Qualification Principles of Various Items of Work

Earthwork for Foundation

(a)  Any earthwork item involves one or more of the following activities :

1. Cutting 
2. Filling 
3. Conveying 

(b)  Foundation trenches are quantified to the exact dimensions as given in the drawings. Actual width of excavation may be more for construction convenience but not provided for in the estimate except in cases such as in deeper trenches where benching is required.

(c)  Excavations of areas wider than 1.5 m and 10 sq m in area and depth less than 30 cm are quantified in sq m and termed as surface excavation and different from excavation over area or excavation of trenches. The latter two are quantified in cu m.

(d)  Excavation quantities shall be separately done for different types of soils, viz.

1. Loose/soil Soil : Any soil that yields to the ordinary application of pick & shovel or ordinary digging implements, e.g. organic soil (loam), sand, silt etc. 
2. Hard/dense Soil : Soil which requires close application of pick or jumpers or scarifies to loosen, e.g. stiff clay, gravel etc. 
3. Mud : A mixture of soil and water in fluid or weak solid state. 
4. Soft Disintegrated Rock (not requiring blasting) : Split with crow bars, e.g. lateral, hard conglomerate etc. 
5. Hard Rock (requiring blasting). 
6. Hard Rock (blasting prohibited) : Prohibited for any reason, e.g. safety etc. and excavation has to be carried out by chiseling, wedging etc. 

To identify the nature of soil, details are taken from trial pits or bore holes, which are normally made to assess safe bearing capacity of soil.

(e)  Lead and Lift

• Lead: Horizontal distance through which the excavated soil is to be conveyed in order to be dumped or filled. 
• Lift - Vertical distance through which the excavated soil is to be conveyed in order to be dumped  filled. 

The quantities of earth that require additional lead and lift should be separately prepped. Normally, initial lead and lift ace taken as 10 m and 2 m. respectively Every 10 m or part thereof over 30 m will constitute an additional lead. Similarly, every 1 m or part thereof over the initial lift of 2 m will constitute an additional lift.

(f) Filling in the sides of trenches with excavated earth is not separately quantified unless done with soil other than excavated earth.

(g)  Earthwork in plinth filling is calculated as a separate item (even if done with the excavated soil).

(h)  Extra earth required or such filling is brought from outside and surplus earth, if any is carted away. (After using for filling low lying areas in order to raise the general level of ground etc.)