Sidharth Foundation Housing — ECR Bliss

ECR, Chennai

680 nos. of 500mm dia piles at 19m depth for the ECR Bliss project, completed in 60 days.

Project Overview

The ECR Bliss development required 680 bored cast in-situ piles of 500mm diameter carried to 19 metres through the coastal sandy strata of the East Coast Road belt.

Bentonite slurry was circulated continuously to hold the bore open in the loose marine sand, with slurry properties monitored through the shift.

Piles were tested for capacity by vertical load test as per IS 2911 Part 4 before the structure was released for casting.

Scope of Work

Setting out and verification of pile positions against the structural grid at ECR, Chennai, jointly signed off with the client's site engineer.
Boring / driving of 680 piles at 500 mm diameter to a founding depth of 19 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 ECR, Chennai, 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
680 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 500 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.