Construction process of highway bridge and culvert bearing platform

Abstract

The invention discloses a highway bridge and culvert bearing platform construction technology, and belongs to the field of highway bridge and culvert bearing platform construction, and the highway bridge and culvert bearing platform construction technology comprises the following steps: 1, construction preparation: compiling a construction scheme through a construction drawing, carrying out survey lofting according to design coordinates, and preparing raw materials, equipment and a construction site; 2, foundation construction, wherein after a foundation pit is excavated through cooperation of machinery and manual work, foundation treatment and cushion layer construction are conducted; (3) steel reinforcement framework construction: finishing steel reinforcement processing according to a design drawing, arranging main reinforcements to finish stirrup binding, and then mounting the steel reinforcements; fourthly, formwork installation and concrete pouring are conducted, specifically, formwork installation, reinforcing and pasting are conducted, concrete pouring is conducted in a layered mode after anti-leakage measures are set, and pushing is conducted from the short side to the long side of the bearing platform; 5, concrete curing, form removal and quality inspection are carried out; and 6, setting safety and environmental protection measures. According to the highway bridge and culvert bearing platform construction technology, the bearing platform construction process is systematically designed, and the construction quality of the highway bridge and culvert bearing platform is improved.

Description

Technical Field

[0001] The present invention relates to the technical field of highway bridge abutment construction, and particularly to a construction technology for highway bridge abutments. Background Art

[0002] With the growth of highway traffic volume and the increase of bridge spans, as a key structure of the bridge foundation, the abutment needs to have higher bearing capacity and durability. In the existing construction of highway bridge abutments, the excavation of the foundation pit is easily affected by groundwater and soft soil layers, the support cost is high and the cycle is long. The hydration heat of mass concrete leads to the risk of temperature cracks, and it is difficult to accurately control the temperature with traditional maintenance measures. Therefore, a construction technology for highway bridge abutments is needed to systematically design the processes such as foundation pit excavation, concrete pouring, and maintenance during the construction of the abutment, so as to improve the construction quality of highway bridge abutments. Summary of the Invention

[0003] The purpose of the present invention is to provide a construction technology for highway bridge abutments, which systematically designs the construction process of the abutment and improves the construction quality of highway bridge abutments.

[0004] To achieve the above purpose, the present invention provides a construction technology for highway bridge abutments, including the following steps: Step 1, construction preparation: Prepare a construction plan through construction drawings, conduct survey and lofting according to the design coordinates, and prepare raw materials, equipment, and the construction site; Step 2, foundation construction: After mechanically and manually excavating the foundation pit, conduct base treatment and complete the construction of the cushion layer; Step 3, construction of the steel bar framework: Complete the steel bar processing according to the design drawings, set the main steel bars and complete the binding of stirrups, and then carry out the steel bar installation; Step 4, formwork installation and concrete pouring: Install and reinforce the formwork, set leakage prevention measures, and then pour the concrete in layers, advancing from the short side to the long side of the abutment; Step 5, concrete curing, form removal, and quality inspection; Step 6, set safety and environmental protection measures.

[0005] Preferably, in Step 1, technical preparation: Complete the review of the design drawings of the abutment, prepare a special construction plan, and conduct technical disclosure; Survey and lofting: According to the design coordinates, use a total station to set out the abutment side line and axis, and set control piles; Materials and equipment: Prepare steel bars, formwork, concrete, cushion layer materials, and water stop steel plates; Prepare excavators, cranes, concrete pump trucks, vibrators, welding machines, and steel bar processing machinery; Remove the floating slurry on the pile head, chisel to the fresh concrete surface, straighten the anchor steel bars on the pile top, level the site, set drainage ditches to prevent water accumulation, and complete the cleaning of the construction site Preferably, in step two, the foundation pit excavation method is as follows: mechanical excavation is combined with manual trimming, and the bottom of the foundation pit is 0.5 - 1.0 m wider than the size of the bearing platform on each side; the slope gradient is determined according to the soil quality, and steel sheet piles or wooden piles are used for support in soft strata. Base treatment: After excavating to the design elevation, the base is manually cleaned, rammed and leveled; the bearing capacity of the foundation is detected, and if the bearing capacity of the foundation is insufficient, it is backfilled with gravel or crushed stone.

