Occupational safety operation instructions for the

Occupational safety operation instructions for bridge foundation engineering

1 purpose: to ensure the safety of bridge foundation engineering construction and pile foundation operation, and prevent casualties; At the same time, optimize the construction environment, maintain the surrounding environment, ensure low consumption and energy conservation, and ensure the health and safety of employees

2 scope of application: safe operation and environmental protection of bridge foundation engineering construction

3 reference: Technical Specification for the adjustment and construction of highway engineering according to the above methods and relevant environmental protection laws and regulations

4 specific requirements:

4.1 open cut foundation

4.1.1 when excavating the foundation pit, if it has an impact on adjacent buildings (structures) or temporary facilities, safety protection measures should be taken

4.1.2 when excavators and other machinery excavate the foundation at the top of the pit, the safe distance between the machine body and the pit edge should depend on the depth, slope and soil quality of the foundation pit. Generally, it should not be less than 1.0m; When stacking materials and machines and tools, it should not be less than 0.1. Generally, it is often used 1 gram per 10000 8m

4.1.3 when the mast bucket or belt conveyor is used for excavation, check whether the bucket ropes, hooks, machines and tools are intact and firm. When lifting the bucket, the operators in the pit should hide outside the lifting range of the bucket. When the bucket is not in use, it should be removed in time and should not be hung

4.1.4 when excavating the foundation in water, safety facilities such as ladders should be provided to facilitate access to the foundation pit

4.1.5 during excavation, when the pit cracks along the top surface, the pit wall collapses, or water and sand gushing affect the stability of the foundation pit slope, reinforcement and protection should be immediately carried out

4.1.6 when mechanical pumping and drainage is required for foundation pit excavation, sufficient pumping and drainage equipment must be equipped, and pumps and pipelines must be firmly placed *

4.1.7 for the construction of small bridges and culverts, if the passage of vehicles cannot be guaranteed, the access roads or bridges (culverts) should be built in advance, and "no passage" signs should be set at both ends of the highway where the bridges and culverts are built

4.1.8 when freezing method is used to excavate foundation pit in cold areas, it should be frozen layer by layer and excavated layer by layer according to geology, hydrology, temperature and other conditions

4.1.9 if blasting is required for foundation pit excavation, it shall be handled in accordance with the current national safety regulations for blasting (gb6722-86)

4.2 island building and cofferdam

4.2.1 when the suction dredger blows sand to build an island, no ships are allowed to enter the operation area; No pedestrians are allowed on the pontoon carrying the suction pipe

4.2.2 the structure of various cofferdams and foundation pit supports set for foundation excavation works must be firm *. During foundation construction, it is strictly prohibited to collide with the support and place heavy objects on the support during excavation, hoisting, concrete pouring and other operations. In case of looseness and deformation of cofferdams and supports during construction, they shall be reinforced in time, and they shall be withdrawn immediately when endangering the safety of operators

4.2.3 when the foundation pit is deep, people should be hung around to go up and down the escalator

4.2.4 the removal of foundation pit support should be carried out under the guidance of the construction director. The removal of support shall be carried out in coordination with the backfilling of foundation pit. Safety measures must be taken when there is a risk of pit wall collapse

4.2.5 in case of flood or drift ice during operation in the cofferdam, the operators shall be evacuated immediately

4.3 bored cast-in-place pile foundation

4.3.1 after the drilling machinery is in place, the drilling rig and supporting equipment should be comprehensively inspected. Rig installation must be stable and firm; The drill frame shall be equipped with diagonal bracing or wind rope

4.3.2 for impact drilling, the drill cone, winch and steel wire rope selected should be configured appropriately. When the steel wire rope is fixed with the drill cone with rope clamp, the number of rope clamps should match the diameter of the steel wire rope. In the process of impact, the relaxation of steel wire rope should be appropriate

4.4 the cables used by forward and reverse circulation drilling rigs and submersible drilling rigs should be checked regularly, and the joints must be bound firmly to ensure that they are watertight and leakage free; The place often soaked in water and mud shall be erected overhead. When moving the drill, do not squeeze the cable and Feng Shui pipeline

4.4 when a submersible drilling rig is drilling, it is generally necessary to check the sealing condition of the primary motor when completing a drilling pile. The drilling speed should be controlled according to geological changes to ensure safe operation

4.3.5 use punching and grabbing or percussive drilling. When the drill bit is raised close to the bottom edge of the protective Jane, it should be decelerated and lifted steadily, and it is not allowed to collide with the bottom edge of the protective Jane and hook the protective Jane

