Technical disclosure of circular pipe culvert construction
No: No: 20 10 10 1.
Project name disclosure site construction site
The person in charge of the engineering department of the disclosure organization unit, the disclosure person
Receiving person in charge of the construction unit
I. Overview of the Project
Circular pipe culvert, perpendicular to the road. The culvert is 44 meters long, with straight walls at the entrance and exit and tapered slopes on both sides. Circular culvert adopts reinforced concrete flat-mouth pipe with diameter of 1.5m, and culvert joints adopt joints.
Second, the construction preparation
1. Pay-off accurately according to the construction drawings, release the center line pile position, and carry out technical review carefully before construction.
2. Before the construction, the technical director and the builder on the construction site should comprehensively check the construction preparation, conduct technical safety disclosure and safety education step by step, and ensure the implementation of safety technology management in ideology, organization and measures.
Third, the construction content
1, foundation pit excavation:
(1), good drainage should be maintained during foundation pit excavation, and a collecting well should be dug outside the foundation pit to facilitate the thorough drainage of the basement.
(2) Excavators are used for foundation excavation with manual excavation. During excavation, surveyors shall release the elevation of basement in time, and overbreak is strictly prohibited. When the excavation reaches the design elevation of +20cm, the remaining 20cm soil will be excavated manually to avoid mechanical disturbance to the foundation soil.
(3) After foundation pit excavation, the bearing capacity of foundation should be checked. The design bearing capacity of culvert foundation should not be less than 160KPaa. After being qualified, it shall be properly trimmed, and 30cm thick gravel cushion and pouring base shall be laid in the shortest time.
2, foundation construction:
1) substrate treatment
Before filling the gravel cushion, the foundation surface should be leveled and compacted, and the elevation line of the foundation surface should be controlled. According to the thickness of the middle and end of the backfilled gravel, the gravel should be filled and compacted in layers. Gravel shall be hard gravel and shall not contain impurities such as plants and garbage. The maximum particle size of gravel is not more than 50mm, the silt content is not more than 5%, the pebble particle size is 5 mm-60 mm, the gradation is good, and the water absorption rate is not more than 5%. Gravel should be prepared before construction.
2) Precautions:
(1) Check the foundation before paving, the slope must be stable, and drainage measures should be taken to keep the foundation pit free of water.
(2) Nail the marker pile to control the thickness of the filler. The bottom of the intermediate cushion should be at the same elevation according to the design requirements. At the junction of intermediate cushion and end cushion with different heights, the bottom of the foundation pit should be dug into steps or slopes, and the cushion construction should be carried out in the order of deep first and then shallow.
(3) After filling the soil, it should not be exposed for too long, and the foundation should be poured in time.
3, circular pipe culvert construction method:
1), pipe joint installation:
First, the preparation work before installation
Before laying the pipeline, remove the sundries in the pipe pit, strengthen the foundation pit support, and eliminate the accumulated water in the foundation pit, then play the center line of the pipeline on the flat foundation and check the elevation of the flat foundation surface.
B, pipeline quality requirements
Buy round pipe culvert from the manufacturer designated or recognized by the supervisor and the owner. The circular tube culvert adopts reinforced concrete pipe with the diameter of1.5m. The quality inspection of the finished pipe joint is divided into the size inspection of the pipe joint and the strength and water absorption inspection of the pipe joint. The former is measured with a universal measuring tool (steel ruler), while the latter is measured with a set of testing tools. The pipes must be attached with the factory certificate and can be used only after passing the inspection according to the industry standard. When transporting, choose a car or tractor. Tire truck crane is used for loading and unloading. During loading, unloading and transportation, rice joints, skids or squares should be laid on the car, and the pipe joints should be carefully fixed to avoid collision and damage to the pipe joints. It is forbidden to throw the pipe joint directly out of the car. Pipes should be kept intact during loading, unloading and transportation. Before installation, check the appearance quality of the pipeline. If there are defects in the pipe body and nozzle that do not affect the use, epoxy mortar or other qualified materials can be used to repair them.
C, pipeline installation
According to the pipe diameter and site conditions, manual and mechanical installation is adopted. When laying pipelines, arrange the pipelines first, then correct the lines, and strictly control the center line and elevation. Pipelines should be laid from downstream to upstream, and the centerline and elevation of the pipeline should be controlled by midline method or sideline method.
D. Survey recheck: After the pipeline is stable, recheck the water level and elevation again to make the longitudinal slope of the pipeline meet the design requirements, and then the construction of the next process can be carried out.
E, safety tube quality standards
Warranties: The pipeline must be padded, the slope at the bottom of the pipeline shall not be reversed, and there shall be no debris such as mud, masonry, mortar and wood blocks in the pipeline. Inspection and acceptance: according to the road conditions and equipment conditions, use dump trucks to ensure the allowable deviation of pipes and the tools used by inspectors to transport pipe joints, and use 8T truck cranes to load and unload pipe joints. In the process of loading, unloading and transportation, the bottom of each pipe joint should be covered with straw or 30-50 cm sand cushion to make the force uniform. The edges should be wedged with wooden blocks and logs, and the edges should be protected with straw and tied with ropes to prevent the pipe joints from rolling and colliding with each other.
2) Concrete is poured outside the pipe wall to fix the culvert pipe.
3) Joints: the culvert joints adopt sliding apron joints, and the width of the culvert joints is not more than 5 mm. The inside and outside of the joints are filled with asphalt hemp to form a flexible sealing layer, and then the joints are wrapped with two layers of asphalt-impregnated felt, with the width of 15cm.
3.4, ancillary works:
1, culvert entrance and exit
1) I-wall
According to the design size, release the sideline of the subsidiary structure, pull the control line, and set up the erection scaffolding. Pay attention to the slope of wing wall during construction. The splayed wall and the platform body are separated by foam boards as settlement joints. When the weight is light or not high from the ground, the materials can be transported directly by the simple horse stool springboard. When the weight is larger or higher than the ground, the materials can be transported to the scaffold support plate by fixed boom crane or mast crane. When laying, scaffolding should be erected around the wall, materials should be piled up, and construction personnel should be supported to mark and tick off joints on the masonry surface. Scaffolding should be built with steel pipes.
2. Tapered slope
Tapered slopes are set on both sides of the entrance and exit, and the bottom is paved with 10cm thick gravel cushion, and then paved with 30cmM7.5 mortar rubble. The jointing mortar is full, the jointing width and staggered joint distance meet the requirements, the jointing is firm and tidy, and the depth and type meet the requirements.
3. Installation of concrete cover plate and well ring: manhole cover plate and well ring are prefabricated centrally and transported to inspection wells by car during construction. After the completion of well masonry, the prefabricated well ring and manhole cover shall be placed in a balanced manner according to the design requirements to ensure that they are consistent with the road elevation.
Preparation: review: release: