Construction process of culvert
Culvert stands for a structure that facilitates the water to stream under a road or railway.
Generally, two types of culverts are built up along the road which range from RCC culvert and Masonry Culvert. The culverts are accessible in different shapes like round, elliptical, flat-bottomed, pear-shaped, and box-like constructions. Based on water flow capacities, duration and installation of bedding and backfill, the culverts are classified as follow :-
• Pipe culvert (single or multiple)
• Pipe-Arch culvert (single or multiple)
• Box culvert (single or multiple)
• Arch culvert
• Bridge culvert
• Metal box culvert
Construction method of culvert :-
Initially, digging of excavation pit is done for the foundation slab. The casting of foundation slab is performed as one unit for both the abutments.
Series of parallel bars with 8 mm dia @200 mm c/c are placed on the slab.
First 400 mm of the bar is built to stand on the slab and the remaining portion is folded over maintaining exact angles.
These bars are known as skin reinforcement.
Formwork is settled for repeated casting of the structure.
Casting is performed in two layers of 200 mm.
Based on the shape of the abutment, the skin reinforcements are bent at necessary angle. Formwork is fixed and casting is done in normal way.
At 0.5 m over the ground level, the weep holes are arranged to discharge the water that is stored on either side of the abutment. Diameter of weep holes remains 75 mm @ 1m c/c.
The construction is done in normal way unless the dirt wall is finished.
The reinforcement for the abutment cap is fastened and the form work is settled.
After that, the casting of abutment cap is accomplished.
Abutment cap is cured for minimum 1 week, then the formwork for slab is settled.
The reinforcement of slab is fastened at the time of retaining the required camber.
Concreting of slab is performed in normal way.
Curing of the slab is done for 28 days.