ANALISIS PERILAKU LENDUTAN STRUKTUR JEMBATAN LEMAH IRENG 1 AKIBAT PENGARUH METODE PELAKSANAAN KONSTRUKSI
FRISCA PRESTASIANA ANGGARINI, Dr. Ing. Ir. Andreas Triwiyono
2016 | Tesis | S2 Teknik SipilJembatan Lemah Ireng 1 merupakan salah satu jembatan pada Jalan Tol Semarang-Solo tahap 1 ruas Semarang-Bawen paket V (Tinalun-Lemah Ireng). Pembangunan jembatan dilakukan dengan Free Cantilever Method (FCM) dan Free Shoring Method (FSM). Pada masa konstruksi terjadi perubahan urutan perpindahan traveller dan perubahan material pasir dibandingkan perencanaan. Penelitian ini bertujuan untuk mengetahui lendutan struktur pada masa konstruksi akibat perubahan tersebut dan memberikan skema tahap pelaksanaan aktual. Dalam penelitian ini digunakan fasilitas Construction Stage Analysis dari program komputer Midas Civil 2011 Trial Version. Input dalam program Midas Civil hanya berupa geometri struktur jembatan, sifat material, beban yang bekerja selama masa konstruksi, dan skema pelaksanaan konstruksi. Perubahan urutan perpindahan traveller mengakibatkan proses closure pada setiap kantilever tidak serentak dilakukan, sehingga beberapa kantilever mengalami hanging. Kantilever yang mengalami hanging adalah FSM 1 (28 hari), P1R (191 hari), P4L (30 hari), P4R (71 hari), P6L (81 hari), dan P7L (146 hari). Hasil penelitian terhadap perilaku lendutan Jembatan Lemah Ireng 1 menunjukan bahwa bentang kantilever terpendek mengalami hanging paling lama (191 hari) dan memiliki nilai penurunan lendutan paling kecil bila dibandingkan kantilever lainnya yakni 1,185 cm. Sementara itu, bentang kantilever terpanjang mengalami hanging selama 71 hari dan memiliki nilai penurunan lendutan paling besar bila dibandingkan kantilever lainnya yakni 1,8013 cm. Panjang bentang kantilever mempengaruhi lendutan struktur jembatan segmental. Nilai lendutan maksimum secara keseluruhan di akhir konstruksi pada Jembatan Lemah Ireng 1 terletak di struktur FCM 4 segmen 12. FCM 4 memiliki jumlah segmen paling banyak, yakni 16 segmen. Nilai lendutan maksimum P4L di akhir konstruksi sebesar -11,2411 cm, sedangkan P4R sebesar -10,9175 cm.
Lemah Ireng 1 Bridge located in Semarang-Solo Toll Road stage 1 Semarang-Bawen segment package V (Tinalun-Lemah Ireng). The construction of the bridge was performed by using Free Cantilever Method (FCM) and Free Shoring Method (FSM). In the construction period, there were changes in sequence of traveller displacement and sand material changes compared to the design. This study aimed at identifying the deflection of structure in construction period due to the changes and providing the scheme of actual contruction stages. In this study, Construction Stage Analysis facility was employed from computer program Midas Civil 2011 Trial Version. The input of Midas Civil program was only the geometry of bridge structure, material features, working load during construction period, and the scheme of construction implementation. The changes of traveller displacement sequence made closure process in each cantilever not performed simultaneously, so that several cantilevers underwent hanging. Cantilevers underwent hanging were FSM 1 (28 days), P1R (191 days), P4L (30 days), P4R (71 days), P6L (81 days), and P7L (146 days). The result of study toward the deflection behavior of Lemah Ireng 1 Bridge showed that the shortest cantilever span underwent hanging the longest (191 days) and having the smallest decrease value of deflection when compared to other cantilever, that was 1,185 cm. Meanwhile, the longest cantilever span underwent hanging for 71 days and having the biggest decrease value of deflection when compared to other cantilever, that was 1,8013 cm. The length of cantilever span affected the deflection of segmental bridge structure. The maximum value of deflection thoroughly at the end of construction in Lemah Ireng 1 Bridge was located in FCM 4 structure segment 12. FCM 4 had the biggest number of segments, that was 16 segments. The maximum value of deflection P4L at the end of construction was -11,2411 cm, whereas P4R was -10,9175 cm.
Kata Kunci : balance cantilever method, construction stage analysis, Midas Civil, deflection in construction period.
