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Asia Noise News Building Acoustics Environment Industrial Vibration

Building Vibration Limits in Indonesia

A lot of activities and businesses have the potential to have negative effects to their environment because of the vibration that they produce. For example, construction (for example during piling), mining and and other vibration-generating activities. This vibration can disturb the comfort and health of people around it, and even can have destructive effects to nearby buildings.

In Indonesia, the vibration limit is regulated through Ministerial Decree of Ministry of Environment No. 49 Year 1996. This regulation was made to ensure healthy environment for human and other living creatures to live in. Consequently, the vibration generated from human activities need to be regulated.

In this regulation, businesses and activities are required to:

  1. Comply to the vibration limit in the decree. This is required for businesses and activities to obtain certain relevant permits to be able to operate.
  2. Use vibration reduction equipment
  3. Report vibration monitoring activities at least once in 3 (three) months to the Governor, Minister, Government agencies that are responsible to control environmental impact, other technical institutions that is responsible for the activities and other organizations that might need the vibration monitoring report.

The vibration limit is separated into few parts which are:

  1. Vibration limits for health and comfort
  2. Mechanical vibration limits based on its destructive effects
  3. Mechanical vibration limits based on building types
  4. Shock limits

The following table and graphs is the vibration limit for health and comfort:

Conversion:

Acceleration = (2πf)2 x displacement

Velocity = 2πf x displacement

The graphic representation of the table above is as follows:

The table below is the vibration limits based on the destructive effects:

As seen above, the peak velocity limit from the vibration is separated into 4 categories which are:

  • Category A: non-destructive
  • Category B: Possibly destructive for plastering (crack, or in certain cases the plaster can fell off the wall) 
  • Category C: Possibly destructive for structural components that bear loads
  • Category D: High risk of destruction of load bearing walls

The following graph is the vibration limit based on destructive effects in a graphical form:

Mechanical vibration limit can also be categorized into the types of buildings. The buildings are categorized into 3 which are:

  1. Buildings for commercial, industrial, and other similar use.
  2. Residential and other buildings with similar design and usage
  3. Structures that are sensitive to vibration and cannot be categorized into category 1 and 2, for example preserved buildings with high cultural value

Below is the vibration limits for the building category above:

The table below is shock limit for buildings:

CategoryBuilding TypeMaximum velocity (mm/s)
1Old buildings with high historical value2
2Buildings with existing defects, cracks can be seen on the walls5
3Buildings with good condition, minor cracks on plaster is acceptable10
4Buildings with high structural strength (for example industrial building which is made from concrete and steel)10 – 40

The ministerial decree also describe the measurement and analysis method for vibration as follows:

  1. Instruments:
    1. Vibration transducer (Accelerometer or seismometer)
    2. Vibration measurement device or analysis device (Vibration meter or vibration analyzer)
    3. 1/3 octave or narrow band filter
    4. Signal recorder
    5. FFT Analyzer
  2. Measurement procedure:
    1. Vibration measurement related with health and comfort:
      • Place transducer on the floor or other vibrating surface, and connect it to the measuring device with filtration
      • Set the measuring instruments to measure displacement. If the measuring instruments do not have that on display, the conversion from acceleration or velocity can be used
      • Reading and recording is conducted for frequency between 4-63 Hz or with signal recording device
      • Measurement results with at least 13 data shall be plotted on graph
    2. Vibration measurement for structural health:
      • The measurement method is similar with the vibration measurement above, however the physical measure that is assessed is the peak velocity.
    3. Evaluation
      • The 13 data which are plotted on graph shall be compared with the vibration limits. The vibration is considered above the limit if the vibration level exceeds the limit at any frequency.

Definition

The definition used in the regulation of ministry of environment No 49 Year 1996 is as follows:

  1. Building structure is a part of building that is planned, calculated, and functioned to:
    • Support any kind of load (static load, dynamic load, and temporary load)
    • Functioned for building’s stability as a whole. For example: frame and bearing wall
  2. Structure’s component is a part of a building structure that contributes to structure’s function. For example: beams, columns, and slab.
  3. Bearing wall is a building structure which is a vertical plane that is functioned to support loads on top of it such as slab or roof.
  4. Non-structure components are parts of building that is not planned or functioned to support load. For example partition walls, door and window frames, etc.

Destructive impact on structure and non-structure:

  1. Destructive impact on structure: Destructive impacts that can endanger building stability (for example destruction of columns that potentially make a building collapses)
  2. Destructive impact on non-structure: Not dangerous to building stability, but can be a danger for building occupants (for example: when a partition wall collapses, it will not make the building collapse, but can injure occupants)

Degree of building destruction:

  1. Light: not dangerous for building stability and can be fixed without reducing building’s strength
  2. Moderate: Destruction that can reduce structural strength. To fix this, added reinforcement must be used.
  3. Severe: Degree of destruction that can endanger the building and potentially makes the building collapses.

