Construction sequence of tunnel steel fiber reinforced concrete
1、 Construction sequence of cave entrance
Excavation of soil and rock at the entrance of the tunnel → Setting up a circular intercepting ditch → Trimming the section and slope → Timely temporary reinforcement of the slope → Entering the tunnel
2、 Construction sequence of tunnel excavation
Class II and III surrounding rocks:
Measurement and layout → advanced support → excavation of advanced guide tunnel in the middle partition wall until it is fully connected → lining of the middle partition wall → advanced support → excavation of advanced guide tunnel in the left (right) side wall until it is fully connected → lining of the side wall → advanced support → excavation of the left (right) upper circular section (Class II) or the left (right) upper half section (Class III) → lining of the left (right) arch ring → excavation of the left (right) lower half section
Class IV surrounding rock:
Measurement and layout → Excavation of advanced guide tunnel for middle partition wall until it is fully connected → Lining of middle partition wall → Excavation of advanced guide tunnel for left (right) side wall until it is fully connected → Lining of side wall → Excavation of left (right) upper section → Lining of left (right) arch ring → Excavation of left (right) lower section
Note: After the construction of the partition wall is completed, excavation shall be carried out as a single hole.
3、 Construction sequence of tunnel lining
Measurement and layout → Middle partition wall lining → Left (right) side wall lining → Left (right) arch ring lining → Left (right) inverted arch lining (Class II-III rock) → Maintenance
Note: After the construction of the partition wall is completed, excavation shall be carried out as a single hole.
4、 Construction sequence of cement concrete pavement inside the tunnel
Acceptance of grassroots (or leveling layer) → measurement and layout → erection of formwork and placement of tie rods, etc. → concrete mixing → transportation of concrete to the construction site → paving of concrete → insertion and flat plate vibration → vacuum water absorption → mechanical leveling → manual smoothing and roughening → curing → cutting and grouting joints → curing
Construction sequence of steel fiber reinforced concrete for bridges
1、 Construction sequence of bored pile
Construction preparation → Measurement and layout → Setting up protective structures → Positioning drilling frame → Drilling and first hole cleaning → Placing steel cages, conduits, and second hole cleaning → Pouring underwater concrete → Measuring concrete surface elevation → End of conduit removal
2、 Expand the sequence of basic construction
Construction preparation → measurement and layout → cofferdam pumping → excavation of foundation pit → detection of foundation pit size → formwork erection → concrete mixing and pouring → maintenance
3、 Construction sequence of pier cap and pier body
Construction preparation → measurement and layout → installation of formwork → binding of steel bars → layered pouring of concrete
4、 Construction sequence of tie beams, columns, and cover beams
1. Construction sequence of tie beams (underwater)
Construction preparation → cofferdam pumping → installation of bottom and side formwork → reinforcement binding → pouring and curing of concrete
2. Construction sequence of columns
Construction preparation → Scaffolding support → Binding steel bars → Installing formwork → Pouring concrete for curing
3. Construction sequence of cover beam
Construction preparation → Support installation → Laying bottom plate → Binding steel bars → Installing side formwork → Pouring concrete for curing → Removing support
5、 Construction sequence of precast beams and slabs (prestressed beams and slabs)
Foundation treatment → Pouring pedestal → Installing slab beams and placing corrugated pipe samples → Binding steel bars and installing corrugated pipes → Pouring concrete bottom plate → Placing inner core formwork → Pouring concrete → Taking mold core → Cleaning holes and curing → threading prestressed tendon bundles (steel hinge lines) → Tensioning → Grouting and pouring head concrete
6、 Construction sequence of precast beams and slabs
Measurement and layout → guide frame assembly in place → prefabricated beams and slabs transported to the site → precise layout and installation of supports in place → installation of beams and slabs in place → acceptance inspection
7、 Construction sequence from simple support to continuous construction
Set up temporary supports and install beams and slabs → Install permanent supports and install bottom formwork → Bind steel bars according to the construction drawing of the cast-in-place section, and design continuous longitudinal steel bars → Install prestressed corrugated pipes → Erect side formwork → Pour the cast-in-place section (concrete needs to be reinforced with high-efficiency water reducing agent, using micro expansion cement, and compacted by vibration) → Timely curing → After the strength of the cast-in-place concrete reaches 100% of the design strength, tension the prestressed continuous bundle → Grouting → Remove temporary supports → Connect the beams and slabs horizontally → Lay the bridge deck steel mesh (the longitudinal steel bars of the steel mesh continuously pass through the cast-in-place section) → Pour the bridge deck concrete
8、 Construction sequence of bridge deck engineering
Install drain pipe → pour guardrail concrete → bind bridge deck steel bars → mix and pour concrete → install guardrail → set expansion joints
9、 Construction sequence of bridge channel
Measurement and layout → cofferdam pumping → manual excavation of foundation pit with excavator → foundation pit shaping → pouring of rubble concrete foundation → pouring of rubble concrete abutment → pouring of abutment cap → hoisting of beams and slabs → construction of bridge deck system → maintenance
10、 Construction sequence of box culvert
Measurement and layout → manual excavation of foundation pit with excavator → foundation pit shaping → laying of bottom slab concrete → formwork erection → first concrete pouring of culvert body 30cm above the bottom slab → formwork erection → second concrete pouring of remaining parts → curing → backfilling
