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Special construction scheme in winter and rainy season
Special construction scheme in winter and rainy season (I)

The construction of this project will be affected by natural factors such as temperature, humidity and rain. In order to ensure the quality of the project, during the winter construction, it is necessary to designate a special person to master the temperature change and convey the meteorological and temperature information in time. And keep records of climate and temperature at any time, and have technical measures and material preparation for actual cooling.

A, winter construction management measures:

1) Clear responsibilities, do a good job in technical disclosure of winter construction, ensure that each working procedure is organized according to regulations, specifications and technical measures, carefully record winter construction and organize construction technical files.

2) Before winter, the project department should monitor the welders (thermometers) of various professional types on site.

Admixture mixing and aerial work personnel should carry out technical disclosure and training, and master the winter construction scheme, construction method, quality standard, technical type of work and operation points.

3) During the winter construction, special personnel shall be responsible for timely recording the winter construction measures such as antifreeze dosage, raw materials and heating, concrete curing and measurement, maintenance of test block production, heat preservation and management of heating facilities, etc., and the main technical leaders and quality inspectors shall conduct spot checks to grasp the quality status in time and correct the problems found in time, thus effectively ensuring the engineering quality. Unused bricks are covered with straw curtains.

B, sand pile is not allowed to contain ice, ice should be stacked on the frozen surface, heating and melting rear can use.

C, normal temperature construction should appropriately increase the consistency of winter masonry mortar, which can be solved by lime putty. When using mortar, the temperature should not be lower than 50℃ ..

D, mixing mortar heated with water, when the temperature exceeds 800C, it should be noted that water shall not be directly mixed with cement to prevent false setting.

E, the time of mixing cement mortar in winter should be appropriately extended, generally 0.5~ 1 times longer than that at room temperature.

F, it is forbidden to use the frozen mortar, frozen mortar is not allowed to use hot water mixing, masonry cement mortar should not be mixed with water.

(4), the construction requirements

A, in the process of ensuring mortar masonry, meet the requirements of the lowest temperature, and mix with it. It is not advisable to modulate too much at one time, and the superposition time is too long.

B, the lowest temperature is equal to or lower than -50C, masonry bearing masonry mortar label should be according to the normal temperature construction level.

C, brick masonry horizontal and vertical mortar joint average thickness is not more than 10mm, individual mortar joint thickness is not less than 8 mm, often check the thickness and uniformity of mortar joint during construction. Before coming off work, fill the vertical mortar joint without mortar. At the same time, cover the masonry surface with thermal insulation materials such as straw curtains. When going to work, sweep the frost and snow off the brick surface, and then continue the construction. During winter construction, the daily elevation difference and temporary discontinuous elevation difference of masonry should not be greater than1.2m. ..

2, concrete and reinforced concrete engineering

(1), Portland cement shall be preferred for concrete prepared in winter, and the cement grade shall not be lower than No.2. The main project engineering and technical measures are as follows:

1), masonry engineering

(1) When the daily average temperature is above +50C, the normal temperature construction method can be adopted;

(2) When the average temperature of the day is 0~ 100C, the mortar should be mixed with hot water, and 3% sodium chloride "salt" should be added, and 5% sodium chloride should be added below-100 C. ..

(3) Masonry materials should be

(4) Bricklaying must be carried out at room temperature, and masonry should be properly watered and wetted. After wetting, the dosage of cement should not be less than 300 kg/m3, and the water-cement ratio should not be greater than 0.6. When it is lower than -30C, anti-freezing measures should be taken, that is, raw materials should be heated, and the forming temperature and heating temperature of concrete should be determined according to the temperature. The mixing time of concrete for construction in winter is increased by 50% compared with that at room temperature.

2), reinforced concrete engineering:

A. Selection of admixture: antifreeze meeting national standards, with product certificate and instruction manual should be selected, and the dosage is 2-3% of cement dosage.

B concrete protection in winter: generally, concrete mixed with antifreeze is not covered. When the temperature is lower than-100C, the surface of beam and column of side formwork shall be covered with plastic film and straw curtain.

