14 to prevent external force collision, violent vibration and damage to buildings.
15 when demolishing old buildings, safety measures should be formulated and professional teams should be assigned to demolish them. It is strictly forbidden to take the way of hollowing out and knocking down.
2) to prevent the collapse of tall formwork supports and various tool formwork projects (including slip forms);
(1) According to the design and specification requirements, prepare the formwork support erection and dismantling scheme and implement it; Organize experts to review the special construction scheme and design calculation data of ultra-high, overweight and long-span formwork support system. The so-called super-high, overweight and long-span formwork support system refers to the formwork support system with a height greater than 8m, or a span greater than 18m, or a total construction load greater than 10kN/m2, or a concentrated line load greater than 15kN/m;
(2) Design and calculation of tall formwork support, the main contents are as follows:
Calculation of static load and dynamic load bearing capacity of support;
Bending, shearing and deflection calculation of formwork bottom plate and wood lining plate;
Calculation of bending, shearing and deflection of supporting beams (large and small rods);
Strength calculation of pipe jacking steel pipe;
Calculation of anti-sliding force of fasteners;
Calculation of overall stability of formwork support.
(3) according to the design scheme and specification requirements, erection of formwork support. Materials, specifications, poling top bracing, bracing, sweeping bar, vertical and horizontal tie bar spacing, vertical and horizontal bracing erection, fastener quantity, release agent coating, formwork support technology, etc. shall meet the requirements of design scheme and quality and safety specifications to ensure the overall stability of formwork support. Before pouring concrete, the formwork support shall be inspected and accepted.
(4) Formwork support should use steel support materials as support columns, and steel support materials and bamboo support materials with serious corrosion, deformation, fracture, desoldering and bolt looseness should not be used as support columns; For ultra-high, overweight and long-span formwork support, reinforced support system should be adopted to ensure its strength and stiffness. The supporting column foundation should be firm, flat and dense, and the settlement of formwork support system (including beam arch) should be strictly controlled according to the design calculation. Support column joints should be correct, and the roots should be padded. Braces and columns should be firmly tied together to form a whole.
⑤ The materials, components, jacks and other equipment used to make the slipform shall have certificates, and the welding quality of each part of the operating platform shall meet the design requirements, and the hydraulic lifting formwork shall be commanded in a unified way. Operating platform should limit the construction load, strictly control the strength of concrete formwork not less than 0.2MPa. Sliding operators should be trained and qualified, and hold relevant certificates.
⑥ The formwork support should not directly bear the additional impact vibration force of the concrete delivery pump pipe or the impact force of the tower crane unloading hopper, and effective preventive measures should be taken.
⑦ When pouring concrete on formwork support, column, beam and floor slab (roof slab) should be poured first, and then cantilever beam and cornice should be poured to prevent the support from instability due to eccentric load.
⑧ Strictly control the load borne by the formwork support, and the construction load of the formwork and its supporting system shall be evenly distributed and shall not exceed the design requirements; However, when the formwork support is unstable, inclined or sinking due to overload, eccentric load, external impact vibration and other factors, all personnel in the operation area should be evacuated to a safe area urgently to ensure personal safety, and then appropriate elimination measures should be taken.
3) Scaffolding collapse prevention:
(1) For scaffolding used in multi-storey and high-rise buildings, a special construction technical scheme shall be prepared; Floor-standing steel pipe scaffold, cantilever scaffold, portal scaffold, hanging scaffold, attached lifting scaffold, hanging basket scaffold, etc. If the height exceeds 50m, special design and calculation (calculation of bearing capacity, strength and stability, etc.) shall be carried out. ).
(2) Operators who set up and dismantle scaffolding must receive special training and hold relevant certificates.
(3) Scaffolding materials, fasteners and shaped components shall meet the quality standards stipulated by the state. Before use, it should be checked and accepted, and those that do not meet the requirements are not allowed to be used.
(4) The scaffold structure must be set according to the national standards and design requirements. According to the regulations, bracing and tie rods are set with buildings, the allowable verticality of cage and its overall stability; And in accordance with the provisions, set up protective railings, set net, bag net and other protective facilities, frame plate laid tightly, no probe plate and gap plate.
⑤ Scaffolding shall be inspected and accepted by sections to ensure that it meets the quality and safety requirements. During the construction period, regular and irregular inspections should be organized (especially after strong winds, rain and snow), and a management system for scaffold use should be strictly established.
⑥ The attached lifting scaffold shall be initially inspected by a special inspection department. After it is qualified, it shall be issued with a use certificate before it can be used.
⑦ Attached lifting scaffolding must have safe and reliable lifting equipment and safety devices such as falling prevention, eversion prevention and synchronous early warning monitoring. The vertical supporting main frame and horizontal supporting frame of steel structure must be connected by welding or bolts, and fasteners shall not be used to connect with steel pipes. When lifting the frame body, unified command should be given, and patrol should be strengthened to prevent collision, resistance, impact, tilt and shaking of the frame body. If there is danger, stop the machine immediately for investigation.
⑧ The floor-type steel pipe scaffold should be erected in double rows, the cross section of the stud joint should be staggered by one step, the root should be placed on a long pad or bearing, and the sweeping rod should be tied up in accordance with the regulations. The ground supporting the vertical pole should be smooth and tamped to prevent the vertical pole from being suspended due to foundation sinking.
Pet-name ruby cantilever beam at the bottom of the cantilever scaffold should be made of steel, and the cantilever beam should be firmly fixed on the beam surface or floor with embedded buckles with strength meeting the requirements, and the height of the shelf should be set up according to the design requirements, and the cable-stayed steel rope should be used as part of the unloading device.
