Road Bridge — Manali New Town

Manali New Town, Chennai

Deep foundation works for a road bridge substructure at Manali New Town for IVRCL.

Project Overview

Bridge substructure piling executed for IVRCL at Manali New Town. Railway and road bridge foundations are a core specialisation of Sri Saai Pile Foundation.

Large diameter bored cast in-situ piles were installed and socketed into the hard strata, with chisel energy monitored to identify the termination stratum.

The works were completed to the satisfaction of the client's engineers with full documentation of bore logs and concrete records.

Scope of Work

Setting out and verification of pile positions against the structural grid at Manali New Town, Chennai, jointly signed off with the client's site engineer.
Boring / driving of the full pile schedule using the large diameter bored cast in-situ piles.
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 Manali New Town, 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
The full pile schedule executed in a planned sequence to keep rigs clear of freshly cast piles.
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 designed 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.