stages according to the progress; It can be delivered only after passing the acceptance, and the scaffold shall be submitted for signature. Scaffolding shall be accepted by the competent foreman, technician, scaffolder, team leader and full-time safety officer.

Five, scaffolding use, maintenance, maintenance technical measures

1, the scaffold shall be inspected by designated personnel every day to check whether the columns and plates are sinking or loose, whether the fasteners of the frame body are slipping or loose, and whether the parts of the frame body are complete.

2, completes the scaffolding foundation drainage, after the rain to conduct a comprehensive inspection of scaffolding frame body foundation, it is forbidden to scaffolding basement water sinking.

3. The operating layer construction load shall not exceed 270KG//m2, and the cross bar support and cable wind rope shall not be fixed on the scaffold. It is forbidden to hang heavy objects on scaffolding.

4. It is forbidden for anyone to dismantle any parts on the scaffold at will.

5. In case of gale, fog, heavy rain and heavy snow with magnitude 6 or above, scaffold operation should be suspended, and operation can be continued only after inspection.

Six, scaffolding matters needing attention

1, steel pipes with an outer diameter of 48mm and 5 1mm are strictly prohibited to be mixed.

2. At the master node, the distance from the center line of fasteners such as fixed horizontal bar or vertical horizontal bar, bracing and lateral support to the master node is not more than150 mm. ..

3. The length of each rod end protruding from the edge of the fastener cover plate should not be less than 140mm.

4. The opening of the butt fastener should face the inside of the shelf, with the bolt facing up and the opening of the right-angle fastener not facing down to ensure safety.

5, shelf homework personnel must hold relevant certificates, wear safety helmet, fasten your seat belt.

6, in strict accordance with the erection scheme construction; Even the wall and bracing should be set in time, and shall not lag more than two steps.

7, in the process of erection, should pay attention to adjust the verticality of scaffolding, the maximum allowable deviation is100 mm. 。

Seven, scaffolding material dosage plan

Material Name Unit Quantity Entry Time

After the T 20 foundation of scaffold pipe is backfilled,

After backfilling the foundation of 1500 with right-angle fasteners,

400 After the foundation of docking fastener is backfilled.

After the rotary fastener foundation is backfilled for 500.

After the foundation of scaffold 1270 is backfilled,

After backfilling 900 dense mesh nets 1.8×6M.

After the flat screen 2×3M 240 slab foundation is backfilled,

Eight, scaffolding plan, elevation

I. Overview of the Project

This project is a commercial and residential building project of Hongyang Garden in Tangshan City, located on the west side of Torch Road in Tangshan City. Prepared by Tangshan Hongyang Real Estate Development Company through bidding, Tangshan Guo Wang Construction and Installation Co., Ltd. won the bid. The construction period is 333 days, and it is required to start on June 1+00, and be completed and delivered on October 30, 2002. The project is designed by Tangshan Planning and Architectural Design and Research Institute, and the building plane is a 5-unit combined strip residential building. The building area is 16757.66M2 (including basement area of 23 10M2). The basement is one and a half floors, and the main body on the ground is six floors. The basement is 2.2M high, the first floor is 3.6M high, the second floor is 3.0M high, and the third to sixth floors are 2.9M high. Huxing combination is one staircase and two households, the first and second floors are commercial and the third to sixth floors are residential. The project is a frame structure. This scheme is compiled according to the Technical Specifications for Temporary Electricity Use in Construction Sites (JGJ46-88), Safety Specifications for Power Supply in Construction Sites (GB50 194-93), Safety Inspection Standards for Construction (JGJ59-99), Detailed Rules for the Implementation of Safety Inspection Standards for Construction in Hebei Province and other standards.

Second, the distribution system layout

1, system form selection

This project adopts 250KVA transformer for direct power supply. According to the location, quantity and site conditions of all electrical equipment in the construction scheme, it is proposed to adopt radial and trunk or hybrid distribution systems, and the distribution boxes and electrical equipment are radial to ensure that the equipment does not interfere with each other. The construction site is divided into four roads. The first road is the rubber copper core cable of the steel shed, which is set from the main box to the steel shed and distributed at two poles. The diode distribution box is divided into six paths to supply power to the reinforcement shed and the welder shed respectively; In the second way, rubber copper core cables are arranged between 1# and 2# towers, and the main box is set to the diode distribution box in the middle of 1# and 2# towers to supply power to the tower crane, mixing station and five roads upstairs respectively; The third way is the same as the second way; The woodshed on the fourth road. The cross section of the rubber copper core cable main box is set as the two-pole distribution of the wooden shed, and the two-pole distribution is divided into four ways to supply power to the chainsaw and planer. (See the floor plan for specific layout).