[0006] Preferably, for pouring the cushion layer: lay a 10 cm thick C15 concrete cushion layer, and the surface is leveled to serve as the bottom formwork of the bearing platform; the edge of the cushion layer extends 10 cm beyond the outline of the bearing platform, and a drainage slope is set around.

[0007] Preferably, in step three, for steel bar processing: cut the steel bars according to the design drawings, the main steel bars are connected by straight thread sleeve or welded, and the stirrups are tied; the anchoring steel bars at the top of the pile are welded to the steel bars of the bearing platform. Steel bar installation: Snap lines on the cushion layer for positioning, first tie the bottom steel bar mesh, and then set up the side steel bars and the top mesh; control of the cover thickness: use concrete cushion blocks, with a spacing ≤ 1 m, and the cushion blocks on the side are denser.

[0008] Preferably, after the steel bars are installed, embedment parts are installed. Embed steel bars in the pier column and fix them with angle steel brackets, with a deviation ≤ 5 mm.

[0009] Preferably, in step four, for formwork erection: use combined steel formwork or bamboo plywood, and reinforce it with double-row steel pipes + tie bolts on the outside, with a spacing ≤ 60 cm; paste double-sided tape at the formwork joints to prevent leakage of mortar, and apply release agent on the inside. Inspection and acceptance: The deviation of the formwork verticality ≤ 3 mm, the deviation of the axis position ≤ 15 mm, the error of the top elevation ± 10 mm. If the acceptance is qualified, if not, adjust the formwork.

[0010] Preferably, after the formwork is accepted, the concrete is poured in layers, with each layer thickness ≤ 30 cm, and vibrated thoroughly with an inserted vibrator; push forward from the short side to the long side of the bearing platform, and strengthen the vibration around the top of the pile; bury cooling water pipes, and the temperature difference between the inside and outside of the concrete ≤ 25 °C; cover and moisturize in summer, and set up a warm shed for heat preservation in winter.

[0011] Preferably, in step five, for concrete curing: cover with geotextile and sprinkle water for curing ≥ 7 days after the concrete has finally set; use cotton-padded quilts for covering + warm air heaters for heat preservation in winter. Concrete formwork removal: Remove the formwork after the concrete strength ≥ 2.5 MPa, and tap and unload gently. Quality inspection: Conduct inspections on concrete strength, steel bar cover thickness, axis deviation, and surface flatness.

[0012] Preferably, in step six, set up protective railings and warning signs around the foundation pit, and provide night lighting; control of dust: cover the bare soil with dust-proof nets and sprinkle water to reduce dust; the waste water is discharged after being treated in the sedimentation tank, and the construction waste is centrally cleared.

[0013] Therefore, the present invention adopts the above-mentioned construction process for the bearing platform of highway bridges and culverts to ensure that the structural strength, durability and geometric dimensions of the bearing platform meet the design requirements, solve the problems that the foundation pit excavation is easily affected by groundwater and soft soil layers, the support cost is high and the cycle is long, and the risk of temperature cracks caused by the hydration heat of mass concrete, and improve the construction quality.

[0014] The technical solution of the present invention will be further described in detail below with reference to the accompanying drawings and embodiments. Description of the Drawings

[0015] Figure 1 It is a process flow chart of an embodiment of the construction process for the bearing platform of highway bridges and culverts of the present invention. Detailed Embodiments

[0016] In order to make the purpose, technical solution and advantages of the embodiments of the present invention clearer, the embodiments of the present invention will be further described in detail below with reference to the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are only used to explain the embodiments of the present invention, and are not used to limit the embodiments of the present invention. All other embodiments obtained by those of ordinary skill in the art based on the embodiments in this application without creative efforts belong to the scope of protection of this application. The examples of the embodiments are shown in the accompanying drawings, where the same or similar reference numerals denote the same or similar elements or elements with the same or similar functions throughout.

