"[
ABSTRAKAdanya peningkatan KLB (Koefisien Lantai Bangunan) pada daerah padat di
Jakarta, memungkinkan para pemilik gedung melakukan perluasan bangunan
secara vertikal dengan menambah struktur baja di atas struktur beton bertulang
eksisting. Seringkali sambungan rigid dipakai pada sambungan kolom dasar
struktur baja di atas struktur beton dengan mengasumsikan terjadi hubungan
menerus antara baja dengan beton. Pada kenyataanya asumsi ini belum tentu
benar akibat dari kemampuan sambungan sesungguhnya yang terbatas oleh
kapasitas dan kekakuannya. Sehingga asumsi tersebut perlu dievaluasi
kebenarannya demi menjaga perilaku struktur dan sambungan.
Untuk itu, penelitian ini melakukan evaluasi hasil perancangan sambungan rigid
pada dasar kolom baja dengan memodelkan sambungan menjadi pegas yang
menghubungkan struktur baja dan struktur beton. Kekakuan rotasi sambungan
dimodelkan secara non-linier untuk mendapatkan perilaku pasca leleh dari analisis
pushover. Kekakuan sambungan diperoleh dari konfigurasi sambungan hasil
perancangan yang melibatkan nilai overstrength factor (Wo) sesuai ketentuan
AISC 341. Pada penelitian ini terdapat 7 variasi kekakuan sambungan yang
didasarkan variasi Wo pada kombinasi gaya-gaya di sambungan dan mutu angkur
(Fu) pada nilai Wo tertentu.
Hasil penelitian menunjukkan penurunan besarnya kekakuan sambungan akibat
penurunan nilai Wo tidak mengurangi aksi sambungan rigid. Adanya variasi nilai
Wo pada perancangan sambungan rigid tidak berpengaruh langsung nilai R dan Wo
dari hasil pushover. Adanya variasi mutu angkur (Fu) juga tidak berpengaruh
signifikan pada perilaku struktur. Hanya sambungan yang didesain dengan Wo = 1
menunjukkan perilaku non linier dan dimungkinkan terjadinya gagal geser. Untuk
menjaga kekuatan di sambungan saat terjadi gempa di luar rencana pada struktur
dan menjamin agar sambungan tetap berperilaku elastik, sambungan perlu
didesain dengan menggunakan Wo minimal sebesar 1,5.
ABSTRACTAn increase in Floor Area Ratio (KLB) in dense areas of Jakarta, enabling
building owners to extend their building vertically by adding the steel frame
structures above the existing reinforced concrete structures. A rigid connection of
steel column bases above the concrete structures is often used by assuming a
continous joint between steel and concrete. In the fact, this assumption is not
necessarily true since the connection behaviour is limited to the capacity and
stiffnesses. This may lead to evaluate the assumption so the overall structural and
connection behaviour are controlled.
Therefore, this research evaluates the rigid connection design by modeling the
column base connections using spring connecting steel frame structures and
concrete frame structures. The non linear rotational stiffness of the spring is
modelled to obtain post yielding behavior from the pushover analysis. The
connection stiffnesses are provided from connection designs involving
overstrength factor (Wo) as prescribed in AISC 341. There are 7 connection
stiffness variations are built in this research based on Wo variations on loading
combinations and anchor grade variations (Fu) for certain value Wo.
The results showed a decrease in connection stiffness due to reduction value of Wo
independent to the connection rigidity actions. Variation of Wo in the rigid
connection design has no direct impact on the value of R and Wo from pushover
analysis. The anchor grade variations has no significant effect on the structural
performance. The non linear behaviour and possibility of shear failure of the
connections are happened only when using Wo = 1. The connections shall be
designed by minimum Wo = 1,5 to ensure the connection strength and the
connection behavior still remains elastically when a greater earthquake force is
subjected to the structure;An increase in Floor Area Ratio (KLB) in dense areas of Jakarta, enabling
building owners to extend their building vertically by adding the steel frame
structures above the existing reinforced concrete structures. A rigid connection of
steel column bases above the concrete structures is often used by assuming a
continous joint between steel and concrete. In the fact, this assumption is not
necessarily true since the connection behaviour is limited to the capacity and
stiffnesses. This may lead to evaluate the assumption so the overall structural and
connection behaviour are controlled.
Therefore, this research evaluates the rigid connection design by modeling the
column base connections using spring connecting steel frame structures and
concrete frame structures. The non linear rotational stiffness of the spring is
modelled to obtain post yielding behavior from the pushover analysis. The
connection stiffnesses are provided from connection designs involving
overstrength factor (Wo) as prescribed in AISC 341. There are 7 connection
stiffness variations are built in this research based on Wo variations on loading
combinations and anchor grade variations (Fu) for certain value Wo.
The results showed a decrease in connection stiffness due to reduction value of Wo
independent to the connection rigidity actions. Variation of Wo in the rigid
connection design has no direct impact on the value of R and Wo from pushover
analysis. The anchor grade variations has no significant effect on the structural
performance. The non linear behaviour and possibility of shear failure of the
connections are happened only when using Wo = 1. The connections shall be
designed by minimum Wo = 1,5 to ensure the connection strength and the
connection behavior still remains elastically when a greater earthquake force is
subjected to the structure, An increase in Floor Area Ratio (KLB) in dense areas of Jakarta, enabling
building owners to extend their building vertically by adding the steel frame
structures above the existing reinforced concrete structures. A rigid connection of
steel column bases above the concrete structures is often used by assuming a
continous joint between steel and concrete. In the fact, this assumption is not
necessarily true since the connection behaviour is limited to the capacity and
stiffnesses. This may lead to evaluate the assumption so the overall structural and
connection behaviour are controlled.
Therefore, this research evaluates the rigid connection design by modeling the
column base connections using spring connecting steel frame structures and
concrete frame structures. The non linear rotational stiffness of the spring is
modelled to obtain post yielding behavior from the pushover analysis. The
connection stiffnesses are provided from connection designs involving
overstrength factor (Wo) as prescribed in AISC 341. There are 7 connection
stiffness variations are built in this research based on Wo variations on loading
combinations and anchor grade variations (Fu) for certain value Wo.
The results showed a decrease in connection stiffness due to reduction value of Wo
independent to the connection rigidity actions. Variation of Wo in the rigid
connection design has no direct impact on the value of R and Wo from pushover
analysis. The anchor grade variations has no significant effect on the structural
performance. The non linear behaviour and possibility of shear failure of the
connections are happened only when using Wo = 1. The connections shall be
designed by minimum Wo = 1,5 to ensure the connection strength and the
connection behavior still remains elastically when a greater earthquake force is
subjected to the structure]"