2, line laying

The distribution trunk line is laid with five-core rubber insulated cable except the lighting branch and mobile distribution box led from the main distribution box. 500 V VV rubber insulated cable is selected for the mobile distribution box and each branch line.

3, electrical equipment selection

(1) Both the main distribution box and the distribution box are equipped with the main automatic air switch and the shunt automatic air switch or breaker switch, and the automatic air switch is used when the working current of electrical equipment is greater than 60A. The automatic air switch is DZ 10, and the circuit breaker switch is HK.

(2) Each electrical equipment has its own dedicated switch box, and the system of "one machine, one brake and one leakage box" is implemented.

(3) The main distribution box is equipped with a 0-450 volt voltmeter and a 0-600 ampere ammeter. ..

(4) Lighting and power share a distribution box, but lighting and power are set separately. Install two-stage leakage protector and circuit breaker switch in the lighting part of each distribution box.

4. Protection device of power distribution system

(1) The whole system adopts TN-S tn-s protection zero connection system. Repeat grounding at the main distribution box and 2# and 3# sub-boxes, and the grounding resistance is less than 10 ohm. The protective wire is specially designed for 2.5 mm square yellow-green BVR multi-strand copper core wire, which is directly laid. All electrical equipment and distribution boxes have zero connection protection.

(2) The protection is connected to zero, and at the same time, a leakage protector is set to implement two-level protection for the main distribution box, distribution box and switch box. The main box adopts DZ 15LE400/430/430 leakage protection. The rated leakage current of the leakage protector selected in the switch box is not more than 30MA. The rated leakage action time is less than 0.1s.

Third, the calculation of total electricity load

See table 1 for electricity consumption of mechanical equipment, and 10% for lighting.

Conversion of electrical equipment with different temporary load rates

Butt welder: PE = sejc.cos =100 * 0.2 * 0.7 = 31.3kw.

Electric welding machine: pe=se JC.cos =22* 0.65*0.45=8kw.

The connection modes of four electric welding machines and butt welding machines can be evenly distributed, but the three-phase imbalance coefficient can be ignored.

S machine =1./kloc-0 /× {k/kloc-0 /× (σ p machine /COSP)}+K2σ s machine =1.1× {0.6× (120.9/)

= 2 13.6 kva

The electricity consumption for lighting is 10% of the electricity consumption of construction electrical equipment.

S total = 1. 1× s machine =1./kloc-0 /× 213.6 = 235kva.

That is 235kva.

After calculation, the total capacity required for power supply on the construction site is less than the transformer capacity provided by Party A, which meets the requirements.

The load calculation of other trunk lines and branches and the selection of distribution box equipment are omitted (see system diagram for details).

Machine required capacity of electrical equipment on the construction site (KVA)

σ p machine-sum of rated power of motor used in construction site (KW)

Average power factor of cosp motor (cosp=0.7 by looking up the table)

K 1- motor also needs coefficient look-up table. K 1 = 0.6

When the electric welding machine needs coefficient lookup table at the same time, K2-K2 = 0.6.

σ s machine-sum of rated number of welding machines on the construction site (KVA)

Four, the construction of temporary electricity layout (figure 1)

Verb (abbreviation of verb) wiring system diagram (attached figure 2)

Table 1 Power List of Electrical Equipment

Please indicate the specification, model, quantity, unit power (kW) and total power (kW) of the motor.

1 tower crane QTZ 250 4 15 60

2 steel bar cutting machine Q 140- 1 1 44

3 cutting machine 1 2.2 2.2

4 mixer 350L 1 5.5 5.5

5 chainsaw 1 4.4 4.4

6 Planer 2 3 6

7 welding machines, 3 sets of 22kVA × 2 sets.

8 vibrator101.11

9 plate vibrator 2 2.2 4.4

10 winch 2 5.5 5.5

1 1 mixer 750l110.

12 grinder 1 2.2 2.2

13 bench drill 1 2.2 2.2

14 bending machine 1 3.5 3.5

15 welder 1 100 kva

Total 60.8 120.9 166 kva.

