Heritage
Badi Patan Devi heritage site, Patna Sahib
At the Badi Patan Devi heritage site in Patna Sahib, the soil under the structures needed strengthening without disturbing a site that stays in use. For the Government of Bihar, we consolidated the soil mass by chemical grouting and installed self-drilling anchors.
- Completed
- December 2025
- Location
- Patna Sahib, Bihar
- Type
- Heritage site
- Client
- Local Area Engineering Organisation, Planning and Development Department, Government of Bihar
CertifiedExperience certificate dated 27 February 2026. Work completed 29 December 2025. Performance: Satisfactory.
Unconfined compressive strength of site soil after PU treatment, in IIT Patna’s tests: 148 kPa to 3,284 kPa.
Cohesion in the triaxial tests: 45 kPa to 560 kPa.
Performance on the Government of Bihar’s experience certificate.
The problem
Strengthening the ground under a working heritage site
The soil mass under the structures needed strengthening, with work that would not disturb the fabric of a heritage site in daily use.
What we did
Chemical grouting and self-drilling anchors
- Self-drilling anchors installed at angles from outside the footprint, reaching beneath the footings.
- Chemical grout injected to consolidate the soil mass under the structures.
- 1Note 1: A heritage structure that stays in use throughout.
- 2Note 2: Settlement cracks in the masonry.
- 3Note 3: Soft, loose soil under the footings.
- 4Note 4: Self-drilling anchors installed at angles from outside, reaching beneath the footings.
- 5Note 5: Chemical grout consolidates the soil mass under the structure.
- 6Note 6: Strength gain measured on soil from the site in an independent laboratory.
Independent laboratory
Measured, not assumed
In August 2025 the Department of Civil and Environmental Engineering at IIT Patna tested soil from the site treated with our PU grout at 5% of its dry weight (UCS to IS 2720 Part 10; triaxial UU to IS 2720 Part 11).
These are results on that soil, from that site. Results vary with soil type, sampling and test conditions, and are not a figure for any other ground.
| Parameter | Untreated | Treated |
|---|---|---|
| Cohesion, triaxial UU | 45 kPa | 560 kPa |
| Friction angle | 31.0° | 49.2° |
| Unconfined compressive strength | 148 kPa | 3,284 kPa |
Services on this job
Methods used
Permeation and chemical grouting
Weak, loose or wet ground strengthened and sealed by resins and gels that fill it without moving it.
Curtain and consolidation grouting
Seepage cut-offs and foundation consolidation for dams, barrages, shafts and structures.
Rock bolting and self-drilling anchors
Rock bolts, self-drilling and prestressed anchors for tunnels, portals, slopes and caverns.
CertifiedExperience certificate dated 27 February 2026. Work completed 29 December 2025. Performance: Satisfactory.
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