Pengaruh Beban Sejumlah Orang Bernyanyi Dan Berjoget Bersama Pada Struktur Lantai Gedung Berbentang Panjang (Studi Kasus Gedung Grha Sabha Pramana UGM)

Abstract

In a previous research carried out by the writer, a natural frequency of Grha Sabha Pramana's second floor is 4.7 Hz and shows that the building is not dangerous to take on the load of even up to 5000 people at graduation or wedding ceremonies held at the building. However, with the low natural frequency, does the building meet safety requirements for large numbers of people to sing and dance in? In this research, experiments were carried out on the same floor to obtain a frequency and displacement, by using 35 people to dance to songs of different frequencies. The experiment resulted in a frequency of 4.175 to 4.822 Hz and in the highest dynamic displacement of 3.31cm. This exceeds the allowed maximum displacement of 2.729 cm, while the numeric analysis displacement and calculation at graduations in the previous research reached a maximum of 2.6 cm. Also, there was great concern and uneasiness on the part of the observers and recorders at the time when 35 people were dancing, which resulted in a maximum displacement of 3.31 cm. The concern would rise in the case of increase in numbers of people dancing, to more than 1000 people, on the floor