The Meteorology, Climatology, and Geophysics Agency reported that there would be 10,789 earthquake activities in Indonesia in 2023. This number is beyond the annual average of 7,000 earthquakes. Of the total number of earthquakes recorded, earthquakes felt by the public occurred 861 times, 24 of them causing significant damage to buildings, mainly residential homes.
“There is a saying it is not the earthquake that is deadly, but rather the failure of the building structure to withstand the seismic loads produced by the earthquake. Indonesia, often affected by seismic activity, faces serious consequences like damage to building structures, especially housing,” said Dr. Dipl.-Ing. Nuraziz Handika, S.T., M.T., M.Sc., Lecturer in the Department of Civil Engineering, Faculty of Engineering, University of Indonesia.
He added that earthquakes induce physical vibrations in buildings and reveal deficiencies in design and construction aspects. These weaknesses compromise structural integrity and increase the risk of fatal damage to the building during an earthquake.
Taking the 2018 Lombok earthquake as an example, Dr. Nuraziz Handika highlighted the problem of detailed reinforcement and connections in buildings, which is one of the biggest causes of damage to building structures. According to him, the quality of building materials, detailed reinforcement, and connections in walls, columns, and beams are the main factors that cause damage and collapse of public facilities, social facilities, residential houses, and other simple buildings when hit by an earthquake.
“To make a building earthquake resistant, it is necessary to pay attention to aspects, such as connections, selection, and preparation of materials before use, details of reinforcing work, anchoring of walls to columns, details of column beam reinforcement, and other things so that they comply with standards. For example, an appropriate anchorage length is required at the connection between the column and the sloof beam, where the column reinforcement at the top and bottom/column foundation should be larger than at least 40 times the diameter,” said Dr. Nuraziz.
Dr. Nuraziz, a lecturer in structures with a research concentration on the phenomenon of cracking and damage to construction materials, revealed that the standard used as a reference is issued by the Ministry of Public Works and Public Housing. Many posters have been made to make it easier for implementers to follow, referring to these standards, which can be downloaded at the link https://teddyboen.com/publications_id.html.
Dr. Nuraziz gave a good example of calculations regarding steel anchors for columns and brick walls to make it easier to understand. He said, “In this case, if the diameter of the reinforcement used is 10 mm, then the minimum length of anchorage should be 40 cm to the right and to the left of the corner of the building. This anchorage is applied to every six layers of brick. Next, iron anchors are cast on the bricklayer as a binder between the column and the wall. In this way, the connection or anchor will comply with the established standards.”
The same principle also applies to joints at mountains (roofs) and wall corners. Proper anchoring is required on the columns in the middle of the wall that connects to the roof gable triangle and on the columns that meet the corner of the wall.
Dr. Nuraziz said that to make a building earthquake-resistant, there are several basic requirements, including good quality building materials, the presence of appropriate structural dimensions, good connections to the main structural elements, and good quality work. It should be noted that this work is not visible to the naked eye and will only be tested when an earthquake occurs. Therefore, comply with the processes and standards in building construction to maintain our collective safety,” said Dr. Nuraziz, a doctoral graduate of the Institut National des Sciences Appliquées de Toulouse, France.
Meanwhile, the Dean of FTUI, Prof. Dr. Heri Hermansyah, ST., M.Eng., IPU said, “In facing the threat of earthquakes that often hit Indonesia, we need to know how the construction of the buildings we live in can provide optimal protection for its occupants. Implementing earthquake-resistant construction principles, such as selecting appropriate materials, strong structural connections, and design that considers vulnerability to shaking, is key in efforts to protect homes from the damaging impacts that may arise from earthquakes.”
