BOX CULVERTS

 

 BOX CULVERTS

 

This item of work deals with construction of Box culverts with approved materials as per the terms of contract agreement.
 1. General

The construction shall confirm to the specific alignment, lines and grades given in the drawing.

The materials used shall adhere to the section 1000 of technical specifications. The concrete used shall be of approved design mix and shall confirm to section 1700 of technical specifications.

2. Procedure

Diversion of Water:

            The requisite and efficient methods are adapted to suit the particular need of diverting the water.

Excavation:

 

1. Layout marking will be done as per approved working drawing and ground levels will be taken and recorded jointly
2. Excavation will be done conforming to the lines, grades, slopes and levels as shown on the approved working drawings, as per the specification clause 304.3.2
3. If required dewatering will be done as per the specification clause 304.3.3
4. All the excavated materials will be disposed such that the working space will not effect, as per the specification clause 301.3.11
5. Excavation in Hard Rock will be done as per specification clause 301.3.5
6. Preparation of foundation will be done as per specification clause 301.3.4
7. if there is any slips & slip outs in the excavation will be removed
8. Filling below foundations up to require level and backfilling will be done with approved material in layers not exceeding 150mm compacted thickness. The compaction will be done with the help of suitable equipment such as mechanical tamper, plate vibrator etc. after necessary watering as per specification clause 301.3.7

          

 

           Concreting:

 Base Slab:  The reinforcement shall be placed in position and shuttering is erected to exact dimensions of base slab and after due checks, base slab is concreted to the top of bottom haunch and joints is maintained as detailed in drawing.

Walls: The walls are cast to bottom level of upper haunch. The procedure adopted will be same as base slab. 

 Top slab: The shuttering is made to support the top slab and necessary care is taken to seal the    joints to avoid slurry loss from concrete through joints.  The steel is positioned and concreted.

The formwork is removed after due time as per norms and blemishes, if found, are made good.

The inlet & Outlet structures, the aprons and floor protection works are constructed in similar progression.

The surroundings are cleared of all surplus stocks, waste materials etc., and cleaned. The structure is finished as per specifications including necessary markings, paints etc., and completed.

3. Equipment/Machinery:

 

1.    Poclain/ JCB

2.    Auto level with accessories

3.    Transit Mixers

4.    Needle Vibrators

5.    Cube Moulds