(6) foundation setting out (ink line): Foundation setting out can be carried out when the strength of cushion concrete reaches more than 30%.
After the initial setting of concrete, the concrete surface shall be calendered.
(5) cushion concrete pouring: after the foundation pit excavation is completed, the small wooden pile controlling the cushion thickness and elevation shall be driven immediately, and there shall be at least one small wooden pile per square meter; Then use 50 around the edge of the foundation pit × 100 square meters of wood; The cushion concrete shall be poured and calendered after initial setting.
When the groundwater drops to about 500 below the foundation pit, it can be excavated.
⑤ The filling rate of concrete around the fixed leg must be more than 95%.
7.
The metal structure of the crane and the metal shell of all electrical equipment shall be equipped with reliable grounding device, and the grounding resistance shall not be greater than 10 Ω.
Mechanical excavation shall be 20cm ~ 30cm higher than the design elevation, and the remaining earthwork shall be excavated manually.
Check the key parts of foundation construction quality according to the instructions of tower crane.
2.
4.
At the same time, the concrete test block shall be retained.
⒀ tower crane foundation concrete maintenance: the concrete construction in this case is in summer, and the concrete maintenance adopts watering and covering maintenance, and the continuous maintenance shall not be less than 7 days.
5.
The concrete shall be fully inserted and pulled out quickly and vibrated evenly to avoid over vibration.
Firstly, use the theodolite to project the foundation positioning axis onto the cushion and snap the ink line to show it; Then measure the foundation sideline according to the design size of the foundation and snap the ink line to show it; Finally, inform the technical director for line inspection.
When the concrete strength of tower crane foundation reaches not less than 90% of the design value, the installation of tower crane superstructure can be carried out.
For the embedding of embedded parts, refer to the following procedures: ① assemble 16 grade 10.9 high-strength bolts and base plates with the embedded bolt positioning frame.
It is required to use full binding.
8.
(7) binding of bottom reinforcement mesh: install the main reinforcement at the bottom of the tower crane foundation and bind it in place according to the corresponding spacing requirements.
(11) acceptance of reinforcement and formwork: after the above work is completed, notify the project technical director and the supervision unit to accept the reinforcement and formwork.
(8) installation and fixation of tower crane embedded foot column: since the tower crane foundation in this case is 1350 high, ensure that the bolt hole on the upper part of the foot column can expose the foundation concrete surface, then install the four embedded foot columns on the standard section of the tower crane, and weld cross braces on the four embedded foot columns for reinforcement; Then use the theodolite to project the positioning axis of the tower crane onto the bottom reinforcement net, snap the ink line and spray white paint, and measure and set out the side line at the position of the embedded foot column; Then, use the backhoe excavator to lift the standard section installed with embedded foot column into the foundation pit and place it on the bottom reinforcement net.
According to the height difference, place steel plates ranging from 1mm / 2mm on the bottom reinforcement net for adjustment until the elevation difference of the four corners is within ± 2mm; Finally, it shall be firmly welded with the bottom reinforcement mesh (9) binding of the upper reinforcement mesh of the foundation: first install the reinforcement stirrup at a spacing of about 1500, and then place the upper main stressed reinforcement in place according to the design spacing for binding.
④ Lift the assembled embedded bolts and embedded bolt positioning frame as a whole and pour concrete.
② In order to facilitate construction, when the reinforcement is bound to a certain extent, the assembled embedded bolts and embedded bolt positioning frame shall be lifted into the reinforcement mesh as a whole.
1、 Construction technical measures 1) tower crane foundation construction process: pile foundation laying → foundation pit dewatering → foundation pit setting out (lime line) → line inspection → tower crane foundation pit earthwork excavation → cushion pouring → foundation setting out (ink line) → line inspection → bottom reinforcement mesh binding → tower crane embedded foot column installation and fixation → upper reinforcement mesh binding → tower crane foundation formwork erection → tower crane foundation reinforcement formwork acceptance → tower crane foundation concrete pouring → concrete curing 2) tower crane foundation construction process ⑴ pile foundation erection: in this case, concrete cast-in-place piles and support piles are used, which can be coordinated with the pile foundation subcontracting construction unit.
The concrete strength grade is C35; 2.
This item is incorporated into the precipitation project and constructed according to the construction scheme of precipitation project.
At the same time, the slope excavation shall be carried out according to the slope coefficient of 1:1.
At the same time, the reinforcement mesh in the area of tower crane embedded foot column shall be strengthened by spot welding, and finally place the bottom reinforcement mesh cushion block.
Process and level the embedded bolt positioning frame to ensure that the perpendicularity between the center line of the positioning frame and the horizontal plane after embedding is less than 1.5/1000.
6.
(4) tower crane foundation pit excavation: a backhoe excavator is used for foundation pit excavation, and a SCD200 level is erected on site to control the base elevation.
(10) foundation formwork erection: 15 rear multi-layer plates are used as panels, 50 × 100 square wood for back ridge, Ф 48 steel pipe as formwork support system for outer ridge.
The upper reinforcement mesh can be bound in quincunx shape.
The flatness of manual excavation is ± 50.
After the project pile is completed, By the way, pile the tower crane.
(3) foundation pit setting out: measure the positioning axis of the tower crane with a theodolite, set out the corresponding distance according to the 1:1 grading coefficient, sprinkle a white gray line, and notify the technical director of the project to check the line.
This item is incorporated into the pile foundation project of the project and constructed according to the construction scheme of pile foundation project.
The specific position is within the position line of foot column measured in the previous step; Then use the level gauge to measure the elevation of the four bolt holes at the upper four corners of the standard section.
To detect the geometric position and dimension error of tower crane foundation, the horizontal error shall be measured within the allowable range, so as to prepare sizing block.
The allowable deviation of foundation surface flatness is 1 / 1000; 3.
Technical measures and quality acceptance 1.
(12) tower crane foundation concrete pouring: in this case, the tower crane foundation concrete adopts commercial concrete, which is poured with the cooperation of automobile pump.
(2) foundation pit dewatering: in this case, the foundation pit dewatering will be combined with the foundation pit dewatering of plot 09, and the foundation pit dewatering will be carried out at the same time.
Double Head Lifting Pin Anchor
The pipe well is used for dewatering, and the observation well is set.
⑥ The detailed drawing of anchor bolts is attached.
The machine foot screw shall be set in strict accordance with the plane size required in the manual, and the allowable deviation shall not be greater than 5mm..
③ Add another 4 pieces Φ 30 reinforcement will be connected with embedded bolts.
The concrete foundation of the crane can be used only after passing the acceptance.