[0017] It should be noted that the terms "including" and "having" and any variations thereof are intended to cover non-exclusive inclusion. For example, a process, method, system, product or server that includes a series of steps or units does not necessarily have to be limited to those steps or units clearly listed, but may include other steps or units not clearly listed or inherent to these processes, methods, products or devices.

[0018] Similar reference numerals and letters denote similar items in the following drawings. Therefore, once an item is defined in one drawing, it does not need to be further defined and explained in subsequent drawings.

[0019] In the description of the present invention, it should be noted that the orientation or positional relationship indicated by the terms "upper", "lower", "inner", "outer", etc. is based on the orientation or positional relationship shown in the accompanying drawings, or the orientation or positional relationship in which the product of the present invention is usually placed during use. It is only for the convenience of describing the present invention and simplifying the description, and does not indicate or imply that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore should not be construed as a limitation of the present invention.

[0020] In the description of the present invention, it should also be noted that unless otherwise clearly specified and defined, the terms "set", "install", and "connect" should be understood in a broad sense. For example, it can be a fixed connection, a detachable connection, or an integral connection; it can be a mechanical connection or an electrical connection; it can be directly connected or indirectly connected through an intermediate medium, and it can be the communication inside two components. For those of ordinary skill in the art, the specific meanings of the above terms in the present invention can be understood according to specific situations.

[0021] Embodiment As Figure 1 shown, a construction technology for the bearing platform of a highway bridge culvert according to the present invention includes the following steps: Step 1, construction preparation: Prepare a construction plan through construction drawings, conduct survey and setting out according to the design coordinates, and prepare raw materials, equipment, and the construction site. Specifically include: Technical preparation: Complete the review of the bearing platform design drawings, prepare a special construction plan, and conduct technical disclosure; Survey and setting out: According to the design coordinates, use a total station to set out the bearing platform side lines and axes, and set control piles; Materials and equipment: Prepare steel bars (HRB400), formwork (composite steel formwork or bamboo plywood formwork), C30 concrete, cushion materials (C15 concrete), and water stop steel plates (if waterproofing is required); prepare excavators, cranes, concrete pump trucks, vibrating rods, welding machines, and steel bar processing machinery; remove the floating slurry on the pile heads, chisel to the fresh concrete surface, straighten the anchor bars on the pile tops, level the site, set drainage ditches to prevent water accumulation, and complete the cleaning of the construction site.

[0022] Step 2, foundation construction: After mechanically and manually excavating the foundation pit, conduct base treatment and complete the cushion construction. Specifically include: Foundation pit excavation method: Use mechanical excavation (excavator) in cooperation with manual trimming. The bottom of the foundation pit is 0.5 - 1.0 m wider than the bearing platform size on each side for easy operation. The slope gradient is determined according to the soil quality (such as 1:0.5 - 1:1), and steel sheet piles or wooden piles are used for support in soft strata.

[0023] Base treatment: After excavating to the design elevation, manually clean the base, tamp and level it; detect the bearing capacity of the foundation (≥ design requirements), and if the bearing capacity of the foundation is insufficient, backfill with gravel or crushed stone.

[0024] Pour the cushion: Lay a 10 - cm - thick C15 concrete cushion, smooth the surface as the bottom formwork of the bearing platform; the edge of the cushion extends 10 cm beyond the bearing platform contour line, and a drainage slope is set around.

[0025] Step 3, construction of the steel bar cage: Complete the steel bar processing according to the design drawings, set the main steel bars and complete the binding of stirrups, and then carry out the steel bar installation. Specifically include: Rebar processing: Cut according to the design drawings, use straight threaded sleeves to connect or weld the main bars, and tie the stirrups; the single-sided weld length of the pile top anchor bar and the base bar is ≥10d (d is the diameter of the bar).

