INNOVATIVE STRUCTURAL HEALTH MONITORING FOR BUILDINGS

INNOVATIVE

STRUCTURAL HEALTH

MONITORING FOR

BUILDINGS

SNAPSHOT

July 2020

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HOW CAN WE HELP PROTECT CRITICAL

ASSETS?

◼ Assess the impact of construction work on the structural

integrity of the building

◼ Enable permanent surveillance of the most worrying

structural defects and / or the building’s general structural

behavior

◼ Support safe construction and / or extension of the

building’s life

◼ Allow you to effectively design corrective actions during

constructions

◼ Ensure construction site safety and building serviceability

◼ Provide a one stop platform for building monitoring

requirements

Strictly confidential – do not reproduce without SGS written consent

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INTRODUCING INTELLIGENT 24/7 MONITORING

SIMPLE 5-STEP PROCESS

Equivalent to hiring a team of inspectors watching your building 24/7

providing you with data and root-cause analysis at a frequency rate of

your choosing

Sensor

Monitoring server

Data flow


Pre-inspection

AIMsight sensors

installation

Permanent

monitoring

Secure data acquisition

and data fusion

Analytics and

reporting

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WHY USE SGS AIMSIGHT TECHNOLOGY?

◼ Monitoring technology is the result of several leaps in sensor

design and data analytics: radical miniaturization of well

established NDT instruments and sensors; and optimized image

processing for accurate displacement detection

◼ Versatile: the chip-based solution is compatible with the most

relevant AIM sensors

◼ Dynamic NDT: more than a snapshot of an asset’s condition, the

technology tracks the evolution of structural behaviors and

defects, and their real-time response to stress events

◼ Certified IoT: advanced self-check features inspired by NDT &

certification procedures

◼ Multi-modal NDT: several parameters can be measured – crack

length and opening, temperature, stress, acceleration and

vibration, displacements – at selected frequencies


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WHAT IS AIMSIGHT TECHNOLOGY?

•Crack size, crack initiation

EMX – Eddy Current Array

•Vibration measurement, modal analysis

•Wire-break detection, impact detection

VIB – Seismic-grade Accelerometer

•Strain measurements, concrete crack gauges

•Load cells

ADS – Strain Gauges

•Displacement measurements, industrial sensors

ADI, ADV, ADD – Anlalog Sensors

•LIDAR vehicle counter

•Frequency measurements, rpm, encoders

MPP – Digital Sensors & I/O

•2D displacement measurements, site surveillance

Smart SHM Cameras

•Acoustic monitoring, falling debris, impact detection

Microphones

Cellular Master Node

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EStrictly confidential – do not reproduce without SGS written consent

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WHERE IS AIMSIGHT TECHNOLOGY USED?

◼ Civil structures:

▪ Buildings, Switzerland (equipped, live)

▪ Tunnel construction sites, Switzerland (equipped, live)

▪ Landslide, Switzerland (equipped, live)

▪ Railway bridges, Bern, Vaud & Graubünden, Switzerland (equipped, live)

▪ Highway / road bridges in USA, Germany, Switzerland (equipped, live)

◼ Oil & Gas:

▪ Offshore platforms, Italy (in preparation)

◼ Power:

▪ Hydropower penstocks, Switzerland (equipped)

▪ Rotary power machinery, Switzerland (R&D project in progress)

◼ Fatigue testing:

▪ SAIPEM: advanced welds (austenitic) for piping O&G

▪ EPFL: test of welds for metallic bridges

▪ University of Applied Sciences Geneva: power gen materials

▪ Purdue university: fatigue test on steel bridges components


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HOW CAN AIMSIGHT TECHNOLOGY BE

APPLIED TO MONITORING OF BUILDINGS?

◼ Solution 1: Building Deflections Tracking Camera

◼ Measurement of the motion, deflections and

deformations of the building at various levels, such as

ground settlement during during construction or in

service (basic service)

◼ Modal analysis (advanced use)

▪ Detection of stiffness changes (cracking, structural

damage)

▪ Detection of extraordinary wind and seismic loads

▪ Detection of foundation weakness

◼ Technical features:

▪ Alarms can be confirmed by human operator

▪ Edge-computing image-processing (optional)

• Limited bandwidth requirements


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APPLIED TO MONITORING OF TOWERS?

