The Santos Port Authority (APS) has two bidding processes underway to contract for monitoring services: one for vibrations and the other for noise. For the first, the deadline for submission of proposals, opening of the bidding session, and start of price negotiations runs until Monday (29), while for the second, until the following day (30). Both contracts have a 36-month execution period. The evaluation criterion will be the lowest total price per lot.
According to APS, the contracted companies must conduct quarterly measurements at designated points — ten for vibration and 23 for noise — during both day and night, strictly following technical standards.
Vibrations generated by port traffic are measured with sensors (accelerometers) fixed to walls and floors of buildings. Noise is measured using sound level meters (also known as decibel meters) mounted on tripods at ground level in open areas.
“After each measurement campaign (every three months), the company will prepare detailed reports with an analysis of the results obtained, enabling the planning of measures to control noise or vibration levels, if these exceed the thresholds established in legislation,” said APS.
The consolidated monitoring results are retained by the Port Authority itself. They are submitted annually to the Brazilian Institute of Environment and Renewable Natural Resources (Ibama), the federal licensing authority, to prove compliance with the conditions of Operating License No. 2017, granted to the Organized Port of Santos.
Measurement values
For vibrations, the measured values must not exceed limits established in standards to prevent damage to buildings (DIN 4150-3) and to ensure human comfort (DD Cetesb /E and ISO 2631-2). The values vary depending on the type of building (e.g., hospital, residence, historic building) and the time of day (daytime or nighttime).
In the first standard, for example, limits range from 20 to 50 millimeters per second (mm/s) for commercial and industrial buildings; from 4 mm/s to 20 mm/s for residential buildings; and from 3 mm/s to 10 mm/s for vibration-sensitive buildings of high intrinsic value (historic).
For noise, corrected sound pressure levels must not exceed the limits of Brazilian Standard (NBR) 10151:2020. These vary according to the type of zone (strictly residential, mixed, industrial, etc.) and time of day. In predominantly industrial areas, for example, the limits are 70 dB (decibels) during the day and 60 dB at night.
What they are
Vibration is the oscillatory mechanical movement of solids (such as soil or buildings), which can damage structures or cause discomfort. It is measured in millimeters per second (mm/s) of peak velocity according to international standards. Noise, more commonly understood as sound pollution propagating through the air, must be monitored to ensure adequate levels that do not disturb the population. It is measured in decibels (dB).
Analysis ensures planning to maintain standards
In a statement, APS clarified that a single or a few measurements above the recommended limits do not, in themselves, constitute a problem. “Only from a historical series is it possible to analyze how noise and vibration levels behave in the study area.
From an analysis of the overall scenario, it is possible to plan and implement short-, medium-, and long-term measures to maintain noise and vibration levels within established standards,” the authority explained.
Monitoring has been carried out by the Port Authority for some time. The results, according to the agency, identified vehicle traffic on port roads and their surroundings as the main source of both noise and vibrations.
“In the effort to maintain levels within recommended standards, APS has implemented improvements to the port road system, gradually replacing cobblestone pavement with asphalt pavement, which is an example of a measure that can be applied to control both noise and vibration levels,” APS added.
Source: A Tribuna