[0026] Rebar installation: mark the lines on the cushion layer for positioning, tie the bottom steel mesh first, and then erect the side steel bars and the top mesh; Protective layer thickness control: Use concrete pads with a spacing of ≤1m and increase the density of side pads.

[0027] After the steel bars are installed, the embedded parts are installed. The embedded steel bars in the pier are accurately positioned and fixed with angle steel brackets with a deviation of ≤5mm.

[0028] Step 4: Formwork installation and concrete pouring: Formwork installation and reinforcement pasting, setting up leak-proof measures and then pouring concrete in layers, from the short side of the foundation to the long side. Specifically include: Formwork support: Use combined steel formwork or bamboo plywood, reinforce the outside with double-row steel pipes + tension bolts, with a spacing of ≤60cm; stick double-sided tape on the formwork joints to prevent leakage, and apply release agent on the inside.

[0029] Inspection and acceptance: the verticality deviation of the template is ≤3mm, the axis deviation is ≤15mm, the top surface elevation error is ±10mm, the acceptance is qualified, if not, adjust the template.

[0030] After the formwork is accepted, the concrete is poured in layers, with each layer ≤30cm thick and compacted with an inserted vibrator; push from the short side of the pedestal to the long side to avoid cold joints; strengthen vibration around the top of the pile; bury cooling water pipes, with a temperature difference of ≤25℃ between the inside and outside of the concrete; cover to keep moisture in summer and build a greenhouse to keep warm in winter.

[0031] Step 5: Concrete curing, demoulding and quality inspection, including: Concrete maintenance: After the final setting of concrete, cover it with geotextile and sprinkle water for maintenance for ≥ 7 days; keep the surface moist, and use quilts and heaters to keep warm in winter.

[0032] Concrete demoulding: demould after the concrete strength is ≥2.5MPa (about 24~48 hours), tap and unload gently to avoid damage to corners.

[0033] Quality inspection: Concrete strength (28-day compression test of test block), steel bar protection layer thickness (±5mm), axis deviation (≤15mm), surface flatness (≤8mm / 2m), no cracks, honeycomb surface ≤0.5%.

[0034] Step 6: Set up safety and environmental protection measures, including: Protective railings and warning signs are installed around the foundation pit, and there is sufficient lighting at night; dust control: bare soil is covered with dust-proof nets, and water is sprinkled to reduce dust; wastewater is discharged after treatment in sedimentation tanks, and construction waste is centrally transported away.

[0035] The general construction process is as follows: Measurement and lofting → Foundation pit excavation → Subgrade treatment → Cushion casting → Steel bar binding → Formwork installation → Concrete casting → Curing and form removal → Foundation pit backfilling.

[0036] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention rather than to limit them. Although the present invention has been described in detail with reference to the preferred embodiments, those of ordinary skill in the art should understand that they can still modify or equivalently replace the technical solutions of the present invention, and these modifications or equivalent replacements cannot make the modified technical solutions deviate from the spirit and scope of the technical solutions of the present invention.

Claims

1. A highway bridge and culvert cap construction process, characterized by: The following steps are involved: Step 1, construction preparation: prepare the construction plan through the construction drawings, measure and lay out according to the design coordinates, and prepare raw materials, equipment and construction sites; Step 2: Foundation construction: After the foundation pit is excavated by machinery and manual labor, the base is treated and the cushion layer is constructed; Step 3: Steel bar skeleton construction: complete steel bar processing according to the design drawings, set the main bars, complete the stirrup binding, and then install the steel bars; Step 4: Formwork installation and concrete pouring: Formwork installation and reinforcement pasting, setting up leak-proof measures and then pouring concrete in layers, from the short side of the foundation to the long side; Step 5: Concrete curing, demoulding and quality inspection; Step 6: Set up safety and environmental protection measures.