Written by:

Hizkia Natanael
Acoustic Engineer
Phone: +6221 5010 5025
Email: hizkia@geonoise.asia

Categories
Asia Noise News Building Accoustics

Noise and Vibration Monitoring for Construction Sites

In a densely populated city like Bangkok, most of the construction projects are surrounded by condominiums, offices or residential areas. The construction sites must control the noise and vibration that may affect the surroundings. Construction sites need to control the noise and vibration levels that they produce following the EIA standard.

To manage this, noise and vibration instruments are installed which automatically will send alarms to the construction company if the thresholds are exceeded.

Noise Monitoring Station

Sound level meter class 2 according to IEC61672-1 standard which can collect the data of SPL, LEQ and LMAX. These instruments are calibrated before they are installed at a construction site. The system has a LED display and warning light when noise levels in the site are over a trigger level, which is referred to in the standards for maximum sound levels around construction sites.

According to the announcement of National Environment Board no.15 BE.2540 (1997) in the topic of “Standard loudness”, the average sound 24 hour must not exceed 70 dBA and the maximum peak level must not exceed 115 dBA.

Sound level meter are designed to be used outdoors and an additional LED display was added by Geonoise which is a professional sound and vibration company. Sound level meter with LED display also can analyse the loudness in percentile (Statistical,Ln) or analyse the frequencies in 1/1 and 1/3 octave bands. In addition to storing vibration data, you can also create level notifications in Alarm Alert format before vibration levels exceed the standard value for monitoring the activities being performed.

Vibration Monitoring

In the construction industry, transportation Industry and most large industries vibrations will occur.
High vibration levels will cause structural damage to buildings, bridges, structures as well as nuisance or health risks to occupants in exposed (residential) buildings.

Therefore, it is necessary to comply with the standard of vibration in a building according to the Announcement of the National Environment Board Announcement No. 37, BE 2553 (2010) Re: Determination of Standard Vibration to Prevent Impact on Buildings and the measuring instruments need to comply with DIN45699-1.

At construction projects in Bangkok, most cause a lot of unwanted noise and vibrations. Vibration caused by construction projects are caused by piling work as well as the increased traffic of large trucks that enter and exit the construction site. To prevent that vibration levels will be exceeded, a vibration monitoring system will have to be installed.

The Announcement of the National Environment Board No. 37, BE 2553 Vibration standards to prevent impacts on buildings is the main regulation to comply with for construction sites in Thailand. The vibration standards are derived from DIN 4150-3 whereas buildings are classified into 3 types.

Building types according to DIN 4150-3:

  • Type 1 buildings such as commercial buildings, public buildings, large buildings, etc.
  • Type 2 buildings such as residential buildings, dormitories, hospitals, educational institutions, etc.
  • Type 3 buildings, such as archaeological sites or buildings that cultural values but not strong, etc.

In addition to storing vibration data, you can also create level notifications in Alarm Alert format before vibration level exceed the standard value for monitoring the activities being performed.

Categories
Asia Noise News Building Accoustics

Exploring Jakartan Public Transportation Through The Sound

Jakarta, the capital city of Indonesia, is home to 10 millions of Indonesia population. Recently the Indonesian government is being sued by a group of activists and environmentalists due to the unhealthy air quality in Jakarta. The plaintiff hopes that through the lawsuit, the Indonesian government can improve existing policies to address the air pollution issues.

On 18 Jul, according to the Switzerland-based pollution mapping service AirVisual, the Air Quality Index (AQI) of Jakarta is 153, categorized as unhealthy and may cause increased aggravation of the heart and lungs. The recommendation upon this condition is to wear a pollution mask and use air purifiers inside the room. The AQI Measures five criteria air pollutants (particulate matter, sulphur, dioxide, carbon monoxide, nitrogen dioxide, and ozone), and converts the measured pollutant concentration in a community’s air to a number on a scale of 0 to 500.

Air Quality Index – AirVisual

Jakarta is one of the largest urban agglomerations in the world. The uncontrolled increase in urban population is proportional to the number of the vehicle in Jakarta. According to Badan Pusat Statistik (Statistics Indonesia), the growth of motorized vehicle in Jakarta is 5,35% every year, on the other hand, this growth will increase the number of pollution in Jakarta. This statement is supported by the acting head of Jakarta Environment Agency, Andono Warih, the fuel residue of motorized vehicles was the main contributor to severe air pollution as 80 per cent of vehicles powered by diesel fuel operated from Jakarta Greater Area (Jabodetabek) to the capital.

