What are the main types of grouting covered?

The code details methods like permeation grouting, compaction grouting, and fracture/claquage grouting, using suspension (cement-based) or solution (chemical) grouts (Clause 4).

What is the recommended limit for grouting pressure?

Grouting pressure should generally not exceed 0.25 kgf/cm² per metre of overburden to avoid hydraulic fracturing and ground heave (Clause 5.3.3).

What records need to be kept during grouting?

Essential records include grout mix proportions, volume of grout injected, injection pressures, and any ground movement or water level changes (Clause 6.2).

How is the permeability of rock assessed for grouting?

Through in-situ water pressure tests, often expressed in Lugeon units, to determine the rock mass's capacity to accept grout (Clause 6.3).

IS 9012

: 1978

Grouting for Foundation Improvement - Code of Practice

CurrentSpecializedCode of PracticeGeotechnical · Demolition, Renovation and Repair of Structures

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This code of practice provides guidelines for improving foundation soils and rocks through grouting. It details the materials, methods, equipment, and procedures for various grouting techniques, including permeation, compaction, and fracture grouting, along with essential quality control and record-keeping practices.

Provides a code of practice for grouting techniques aimed at improving the strength and stability of foundations.

Quick Reference Values

Maximum Grouting Pressure0.25 kgf/cm² per metre of overburden (approx. 25 kPa/m)

Initial Grout W/C Ratio (by volume)10:1 to 5:1

Final Grout W/C Ratio (by volume)0.5:1

Lugeon Value Definition1 Lugeon = 1 litre/min/metre of hole at 10 kgf/cm² pressure

Bentonite Content in Cement Grout1 to 5 percent by weight of cement

Maximum Pumping Distance (Typical)up to 300 m

Practical Notes

Grout refusal criteria (maximum pressure or minimum flow) must be defined before work starts to prevent ground damage and ensure effectiveness.

Conducting a trial grouting program on-site is crucial to optimize grout mix, injection pressure, and hole spacing for specific ground conditions.

Constant monitoring of adjacent structures for heave or settlement is critical, especially when performing compaction or fracture grouting.