Entering the rainy season soon, the southern region is experiencing heavy rainfall, and the high temperatures and heavy rain in summer have caused many difficulties for construction. Therefore, safety precautions for construction during the rainy season are of great significance. Today, we will collect and organize super practical techniques for site protection during the rainy season. Let’s take a look together.
Construction site drainage
one
1. Before the rainy season, special attention should be paid to inspecting the underground floors of key prevention areas in the project. A 300mm × 500mm drainage ditch should be set up along the ground around the main body. When it rains, a water pump should be equipped to drain the water from the collection pit and discharge it into the drainage ditch on the ground.
2. Organize the construction site to ensure smooth drainage.
3. Check the drainage facilities inside and outside the site to ensure that the drainage equipment is in good condition, so as to ensure that the accumulated water can be discharged in a short time after a rainstorm. According to the actual situation, the principle of using the nearest collection well on the construction site as the site drainage collection point.
Storage and stacking of raw materials and semi-finished products
two
1. When steel bars are stacked on the construction site, they should be placed in a higher location that is not affected by rainwater erosion. At the same time, the lower part of the steel bars should be padded with wooden blocks or other materials to a height of not less than 200mm. For processed steel bars, they should be placed in a sheltered place inside the steel bar processing shed as much as possible to prevent the steel bars from being corroded and embroidered by rainwater.
2. To set up a warehouse, it is necessary to ensure that the warehouse is protected from rain and the ground is moisture-proof to prevent moisture. Other materials should be stacked according to their properties.
3. All materials are required to be stacked in a safe place no less than 3m outside the slope of the foundation pit, and materials that are prone to scattering should not be stacked next to the slope.
Earthwork
three
1. The moisture content of the backfill soil, which has just been laid but not yet compacted, should be strictly controlled during the rainy season. Sampling and testing should be conducted in a timely manner to control the moisture content of the backfill soil within the design requirements. If the moisture content is too high, measures such as loosening, drying, or even mixing with dry soil can be taken; If necessary, the soil source should be covered in advance to avoid the appearance of rubber soil.
2. If soaked in rainwater, the soft lime soil at the water accumulation point should be removed and replaced with new lime soil for compaction. The soaked lime soil should be dried before compaction. Lime and soil should be prepared and covered with plastic film in case of rain.
slope engineering
four
1. During rainy season construction, it is prohibited to stack materials within 1 meter of the slope.
2. Before construction during the rainy season, check for any deviation or cracks on the slope, and use cement mortar to find the slope towards the drainage ditch, ensuring that there is no water accumulation around the slope.
3. Keep a good record of slope settlement, and measure it at any time in case of heavy rain or above.
Reinforcement engineering
five
1. Steel bars should be brought into the site in an appropriate amount according to the progress of the project. The storage of steel bar raw materials should not be excessive. The raw materials on site should be used first before entering the site, and then after entering the site, to avoid serious corrosion of the steel bars due to prolonged storage time. The corroded and contaminated steel bars must be cleaned before use. The steel bar raw materials and finished steel bars entering the site should be neatly stacked according to specifications, and should be padded at least 200mm off the ground. In case of rain, they should be temporarily covered with plastic cloth.
2. Welding work is strictly prohibited during thunderstorms. In case of special circumstances during welding, necessary rainproof measures must be taken to prevent rainwater from wetting the welding joints and causing changes in the performance of steel bar connections, thereby affecting the quality of the project.
3. If the tied steel bars encounter rainy weather, the steel bars should be derusted and cleaned according to the situation after rain. Steel bars that are corroded or covered with sludge should not be used in the project.
template engineering
six
1. The templates and square timber stacked on site should be neatly stacked and placed at least 200mm off the ground, covered with tarpaulins to avoid deformation caused by sun and rain exposure.
2. The supported wall formwork should be covered in case of heavy rain without pouring concrete to prevent the failure of the release agent due to rain. After rain, it is necessary to carefully check the flatness, verticality, and adhesion of the release agent. Only after passing the inspection can concrete be poured.
Concrete engineering
seven
1. When encountering heavy rain during concrete pouring, the poured concrete should be compacted and compacted, and construction joints should be left in appropriate positions according to the specifications. The pouring should be stopped immediately, covered with plastic cloth, and firmly tied with steel bars to prevent it from being blown away by the wind. In case of light rain during the pouring of the roof concrete, timely vibration, compaction, and covering should be carried out to ensure that the cement slurry is not lost.
