Coromandel Engineering Constructions
Pondicherry
600 nos. of 600mm dia bored cast in-situ piles taken to 25m depth and completed in 60 days.
Project Overview
One of our largest bored cast in-situ packages, executed for Coromandel Engineering Constructions at their Pondicherry development. The scope covered 600 piles of 600mm diameter socketed to a founding depth of 25 metres.
Boring was carried out by the Direct Mud Circulation (DMC) method as per IS 2911 Part 1 Sec 2, with bentonite circulated under pressure to keep the bore stable and to flush the bored muck to the surface. Hard strata was penetrated using appropriately weighted chisels until the specified socketing was achieved.
Reinforcement cages were lowered after the specific gravity of the outflow confirmed a clean bore, followed by tremie concreting in a continuous pour.
Scope of Work
- Setting out and verification of pile positions against the structural grid at Pondicherry, jointly signed off with the client's site engineer.
- Boring / driving of 600 piles at 600 mm diameter to a founding depth of 25 m using the bored cast in-situ pile (dmc method).
- Fabrication, lowering and centring of reinforcement cages with cover blocks to the specified concrete cover.
- Continuous tremie concreting of every pile with cube sampling and pour records maintained per pile.
- Chipping back to cut-off level, disposal of muck and handover of the as-built pile schedule.
Machinery & Plant Deployed
- Tractor mounted rotary DMC rigs with mud pumps and circulation tanks
- Bentonite mixing and desanding plant with specific gravity check kit
- Weighted chisels for penetrating hard laterite and boulder strata
- Reinforcement cage fabrication yard with bar bending and cutting machines
- Tremie pipe assembly with hopper for continuous concrete placement
- Transit mixers with on-site slump and cube testing
Execution Timeline
Mobilisation
Rigs, cages, casings and site establishment moved to Pondicherry, with access roads and working platform levelled for rig movement.
Trial pile & test bore
A trial pile was executed and observed against the borelog to confirm strata, penetration rate and concrete consumption before the production schedule opened.
Production piling
600 piles executed in a planned sequence to keep rigs clear of freshly cast piles, holding the 60 days programme.
Testing & handover
Load and integrity testing on the agreed sample of piles, followed by trimming to cut-off level and handover of records to the main contractor.
Load Testing & Quality Results
| Initial load test | Test pile loaded in increments to 2.5 times the design working load as per IS 2911 Part 4, with each increment held until the settlement rate stabilised. Safe working load confirmed for the 600 mm pile section. |
|---|---|
| Routine load test | Working piles from the production schedule tested to 1.5 times design load. Settlement at test load and residual settlement after unloading remained within the permissible limits laid down in the code. |
| Pile integrity test | Low-strain integrity testing carried out on sample piles; reflectograms showed continuous shafts with no necking or discontinuity down to the founding level. |
| Concrete cube testing | Cubes cast from every pour and tested at 7 and 28 days, with all results meeting or exceeding the specified grade. |
Site Gallery
Technical terms used above are explained in our piling glossary.
Scope Highlights
- Tractor mounted rotary DMC rigs deployed in multiples to hold the 60-day programme
- Bore cleanliness verified by specific gravity checks before every concrete pour
- Continuous tremie concreting with cube testing on site
Project Details
- Client
- Coromandel Engineering Constructions Ltd.
- Location
- Pondicherry
- Status
- Completed
- Technique
- Bored Cast In-Situ Pile (DMC Method)
- No. of Piles
- 600 piles
- Pile Diameter
- 600 mm
- Depth
- 25 m
- Duration
- 60 days
