20 10 First Construction Practice Counseling: Preventing Building Collapse Accidents

1. Mechanical demolition shall be carried out according to the operation sequence.

(1) When the building is demolished by machinery, it should be carried out step by step from top to bottom; Non-load-bearing structures should be removed first, and then load-bearing structures should be removed. The demolition of frame structure buildings must be carried out in the order of floor, secondary beam, main beam and column. For buildings that are only partially demolished, the remaining parts must be reinforced first, and then demolished separately.

(2) During the construction period, there must be someone who is responsible for monitoring the structural state of the demolished building and making records. When the trend of unstable state is found, the operation must be stopped and effective measures must be taken to eliminate hidden dangers.

(3) During the demolition construction, the construction shall be carried out according to the mechanical equipment and hoisting scheme selected by the construction organization design, and it is forbidden to overload the operation or expand the scope of use at will. The site used for mechanical equipment must ensure sufficient bearing capacity. The machine shall not rotate and walk at the same time during operation.

(4) During high-altitude demolition, large components or heavy materials must be lifted by crane in time. After the demolition of materials should be cleaned up in time and piled up in the designated place. Don't throw them down.

(5) When lifting with two cranes, the load of each crane shall not exceed 80% of the allowable load, and the first crane shall be tried, and the two cranes shall be kept in synchronous operation during construction.

(6) The crane driver who dismantles the hoisting operation must strictly implement the operation procedures. Signal commanders must operate according to the current national standard "Lifting Command Signal" GB5082.

(7) When the steel roof truss is dismantled, it must be fastened with ropes, and the gas welding cutting operation can only be carried out after the crane is hoisted stably. In the process of lifting, auxiliary measures should be taken to keep the hoisted object in a stable state.

(8) When the bridge is demolished, the ancillary facilities, pendants and guardrails of the bridge deck shall be demolished first.

2. Before cast-in-place concrete construction, the calculation should be accurate.

(1) Before the formwork support construction, the existing flexible concrete project must be strictly designed and calculated, and a targeted, safe, reliable and feasible construction organization design scheme must be worked out, and approved by the superior safety technology department.

(2) During formwork support operation, it is necessary to ensure that the formwork support meets the design safety technical requirements, and the shapes, sizes and mutual positions of various parts of engineering structures and components are accurate; The supporting materials must have sufficient strength and rigidity, and can reliably bear the weight and lateral pressure of newly poured concrete. And various loads in the construction process; Template design requires simple structure, convenient disassembly and assembly, and convenient steel binding and installation to meet the technological requirements of concrete pouring and maintenance.

3. Prevent the collapse of deep foundation pit and tomb pit slope.

(1) Before the construction of deep foundation pit, the operators must organize the construction according to the construction organization design and construction scheme.

(2) Before the construction of deep foundation pit, we must master the engineering environment of the site, such as understanding the location and depth of the building plot and its nearby underground pipelines and buried objects.

(3) During the construction of deep foundation pit in rainy season, attention must be paid to the drainage of ground rainwater to prevent rainwater from flowing back into the foundation pit, and at the same time, attention should be paid to the infiltration of rainwater to prevent the slope collapse accident caused by the decrease of soil strength and the increase of soil pressure.

(4) Open ditches and collecting wells must be set in the foundation pit to eliminate sudden open water in the rainstorm.

(5) It is forbidden to build machinery in dangerous areas such as high slopes with overloaded materials around slopes or foundation pits.

(6) The distance between the construction road and the edge of the foundation pit should meet the requirements, so as not to disturb the pit wall.

(7) Two protective fences with a height of 1.2m must be set around the deep foundation pit. Protective fence should be solid and reliable, and skirting board should be set at the bottom to prevent falling objects from hurting people.

(8) When working in deep foundation pit, escalators or other forms of passages must be set up reasonably, and the escalator structure should be firm and reliable to ensure the safety and convenience of personnel going up and down.

(9) safe voltage below 36V must be used for foundation pit lighting, and the line erection shall meet the requirements of construction electricity specification.

(10) During foundation pit operation, steel wire mesh, cement or other materials should be used for slope protection of foundation pit with poor soil quality and long construction period.

4. It is strictly prohibited to pile up building materials on scaffolding.

At the construction site, workers do not pay attention to the safety of scaffolding and pile things up at will. In order to facilitate their own work, fixing formwork support, cable wind rope, pipeline for pumping concrete and mortar on scaffolding, or stacking building materials together will lead to scaffolding collapse. In order to prevent collapse accidents, attention should be paid to:

(1) During formwork operation on the construction site, the support rod shall not be fixed on the scaffold or operating platform.

(2) The cable wind rope of derrick and other equipment cannot be installed on scaffolding or operating platform.

(3) The conveying pipeline of concrete or mortar pump should be arranged separately, and it should not be fixed by scaffolding or operating platform.

(4) Do not install hoist and other equipment on the scaffold to lift materials and objects at will.

(5) The construction load on scaffolding and operating platform shall be hung with the set load limit card according to the design requirements, and no one shall arbitrarily pile up items to overload them.

5. Manual excavation of earthwork should pay attention to operating procedures and methods.

When excavating earthwork, it must be done from top to bottom. It is forbidden to use the methods of digging holes, hollowing out footings and digging "suspended soil" to prevent landslide accidents.

When many people dig at the same time, they should keep enough safe distance, the horizontal spacing should not be less than 2m, and the vertical spacing should not be less than 3m. Face-to-face excavation is prohibited.

When digging with a pickaxe, it is forbidden to wear gloves to avoid tools falling off and hurting people.