2. Strengthen the treatment of temporary construction joints after rain, remove any remaining slurry or weak areas, clean up any dirt or accumulated water in beams, slabs, and walls, and only continue pouring concrete after acceptance inspection.
3. To ensure the quality of concrete, during the rainy season construction period, concrete mixing manufacturers are required to adjust the water consumption of concrete in a timely manner according to the actual moisture content of sand and stone, to ensure the quality of concrete. And regularly send people to the mixing plant to inspect its sand and stone stacking yard, cement warehouse, check the mud content of sand and stone, and the rainproof condition of cement. It is strictly prohibited to use sand, stone, and failed cement with excessive mud content in the project.
Masonry and plastering works
eight
1. Before masonry during the rainy season, the moisture content of various bricks or blocks should be tested. Do not use dry bricks on the wall, and also prevent excessive water absorption. To prevent the blocks from getting too wet or soaked in rainwater, plastic cloth should be used to cover the blocks (bricks) when it rains. Blocks (bricks) with high moisture content should be dried properly before use. Construction should be stopped during moderate or heavy rain, and rainproof measures should be taken on the masonry surface.
2. If there is a phenomenon of slurry flowing along the wall during masonry, it indicates that the moisture content of the blocks (bricks) has reached saturation. Therefore, dry bricks and wet bricks should be used in combination for masonry, or mortar with lower consistency should be used.
3. Cement should be stored in the warehouse, and a brick ridge wall with a height of 300mm above the outdoor ground should be built on the warehouse floor. Scaffolding boards and oil felt should be laid on the wall to prevent the cement from getting damp. Effective maintenance should be carried out around the cement warehouse, and drainage ditches should be dug to prevent rainwater from flowing into the warehouse.
4. The sand and gravel yard should have good drainage measures to prevent soil from flowing into the yard during rain.
5. The mortar mixing should be centralized, and the mixing plant should be equipped with rain shelters. Vehicles transporting mortar should be covered with rain covers to prevent rainwater from entering the mortar.
6. The project tester regularly measures the moisture content of sand and stone based on weather conditions. It is required to measure the moisture content of sand and stone before construction, adjust the mix proportion in a timely manner, and strictly control the mortar consistency.
7. During rainy weather, outdoor masonry work is prohibited. When masonry is necessary in sporadic light rain, the mortar consistency should be appropriately reduced.
Roof engineering
nine
1. Roof construction should be carried out during the rainy season, and close attention should be paid to the local recent weather forecast. Construction should be carried out on sunny days, and waterproofing operations are strictly prohibited in the rain. Cover the constructed areas with plastic sheeting; When the waterproof layer is found to be damaged by rainwater erosion after rain, it should be reworked and redone.
2. During the transportation and storage of roof insulation materials, rain is strictly prohibited and moisture should be prevented.
3. When laying insulation layer on the roof, it is advisable to divide it into small construction sections and timely prepare the upper leveling layer to prevent sudden rainfall from wetting and soaking the insulation layer.
4. The holes that pass through the insulation layer, leveling layer, and reserved anchor hooks should be temporarily sealed and covered at all times to prevent rainwater from entering.
5. When laying the waterproof layer, before construction, the moisture content of the leveling layer and the bonding test should be carefully tested according to the technical requirements of the materials used. Construction can only be carried out after meeting the technical requirements to ensure the quality of the waterproof layer laying.
6. BIM engineers such as rainwater downpipes should strive to install them as early as possible to prevent roof rainwater from washing away from the exterior walls and polluting the exterior decoration. Before installing rainwater pipes for internal drainage, temporary drainage roads should be established to prevent rainwater from accumulating inside the pipes due to obstruction.
waterproofing engineering
ten
1. External wall waterproofing engineering is prohibited from construction on rainy days, and the moisture content of the waterproofing base must be within the range required by the specifications (not greater than 4%).
2. During the construction of the cushion layer concrete, the drainage slope should be prepared according to the requirements, and a water accumulation pit should be set up at the edge of the pit to pump water in a timely manner.
3. Waterproof construction in poorly ventilated areas such as bathrooms and fire pump rooms should adopt ventilation and exhaust measures to ensure air circulation, personal protection, and fire prevention and control work.
4. When carrying out exterior wall waterproofing construction, close attention should be paid to the stability of the slope soil. After each rain, the displacement of the slope should be checked, and construction should be stopped when the displacement is large.
Decoration Engineering
eleven
1. It is best to carry out indoor decoration after the completion of the roof and floor works, or to start with the floor and block all kinds of holes and board joints to prevent water leakage from the upper floor downwards. And seal the windows and elevator shafts, and install water barriers in the stairwells on each floor.
2. Outdoor plastering should be promptly covered to prevent sudden rainfall erosion. It is strictly prohibited to carry out exterior wall decoration work during rainfall.
3. The installed doors and windows should be managed by someone, and should be closed and locked in a timely manner during rainfall to prevent damage from wind and rain.
4. All kinds of doors, windows, fine wooden products, and other types of keel and decorative materials, glass, accessories, etc. must be strictly prohibited from being exposed to rain and moisture during transportation and storage to prevent adhesion, deformation, or rusting.
5. Gypsum strip board, paper faced gypsum board, gypsum coated composite board, and other high-quality partition materials are strictly prohibited from being exposed to rain, water, and moisture to prevent material denaturation and potential quality hazards.
6. Exterior wall coatings should be applied on sunny days.
curtain wall engineering
twelve
1. Curtain wall construction should not be carried out in windy or rainy weather, and sealant construction should not be carried out in rainy weather or when the rain is not dry.
2. Electrical equipment and power tools used for curtain wall engineering must undergo insulation voltage testing. And check whether the insulation device is intact before the rainy season construction, and rectify it in a timely manner if it does not meet the requirements.
3. The aluminum and aluminum-plastic panels that go upstairs must be firmly fixed to prevent injury from strong winds.
Temporary electrical safety
thirteen
1. During the rainy season, regular and designated personnel should inspect the insulation condition of temporary electrical facilities, check for any damage to power lines, and promptly address any issues found.
2. The temporary power supply line on site adopts a three-phase five wire wiring system, with mechanical and electrical equipment switch boxes, lighting fixtures, and rain proof facilities. All mechanical and electrical equipment must be equipped with a single switch, and it is strictly prohibited to use one switch for multiple purposes. Leakage protectors should be installed. When stopping work, the switch should be pulled to cut off the power, and the switch box should be locked. Before use, it should be inspected and tested.
3. Qualified leakage protection devices must be installed inside the distribution box, and the sensitivity of the leakage protection devices should be checked in a timely manner. The electrical box door should be closed at all times.
4. Personnel engaged in electrical operations must hold certificates, wear labor protection equipment, and work simultaneously with two people, one working and the other supervising.
Tower crane foundation and hoisting
fourteen
1. After a rainy day, tower cranes should be inspected for their routes and roadbeds in a timely manner, and operate empty vehicles. Only after confirming that there are no problems can they be officially lifted.
2. Observe the settlement of the foundation and make observation records. If there is settlement, it should be dealt with immediately to ensure the safety of the tower crane during use. The hoisting operation shall be stopped in case of heavy rain, rainstorm and strong wind.
3. High altitude operators working after rain should pay attention to anti slip measures and wear rubber soled shoes. Hard soled shoes are not allowed for high-altitude operations. The grounding resistance value of the tower crane should be measured, and its resistance value should not exceed 4 Ω.
4. Excavate a 200mm x 300mm drainage ditch around the tower crane foundation and connect it to the temporary drainage ditch on site. Plaster the inside and set a 5 ‰ slope towards the temporary drainage ditch at the bottom of the ditch.
5. Four settlement observation points are set up on the tower base, and settlement observations are conducted regularly and after rain to promptly address any issues that arise.
Scaffolding Engineering
fifteen
1. Check that the outer frames, especially those at high altitudes, have been designed and installed with relatively complete lightning protection devices.
2. During the rainy season, necessary anti slip facilities should be installed in areas where personnel pass, such as work faces and horse tracks.
3. Install a drainage ditch outside the scaffolding pole to promptly drain rainwater, in order to prevent the scaffolding foundation from being soaked in rainwater and causing foundation subsidence. Assign a dedicated person to check the effectiveness of the pole pad and whether there is any collapse before the rain; Whether the foundation sinks after rain, whether the poles sink, and whether the scaffolding is deformed. If there are any abnormalities, they must be quickly reinforced and repaired.