Jakartan can contribute directly to overcome air pollution issues. Public transportation is an environmentally friendly mode of getting around. Because public transportation carries many passengers on a single-vehicle, thus it can reduce the number of vehicles as well as reducing the number of emissions from transportation in a dense urban area. Further, public transportation can help Jakarta to reduce the smog, to meet air quality standards and to decrease the health risk of unhealthy air quality. 

The urban transportation system in Indonesia consists of buses, trams, light rail, metro, rapid transit and ferries. Particularly in Jakarta, urban rail-based transportation, such as Commuter Line Train, Light Rail Transit (LRT) and Mass Rapid Transit (MRT), provides mobility and access to the urban area.

MRT Jakarta Phase 1 – MRT Jakarta

The first phase of MRT Jakarta (MRT-J) has been operating since March 2019. In daily operation, the train runs from Lebak Bulus Grab Station to the Bundaran HI Station. There are 13 stations along the railway; the underground stations are Bundaran HI, Dukuh Atas BNI, Setiabudi Astra, Bendungan Hilir, Istora Mandiri, and Senayan Station. Meanwhile, the overground stations are ASEAN, Blok M, Blok A, Haji Nawi, Cipete Raya, Fatmawati, and Lebak Bulus Grab Station. The MRT-J only needs 30 minutes to travel along the 16 kilometres railway, starting from Lebak Bulus Grab Station in South Jakarta to the Bundaran HI Station in Central Jakarta.

There are 16 train lines available to take the passengers getting around. Based on the MRT-J website, In weekdays operation, the trains operate at 05.00 WIB to 24.00 WIB with a total of 285 trips. Meanwhile, in weekend operation, the trains run at the same hour with a total of 219 trips.

During the promo operation (1 April – 12 May), the average number of daily passengers reached 82,643, whereas after the full tariff was applied, the average per day was 81,459.

The following pictures will show you the scenes of MRT Jakarta.

So what do you think? Have you tried getting around using MRT Jakarta? If you have never, try immediately and feel the different sensation of Public Transportation in Indonesia.

Further, through this article, I would like to invite you, explore the MRT Jakarta through a different perspective, that may be for a group of people this method is still rarely used, a sound.

Do you realize that sound can tell us about character, place, and time? Sometimes, it informs us in ways visuals can’t, and that is the idea of what we are going to do right now. Later you will hear, a file of recorded sound of MRT-J in its daily operation.

The sound was recorded by the soundwalk method, any excursion whose primary purpose is listening to the environment. It is exposing our ears to every sound around us no matter where we are. We may be at home, walking across a downtown street, or even at the office. Meanwhile, in this case, our environment is inside the line of MRT Jakarta. The goal is to capture any sound sources that exist during the operation of MRT-J, including the activity of the passengers.

The sound was recorded by using a mounted microphone on the iPhone X at a level of 1.2 m above the ground. The following sound is a recorded environment while the MRT-J was travelling from Bundaran HI Station to Setiabudi Astra Station, the duration of recording sound is 4 minutes and 40 seconds. Please use an earphone or any similar devices to listen to the audio for a better experience.

Caution: please set the volume around 50 – 70 % of the maximum volume.

After listening to the sound, can you identify what sound sources are presented in the recording? Here are the sound sources that I have identified:

  1. Engine sound increases speed
  2. Public Address system
  3. Engine sound
  4. Rail friction
  5. Passengers’ activities (cough, sneeze, conversation, footsteps, etc.)
  6. The sound of the door opening
  7. Brake squeak

Now we have identified the sound sources that are presented in the recording. But, do you know how many decibels that I have to endure while travelling using the MRT-J? In this article, manual measurements of noise levels were performed with a sound level meter in the MRT Jakarta with passengers on its usual route. A-weighted sound level measurements were recorded directly from one station to the next during the time between 08:00 and 09:00, using a calibrated microphone on a stand at a level of 1.2 m above the ground. The results of equivalent continuous A-weighted noise levels Leq (LAEq) in the MRT-J with passengers on its usual route from one station to the next is shown in Chart 1. 

Leq is the A-weighted energy means of the noise level averaged over the measurement period. The results from the measurements show that the A-weighted noise level is varied between 77 dB to 82 dB. Further, if we look closely into the Chart, the noise level is fluctuating. It can be caused by a lot of factors, such as: 

  1. The position of MRTJ (When MRT-J inside the tunnel, the noise can be levelled up due to the reflection phenomenon).
  2. Speed (The machine indicates producing a higher noise when in the maximum speed).
  3. Path Crossing.
  4. The Public Address System Volume.

