What is the maximum depth I can excavate without any support?

1.5 m, provided the sides are vertical and the ground is not loose or soft. For depths greater than 1.5 m, shoring or sloping of sides is required (Clause 6.1).

How far should the excavated soil (spoil) be kept from the trench edge?

A clear space of at least 1 m should be maintained between the edge of the excavation and the excavated material to prevent overloading the sides (Clause 10.1.2).

What are the requirements for ladders in a trench?

Ladders must be provided for access/egress in any trench deeper than 1.5 m. They should be spaced no more than 30 m apart and extend at least 1 m above the landing (Clause 10.1.4).

When does excavation support need to be designed by an engineer?

For excavations deeper than 4 m, or in very poor soil conditions, or near existing structures, a detailed design of the support system by a qualified engineer is required.

IS 14698

: 1999

Code of practice for safe working in excavation with and without support

CurrentFrequently UsedCode of PracticeGeotechnical · Tunneling and Underground Structures

Download PDF BIS Portal Google

This code provides guidelines for safe practices in excavation works, both with and without temporary support systems. It covers aspects like site investigation, soil classification, methods for shoring and strutting, and general safety precautions to prevent accidents like cave-ins.

Provides safety requirements and practices for excavation work, including temporary support systems for trenches, pits, and foundations.

Quick Reference Values

Maximum depth for unsupported vertical excavation1.5 m

Minimum distance of excavated material (spoil) from trench edge1.0 m

Maximum spacing of ladders for access/egress in trenches30 m

Minimum extension of a ladder above the landing point1.0 m

Depth beyond which trenches require support or sloping1.5 m

Depth beyond which a support system requires specific design by an engineer4.0 m

Practical Notes

Always classify the soil before starting excavation to determine the need for and type of support; do not rely on visual inspection alone.

Ensure spoil heaps (excavated material) are kept at a safe distance from the trench edge (min 1m) to prevent surcharge load and material falling back into the excavation.

Regularly inspect the excavation sides and the support system, especially after rain or nearby vibration, for any signs of distress or failure.