12 research outputs found
Corrosion Effects on the Mechanical Properties of Spun Pile Materials
No full textPrestressed concrete piles with closed-ended circular hollow sections (spun piles) are sometimes used as foundations for pile-supported wharves. Due to a reduction in the rebar area, concrete compressive strength, yield strength of PC-bar, and bond strength between PC-bar and concrete, corrosion attacks typically lower the performance of spun piles in the marine environment. A comprehensive analysis of the corrosion effect on the mechanical properties of the spun pile materials is crucial to assess the performance of corroded spun plies. Using a three-dimensional finite element analysis (FEA), this study aimed to evaluate the impact of corrosion on the mechanical properties of the material used in spun pile construction. We simulated the effect of nonuniformly distributed corrosion products using a volumetric strain expansion over 0–75 years. The FEA results provided the stress–strain relationship of the corroded spun pile materials and the bond–slip relationship between the corroded PC-bar and concrete. We proposed equations for predicting the deterioration degree of the mechanical properties of corroded spun pile materials and compared them to those presented in previous studies. It was shown that the compressive strength of the corroded cover concrete decreased significantly after the corrosion degree reached 12%, which the previous research had not expected. The bond strength reduction was inverse exponential against the elapsed years after the corrosion degree reached 1.3%. Moreover, the yield strength of PC-bars decreased linearly with the increase in the corrosion degree
Simplified Method for Nonlinear Seismic Response Analysis of Corroded Pile-Supported Wharf
No full textFiber-based finite element analysis (FB-FEA) has been widely recognized for its ability to reproduce experimental results and is also a reliable method for evaluating the nonlinear seismic response of pile-supported wharves (PSWs). Design practice often employs frame analysis (FA) due to its easy implementation. To precisely reproduce the nonlinear seismic response of PSW using FA, it is necessary to configure mechanical properties such as the hinge property correctly. However, it is unclear whether the hinge properties proposed in previous studies can be applied to PSWs with spun piles. In this study, a novel FA method was developed to investigate the nonlinear seismic response of PSWs with corroded spun piles considering PC bar area reduction, deteriorated material properties, the bending stiffness reduction factor, and the moment–curvature relationship of the spun pile. The nonlinear seismic response of corroded PSWs was determined by performing pushover analysis using three methods: FA using the method of the previous study (FA-1), the proposed FA method (FA-2), and FB-FEA. As regards PSW foundations, vertical pile and batter pile configurations were considered. The pushover analysis results were compared in terms of several parameters, such as the natural period, plastic hinge formation, and load capacity of the corroded PSWs. The FA-2 results agreed very well with the FB-FEA results, while the FA-1 results were less precise with respect to the natural periods and load capacities of corroded PSWs. The results indicated that the bending stiffness reduction factor, moment–curvature relationship, and axial load–bending moment (P–M) capacity of the corroded spun piles should be appropriately defined. Corrosion had greater negative impacts on the compressive axial load and bending moment capacities of the spun pile than on its tensile axial load capacity
Evaluasi Struktur Bangunan Gedung Beton Bertulang Berusia 50 Tahun Bedasarkan SNI 1726 2012 dan SNI 2847 2013
Get PDFPenelitian ini membahas penilaian bangunan beton bertulang yang berusia 50 tahun berdasarkan standar perencanaan bangunan terbaru. Studi kasus yang dipakai adalah gedung Cipta yang terletak di Merdeka Barat, Jakarta. Survei lapangan dan uji laboratorium dilakukan untuk mengamati kondisi terkini dari struktur bangunan. Satu tes destruktif dan tiga tes non-destruktif dilakukan untuk mendapatkan kekuatan tekan beton aktual dan jumlah tulangan yang terpasang dalam elemen struktur. Berdasarkan kekuatan material eksisting, analisis struktur 3 dimensi yang diterapkan untuk mengevaluasi kekuatan nominal elemen beton bertulang. Dalam penilaian ini, gedung Cipta dievaluasi berdasarkan persyaratan struktur rangka pemikul momen khusus. Hasil pengamatan menunjukkan bahwa bangunan Cipta masih aman untuk menahan beban gravitasi. Disisi lain, struktur bangunan ini tidak memenuhi persyaratan untuk struktur rangka pemikul momen khusus. Penelitian ini menunjukkan bahwa bangunan beton yang berusia 50 tahun diperkuat hanya didesain untuk beban gravitasi
Site-Specific Earthquake Ground Motions for Seismic Design of Port Facilities in Indonesia
No full textIn Indonesia, infrastructure, such as port facilities, has been damaged by earthquakes. Therefore, evaluating rational earthquake ground motions (EGMs) for seismic design is necessary to mitigate earthquake disasters in the future. The EGMs in the Indonesian Seismic Code are stipulated based on the ASCE standards and not on site-specific ones. This study aims to propose site-specific EGMs for the seismic design of port facilities in Indonesia. The EGM records and ground data in Indonesia were used for analysis. The EGM incidents in the bedrock were evaluated with deconvolution analysis. The obtained EGMs were amplitude-adjusted to peak ground acceleration similar to that of the EGMs in the bedrock in the Indonesian Seismic Code. A seismic response analysis considering nonlinear soil characteristics was conducted, and 144 EGMs at port sites were obtained. Considering the variation in the obtained EGMs, we propose site-specific EGMs for the seismic design of port facilities. A comparison of the proposed EGMs with those in the design code reveals that the difference between them is significant