2. The highway bridge and culvert cap construction process according to claim 1 is characterized by: In step one, technical preparation: complete the review of the foundation design drawings, prepare a special construction plan, and conduct technical briefing; Surveying and setting out: according to the design coordinates, use the total station to lay out the edge line and axis of the foundation and set control piles; Materials and equipment: Prepare steel bars, formwork, concrete, cushion materials, and water-stop steel plates; prepare excavators, cranes, concrete pump trucks, vibrators, electric welders, and steel bar processing machinery; remove floating slurry from the pile head, chisel until the fresh concrete surface, straighten the anchor steel bars on the pile top, level the site, set up drainage ditches to prevent water accumulation, and complete the cleaning of the construction site.

3. The highway bridge and culvert cap construction process according to claim 2 is characterized by: In step 2, the foundation pit excavation method: mechanical excavation combined with manual finishing, the foundation pit bottom is 0.5~1.0m wider than the size of the foundation platform on each side; the slope gradient is determined according to the soil quality, and steel sheet piles or wooden piles are used for support in soft strata; Base treatment: After digging to the designed elevation, clean the base manually, compact and level it; test the bearing capacity of the foundation, and replace it with gravel or crushed stone if the bearing capacity of the foundation is insufficient.

4. The highway bridge and culvert cap construction process according to claim 3 is characterized by: Pouring cushion layer: Lay a 10cm thick C15 concrete cushion layer and smooth the surface as the bottom formwork of the pedestal; the edge of the cushion layer extends 10cm beyond the outline of the pedestal and drainage slopes are set around it.

5. The highway bridge and culvert cap construction process according to claim 4 is characterized by: In step three, steel bar processing: cutting according to the design drawings, main bars are connected or welded with straight thread sleeves, and stirrups are tied; the pile top anchor steel bars are welded with the cap steel bars; Rebar installation: mark the lines on the cushion layer for positioning, tie the bottom steel mesh first, and then erect the side steel bars and the top mesh; Protective layer thickness control: Use concrete pads with a spacing of ≤1m and increase the density of side pads.

6. The highway bridge and culvert cap construction process according to claim 5 is characterized by: After the steel bars are installed, the embedded parts are installed. The steel bars are embedded in the piers and fixed with angle steel brackets with a deviation of ≤5mm.

7. The highway bridge and culvert cap construction process according to claim 6 is characterized by: In step 4, the formwork is supported by using a combination steel formwork or bamboo plywood, and the outer side is reinforced with double-row steel pipes + tension bolts, with a spacing of ≤60cm; double-sided tape is pasted on the template joints to prevent leakage, and a release agent is applied on the inner side; Inspection and acceptance: the verticality deviation of the template is ≤3mm, the axis deviation is ≤15mm, the top surface elevation error is ±10mm, the acceptance is qualified, if not, adjust the template.

8. The highway bridge and culvert cap construction process according to claim 7 is characterized by: After the formwork is accepted, the concrete is poured in layers, with each layer ≤30cm thick and compacted with an inserted vibrator; advance from the short side of the pedestal to the long side, and strengthen vibration around the top of the pile; bury cooling water pipes, and the temperature difference between the inside and outside of the concrete is ≤25℃; cover in summer to keep moisture, and build a greenhouse to keep warm in winter.

9. The highway bridge and culvert cap construction process according to claim 7 is characterized by: In step 5, concrete curing: after the concrete has finally set, cover it with geotextile and sprinkle water for curing for ≥ 7 days; in winter, cover it with a quilt + use a heater for heat preservation; Concrete demoulding: demould after the concrete strength is ≥2.5MPa, tap and unload gently; Quality inspection: Conduct inspections on concrete strength, steel bar protection layer thickness, axis deviation, and surface flatness.

10. The highway bridge and culvert cap construction process according to claim 9, characterized in that: In step six, protective railings and warning signs are installed around the foundation pit, and lighting is provided at night; for dust control: bare soil is covered with dust-proof nets, and water is sprinkled to reduce dust; wastewater is discharged after being treated in sedimentation tanks, and construction waste is centrally removed.

Images