C. When using admixtures in concrete engineering department, it should be noted that the external admixtures should be transported and stacked in strict accordance with the product instructions. When using admixtures, a special person must be appointed to ensure the accuracy of the mixture ratio, and it is strictly forbidden to mix them wrongly or in an incorrect amount.

D, steel cold drawing can be carried out at negative temperature, the temperature should not be lower than-100C, and snow prevention measures.

E. Form removal of concrete mixed with antifreeze: It is not advisable to remove the form during negative temperature curing. When the surface temperature and ambient temperature of concrete after formwork removal are greater than 200C, thermal insulation measures should be taken. In the process of form removal, if it is found that the concrete is frozen, which affects the safety and quality of the structure, the demolition should be stopped immediately, and the demolition work can continue only after it is properly handled.

3), concrete construction requirements

A, concrete in winter to solve the problems such as antifreeze, rain.

B, completes the outdoor site drainage unblocked, drainage debris sent someone to clean up at any time.

C, prepare plastic film, cover the concrete in time when necessary, to prevent the rain from directly washing the concrete surface.

D, pay close attention to the weather forecast, and stop construction when the temperature is lower than the construction temperature.

E, strengthen the waterproof measures of cement warehouse, mixer to build fortification canopy.

F, according to the change of sand moisture content, timely adjust the water consumption of concrete.

G, template before water wet to grasp the weather forecast in time, in case of freezing.

3. For problems that have special requirements for winter construction and are not within the above scope, you can directly contact the construction unit, design department, supervision department and relevant departments to formulate special construction plans for the above problems. Other unfinished matters shall be implemented in accordance with the Code for Winter Construction and relevant national standards and documents. It is forbidden to carry out construction beyond the scope of winter construction specifications.

3, finished product protection measures

A, strengthen the professional ethics education of construction site operators, and it is forbidden to damage the finished building.

B, after concrete pouring, covering protection measures should be taken to prevent rain and snow and man-made damage.

C, when the temperature is normal, the normal maintenance of concrete, meet the requirements of ripping, prevent accidental damage.

D, after the completion of the construction floor, cover and protect it with sawdust, and then remove the sawdust after the work is completed.

E, each operation unit should accept unified entrance education when entering the site, and educate the workers on the awareness of finished product protection respectively, and respect each other's labor achievements.

F, floor set up a unified supervision inspector (the builder part-time), found that someone illegal operation, damage to the finished product should be stopped in time.

G, all construction personnel to participate in the coordination meeting on time, establish the unified command, communication and network system of the project manager, and make a form, one for each person.

H, in addition to the above cooperation measures, the establishment of a coordinated cooperative relationship and a good style of mutual service and support are the prerequisites for the successful completion of the whole project and the expected purpose. In order to achieve the same goal, we should respect each other and learn from each other.

4, temporary electricity measures

A, the electrical appliances in the distribution box and switch box must be reliable and in good condition. Do not use damaged and unqualified electrical appliances, and strengthen the electrical maintenance of electrical appliances.

B, switch electrical appliances in the switch box can be used to cut off the power supply of electrical appliances under any circumstances. It is forbidden to expose the fuse box and connect the metal wire to the switch box.

C, formulate ten basic safety operation requirements to prevent electric shock injury.

D, before using electrical equipment, you must check whether the lines, plugs, sockets and leakage protection devices are in good condition. Non-electricians are not allowed to wire.

E. When electrodes such as hand-held electric vibrators are used for wet operation, electricians should connect the power supply and install leakage protectors. Before operation, operators must wear insulating shoes and gloves.

F, it is forbidden to use the illuminator for baking and heating, and it is forbidden to use electric furnaces and other electric heaters without authorization.

G, electrical appliances must be overhead, not on the ground, the construction floor at will, such as must pass through the bottom, to have road protection, materials and drivers are not allowed to grind wires.

H, special type of work must hold relevant certificates, have a high sense of responsibility for the safe use of electricity and the spirit of being extremely responsible for the work. During operation, it must be installed safely, dismantled thoroughly, maintained in time and used correctly.

