CASE STUDIES

BBCI FRIJWIJK

WRITTEN BY

Arjan Tabak

ENVIRONMENTAL MONITORING DURING CONSTRUCTION ACTIVITIES IN PERSPECTIVE THROUGH ANALYSIS OF HISTORICAL DEFORMATIONS

Johan Brouwers – Architectural Project Manager at BBCI Frijwijk

BBCI Frijwijk is a specialist firm in the field of structural and civil engineering inspections for construction and infrastructure projects. They focus on monitoring the environment during construction activities and use this information to provide advice on minimizing any damage and nuisance. To do this, they use a range of local measurement techniques such as noise measurements, vibration measurements, and total stations.

1. Eye for quality

Johan Brouwers works at BBCI Frijwijk as Construction Project Manager and is a certified Registered Expert. This makes him the first point of contact for the client during the entire project, from set-up to aftercare. Johan’s daily tasks include preparing complex plans and recommendations, directing project execution and supervising survey personnel. He also closely follows technological developments in the industry in order to find the right partners and expand BBCI’s services wherever possible. His goal is to relieve his clients as much as possible by minimizing damage and inconvenience in the project environment in the monitoring process. This customer focus is reflected in his eye for his clients’ budget, quality, and interests, often making him a full part of the internal project team.

“Sometimes I get calls asking if we can start measuring tomorrow.”

Environmental damage from construction work can easily run into the thousands to tens of thousands of euros.

2. Unknown starting situation for operations

Deformation measurements are an important aspect in environmental monitoring. BBCI offers this service in the form of levels, total stations and GPS, among others, and in this way can detect any deviations from the starting situation in a timely manner. Here, however, is a thorny issue. Monitoring is often a secondary consideration when planning a project, despite its great importance for risk management and dealing with any claims from the environment. As a result, BBCI is often not involved until relatively late in the process, leaving no clear picture of the situation before construction work begins. “Sometimes I get a call asking if we can start measuring tomorrow,” Johan says. “Construction is then often about to start.” This makes it difficult to separate the effects that occur as a result of the work from movements that were already underway at the site. And that while the cost of damage can range from several thousand euros (cosmetic damage) to several tens of thousands of euros (structural damage), a historical measurement archive could provide a solution, but this was hardly ever available before.

“With Sensar’s data, I can put the measured deformations during construction into perspective.”

Water leveling performed by BBCI Frijwijk on a property on the Mauritskade in Amsterdam.

3. Estimating project risks with InSAR.

It was in this capacity that BBCI Frijwijk came into contact with Sensar. Because of the availability of historical data, even from 1992 if necessary, our InSAR satellite measurements provide this much-needed measurement archive. “With the data from Sensar, I can put the measured deformations during construction into perspective,” says Johan. One of the projects BBCI and Sensar have collaborated on is the Mauritskade in Amsterdam. Here an old building was renovated and adapted for its future function as a hotel. In doing so, it was important that there were no significant disturbances in the busy built-up area, with various objects such as quays, bridges, hotels, and the Tropenmuseum. Thanks to our data, BBCI’s client immediately gained insight into the risks in the project’s surroundings, without having to wait a year for the results of a conventional monitoring campaign. This allowed construction to begin immediately, with insight into the limits within which the work had to remain for minimal impact on the environment. In addition, the InSAR dataset provided a broad view of the environment; due to the size of the satellite images, all objects within a radius of hundreds of meters around the project site can be measured easily and efficiently.

InSAR measurements on and around the building being renovated.

4. Construction without delay

Through its cooperation with Sensar, BBCI can now offer its clients a new technique, which allows a better local risk assessment of environmental effects, and immediate start of work. And at a lower cost than a conventional measurement campaign! Because of the local level, in most cases large complex measurements can be saved and intensive measurements only need to be made where necessary. This saves on the cost of (real-time) monitoring and possible claims. In addition, immediate action can also be taken in the event of any deviations, which minimizes inconvenience to local residents.