PNC Pune City Outer Ring Road Project

Project Overview

The Pune City Outer Ring Road is a prestigious infrastructure project aimed at decongesting traffic around the industrial hub of Chakan. Rocktech is spearheading the challenging rock excavation phase of this project, which involves handling a massive volume of approximately 1.5 Lakh Cubic Meters of hard rock (Equivalent to excavating 60 Olympic-sized swimming pools of solid rock)

The Technical Challenge: Protecting Green Concrete

High-volume blasting usually carries a risk of high-intensity vibrations. In this project, the primary challenge was to execute massive blasts in close proximity to:

• Freshly Poured Concrete Piers: Blasting near "green" (recently poured) concrete is extremely sensitive, as even minor vibrations can disturb the setting process and structural integrity of the bridge piers.
• Residential Proximity: Managing noise and vibrations for nearby settlements in the Chakan area.

The Rocktech Execution Strategy

1. Integrated Excavation Methodology

We adopted a hybrid approach to maximize efficiency and safety:

• Systematic Drilling: High-precision patterns to ensure uniform fragmentation.
• Controlled Blasting: Used primarily in hard rock strata where mechanical means were insufficient.
• Mechanical Excavation: Deployed in softer patches to minimize the need for blasting near the most sensitive zones.

2. Advanced Blast Engineering

To safeguard the newly constructed highway piers, we implemented:

• Optimized Sequencing: Using millisecond delays to split the total explosive energy, reducing the overall vibration impact (Peak Particle Velocity).
• Vibration Modeling: Predicting the impact on concrete structures before every blast to ensure they remained well within permissible safety limits.

Current Project Status

• Status: Ongoing
• Total Volume: ~1,50,000 Cubic Meters
• Key Milestone: Successful execution of multiple blast cycles without any impact on the structural health of nearby concrete piers or residential units.

Technical Specifications

• Location: Near Chakan, Pune
• Principal Contractor: PNC Infratech Ltd.
• Work Type: Roadway Rock Excavation & Slope Cutting
• Technique: Controlled Blasting & Mechanical Hybrid Excavation
• Safety Protocol: Continuous Vibration Monitoring for Structural Safety