Application of DAS (Distributed Acoustic Sensing) in New Factory Building Renovation

1. Background Overview

During the construction of new factory buildings or the renovation of existing ones, characteristics such as complex construction vibrations, densely packed pipelines, stringent structural safety requirements, and tight construction schedules are often present. Particularly in industries like high-end manufacturing, electronics and semiconductors, energy and chemical engineering, and biopharmaceuticals, new factory buildings typically integrate numerous underground utility tunnels, pressure pipelines, cable trays, and precision equipment. This imposes higher demands for monitoring vibrations, abnormal intrusions, and structural safety during the construction process.

Traditional monitoring methods (such as point-type vibration sensors, manual inspections, or video surveillance) suffer from issues like limited coverage, high installation and maintenance costs, and insufficient real-time capability, making it difficult to meet the needs of large-scale, continuous, and detailed monitoring.

The Distributed Acoustic Sensing (DAS) system, utilizing the optical fiber itself as the sensing medium, provides a comprehensive, real-time, and long-term online monitoring solution for new factory building renovations.

2. Brief Overview of DAS Technical Principle

The DAS system is based on the principle of coherent Rayleigh scattering. It injects narrow-linewidth laser pulses into standard single-mode optical fiber and collects the backscattered signals from all points along the fiber. When external vibrations, impacts, or acoustic waves occur, they induce local strain changes in the fiber, which in turn alter the phase or intensity of the scattered signal.

Through high-speed data acquisition and signal processing algorithms, the DAS system transforms the entire fiber into a continuously distributed "virtual sensor array", enabling precise localization and characteristic identification of vibration events.

Its core advantages include:

✅ A single fiber can achieve continuous monitoring over several to tens of kilometers

✅ Spatial resolution can reach meter-level or higher

✅ Supports all-weather, maintenance-free, real-time monitoring

✅ Suitable for complex environments and harsh operating conditions

3. Typical Application Scenarios in New Factory Building Renovation

3.1 Construction Vibration Monitoring and Structural Safety Assessment

During factory renovation, construction activities such as piling, demolition, cutting, and drilling generate continuous or transient vibrations that may impact existing structures, equipment foundations, or adjacent buildings.

By deploying optical fiber along building foundations, floor slabs, or key structural components, the DAS system enables:

✅ Real-time monitoring of construction vibration intensity and spectral characteristics

✅ Spatial localization and temporal recording of vibration events

✅ Automatic alarm triggering for abnormal vibrations

✅ This provides reliable data support for risk assessment, construction process optimization, and responsibility attribution during the construction phase.

3.2 Safety Monitoring for Underground Pipelines and Utility Tunnels

New factory buildings often contain numerous underground water supply and drainage pipelines, gas pipelines, process piping, and utility tunnels. Accidental excavation, impact, or leakage during renovation poses serious safety hazards.

The DAS system, with fiber deployed along pipelines or within tunnels, enables:

✅ Detection of construction machinery proximity and abnormal excavation activities

✅ Monitoring of abnormal pipeline vibrations and impacts

✅ Early warning for events like leaks or ruptures

Compared to traditional point-sensing solutions, DAS offers the significant advantage of long-distance, gap-free coverage.

3.3 Perimeter and Construction Zone Intrusion Monitoring

During factory renovation, construction areas often face challenges such as complex personnel traffic and difficult management. By deploying fiber on fences, walls, or ground surfaces, DAS can achieve real-time monitoring and alarm generation for:

✅ Unauthorized climbing or scaling

✅ Nocturnal abnormal intrusion

✅ Illegal entry into restricted construction zones

This effectively enhances safety management during the construction phase.

3.4 Protection of Precision Equipment and Sensitive Areas

For factories involved in semiconductors, precision manufacturing, or laboratories, certain equipment is highly sensitive to vibration. The DAS system can perform high-sensitivity vibration monitoring around critical equipment for:

✅ Construction impact assessment

✅ Equipment operating environment monitoring

✅ Vibration limit exceedance alarms

This assists users in achieving parallel operation of construction and production safety during the renovation process.

4. Core Advantages of Applying DAS in Factory Building Renovation

✅ Construction-Friendly: Can utilize existing communication fiber or be installed concurrently, offering flexible deployment with minimal disruption to construction.

✅ Full-Lifecycle Monitoring: Applicable during the construction phase and extendable to long-term operational monitoring after the factory becomes operational.

✅ High Reliability: Fiber is passive and intrinsically safe, suitable for environments with strong electromagnetic interference or flammable/explosive hazards.

✅ High Data Value: Supports raw data and demodulated data output, facilitating in-depth analysis and system integration.

5. Application Value and Future Outlook

As new industrial facilities evolve towards intelligent, digital, and unmanned operations, DAS is gradually transitioning from an "auxiliary monitoring tool" to a fundamental sensing infrastructure.

In the context of new factory building renovation, DAS not only enhances construction safety and management efficiency but also lays a solid data foundation for future plant operation, asset management, and intelligent maintenance, offering significant economic and social value.

In the future, combined with AI-powered intelligent recognition algorithms, digital twin platforms, and multi-sensor fusion technologies, the application potential of DAS in the industrial facility domain will be further unlocked.