Freyssinet Total Technology has successfully conducted an important seminar on 25th October 2018 in Hotel Grand Sheraton – South Jakarta. The Seminar was organized in collaboration with FPC ITALIA, HPJI (Himpunan Pengembangan Jalan Indonesia/Association of Indonesian Road Development) and HAKI (Himpunan Ahli Konstruksi Indonesia/Indonesian Association of Civil and Structural Engineering). All the participants were invited exclusively by Freyssinet, HPJI, and HAKI. A total of 162 important attendees from Consultant/Designer, Contractor, Public Works Department, Aviation Expert, Developers, and many more were listed in the participant list on the day of the seminar.
This Seminar was highly anticipated by all the attendees because Indonesia has just recently suffered 2 major earthquakes in Lombok and Palu-Sulawesi in the last three months. In the beginning of August 2018, a 6.9 Mw magnitude earthquake hit Lombok and caused 563 people died. The last one, on 28th September 2018, a strong earthquake and tsunami happened in Palu and Donggala in Sulawesi Island. This particular earthquake caused 2.256 people died, 10.679 people injured, and 1.075 people missing. With such a catastrophic effect from those two earthquakes, such earthquake related topic has been listed as a national concern. The Seminar was expected to provide different perspectives on how to answer such demanding earthquake issue in Indonesia.
The Seminar was opened by Freyssinet Total Technology’s Managing Director, Mr. Vincent Bernier. Through his opening speech, Mr. Bernier addressed the importance of having seismic protection system in the structure, from the extra safety benefit, better structural performance, until the cost benefit from the global cost perspective.
The opening speech was continued by Ir. Iwan Zarkasi, M.Eng.Sc, the Leader of Association of Indonesian Road Development (HPJI) and the Director of Bridge Engineering in Directorate General of Indonesian Highways (right side), he mentioned the importance of this type of seminar to give awareness and education to the technical practitioners and structural users in Indonesia. Mr. Zarkasi also reminded all the attendees to have a better understanding of an anti-seismic structure. And he added that as the consequence of Indonesia’s geographical location, it is a fate for Indonesian people to deal with such heavy earthquake potential in most of Indonesian regions.
Prof. Ir. Iswandi Imran MA.Sc., Ph.D, the Head of Research Center for Disaster Mitigation Institute Technology Bandung opened up the technical presentation session. As the Keynote speaker, Prof. Imran delivered an important message on how the Indonesian Design Code would react to such a high earthquake potential. Prof. Imran described the development of the recent seismic map in Indonesia from 2002, 2012, until the recent 2017. It is worth mentioning that the new seismic hazard map 2017 has been updated with a detection of 295 active faults while the previous 2012 map was made with only 95 active faults detected. This 2017 seismic hazard map and the new under-development seismic design code are indicating higher seismic risk in most of the regions in Indonesia and more stringent seismic design requirements for structures in Indonesia.
Prof. Imran also presented the two common approaches of seismic design according to the new under-development Indonesian seismic design code which probably will be released on 2019. Conventional ductility approach and base isolation method were evenly discussed in order to give a better comparison between these two approaches. Strengths and weaknesses of each approach were pointed out, letting the Structural Users to decide in which method is more favorable for them. An experience from the previous Lombok and Sulawesi earthquakes was also discussed, highlighting the importance of fundamentals structures such as hospitals, airports, and essential bridges to be still in operation after earthquake. Seismic isolation systems in such fundamental structures can be a better solution to solve the issue.
The technical session was continued with another presentation by Tri Suryadi ST, MT . In his capacity as the ISOSISM Seismic Division Manager of Freyssinet Total Technology, Mr. Suryadi presented 3 different methods of seismic analysis for isolated structures. Simplified Single Degree of Freedom Analysis, Linear MDoF Response Spectrum Analysis, and Nonlinear Time History Analysis are the 3 calculation methods that were presented briefly to the audience. The presentation was ended with some references of seismic isolation system applications in buildings, bridges, industrial structures, and seismic retrofitting in existing buildings.
Ir. Tony Budianto Sihite, MT. the Director of Delta Global Structure presented the application of Seismic Isolation System in his on-going Jakarta-Cikampek Elevated Toll Project. Known as one of the most prestigous infrastructure projects in Indonesia right now, JAPEK Project utilizes 1448 Pcs LRB supplied by Freyssinet as the bearing Isolators. It is proven in this project that the use of seismic isolation system reduces more than 70% of elastic earthquake force and enables the designer to obtain cost saving and constructability requirement due to size reduction of piers and foundations.
Mr. Sihite’s presentation ended the morning technical session, all the speakers were invited to receive appreciation souvenirs prepared by the Seminar Committee. Mr. Vincent Bernier himself handed out the souvenirs to the speakers and moderator as the appreciation to their contribution in the Seminar.
The afternoon technical session started with a comprehensive presentation by Stefano Barone, M.Eng., M.Sc. As the R&D Engineer from FPC ITALIA, Mr. Barone presented a complete explanation of the Seismic Isolation Concept and all the Seismic Protection Devices characteristics and functions. Devices such as High Damping Rubber Bearing, Lead Rubber Bearing, Pendulum System Bearing, Shock Transmission Unit, Fluid Damper, Prestressed Damping Spring, and Displacement Dependent Device (DDD) were individually presented to the audience. At the end of the presentation, Mr. Barone also presented the capability of Freyssinet’s Internal Laboratories in Milano – ISOLAB.
The technical session continued with a presentation from Dr.Ing. Josia Irwan Rastandi, ST. MT. As an Earthquake Engineering Lecturer in Universitas Indonesia and Principal of PT. Risen Engineering Consultant, Dr. Rastandi presented a comparative study of fixed based and isolated structure of an “L” shaped building according to ASCE 7-16. From the study, he revealed that the use of isolation system generates much smaller inter story drifts of the building that reflects un-damaged nonstructural elements inside the building. Having a better performance level on the building with base isolation system, it also shown that this system leads to cost saving in the volume of rebars and concrete.
At the last technical session, Ir. Budi Santoso, MT. presented the application of seismic isolator bearing in Kali Kenteng Bridge. Mr. Santoso is the Director of PT. Pratama Daya Cahya Manunggal, a well-known consultancy company of bridges design in Indonesia. In his presentation, it was revealed that the original design of the project was not using any seismic isolation devices. Mr. Santoso as the design reviewer proposed Lead Rubber Bearings as the isolators to reduce high demanding earthquake force on the originally designed substructure. And with this isolation system, the project can be still running without too much delay due to excessive strengthening if the conventional design is maintained.
Most of all the participants stayed until the end of the Seminar. A very pleasant and constructive atmosphere was shown during the Seminar. Freyssinet Total Technology has received many feedbacks and queries from the participants during and after the Seminar. Through this Seminar, Freyssinet would like to convey a better understanding and awareness of an anti-seismic system in the structures to all the design practitioners, contractors, owners, and structural users. With this being said, we would like to send our gratitude and appreciation to all the participants, moderators, presenters, and especially to HPJI and HAKI for all the positive feedbacks and contributions to this Seminar.