1. Classification and use of culverts
【Formula】Pipe arch cover box waterway line
Culvert is an important part of urban road subgrade engineering, culvert has pipe culvert, arch culvert, cover culvert and box culvert. Small cross-section culverts are usually used for drainage, and are generally referred to as pipe culverts in the form of pipe culverts. Large-section culverts are divided into arch culverts, cover culverts, and box culverts, which are used as pedestrian passages or roadways.
2. Technical points of pipe culvert construction
【Formula】Seat seam groove bed symbol
(2) When the pipe culvert is designed as a concrete or masonry foundation, a concrete pipe seat should be set on the top of the foundation, and the top arc surface should be closely attached to the pipe body to make the pipe section evenly stressed.
(3) When the pipe culvert is a non-concrete (or masonry) foundation and the pipe body is directly set on the natural foundation, the soil layer at the bottom of the pipe should be compacted according to the design requirements, and the arc-shaped pipe seat that is closely attached to the arc of the pipe body should be made, and attention should be paid to keeping the integrity of the pipe section when installing the pipe section. When the bearing capacity of the soil layer at the bottom of the pipe does not meet the design requirements, it should be treated and reinforced according to the requirements of the specification.
(4) The settlement joint of the pipe culvert should be located at the joint of the pipe joint.
(5) The ditch bed of the pipe culvert inlet and outlet should be straight, and the connection with the upstream and downstream diversion and drainage systems should be smooth and stable.
(6) The construction of pipe culverts buried with prefabricated pipes shall comply with the relevant provisions of the current national standard "Code for Construction and Acceptance of Water Supply and Drainage Pipeline Engineering" GB50268-2008.
(7) The end wall and wing wall of the pipe culvert shall comply with the provisions of Section 5.5 of the current national standard "Code for Construction and Acceptance of Water Supply and Drainage Structure Engineering" GB50141-2008.
3. Technical points of culvert and cover culvert construction
【Formula】Dig and fill the water force amplitude, circle the wall back to the seam step
(2) According to the road construction process, the whole construction or sub-frame construction can be adopted. During the construction of the frame, the width of the temporary road should meet the requirements of the current traffic, and the slope should be stable. When support is required, the construction design of the supporting structure should be carried out before construction.
(3) The excavation of the culvert foundation groove in the excavation area should meet the design requirements, and the slope should be stable, and the culvert in the filling area should be filled to the culvert base elevation, and the structural construction should be carried out in time.
(4) When there is groundwater, the groundwater should be reduced to 500mm below the basement before construction, and the precipitation should be carried out continuously until the project is completed to the groundwater level of more than 500mm and has the ability to resist floating and leakage before the precipitation can be stopped.
(5) The bearing capacity of the culvert foundation must meet the design requirements and should be confirmed to be qualified by inspection.
(6) The arch ring and the upper end wall of the arch should be constructed simultaneously and symmetrically from both sides to the middle.
(7) The backfill on both sides of the culvert should be selected only after the protective layer of the waterproof layer of the main structure is completed and the mortar strength of the protective layer reaches 3MPa. When backfilling, both sides should be symmetrical, and the height difference should not exceed 300mm.
(8) The installation of expansion joints and settlement joints should be accurate and firm, and the width of the joints and the caulking materials should meet the requirements.
(9) The underground pipeline serving the culvert should be synchronized with the main structure.
4. Preparation for box culvert jacking
【Formula】Field and road precipitation adjustment and protection, machine material and manual line application.
(1) Operating conditions
(1) The site should be "three links and one level" to meet the design requirements of the construction plan.
(2) Complete the line reinforcement work and the layout of the measurement points for the monitoring of the existing lines.
(3) Complete the investigation of above-ground structures and underground pipelines within the scope of work pit operation, and carry out alteration or take protective measures.
(4) The precipitation of the project (if necessary) meets the design requirements.
(2) Machinery and equipment, materials
Enter the site as planned and complete the acceptance.
(3) Technical preparations
(1) The construction organization design or construction technical plan shall include the jacking force calculation, back design, existing line reinforcement plan, monitoring plan, emergency plan, etc.
(2) All construction personnel shall be trained and technical safety will be disclosed.
(3) Complete the construction survey and pay-off.
(4) The relevant approval and acceptance procedures of the competent department of the existing line have been completed.
5. The content of the box culvert jacking construction organization design or construction technical plan
【Formula】Top back plus supervision
The construction organization design or construction technical plan should include jacking force calculation, back design, existing line reinforcement plan, monitoring plan, emergency plan, etc.
6. Box culvert jacking process
【Formula】The water pit is used as a separator, and the tasting and measurement will be dismantled.
On-site investigation→ engineering precipitation → work pit excavation→ back production→ skateboard production→ laying lubrication isolation layer→ box culvert production→ jacking equipment installation → existing line reinforcement → box culvert test jacking → soil jacking → monitoring and measurement→ box body in place→ dismantling and reinforcement facilities→ dismantling the back and jacking equipment→ working pit restoration.