I, timely eliminate hidden dangers, regular inspection, regular maintenance, regular publicity.

J, adhere to the seriousness of the system, all power systems are the price of casualties, so all systems should be consciously and strictly observed.

Special construction scheme in winter and rainy season (2)

I. Principles of compilation

In winter construction, in order to ensure the smooth construction of the winter rainy season project, ensure the construction quality, progress and personal safety of construction personnel, according to the characteristics of this project and the principle of economy and rationality, the winter rainy season construction scheme is specially prepared.

Second, the preparation before construction

1. According to the characteristics of winter construction, a leading group for winter construction safety and quality was established. Team leader: Han Jun.

Deputy Team Leader:, Li

Members: Kong Xinggen, He Tao, Wang, Zhu, Yang Mingkuo.

2. Designate a special person to collect meteorological information, and plan and arrange construction tasks reasonably in advance. Notify the person in charge of site construction in advance when the weather changes suddenly, so as to take anti-freezing measures;

3. Reserve and debug engineering materials, thermal insulation materials, energy equipment, anti-freezing, anti-skid, snow-proof materials, additives, labor insurance supplies and other materials and mechanical equipment. Do a good job of keeping rooms and sheds cold in advance and prepare necessary fire-fighting equipment;

4. Strengthen the management of the construction site, ensure smooth access roads, prevent roads from freezing, take anti-skid measures, and remove ice and snow in time; Effective insulation measures should be taken for electrical equipment and water supply pipe network;

Third, the winter construction plan

(1) Earthwork

1. The roads on the construction site should be kept clear to avoid water or ice on the road surface. Necessary anti-skid measures (such as covering straw bags along the road) should be added to transport vehicles and driving roads.

2. When excavating earthwork on one side of adjacent buildings, measures should be taken to protect the foundation soil of old buildings from freezing injury, and both sides of foundation pit excavation should be covered. During construction, dig and fill as quickly as possible to prevent the foundation from freezing.

3. Drainage measures should be taken in the foundation pit groove to prevent water accumulation, which will cause the lower part of the earth wall to collapse due to repeated freeze-thaw cycles.

4. Necessary insulation measures should be taken at the bottom of the foundation pit after excavation, such as laying straw bags.

5. Before earthwork backfilling, the ice, snow and insulation materials at the bottom of the foundation pit should be cleaned up.

6, backfill work should be continuous, in order to prevent the foundation soil or fill layer from freezing, artificial backfill, each layer of soil thickness is less than 20cm, compaction thickness is 10- 15 cm, backfill soil shall not contain ice, frozen soil, gravel and garbage. It is forbidden to backfill with frozen soil. (2) Drainage works

1, trench excavation adopts mechanical excavation, but the slope coefficient should be increased to ensure that the slope soil on the trench wall will not collapse after freezing and thawing.

2, groundwater discharge according to the construction plan, but should strengthen the anti-freezing management, not drainage should be put forward at any time pump sump side by side to dry the water in the pump and drain pipe, to ensure that the drain pipe does not freeze and freeze the pump.

3. During the construction of pipeline foundation, the operation shall be carried out in an anhydrous state (excluding groundwater), and the raw materials of sand and gravel shall not be frozen or contain ice and snow. Concrete shall be vibrated and compacted in situ.

There should be no earthquake leakage, and the density should reach more than 90%. The concrete pipeline foundation should be covered with straw bags or plastic sheets for protection after the completion of construction, and the concrete foundation should not be frozen before pipeline installation and backfilling, so as not to affect the engineering quality.

4. The formwork of this project is supported by wooden formwork. Before the formwork is installed, the ice, snow and sundries on the cushion should be removed, and the installation should be firm.

5. During the construction when the temperature is lower than 0℃ in winter, the mortar shall meet the following requirements: ① The mortar mixer shall set up a cold-proof shed: 6m×8m×5m, the shed cover shall be made of cement asbestos tiles, and it shall be enclosed with colored plastic sheets, and the shed frame shall be set up with wooden feet and hand poles.