◼ Solution 2: Building Modal Analysis

◼ Acceleration measurement for modal analysis

▪ Detection of stiffness changes (cracking, structural

damage)

▪ Detection of extraordinary wind and seismic loads

▪ Detection of foundation weakness

▪ Confirmation of camera observation

◼ Technical features:

▪ Edge-computing

• On-site calculation of building velocities

• On-site calculation of building motion amplitudes


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◼ Combined solution 1+2: Edge Buidling Monitoring

Concept


Monitoring Data

Measurement

databaseEdge Processing

& Backup

Optional LTE ModemMachine Vision Camera

Optional Accelerometer▪ Highest performance

▪ Lower power requirements

▪ Lower bandwidth requirements

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◼ Combined solution 1+2: Edge Buidling Monitoring

Concept


Monitoring Data

Measurement

databaseEdge Processing

& Backup

Optional LTE ModemMachine Vision Camera

Optional Accelerometer▪ Highest performance

▪ Lower power requirements

▪ Lower bandwidth requirements

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Tunnel

CASE STUDY: GROUND SETTLEMENT,

SWITZERLAND

◼ Surveillance of ground settlement due to tunnel

construction with an autonomous solar system

◼ Low-cost passive markers affixed to existing structures

or to posts

◼ Live measurements of settlements confirmed by land

surveyor measurements

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HIGH-DENSITY MEASUREMENT NETWORK

40+ markers tracked with a single camera !

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ACTIONABLE

RESULTS

◼ Data shared with all stakeholders:

Experts, engineering firms,

construction company

◼ Web access to the data +

construction metadata such as

construction phases / events

◼ Detailed assessment of settlement

causes before reaching the built

zone

◼ Tunneling technique adapted based

on the findings in this zone

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CASE STUDY: GROUND SETTLEMENT,

SWITZERLAND

◼ Surveillance of building settlement due to tunnel

construction

◼ 10 houses & buildings under surveillance

◼ Autonomous solar system

◼ Live measurements of settlements confirmed by

certified land surveyor measurements

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ACTIONABLE

RESULTS

◼ Measurement of absolute and

differential settlement of each corner

of the buildings

◼ Work interruption and remediations

depending on the measured

settlements

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IN THE NEWS

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CASE STUDY: HIGHWAY BRIDGE

DISPLACEMENT, SWITZERLAND

◼ Surveillance of the displacement of bridge pillars,

retaining walls and street level during construction

work

◼ Mains-powered installation with UPS

◼ Ultra agile: 1 week from order confirmation to

installation

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ACTIONABLE MEASUREMENT RESULTS

◼ Web access

◼ Data shared with all stakeholders:

Experts, engineering firms,

construction company, railway

company, owner

◼ Measurement data compared with

calculation results

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MULTI-PURPOSE

◼ Dual-use: Displacement camera + construction site

intelligence

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CASE STUDY: TERRAIN STABILITY

MONITORING, SWITZERLAND

◼ Monitoring of the displacements of a

small penstock after a landslide

◼ Autonomous solar installation

◼ Active infrared lighting

◼ Edge processing and wireless data

transmission

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Position markers

◼ Easy to install

◼ Applied on existing structures or on posts

◼ Compatible with total station measurements

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◼ Georeferenced installation (markers and camera position)

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Displacements

Rainfall

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CASE STUDY: CUT-AND-COVER TUNNEL



Surveillance cameras

Slab deflection monitoring

Strain measurement on stringers

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INFRASTRUCTURE MONITORING: LONG-TERM

& DYNAMIC MEASUREMENT DATA


◼ Static mid-span deflection

◼ Dynamic mid-span deflection

◼ Accelerometer data

◼ Vibration due to traffic

◼ Modal analysis

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INFRASTRUCTURE MONITORING: CAMERA-

