Well cover installation construction process

1, urban road manhole cover construction operation process

1.1 process flow of manhole cover installation process: construction preparation → determine the location of the well, excise the grass-roots level, the surface layer → steel processing and molding → one step of concrete pouring → two steps of concrete pouring → asphalt top layer construction → process inspection

1.2 construction method

1.2.1 new check well wellhead masonry Height and reconstruction check well removal height, required to cover the temporary well cover slightly lower than the design of the road bed, to ensure that the road bed continuous molding. Base layer, asphalt middle and lower layers of continuous construction to ensure the integrity of the pavement structure. Check well location must be marked clearly and accurately in the construction process, each structural layer should be checked before construction.

1.2.2 Well ring reinforcement and well cover installation should be carried out before the construction of the asphalt top layer, according to the size of the well cover and reinforcement of the well ring design requirements, to determine the shape and size of the well ring reinforcement. Generally a square centered on the mouth of the well, the outer wall of the well is 25cm wide out. using a cutter to cut the seam, well circle reinforcement within the scope of the pavement structure excavation, mechanical crushing should be careful construction, is strictly prohibited to disturb the surrounding pavement structure. Pavement structure reserved for small parts of manual chiseling, to ensure that the slot wall straight, neat.

1.2.3 Determine the check well masonry height according to the design requirements of the reinforced well ring. Before installing the reinforcing steel skeleton will be cleaned up in the pit, well wall around the use of low-grade concrete poured dense, and leveling.

1.2.4 Reinforcing steel processing and skeleton size should be consistent with the design and specification requirements. Reinforcing steel skeleton should be square (the original design is round), the skeleton installation should coincide with the location of the wellhead, to ensure the thickness of the protective layer; the skeleton should be firm, avoid stepping on the concrete when pouring.

1.2.5 Pre-embedded bolts are made and installed according to the design requirements, which can be installed at the same time with the well frame, or can be installed when pouring the first step of the concrete by using the mold positioning; the bolts should be placed vertically; the nuts should be tightened before pouring the second step of the concrete, and the bolts should be connected with the concrete and the holes reserved for the well frame effectively.

1.2.6 Make firm, applicable circular wellhead template. Formwork should be easy to install and remove, to ensure that the size of the wellhead and the concrete surface is smooth and clean. Wellhead masonry should be considered to leave a probe brick as the internal mold pivot point, the top of the internal mold should be close to the mouth of the well cover to prevent leakage of slurry, two-step concrete all complete before removing the internal mold.

1.2.7 Well frame, well cover supporting the use of well cover; well cover installation should ensure that the cross font and the direction of travel; well cover with a rotating shaft, the rotating shaft should be welded to prevent damage to the asphalt at the rotating shaft. Well cover elevation should be consistent with the roadway elevation, slope, elevation according to the asphalt paving method and width, standing (flat) along the stone height, etc. to determine.

Note: ○ control points on the standing (flat) along the stone; Δ since the pick-up control points; Δ household installation of temporary control points (led by the acceptance control points); - installation control line (2m), acceptance control line (paving width or length of the balance beam); - Control line for inspection of cross slope (wells located within paving), or longitudinal slope (wells located in the center of the road or on the paving sideline) of the manhole cover; - Centerline of the road or paving sideline; - Curbline or structure profile line.

1.2.8 Concrete pouring should be rinsed with water and fully wet the base groove, concrete pouring is carried out in two steps, the first step is poured to the bottom of the upper layer of reinforcement, after the concrete is finally set picking hair, brushing slurry, starting pads at three points (can be pre-fabricated concrete wedge shaped pads), fastening bolts, and then pouring the second step of the concrete. The concrete should be vibrated and compacted and closely bonded with the chiseled surface around the well. Concrete above the reserved height should ensure that the asphalt around the well cover is greater than the design thickness of the upper layer.

1.2.9 Concrete should be maintained for more than 7 days, during the maintenance period is strictly prohibited crushing damage. According to the construction progress of appropriate mixing of early strength agent or quick-setting agent, shorten the maintenance time.

1.2.10 before the construction of asphalt top layer should be cleaned around the well frame, concrete surface chiseling (also in the concrete before the final set of hair) in order to facilitate the combination of asphalt, concrete surface bonding oil should be sprayed uniformly and bonded firmly. Spraying combined oil and asphalt paving before, should be brushed on the surface of the manhole cover the appropriate amount of diesel fuel to ensure that the manhole cover is not contaminated.

1.2.11 well ring reinforced concrete and well wall, well frame using smeared smooth, well construction waste should be cleaned up in time.

1.3 Specifications and regulations

1.3.1 The wellhead, reinforced well circle and well frame must match.

1.3.2 Excavation and removal of surfacing and base material at the location of the wellhead must not disturb the surrounding pavement structure.

1.3.3 Commercial concrete must be used for pouring; when the concrete curing time is insufficient, early-strength and quick-setting concrete should be used; the concrete must be vibrated densely and combined tightly with the road structure.

1.3.4 Pre-embedded bolts shall not be less than 6; if it is impossible to install pre-embedded bolts, other ways of reinforcing the well frame must be used, such as expansion bolts or reinforcing mesh.

1.3.5 Before installing the manhole cover, the type, size and construction of the cover should be carefully checked to see if it conforms to the design standards, and checked for any damage, cracks and other phenomena.

1.3.6 Before pouring the well circle, the well frame shall be padded and stabilized according to the measured elevation; the inner mold of the wellhead shall be made of shaped template.

1.3.7 The installation of well frame, well cover and accessories must be firm, smooth and correctly positioned. It should be guaranteed to be complete and undamaged.

1.4 Inspection and test

1.4.1 Well cover installation elevation inspection construction project department self-check, according to the installation of the reference control points for inspection; supervision requirements, with the supervision of the inspection and acceptance; asphalt top layer paving (at least 5 days in advance), the construction project department together with the asphalt paving project department joint inspection and acceptance of large-scale or key projects by the Ministry of Engineering to organize the inspection and acceptance. The large-scale or key projects are organized by the engineering department for inspection and acceptance.

1.4.2 Concrete compressive strength test according to the work shift to retain the concrete compressive specimens (not less than three groups), should be in the concrete strength of 90% or more for asphalt top layer paving.

2, construction quality control standards

2.1 appearance quality standards

2.1.1 buried parts installed correctly and firmly, well cover and check the position of the wellhead coincide.

2.1.2 Concrete is vibrated and compacted, the surface is flat, without stone exposure and exposed tendons; concrete is tightly bonded with the cutting surface; the wellhead is flat, polished and perpendicular to the wall of the well; maintenance is timely and there is no cracking.

2.1.3 Well frame and asphalt meet smoothly and combine tightly.

2.1.4 inspection wells clean, no construction debris and other debris.

2.2 Actual measurement and quality control standards Actual measurement and quality control standards are shown in Table 1.