(2) The label of mortar construction in winter should be improved according to the design label. The mixing amount of mortar used in winter construction should be mixed according to the usage of the day, and the mixing mortar should be used up within 4h. The early strength antifreeze should also be mixed in winter construction, and the brick masonry and plastering should be covered with geotextile after completion.

(3) Subgrade construction (lime soil)

(1) lime-soil base should not be constructed in winter. If construction is necessary, it should be carried out when the temperature is high (the daily minimum temperature during construction should be above 5℃), and health preservation and subgrade construction should be carried out in time, and the water content should be reduced as much as possible on the premise of achieving compactness.

(2) During the winter curing period of lime-soil base, antifreeze should be added to lime-soil, such as 3% ~ 5% nitrate. The lime soil after construction rolling should be covered in time, and appropriate amount of water should be sprayed at noon when the temperature is high to avoid the lime soil from freezing.

(4) Lime-flyash macadam base

Before laying lime-fly ash macadam base, the subbase should be thoroughly cleaned, and the floating soil, various sundries and scattered materials should be removed, and the surface should be kept clean without water and ice.

Mixing of mixture: raw materials such as sand and stone should be kept dry, and there should be no water, ice and snow and frozen blocks. If there are caked materials, pick them out so as not to affect the temperature of the mixture. Grasp the water content of the mixture according to the weather and temperature.

Health care: health care by heat storage method: the bottom layer is covered with plastic film to reduce air convection; Then the pavement is covered with two layers of geotextile and grass film, which store heat on the pavement, reduce the heat loss of the pavement and make it harden at a suitable temperature.

Fourth, the rainy season construction scheme

(1) site drainage

1. According to the construction plan, determine the drainage direction by using the natural terrain, and dig the drainage ditch according to the specified slope. In this project, drainage ditches are excavated on both sides of the sidewalk to ensure smooth drainage.

2, in order to ensure smooth roads, pavement hardening or laying gravel, ballast or other materials according to the actual situation.

(2) Earthwork

Earthwork is greatly affected by rain, and if relevant preventive measures are not taken, it may have a serious impact on construction safety and engineering quality.

1, pay attention to slope stability when digging ditches in rainy season. When necessary, appropriately slow down the slope or set up supports, and strengthen the inspection and control of slope and supports during construction. The excavated trench should provide support, and the excavated trench should give priority to gentle slope, supplemented by support. Construction should be stopped when the rainfall has a great influence.

2. In order to prevent rain from washing the slope, cover the slope with plastic sheets.

3, the rain period construction face is not easy to be too big, should be completed by stages, piece by piece. rain

Stop earthwork construction in a large area. When the trench is excavated to the design elevation, the concrete cushion should be accepted and poured in time, and the foundation soaked by rain should be excavated and backfilled to restore the bearing capacity of the foundation.

4. In order to prevent the trench from being soaked, a drainage ditch should be set in the foundation trench during excavation.

5. For the earthwork backfilled before the rain, it should be rolled in time, and its surface should form a certain slope, so that the rain can be discharged automatically.

6. For earthwork piled up on the construction site, measures should be taken to prevent rain from washing around. After the trench construction is completed, we should take the time to backfill.

(2) Concrete engineering

1, template isolation agent before brushing to understand the weather, in order to prevent the isolation agent was washed away by rain.

2. Stop pouring concrete in case of heavy rain, and cover the poured part.

3. Backfill soil supported by formwork shall be compacted and padded. Check whether there is sinking after rain.

Five, the winter rainy season construction safety measures

Firmly establish the idea of safety first and prevention first, properly do all the work of construction safety in winter and rainy season, and do a good job in antifreeze, anti-skid, fire prevention, collision prevention, leakage prevention, poisoning prevention and heat preservation.

1. Provide technical safety education to project personnel on a regular basis. Combined with engineering tasks, safety technical disclosure should be made before construction in winter and rainy season. Equipped with safety protection articles.

2, timely inspection and maintenance of outdoor machinery and equipment, to prevent freezing.

3. Fire prevention measures should be taken in thermal insulation shed, thermal insulation material stacking place and warehouse.