4. During heavy rain, scaffolding must not be erected or dismantled; After heavy rain and strong winds, scaffolding should be inspected and repaired in a timely manner. Only those with safety hazards that have been rectified and qualified can be put into use.
5. The foundation of the scaffold should be solid, and a full-length pad or block should be installed under the upright pole.
6. The dedicated channel for backfill construction erected on the outer frame must be dismantled and erected strictly in accordance with the structural requirements for door openings in relevant specifications, and must be inspected and accepted by the on-site safety officer before use.
road engineering
sixteen
1. Establish a good drainage system in the construction area to prevent rainwater from soaking the roadbed for a long time. When it rains, a dedicated person should be assigned to inspect and promptly clear and release water in areas where water accumulates or is blocked. Dig a horizontal drainage ditch every 5-10m on both sides of the road shoulder to drain rainwater to the side ditch.
2. Concentrate efforts, shorten road sections, accelerate construction progress, and avoid full-scale deployment. During the construction of the second ash crushed stone, attention should be paid to weather changes to ensure that the paving and rolling processes are completed before it rains, in order to prevent the spread of the second ash crushed stone from being poured into the rain without being rolled and unable to continue construction.
3. Take necessary rainproof measures according to local conditions. The compacted layer of lime fly ash and gravel has a certain effect on rain resistance. Therefore, when the roadbed is alive, the gravel layer should be prepared as soon as possible. When the lime fly ash and gravel arrive on site and suddenly it rains and there is no time to spread and compact, they can be temporarily piled up in large piles, compacted on the surface, or covered with tarpaulin.
Equipment installation project
seventeen
1. For the protection of raw materials and semi-finished products, those that can enter the warehouse or floor should be stacked high and ensure good ventilation, especially for the insulation materials entering the site, which are strictly prohibited from being rained or soaked. Rainproof measures must be taken in a timely manner. The mechanical and electrical warehouse should have measures to prevent water ingress. It is advisable to install exhaust fans in the warehouse where electrical materials or other moisture-proof materials and equipment are stored to maintain ventilation inside the warehouse.
2. Materials stored outdoors, such as pipelines and equipment, should be elevated and covered with plastic sheeting in case of rain.
3. After unpacking the mechanical and electrical equipment entering the site, rainproof measures must be taken and outdoor storage should be minimized as much as possible.
4. The reserved holes for equipment should be well protected against rain. If the equipment in the underground part of the construction site has been installed, measures should be taken to prevent the equipment from getting damp or soaked in rainwater.
5. Mechanical and electrical processing equipment such as shearing machines and threading machines should have rainproof facilities.
6. Outdoor welding operations should not be carried out on rainy days; Indoor welding operations should pay attention to the dryness of the work area; Before welding during the rainy season, it is advisable to dry the welding rods; Effective ventilation measures should be taken during welding operations in confined spaces.
lightning protection
eighteen
1. To protect buildings, mechanical and electrical equipment, people, and livestock from lightning damage and injury, lightning rods, lightning strips, lightning arresters, down conductors, and grounding electrode groups are generally installed for lightning protection.
2. The integrated decoration of temporary work sheds, construction work platforms, and dormitories on construction sites require lightning protection and grounding measures to be taken according to the actual situation. Set up lightning rods, down conductors, and grounding level groups for lightning protection.
3. The lightning protection device must have good grounding, and the grounding resistance of the grounding device must be regularly checked and measured. The grounding resistance of its independent grounding electrode should not exceed 4 Ω, otherwise it should be dealt with in a timely manner.
4. Regularly inspect the lightning protection grounding device and strengthen daily maintenance, focusing on checking whether the grounding wire is damaged, broken, or corroded.
5. During the lightning season, observe the lightning activity. In weather with lightning and electricity, construction personnel should move indoors and not arrange outdoor high-altitude or outdoor operations.
6. Lightning protection measures for mechanical equipment. During the installation of on-site construction equipment such as tower cranes, grounding should be done properly. After the foundation of the building project is formed, the tower crane must be connected to the lightning protection grounding of the foundation. The power supply PE line of the tower crane power supply system is grounded together with the tower crane. The top and bottom of the external elevator guide rails are grounded separately. Install suitable surge protection devices (SPD) inside the distribution box.
Article source: Architectural Technology Magazine
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