4.3.6 mud used in drilling. Mud circulation and purification system should be set, and attention should be paid to prevent or reduce environmental pollution

4.3.7 when the drilling rig stops drilling, the drill bit must be lifted out of the hole and placed on the drill frame, and shall not stay in the hole

4.3.8 if the buried pile casing has not been drilled or the pile casing has not been pulled out, the top cover of the pile casing shall be added or the safety shield shall be laid

4.4 bored and immersed cast-in-place pile foundation

4.4.1 bored cast-in-place piles should be constructed in dense soil or rock layers with no or little water. In case of deep excavation or water seepage, measures such as hole wall support, drainage and precipitation shall be taken to strictly prevent hole collapse

4.4.2 when digging holes manually, the stability of the hole wall and the lifting equipment should be checked frequently. The machines and tools unearthed at the top of the hole are convenient and fast, which should be managed by a specially assigned person, and a fence higher than the ground should be set. Soil slag and heavy machines and tools should not be piled at the hole opening; Standing ladders shall be provided for the access of operators; Red warning lights should be hung during night operation; When the hole digging is suspended, the orifice shall be set with a cover and a sign

4.4.3 a protective cover should be set on the top of the head of the excavation personnel in the hole. When the borrow bucket is lifted and lowered, the excavator should work under the cover. When pouring concrete in one of the two adjacent holes, the excavation personnel of the other hole shall stop working and withdraw from the well hole

4.4.4 for manual hole digging, in addition to regularly checking the gas condition in the hole with high labor intensity, the following provisions should be observed

(1) before the hole digging personnel go down to work, the air in the hole should be discharged and replaced with a blower

(2) ventilation measures should be taken when the carbon dioxide content exceeds 0.3%. Ventilation or shift work should also be taken when the content does not exceed the regulations, but the operators feel uncomfortable breathing

(3) when the air pollution exceeds the level III standard concentration value of air pollution specified in the current atmospheric environment quality standard (gbhz-), manual hole digging operation shall not be adopted without safe and reliable measures

4.4.5 when the depth of manual excavation exceeds 10m, mechanical ventilation should be adopted. When using an air pick to drill rock, the air supply should be increased to blow away the stone powder produced by rock drilling. The maximum depth of manual excavation should not be greater than 15m

4.4.6 when the rock in the hole of the dug pile needs to be blasted, the shallow hole blasting method should be adopted, the amount of explosives should be strictly controlled, and the relevant provisions in the current national blasting safety regulations (GB) should be handled

4.4.7 sinking cast-in-place pile adopts vibration extractor. When hammering or vibrating sinking construction, it can be handled in accordance with the relevant provisions of "sinking pile foundation" in this section. Before construction, check whether the pipe joint is firmly connected with the pile cap * and whether the pile tip is flexible. All machinery and working platforms shall be stable and firm. When floating pipe sinking and pipe pulling operations are adopted, the relevant provisions in "sinking pile foundation" and "pile pulling" in this section can be handled

4.5 before foundation excavation, it is necessary to debug and check whether the construction machinery is normal: whether the noise, exhaust emission and energy consumption are normal, and if so, it can be used after timely maintenance and qualification

4.6 if the foundation is to be blasted, it is necessary to use initiating explosive devices safely according to the relevant specifications for the use of initiating explosive devices in this operation document to prevent explosion and fire

4.7 it is strictly forbidden to over control or disorderly control the foundation of the dry bridge, resulting in vegetation damage or water and soil loss

4.8 reasonably organize the drainage of foundation pit: pump the slurry water in the foundation pit to the cliff side sedimentation tank with a water pump or slurry pump, and it is strictly forbidden to pump the slurry water directly into the river

4.9 in case of oil leakage in construction machines and tools, it should be repaired immediately. To prevent polluting the river

4.10 the wastes and construction garbage during construction should be cleaned up in time and transported to the designated spoil ground

4.11 reasonably calculate the number of mechanical shifts, labor and materials required for each process to avoid energy waste

4.12 a special reinforcement fabrication room should be set up, and a face shield should be used when welding reinforcement

4.13 the environmental protection requirements of the concrete mixing plant shall be implemented in accordance with the relevant provisions of the concrete pavement construction mixing plant

4.14 during concrete transportation, the transport vehicle shall be equipped with a fence to prevent spillage and leakage and prevent concrete waste. Bring earplugs when ringing