4. It is forbidden to use high-power heating equipment such as electric furnace and electric heater in dormitory area.

5, winter and rainy season construction safety to formulate specific measures and rules and regulations, headed by the main leaders, to the specific person in charge, to form a layer after layer, layer by layer to implement the good construction atmosphere of quality and safety.

Special construction scheme in winter and rainy season (3)

A, subgrade construction technology in winter

When the average temperature of day and night is lower than -3℃ and it lasts for more than 10 days in repeated freezing and thawing areas, subgrade construction is called subgrade winter construction. When the average day and night temperature rises above -3℃, but the frozen soil has not completely melted, construction should also be carried out in winter.

(1) subgrade works that can be carried out in winter

1. If it is necessary to change soil after rivers and lakes in swamp areas are frozen to a certain depth, the soft soil and silt layer on the original ground can be dug out and replaced with other qualified fillers during the freezing period.

2. Cutting in areas with flowing soil and quicksand with high water content can be excavated during the freezing period.

3. In the floodplain area, the water level is low in winter, and the foundation pit can be excavated to build protection works, but heating and heat preservation measures should be taken.

Pay attention to maintenance.

4. The cutting or half-filled and half-dug section of the rock section can be excavated.

(2) Subgrade engineering not suitable for winter construction

1, expressway in unfavorable geological area, soil subgrade of Grade I highway, and embankment of highway below Grade II.

2, uproot the original turf on the ground, dig and fill the stage.

3. Renovation of subgrade slope.

4. Fill the dam that will be submerged in the low-lying area of the river beach.

(3) Preparation before subgrade construction in winter

1, queue the winter construction projects according to time, and prepare the implementation construction organization plan.

2, winter construction projects should be on-site lofting before freezing, () protect the control pile and set up obvious signs to prevent being buried by ice and snow.

3. Before freezing, the filled steps on the slope should be removed, and the surface covering layer and exposed rock mass of rock excavation should be removed.

4. Maintain vehicles, machines and equipment needed for winter construction, and prepare engineering materials during winter construction.

5. Prepare the living facilities, heating and lighting equipment, fuel and other materials needed by the construction team for the winter.

(4) Filling embankment in winter

1. Unfreezed sand, gravel and pebble soil, excavated stone slag and other soil with good water permeability shall be used as embankment filler for winter construction.

2. When filling the embankment in winter, it should be filled horizontally according to the full width of the cross section, and the loose laying thickness of each layer should be reduced by 20 ~ 30% according to the normal construction, and the maximum loose laying thickness should not exceed 750px. The degree of compaction shall not be lower than the requirements of normal construction. The soil filled on the same day must be rolled on the same day.

3. When the height of the embankment is away from the bottom of the road bed 1m, the filling shall be stopped after compaction.

4. Embankments with filling less than 1m at the junction of excavation and filling should not be filled in winter.

5, winter construction borrow pit should be far away from the foot of the fill slope. When it is necessary to borrow soil near the embankment due to conditions, the distance from the inside of the borrow pit to the foot of the fill slope shall not be less than 1.5 times of the normal construction berm.

6. Embankment filled in winter shall be compacted by over-filling on each layer and side according to the requirements of design and construction technical specifications. After winter, trim the slope, cut off the excess part and pat it down or reinforce it.

(5) winter construction excavation cutting surface frozen soil method,

1. Blasting frozen soil method: When the freezing depth is greater than 1m, this method can be used to blast frozen soil. The drilling depth is 0. The spacing of drilling holes is 1 ~ 1.3 times the depth of frozen soil, and it is arranged in a staggered quincunx shape.

2. Mechanical freezing breaking method: The frozen soil below 1m can be broken and removed by using special freezing breaking machines such as frozen soil plough, frozen soil saw and frozen soil shovel.

3. Artificial freezing method: when the frozen layer is thin and the frozen area is not large, it can be exposed to the sun, burned and boiled with hot water.

Freezing method, water needle thawing method, steam exothermic thawing method and electric heating method are used to expand or melt the frozen layer, supplemented by manual excavation.