Moreover, the level of continuous noise in Chart 1 represents a quite noisy environment. According to The National Institute on Deafness and Other Communication Disorders, states that Long or repeated exposure to sound at or above 85 dB can cause hearing loss. Thus, according to the measurement results, I suggested you wear ear protection during commuting by MRT-J. The earplug is one of the equipment that we can use to protect our hearing; you only need to spend a few thousand rupiahs for this. Wearing earplugs can help you to reduce the noise by 18 – 34 dB, it depends on the models/brand. For more accurate results, we need to do a complex measurement, such as:

  1. Add measurement point (In this article, the measurement was done only in a measurement point, at the second car of the line).
  2. Add a velocity as a measured parameter.
  3. Add the measurement time; the measurement can be done during the operation hour, non-stop. (05:00 – 24:00 WIB).

Nonetheless, the idea of showing the measurement results is spreading noise awareness. Noise sticks with you around, even common sounds you hear at work or home can contribute to long term hearing loss and other health risks, they are everywhere, but only a few people are aware of it. Noise pollution is a health threat nobody is talking about. Here are some parameters to help you determine acceptable — and dangerous — noise levels:

  • 45 dB: nightly noise ordinance threshold set by many municipalities concerned with industrial noise exposure for residents
  • 65 db+: exposure for prolonged periods can cause physical and mental fatigue
  • 85 dB+: can cause permanent hearing loss if exposed for extended periods
  • 85-120 dB: dangerous over 30 minutes of exposure
  • 120-130 dB: can cause permanent hearing loss for exposure over 30 seconds
  • 130 dB+: not only are these noises painful, but hearing protection should always be used if avoidance is not possible.

Everyone needs to take care of their ears and hearing, as damage to the auditory system could be irreparable. The loss because of the noise exposure is gradual; you might not notice the signs, or you ignore them until they become more apparent. Please do protect your ears. 

Reference:

https://www.theguardian.com/world/2019/jul/02/jakarta-residents-to-sue-government-over-severe-air-pollution

http://support.airvisual.com/knowledgebase/articles/1185775-what-is-aqi

https://doi.org/10.1016/j.ecss.2018.10.017

https://jakarta.bps.go.id/publication/2018/10/03/cb1285d8dbe8be8754a5830d/statistik-transportasi-dki-jakarta-2018.html

https://en.tempo.co/read/1214627/jakarta-air-pollution-mostly-caused-by-motorized-vehicles-agency

https://www.nationalexpresstransit.com/blog/why-is-public-transportation-good-for-the-environment/

https://www.businesstimes.com.sg/asean-business/indonesia-accelerating-urban-transportation-development-with-public-private

Westerkamp, Hildegard (1974). “Soundwalking”. Sound Heritage

https://www.ncbi.nlm.nih.gov/pmc/articles/PMC5308171/

https://www.sensear.com/blog/noise-is-everywhere-how-to-deal-with-it-does-it-create-a-dangerous-environmenthttps://www.womenshealthmag.com/health/a19599097/noise-pollution/

Categories
Asia Noise News

Hong Kong, construction noise, fines !

Hong Kong (HKSAR) –      The main contractor and sub-contractors of the construction works at Queen Elizabeth Hospital caused noise nuisance by conducting works during holidays. They were convicted and fined a total of $60,000 at Kwun Tong Magistrates’ Courts today (October 26) for contravening the Noise Control Ordinance (NCO).

A spokesman for the Environmental Protection Department (EPD) said that the department received a public complaint this April against construction works being carried out during holidays at Queen Elizabeth Hospital, Yau Ma Tei. EPD staff hence conducted a surprise check at a construction site in the hospital on a Sunday, and found a worker carrying out construction works using an electric grinder.

The emitted noise affected hospital users as the construction site was only 20 metres away from Block D of the hospital. In addition, the contractor and its sub-contractors did not possess a valid Construction Noise Permit (CNP). The EPD subsequently initiated prosecutions against the main contractor and its sub-contractors of the construction works under the NCO upon completion of evidence collection.

According to the NCO, anyone who uses powered mechanical equipment for construction works or carries out prescribed construction works (such as handling debris or hammering) in a designated area during restricted hours (between 7pm and 7am the next day on weekdays or any time on a public holiday) shall apply for a CNP.

The construction works shall commence only when the CNP has been granted upon completion of assessment to support that its noise level would comply with regulatory requirements. First-time offenders are liable to a maximum fine of $100,000. A maximum fine of $200,000 may be imposed on second or subsequent convictions.

hong kong construction noise fines
hong kong construction noise fines

The spokesman reminded members of the construction sector that they should manage and arrange their works properly.

They should neither use powered mechanical equipment nor carry out prescribed construction works in a designated area during restricted hours. Even with a valid CNP, they should carry out works in strict accordance with the permit, and should also adopt practicable noise mitigation measures, including the erection of fences and noise barriers at the sites, to reduce the impact of noise on the public nearby as far as practicable.