Six, distribution equipment installation technical measures

1, cable laying method:

The cable is buried 600mm below the outdoor natural ground, and 50mm thick fine sand is evenly laid on the cable, and then covered with bricks for protection. When the cable is led out from underground, it shall be protected from 200mm underground to the distribution box with flame-retardant PVC plastic sheath tube. Move the distribution box and use scaffolding to wear plastic pipes for protection.

2. The setting of electrical equipment shall meet the following requirements

(1) In the electrical box at the same level, the power and lighting circuits are set in parallel, and the lighting circuit should be connected to the upper side of the power switch.

(2) The switch box is distributed by the distribution box, and there is a brake leakage in the switch box. It is forbidden to use more than one brake.

(3) The distance between the distribution box and the switch box shall not exceed 30m, and the horizontal distance between the switch box and the electrical equipment it controls shall not exceed 3m.

(4) The distribution box and switch box should be installed in a dry, ventilated and normal temperature place, and there should be enough space for two people to work at the same time around, and nothing that hinders operation and maintenance should be piled around.

(5) The distribution box and switch box are installed correctly and firmly. The distribution box is installed on a solid support. The vertical distance between the lower surface of the fixed distribution box and the ground is 1.4m, and the lower surface of the mobile distribution box is1.2m. The box body of the distribution box adopts 1.5mm iron plate. The incoming and outgoing wires in the distribution box and switch box are arranged at the bottom of the box, and the incoming and outgoing wires are sheathed.

(6) The working zero line in the distribution box and switch box is connected through the terminal board and separated from the terminal board for protecting the zero line. Distribution box shell is connected to zero protection.

3. Indoor wiring

(1) Indoor wiring must use insulated wires and be laid through pipes, with a height of not less than 2.5M from the ground.

(2) The cross section of wires for indoor wiring shall not be less than 2.5M2, and the cross section of copper wires shall not be less than1.5m2..

(3) The indoor lamps and lanterns shall not be less than 2.4M. When it is less than 2.4m, safe voltage must be used.

(4) Indoor joints must be protected by junction boxes.

(5) 2000W incandescent lamp (waterproof bending lamp) and 1000W iodine tungsten lamp are used for site lighting. The lighting lamp is 3.0m from the ground, and the switch is waterproof cable switch. Iodine tungsten lamp metal shell is used for protection and zero connection.

4, outdoor distribution box

(1) There should be enough space for two people to walk around the distribution box. Do not pile up anything that hinders operation and maintenance. There are no shrubs or weeds.

(2) The working zero line in the distribution box should be connected through the terminal board and separated from the terminal board for protecting the zero line.

(3) The connecting wires in the distribution box shall be insulated wires, the joints shall not be loose, and there shall be no exposed live parts. The vertical distance between the bottom of the distribution box and the ground is 1.4M, and the vertical distance between the bottom of the mobile distribution box and the ground is 0.8m ..

5. Matters not covered shall be constructed according to the atlas of building electrical installation and current specifications.

Seven. Technical measures for safe use of electricity

1, where electricity is used for site construction, three-phase five-wire system shall be adopted, repeated grounding shall be done, and equipment protection shall be connected to zero.

2. It is forbidden to use aging and poor insulation wires, and it is forbidden to pull them. Lines should be firmly erected to ensure safety.

3, distribution box should be moistureproof, rainproof, and make zero protection.

4. The load lines of electric construction machinery and hand-held electric machinery shall be multi-strand copper-core rubber-sheathed flexible cables without joints.

5. The installation, maintenance and removal of temporary electricity projects must be completed by electricians, and other personnel are not allowed to construct without authorization.

6. The purchased equipment must meet the corresponding national standards, professional standards and safety standards. Implement the responsibility system for special planes and conduct regular inspection and maintenance. Check the temporary electricity consumption on the construction site once a week (the leakage protector is tested once a month).

Eight, the construction site electrical fire prevention measures

1, the conductor must be selected according to the design section, and it is forbidden to use it in overload. The butt welder, electric welding machine and tower crane cannot be used at the same time. All kinds of wire joints should be firmly connected and well insulated to prevent fire caused by poor contact and increased resistance.

2. It is strictly prohibited to pile up items near the distribution box and switch box, especially flammable items.

3, the use of butt welding machine, electric welding machine, it is forbidden to pile up flammable items around, and supervision by designated personnel, ready for fire prevention equipment nearby.

4. Electric furnaces and electric mattresses are strictly prohibited in the construction site. When using iodine tungsten lamp, keep a safe distance of 500mm from combustible materials.

5, the construction site found a fire to call the police in time.