(6) Cutting excavation in winter

1. When the frozen soil layer is excavated to the unfrozen soil layer, continuous operation and layered excavation shall be conducted. When there is a long pause in the middle, the surface should be covered with snow to keep warm to avoid repeated freezing.

2. The excavation slope should not reach the design line at one time, and 750px thick steps should be reserved, and then the reserved steps should be cut off, and the design slope can not be completed until the normal construction season.

3. When the cutting is dug above the road bed surface 1m, after the temporary drainage ditch is dug, the excavation shall be stopped and the surface shall be covered with snow or loose soil, and the rest shall be excavated after normal construction.

4, cutting excavation in winter must be top-down excavation, it is forbidden to dig from bottom to top.

5. Dig the sunny place first when you start work every day, and then dig the shady place after the temperature rises. In case of underground water during excavation, timely ditch and permanently drain it.

6, winter construction excavation cutting soil should be far away from cutting slope pile top. Generally, the height of the spoil pile should not be greater than 3m, and the distance from the toe of the spoil pile to the top of the cutting slope should not be less than 3m. Deep excavation or soft zone should be kept more than 5m, and the waste residue pile should be leveled. It is forbidden to pile up abandoned soil at the top of cutting slope.

Second, the subgrade engineering construction measures

1, queue up the winter construction projects in turn, and prepare the implementation construction organization plan.

2. Maintain vehicles, machines and equipment needed for winter construction, and prepare engineering materials during winter construction.

3. Prepare the living facilities, heating and lighting equipment, fuel and other materials needed by the construction team for the winter.

4. When embankment is filled in winter, it should be filled horizontally according to the full width of cross section, and the loose laying thickness of each layer is reduced by 20%~30% according to normal construction, and the maximum loose laying thickness is not more than 750px. The degree of compaction shall not be lower than the requirements of normal construction. The soil filled on the same day must be rolled on the same day.

5. When the embankment is away from subgrade 1m, the filling shall be stopped after compaction. Spread a layer of loose soil on the abundant surface for heat preservation, and then compress it after the end of winter, and then fill it in layers to the design elevation.

6, winter construction borrow pit should be far away from the foot of the fill slope.

7. For the embankment filled in winter, the embankment fill width should be wider than the design width of each side fill layer, and the compaction width should not be less than the design width. After winter, trim the slope, cut off the redundant parts, and pat or reinforce it.

Third, the rainy season subgrade construction technology

(A) the rain period construction site selection

1. Generally, sand, gravel, rock areas and cutting waste areas in hilly areas should be selected for subgrade construction in rainy season.

2. Heavy clay, expansive soil and saline soil sections are not suitable for construction in rainy season; Drainage in plain area is difficult, so it is not suitable to arrange construction in rain period.

(2) Preparation before construction in the rain period

1. Conduct detailed on-site investigation and study on the selected construction area in the rain period, and prepare a feasible construction organization plan in the rain period according to the facts.

2。 Construction access roads should be built and protected from rain and sun.

3. Houses, warehouses, parking places for vehicles and tools, and production facilities should be located above the highest flood level or at higher places, and should keep a certain safe distance from the alluvial piles of debris flow ditches.

4. Build temporary drainage facilities to ensure that the working site is not flooded in rainy season and the surface water can be discharged in time.

5, should reserve enough engineering materials and living materials.

(3) Filling embankment in rainy season

1. Except for construction vehicles, other vehicles should be strictly controlled at the construction site in rainy season.

2. Before filling the embankment, a drainage ditch should be dug outside the foot of the fill slope to keep the site free of water. If the original ground is soft, measures should be taken to replace it.

3. The filler should be broken (egg) stone soil, gravel, stone chips and sand with good water permeability. When using excavated soil as filler, it should be filled while digging and compacted in time. Soil with too much water content and can't be dried shall not be used as building filler in rainy season.

4, embankment should be layered filling. The surface of each layer should be made into 2% ~ 4% drainage cross slope. The soil layer filled on that day should be compacted a few days before it rains.