Modification of Reinforced Concrete Retaining Wall at Pilangbango Reservoir Construction Project Madiun, East Java
No full textEvaluasi Kelayakan Struktur Gedung Tinggi Yang Terbengkalai Selama 15 Tahun Terhadap Gempa Berdasarkan SNI 1726 – 2012
No full textStudi Alternatif Bentuk Rangka Jembatan Canai Dingin Untuk Pejalan Kaki Bentang Kecil Terhadap Rasio Berat dan Lendutan
Get PDFPada daerah terpencil banyak ditemui jembatan sederhana (non-engineered bridge) yang mengalami kerusakan. Salah satu alternatif untuk menyelesaikan masalah jembatan pada daerah terpencil untuk pejalan kaki adalah menggunakan jembatan rangka dengan material canai dingin. Jembatan sistem rangka adalah bentuk yang ideal untuk material canai dingin yang rawan mengalami tekuk. Beberapa bentuk jembatan rangka yang banyak diaplikasikan adalah tipe Warren truss, Pratt truss, Howe truss dan K-truss.Penelitian ini membahas pengaruh bentuk rangka terhadap rasio berat dan lendutan yang terjadi akibat beban pejalan kaki pada bentang pendek (L = 4m). Dalam pengembangan bentuk rangka ini mengacu pada bentuk rangka yang banyak diaplikasikan, menggunakan pembebanan sesuai SNI 1725-2016 dan analisa penampang canai dingin berdasarkan SNI 7971-2013. Usulan bentuk rangka yang dihasilkan juga akan dilakukan pengujian beban di laboratorium. Hasil dari penelitian ini diharapkan dapat diusulkan alternatif bentuk rangka baru jembatan canai dingin dengan lendutan yang paling kecil
The Evaluation of Pipeline Protection Influenced by Causeway Embankment Using the Finite Element Method (FEM)
No full textThe construction of embankments over very soft to soft clay, such as reclamation projects, is on the rise. One such development is the reclamation project in the District Manyar, Gresik region of East Java. The seabed in this area is predominantly composed of soft clay. Reclamation involves the construction of a causeway that intersects with a gas pipeline at a depth of 5 m from the seabed. The embankment construction will undoubtedly impact the surrounding area. This study focuses on analyzing the impact of embankment in a reclamation area on soft soil on the underlying pipeline and designing pipeline protection. As a result of this study, the safety factor at each construction stage exceeds the planned safety factor of 1.5. The maximum settlement that occurs in the soil beneath the pipe is 26.91 mm. The maximum stress sustained by the corrugated steel plate (CSP) is 35,499.79 kN/m2, with a lateral deformation of 41.37 mm. The maximum stress occurring on the concrete footing slab is 123.40 kN/m2, which is smaller than the allowable bearing capacity of 128.61 kN/m2
Hydrodynamic Analysis-Based Modeling of Coastal Abrasion Prevention (Case Study: Pulau Baai Port, Bengkulu)
No full textPulau Baai Port, located strategically in the Indian Ocean and considered a vital maritime hub in Indonesia, grapples with persistent challenges related to abrasion and sedimentation, which negatively impact its maritime infrastructure. One of the affected components is the exposed gas pipeline installation along the port’s coastline. The sedimentation rate along Pulau Baai’s coastline is alarming, ranging from 600,000 to 800,000 m3/year, resulting in coastal abrasion at a rate of up to 20 m/year. This study focuses on three scenarios using MIKE 21, including a baseline without alternatives, shore protection alternatives, and jetty protection alternatives. A comprehensive dataset, incorporating bathymetric maps, wave patterns, current data, and sediment characteristics, supports the analysis of coastal dynamics, emphasizing the urgency for intervention. The research introduces the novelty of analyzing coastal abrasion through the exposure of underground pipelines, establishing a relationship between impacting factors such as wave height, tides, sedimentation, and coastal abrasion. Mitigation alternatives, particularly alternative model-2 with jetty protection, are recommended based on a thorough evaluation of the model performance and actual measurements. The results show that Pulau Baai’s sediment, primarily sandy, experiences substantial abrasion and coastline changes, notably in alternatives-2 and -3. The study anticipates potential sedimentation in certain sections of the subsea exposed pipelines in the absence of shore protection. The outcomes of this research provide a foundational guide for informed decision making and strategies to ensure the sustainable functionality of maritime infrastructure in Pulau Baai and similar coastal regions
Evaluasi Kelayakan Struktur Gedung Tinggi Yang Terbengkalai Selama 15 Tahun Terhadap Gempa Berdasarkan SNI 1726 – 2012
Get PDFGedung tinggi di Indonesia khususnya di Surabaya sudah dimulai pembangunannya sejak tahun 90an. Namun dikarenakan terjadi krisis moneter pada tahun 1998 membuat beberapa gedung tinggi di Surabaya menjadi terbengkalai penyelesaiannya. Salah satunya adalah Gedung Apartemen Crystal Garden di Jl. Embong Malang Surabaya yang memiliki 26 lantai. Dan saat ini gedung tersebut akan dimanfaatkan kembali sebagai hunian dan pusat perbelanjaan. Untuk dapat merealisasikan rencana pemanfaatan kembali suatu gedung tinggi, maka diperlukan suatu evaluasi kelayakan pada gedung tersebut terhadap gempa berdasarkan peraturan SNI 1726 2012. Dalam menentukan kelayakan suatu bangunan ditentukan dari parameter kualitas material gedung saat ini dan dari parameter respons struktur terhadap beban gempa. Untuk mengukur kualitas material dibutuhkan serangkaian pengujian struktur beton bertulang. Hasil yang diharapkan adalah dapat diketahui kelayakan bangunan dari segi kualitas material beton bertulang dan dari segi respons struktur gedung terhadap gempa yang akan dibandingkan dengan peraturan terkait yang berlaku di Indonesi