Attending hanging basket scaffold should adopt the finalized framework hanging basket framework, and the hanging basket components should be made of steel or other suitable metal structural materials, and its structure should have sufficient strength and rigidity; The lifting basket should use qualified lifting equipment, with control lifting braking device and anti-overturning device; Operators must be trained and hold relevant certificates.
The cantilever transfer platform used in the construction of 1 1 is designed and calculated. The platform must not be attached to the scaffold to bear the force on the frame, and must be set independently: the cable-stayed ropes hanging on both sides of the platform should be tied to the building to bear the force; The platform load should be strictly limited.
12 Effective isolation and vibration-proof measures should be taken for all lifting equipment, concrete pump pipes and scaffolding in use to prevent the scaffold from being unstable due to vibration and impact.
13 safety measures should be formulated and explained when dismantling scaffolding. Don't even dismantle the wall column first, but dismantle it step by step from top to bottom in order. A warning zone should be set up at the scaffold removal site.
4) to prevent the foundation pit (groove) earthwork collapse:
(1) For the excavation and filling of deep foundation pit, special construction technical schemes such as safety slope of deep foundation pit (trench), soil wall support, high cut slope, pile foundation and underground excavation engineering shall be worked out, and experts shall be organized for review. The so-called deep foundation pit (trough) refers to a foundation pit (trough) with an excavation depth of more than 5m, or a foundation pit (trough) with complicated geological conditions and surrounding environment, although the depth is less than 5m. High cut slope refers to a slope with a rock slope exceeding 30m or a soil slope exceeding 15m; Soil wall support should be calculated and implemented in detail; Excavation and filling shall be organized according to the construction procedures.
(2) According to the foundation excavation depth, soil quality and underground water level, safety technical measures such as retaining the safety slope, adding solid wall support, retaining wall, and setting soil nailing or anchor rod support shall be taken in accordance with the regulations, and illegal excavation of negative slope soil wall is strictly prohibited.
(3) Before earthwork excavation, after confirming the buried depth, location and protection requirements of underground objects such as underground pipelines, civil air defense structures, waste wells and pits, protective measures shall be formulated and approved and signed by the construction technical director before operation. During earthwork excavation, assign special personnel to closely observe and record the settlement and displacement of adjacent buildings (structures) and roads.
(4) When the groundwater level is higher than the bottom surface of the engineering foundation or the surface water makes the soil wall seep, dewatering and drainage measures should be taken; In case of quicksand soil, special safety measures such as pressing, blocking and blocking should be taken; When removing the solid wall support, it should be removed layer by layer in the order of backfill soil, and it should be filled in as it is removed to prevent the slope from collapsing or damaging adjacent buildings.
⑤ When excavating in areas with complex topographical and geological conditions where landslides and collapses may occur, the construction unit and the design unit shall agree on the construction technical scheme and drainage scheme. During the construction of deep foundation pit (trough) and foundation pile and formwork operation in foundation, the construction unit shall designate a special person to supervise and command.
6. In the foundation pit (groove), slope and foundation pile hole, the pile should keep a safe distance. A small amount of building materials should be no less than 1.5m away from the earth wall, and the excavated residual soil should be stacked away from the earth wall 1m, and the height should not exceed1m..
All landowners from the foundation pit (groove) within 3m can not have heavy vehicles or heavy objects, heavy equipment storage; If there are buildings nearby (including temporary structures such as fences), temporary reinforcement measures should be taken.
⑧ During construction in rainy season, water plugging and drainage measures should be taken around the foundation pit (trough), and the accumulated water in the foundation pit should be removed by submersible pump: in winter, the foundation surface should be covered for thermal insulation, and during thawing period, the earth wall should be checked for the collapse danger of losing cohesion due to thawing.
Pet-name ruby if there are traffic and blasting vibration forces using pile drivers or transport vehicles nearby, the soil wall should be reinforced with safety measures.
Attending in the construction work, should always check the safety status of the foundation pit (trough) soil wall, found that the soil wall cracks, peeling, displacement, leakage, soil wall support and adjacent buildings (structures) unstable and other dangerous situations, should be promptly evacuated from the dangerous area of the foundation pit (trough), take corresponding measures to eliminate, when the danger is eliminated, can continue to work.
3 in order to prevent the collapse accident, do the following quality and safety supervision work:
(1) Seriously participate in the review of engineering design drawings, construction organization design and special construction scheme (including calculation), put forward modification opinions, and perform the duties of approval and supervision.
(2) Supervise the construction unit to do a good job in technical disclosure and technical safety training and education, and strictly hold relevant certificates for special operations personnel.
(3) According to the authorization of the government and the construction unit, supervise all parties in the project to seriously implement the quality and safety regulations, norms, standards and regulations promulgated by the state.
(4) Go deep into the site to supervise the quality and safety, and strictly implement the quality and safety inspection and visa system. Without inspection, construction of next working procedure is not allowed.
⑤ When finding the danger of possible collapse (collapse) accident, carefully analyze the reasons, actively study with relevant personnel, put forward elimination and rectification measures, and supervise the implementation. When necessary, the director can issue a temporary shutdown rectification order and report it to the competent leader of the construction unit at the same time, and may not approve the resumption of work before the danger is eliminated.
⑥ Assist and cooperate with the construction unit to summarize and popularize the experience of preventing collapse (collapse) accidents, earnestly draw lessons from the accidents, and actively urge the rectification to prevent similar accidents from happening again.
Safety comes from vigilance, and accidents come from carelessness. We must clearly understand the hidden dangers or accidents of any unsafe accidents. If we can't take effective measures to eliminate it quickly and let it develop, it will form inevitable accidental injuries. This fully illustrates the truth that "safety is no small matter, and prevention is fundamental".
In short, all preventive measures should be "planned, implemented, improved and summarized", and combined with the actual situation, continuous improvement and perfection can achieve good expected results.