5. When the embankment needs to borrow soil in the rain period, the distance from the borrow pit to the toe of the fill slope should not be less than 3m. The depth of the borrow pit should not be greater than 1m when the subgrade is taken longitudinally in the plain area.

(4) Cutting excavation in rainy season

1. Before excavation of soil cutting, dig intercepting ditch 2m away from the top of cutting slope and connect the water outlet.

2, excavation of soil cutting should be layered excavation, each layer should be set up vertical and horizontal drainage slope. Don't excavate the slope to the design elevation at one time, it is 750px thick along the slope, and it will be renovated to the design slope after the rain. Fill and excavation should be dug with the excavation.

Full of goods.

3. When the soil cutting is dug to 30 ~ 30~ 1250px above the design elevation, the excavation shall be stopped and drainage ditches shall be dug on both sides. After the rain, dig to the subgrade design elevation, and then compact.

4. When the strength of soil is lower than the specified value, it should be treated according to the design requirements.

5, the rain period excavation rock cutting, hole should be set horizontally as far as possible. The slope should be brushed from top to bottom according to the design slope, and the slope should meet the design requirements.

Fourth, the rainy season construction measures

This area belongs to temperate continental monsoon climate with strong seasonality. Most of the summer rainfall is concentrated in July and August, and the average annual precipitation in this area is 360mm.

According to local meteorological and hydrological data, the order of related project work can be adjusted predictably.

Try to arrange some projects that are less affected by rain in rainy season. In case of heavy rain and windy weather, no construction will be arranged. Take necessary measures to resume construction immediately after the rain stops.

The rainy season construction mainly adopts the following measures:

1. In the process of construction, it is necessary to keep abreast of the weather changes and do a good job in protecting the construction site. In case of heavy wind and rain, flood control work should be done well to ensure that the project and property are not lost.

2. The soil subgrade in low-lying areas and high-fill areas should try to avoid rainy season construction.

3. Set drainage ditches around subgrade and structures, abandon excavated earthwork in the site, build a continuous earth dam, and drain the accumulated water in the earth dam with a pump in rainy season; The construction access road adopts one-way sloping, so as to strengthen the maintenance work, keep the road drainage facilities unobstructed, and ensure the normal running of vehicles in rainy days and after rain.

4. Rainproof measures for storage yard

Improve the drainage facilities of the mixing station, ensure the smooth rainwater drainage in the field, and equip with enough rain-proof cloth to protect raw materials such as sand and gravel from rain and not reduce the productivity of the mixer; In rainy days, prefabricated members should be erected with simple awnings, and steel bars should be covered with tarpaulins or stored in simple awnings to avoid rusting; Machinery, material warehouse, etc. Should be placed in a higher place, and take waterproof, waterproof and flood prevention measures; Cement must be stored in a high place, stacked according to specifications, moisture-proof and rain-proof. When pouring concrete after the rain, the water content of sand and gravel should be detected at any time, the grading list should be issued again, and the construction mixture ratio should be adjusted in time to ensure the quality of concrete construction.

6. Rainproof measures on the construction site

(1) During subgrade earthwork construction, always keep the site in a good drainage state. For the rainy season construction area, culverts should be completed first and temporary drainage ditches should be built to control surface water. Embankment constructed in rainy season shall be excavated, paved, rolled and leveled in time. The soil layer filled on the same day shall be compacted on the same day, and the compacted surface of each layer shall be made into a cross slope according to the design requirements to facilitate drainage. The paved loose soil shall be compacted as far as possible before it rains to avoid water accumulation. After the rain, motor vehicles are prohibited from going up on the undried subgrade; Strengthen manual drainage on site, and use water pump to force drainage when necessary to ensure that the subgrade is not soaked by water.

⑵ Build temporary drainage ditch on the formed subgrade slope, set temporary water retaining edge on the edge of embankment, and use mortar for necessary protection; For embankments with cultivated shoulders, drainage ditches are set aside every 20 meters or so to discharge water through the drainage grooves to ensure that the subgrade is not damaged by erosion.

(4) Take effective protective measures for excavated ditches and collecting wells to prevent blockage and dredge them in time.