7. Check the box culvert before jacking
【Formula】The strong layer of water level requires the character, and the top person repairs it
(1) The concrete strength of the main structure of the box culvert must reach the design strength, and the waterproof layer and protective layer shall be completed according to the design.
(2) The groundwater level under the jacking operation surface including the roadbed has been reduced to below 500mm under the base, and it is advisable to avoid the construction in the rainy period.
(3) The back construction and line reinforcement meet the requirements of the construction plan, and the jacking equipment and construction equipment meet the requirements.
(4) The installation of the hydraulic system of the jacking equipment and the pre-jacking test results meet the requirements.
(5) Personnel, materials, articles and facilities unrelated to jacking in the working pit are withdrawn from the site.
(6) The cooperation personnel, emergency repair equipment and communication equipment of the line management department have been prepared.
8. Seasonal construction technical measures for box culvert jacking
【Formula】Avoid the temperature of the waterproof slope shed
(1) The box culvert jacking should avoid the rainy period as much as possible. When it is necessary to construct in the rainy season, practical and effective protective measures should be taken for the roadbed and working pit slope to be crossed before the flood season.
(2) During the construction during the rainy period, the ground drainage should be done, and the technical measures such as water retaining cofferdam and drainage interception ditch should be taken around the working pit to prevent the surface water from flowing into the working pit.
(3) When excavating the working pit (groove) during the rainy period, attention should be paid to maintaining the stability of the slope. If necessary, the slope slope can be appropriately slowed down or the support can be set up, and the slope and support can be checked frequently, and the problem should be dealt with in time.
(4) During the winter rainy season, a fixed or movable operation shed should be erected over the cast-in-place box culvert site to avoid the influence of weather.
(5) During the winter rainy period, the construction should ensure that the concrete mold temperature meets the specifications or design requirements.
Yesterday 速记口诀4/23
1. Cable-stayed bridge composition
Cable beam towers
2. The construction method of the tower
The knot body material is prepared, and the naked climb beam is hung
3. Technical requirements and precautions for tower construction
Cross-contamination pours the prop up, depending on the impact of the two pumps
4. Safety measures for tower construction
The tower crane is limited to torsional wind, and the calculation and inspection affect the accident prevention
5. Construction method of main girder of cable-stayed bridge
Push-turn suspension
6. Construction of concrete main beam
No. 0 non-consolidated, wind resistance performance, large span stitching
7. Construction of steel girder of cable-stayed bridge
The qualification is damaged and corroded, and the finished product is coated with the control material
8. Monitoring objects for cable-stayed bridge construction
The tension beam tower is moved
9. The purpose of monitoring the construction of cable-stayed bridges
The feedback determines the pull beam movement
10. The main content of cable-stayed bridge construction monitoring
The shape and range axis deviates from the tower translation, and the cable tower should change the temperature field
Three days agoShorthand mantra 4/21
1. Steel-concrete combined beam composition
Steel girder shear bridge deck
2. Scope of application of steel-concrete knot (group) beam
The large span of the city affects the reduction of its own weight
3. The basic process flow of steel-concrete knot (group) beam
Pre-shear frame plate pouring joints (or mold reinforcement), watering tension and dismantling temporary support
4. Technical points of steel-concrete knot (group) beam
The bracket is accepted and mixed, and the pouring is monitored and dropped by the table
Seven days agoShorthand mantra 4/17
1. Gravity concrete pier construction
Chisel out the waterproof layered blocks
2. Column-type pier construction
Chisel and clear the slurry at one time, and it is a V-pipe mold to fill the shrinking soil
3. Cast-in-place cover beam construction
The whole fast group hangs the pre-cover and disassembles
4. Prefabricated column installation
The wedge hook at the mouth of the cup is removed
5. Installation of prefabricated reinforced concrete cover beams
Chisel off the stable column to check and pour
6、gravity type fortification platform
Clear the poles and lay wet stones
Two weeks agoShorthand mantra 4/10
1. The compressive strength of concrete
15 statistical standard deviations, ten groups of unknown methods
2. Concrete raw materials
Cinder silica boiling powder
3. Concrete construction
Metering, stirring, transportation and watering
4. Raw material measurement
The measuring instrument is checked regularly, and the bone water is added at one time.
5. Concrete mixing
The uniform color does not leave the secretion, and the collapse 2 sticky protection when mixing
6. Concrete transportation
It can tolerate and protect the prohibition of collapse and mixing/condensation leakage and absorption, and the prohibition of collapse and mixing.
7. Inspection before pouring concrete
Molded base embedded rib joint
8. Concrete pouring
The amount of pump is continuous in the same section, and the dispersion of vibration is delayed
9. Concrete curing
Vacuum thin plastic film, covered with sprinkling culture. 5. Keep warm and strong