In case of cables, pipelines, underground buried objects or unknown objects during earthwork excavation, the operation should be stopped immediately, and special personnel should be assigned to take care of them and report to the construction director immediately. It is forbidden to knock, dig and play at will.

When the excavation depth of foundation pit and foundation trench exceeds 2m, protective railings should be set around the pit and trench, which should comply with the relevant provisions in Chapter III of Technical Specification for Safety of Working at Height in Building Construction (JGJ80).

When excavating deep foundation pit, operators should use ladders or set ramps to go up and down. It is forbidden to step on solid wall supports or dig holes in earth walls to go up and down steps.

When throwing soil from the inside to the outside of the foundation pit and trench, the soil should be thrown at least 1.0m away from the edge of the trench, and the height of the mound should not exceed1.5m. ..

During the excavation of deep foundation pit, slope should be placed or solid wall support should be adopted according to the design requirements.

In the construction of unfavorable geological areas with enclosure engineering, the enclosure engineering should be built in sections besides section excavation.

During operation, operators are not allowed to rest on step slopes, deep pits and cliffs. During the operation, the stability of the slope soil wall should be observed at any time. If cracks, looseness, water seepage, support fracture and displacement are found in the soil wall of the slope, the operators should first evacuate the operation site, and immediately report to the construction leader to take effective measures in time, and then continue the operation after the danger is eliminated.

When digging on the slope, the operator should fasten the safety belt. When excavating earthwork with stones on the slope, larger stones must be removed first, and measures to intercept dangerous stones should be set before removing them. During the operation, vehicles and pedestrians are strictly prohibited under the slope.

When excavating in the landslide area, it should be carried out from both sides to the middle of the landslide body. It is forbidden to dig trenches in an all-round way, and spoil should not be piled up in the main landslide area. The excavation of retaining wall foundation trench should be carried out from both sides of landslide to the middle section, and the support should be strengthened, and the back of the wall should be backfilled in time. Assign special personnel to observe during operation to prevent landslide.

When digging near the pole, the earth platform should be reserved for the ridge and pole body that cannot be cancelled. The radius of the earth platform is: pole 1.0- 1.5m, and stay wire1.5-2.5m. The slope is determined according to the soil quality. Datum should be inserted around the earth platform to warn you.

When excavating earthwork in public places such as roads, urban areas and squares. Fences and guard boards should be set up around the work area, warning signs should be set up, and red lights should be set up at night to warn people.

6. Earth mounds for manual earthmoving should not be piled too high.

When moving soil upward in deep foundation pit, firm upper and lower chutes should be set, and the slope of chutes should not be greater than 1: 3, and anti-skid strips should be set, and protective railings should be set on both sides. When two people carry, they should adopt the methods of shoulder synchronization, lifting together and falling together, and must not jump during lifting to prevent jumping off the springboard.

When using hand-operated carts to transport soil, the transport road should be flat, and it is forbidden to push sports cars. The front and rear cars should keep a safe distance of not less than 3m.

When using a winch to lift the soil in a deep well, the winch bracket should be installed firmly and the rope should be firm, and the firmness and reliability of facilities and tools should be checked regularly. Operators below must wear safety helmet and fasten the hat belt. When lifting the loading bucket or basket, the personnel below must avoid or walk to the ground, so as to avoid the loading bucket (basket) or mud and stones falling and hurting people.

When lifting, obey the command of the following personnel; When transporting the loading bucket or basket downwards, the personnel below should be informed first, so as not to hurt the personnel below.

Earthmoving should be piled away from the pit 1. Om, the height shall not exceed 1.5m, so as to avoid the accumulated soil collapsing the pit mouth or mud stones rolling into the pit and injuring the operators below.

7. The crane overturned, broken and collapsed.

Rollover accidents often occur on mobile cranes and tower cranes running along the track. The main causes of the accident are overload, improper support, lifting heavy objects or load rotation and overspeed operation under the condition of unstable foundation. Preventive measures are as follows: crane drivers should strictly implement operating rules to prevent carelessness; In addition to preventing overload, tower crane should also pay attention to the laying and installation of counterweight, ballast and track as required.

Fracture and collapse accidents include structural fracture and parts fracture, such as boom fracture and spindle fracture, which are mainly caused by overload, mechanism and parts defects, illegal operation and natural disasters. Every time you use it, you should check the main components and safety devices to prevent the mechanical parts from being broken and overturned due to damage. In addition, during the operation, when the wind speed exceeds 20m/s, the operation should be stopped. In case of severe weather such as strong wind, rain and snow at 13m/s during installation, the operation shall be stopped.

8. The construction of temporary facilities should comply with the regulations.

Due to the mobility of the construction industry, it is often necessary to build temporary facilities. If it is not properly built, it will easily lead to collapse accidents.

(1) The materials used for temporary facilities such as office and living facilities on the construction site must be solid and stable; The enclosure around the construction site must be neat and beautiful, and all meet the safety requirements.

(2) The construction site must be strictly divided into construction work area and living area, and cannot be mixed.

(3) The project under construction shall not be used as a dormitory.

(4) The construction work area and office area should be clearly divided, with isolation and safety protection measures.

(5) Beds and all kinds of daily necessities in the dormitory should be placed neatly, the number of people in the dormitory should be limited, safe passages should be set, the dormitory door should be opened outwards, the bedding should be neatly stacked, and there is no peculiar smell in the room.

(6) The surrounding environment outside the dormitory is sanitary, and no littering is allowed. Sewage pipes and sinks should be set up, the roads around the house should be flat, and the indoor lighting should be less than 2.4m