IS 2770:1993 Part 2 is the Indian Standard (BIS) for safety code for tunnelling work: part 2 working in soft ground. This standard prescribes safety measures for tunnelling operations in soft ground conditions. It covers essential precautions for excavation, temporary supports (shoring/timbering), ventilation, gas monitoring, and dewatering to prevent cave-ins and ensure worker safety.
Lays down safety requirements for tunnelling operations specifically in soft ground, covering methods, ground stabilization, and support.
Overview
- Status
- Current
- Usage level
- Specialized
- Domain
- Geotechnical — Construction Safety and Practices
- Type
- Safety Code
Also on InfraLens for IS 2770
Practical Notes
! Ensure immediate installation of temporary supports (timbering or steel ribs) right after excavation to prevent sudden face collapse.
! Continuous monitoring for ground settlement and toxic/explosive gases is mandatory in soft soil strata.
! Dewatering must be carefully managed to avoid excessive surface subsidence or instability of adjacent structures.
Frequently referenced clauses
Cl. 4Precautions during Excavation in Soft Ground
Cl. 5Timbering, Shoring and Temporary Supports
Cl. 6Ventilation and Gas Monitoring
Cl. 7Dewatering and Groundwater Control
Cl. 8Emergency Exits and Rescue Procedures
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International Equivalents
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International Comparison — Coming Soon
We're adding equivalent international standards for this code.
Key Values4
Quick Reference Values
minimum ventilation rate6 m³/min per person
max permissible methane concentration1.25%
max voltage for portable lighting24 V
minimum illumination at working face50 Lux
Tables & Referenced Sections
Frequently Asked Questions3
What is the minimum fresh air supply required in the tunnel?+
A minimum of 6 cubic meters per minute per worker must be supplied to ensure a safe breathing atmosphere.
What is the maximum allowed methane concentration?+
All work must be halted and personnel evacuated if the methane concentration in the tunnel exceeds 1.25%.
What is the safe operating voltage for portable lighting in underground wet conditions?+
Portable hand lamps must operate at a maximum of 24 Volts to prevent electrocution in highly conductive environments.
QA/QC Inspection Templates
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QA/QC templates coming soon for this code.