BASED DEFLECTION MEASUREMENT


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Blue: Location subject to traffic loads

Red: No loads (pedestrian area)



Daily thermal cycle


Deflection due to traffic stopped at the light

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CASE STUDY: HISTORICAL BUILDING



◼ Strain and temperature monitoring on all the steel pillars of the

southern façade

Example data:

Stress in the first pillar

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◼ Prestressed concrete slab vibration

monitoring

◼ Modal analysis

◼ Comparison with vibration standards

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◼ Prestressed concrete slab vibration

monitoring

◼ Modal analysis

◼ Comparison with vibration standards

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INFRASTRUCTURE MONITORING: SERVICE

LEVELS

Analysis LevelSe

rvic

e L

eve

lBasic

Basic sensor fee (setup)

Displacement processing fee (bundle for N monthly data points)

Dynamic

Basic sensor fee (setup)

Video processing fee (bundle for N video files with max. M data points)

Advanced

Project planning

Advanced sensor fee (setup)

Processing fee (bundle for N monthly data points)

Cloud:

Image collection is handled by a third-party

No AIMsight on-site technician intervention

Conventional monitoring, typically 24-100 points per day

Attractive if a video surveillance system is already in place

Higher bandwidth requirements

Potential reuse of existing surveillance camera system

Multiples tracking points and references per image

Edge:

AIMsight handles the image collection and processes the images, on site if necessary

AIMsight is the full service provider

Simple camera bundle

Lowest bandwidth requrements

Dynamic load measurements

Can operate with low bandwidth

Optional high accuracy mode with installation and calibration by an AIMsight technician

Tracking of complex motions

Difficult measurement scenarios


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OTHER CASE STUDIES & EXPERIENCE


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CASE STUDY: PILOT BRIDGE IN HAMBURG,

GERMANY

◼ Highway steel bridge

◼ Construction year: 1960

◼ Highly corrosive environment; significant dynamic loading

◼ Higher frequency of inspection needed to extend asset life

◼ 2013 vertical cracks discovered at the abutment cross

sections


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GERMANY

Location of monitoring sensors:


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GERMANY

Sensor PN EMXBA0

Sensor type 0001B_RECT_15X20_SHM

Sensor PS AD196N

Location on plan EQT HTC

Description Crack, with welded plate repair

Comment Installation on 30.05.18; tip of crack on sensor loop #2

Status (01.10.18) Sensor is live; no crack growth since installation

Sensor 1: EQT HTC

Before repair (2013)

Before and after installation of sensor (2018)

AIMsight‘s crack

monitoring sensors

measure initiation

and growth of

specific cracks


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CASE STUDY: PILOT BRIDGE IN FORESTPORT,

NEW YORK, USA

1 bridge server

4 crack gauges

1 LVDT displacement sensor

1 accelerometer

1 video camera

1 solar power supply


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Crack and LVDT sensors Connecting boxPower supply

CASE STUDY: PILOT BRIDGE IN FORESTPORT,

NEW YORK, USA


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CASE STUDY: BRIDGE USE MONITORING,

SWITZERLAND▪ Historical mountain railway viaducts, Switzerland

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SWITZERLAND

▪ Monitoring of the termal behaviour

▪ Dynamic monitoring approach: Dynamic measurements of

emergency braking tests and commercial trains

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SWITZERLAND

▪ Strain gauges on rails (48x)

▪ Strain gauge on bridge damping elements (8x total)

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SWITZERLAND

▪ Optical 2D displacement monitoring of rail ties

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SWITZERLAND

Strain gauges:

Strain in rails during emergency braking

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SWITZERLAND

Optical sensors:

Vertical mid-span displacement due to the passage of trains

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SWITZERLAND

Accelerometers:

Analysis of braking forces during emergency braking tests

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CASE STUDY: FATIGUE TESTS ON BRIDGE

ELEMENTS, PURDUE UNIVERSITY


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Dedicated asset monitoring platform:


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Dedicated asset monitoring platform:


Documents

INNOVATIVE STRUCTURAL HEALTH MONITORING FOR BUILDINGS