Determination of Road Bridge Load -Carrying Capacity

In frame of global European standardization and as consequence of new knowledge concerning the existing bridge reliability, the need for revision of the Technological Standard No. 104 “Load-carrying capacity of road bridges and footbridges” [1] (hereinafter referred to as TS 104) had started up. In the first stage of the revision, the preparation and analysis in the form of Analysis Task (hereinafter referred to as AT) has been worked up by the collective of the Department of Structures and Bridges from the University of Zilina in cooperation with Slovak Road Administration (SRA), National Motorway Company (NMC) and other co-operators among academicians and designers. In the presented paper, the attention is paid to the general concept and basic assumptions of the AT and revised TS 104 for determining the road bridge load-carrying capacity.

Estimating Bridge Reliability by Using Bayesian Networks

As part of an inspection, bridge inspectors assign condition ratings to the main components of a bridge’s structural system and identify any defects that they observe. Condition ratings are necessarily somewhat subjective, as they are influenced by the experience of the inspectors. In the current work, procedures were developed for making inferences on the reliability of reinforced concrete girders with defects at both the cross section and the girder level. The Bayesian network (BN) tools constructed in this work use simple structural m echanics to model the capacity of girders. By using expert elicitation, defects observed during inspection are correlated with underlying deterioration mechanisms. By linking these deterioration mechanisms with reductions in mechanical properties, inferences on the reliability of a bridge can be made based on visual observation of defects. With more development, this BN tool can be used to compare conditions of bridges relative to one another and aid in the prioritization of repairs. However, an extensive survey of bridges affected by deterioration mechanisms is needed to confidently establish valid relationships between deterioration severity and mechanical properties.

Reliability based performance assessment of a roadway bridge under seismic actions

<p>External events represent the most common causes of bridge failure which could indicate distress, partial or total collapse (failure of all substantial parts of a bridge). One of the main environmental factors are earthquakes, which have a high impact on bridges due to irregularities presented in both substructure and superstructure and vulnerabilities acquired by the codes used in its design. This article presents a framework to obtain the reliability index of a bridge under seismic events, using response surface method and first order reliability method, based on random variables that affect the structure capacity (pushover analysis) and the seismic loads (peak ground acceleration). The bridge reliability of the case study is updated using visual inspection techniques. Results indicate that the vulnerable zone on the bridge is its shortest pier and the failure could occur due to high shear concentration in the hinge at the bottom of the pier.</p>

Incorporation of Structural Health Monitoring Coupled Data in Dynamic Extreme Stress Prediction of Steel Bridges Using Dynamic Coupled Linear Models

In this article, an approach for using structural health monitoring coupled extreme stress data in dynamic extreme stress prediction of steel bridges is presented, where the coupled extreme stress data means the extreme stress data with dynamicity, randomness, and trend. Firstly, the modeling processes about dynamic coupled linear models (DCLM) are provided based on a supposed coupled time series; furthermore, the dynamic probabilistic recursion processes about DCLM are given with Bayes method; secondly, the monitoring dynamic coupled extreme stress data is taken as a time series, historical monitoring coupled extreme stress data-based DCLM and the corresponding Bayesian probabilistic recursion processes are given for predicting bridge extreme stresses; furthermore, the monitoring mechanism is provided for monitoring the prediction precision of DCLM; finally, the monitoring coupled extreme stress data of a steel bridge is used to illustrate the proposed approach which can provide the foundations for bridge reliability prediction and assessment.

Evaluasi Keandalan Jembatan Gantung Pejalan Kaki Dengan Variasi Letak dan Jenis Beban Lalu Lintas

ABSTRAKUntuk mendukung pembangunan infrastruktur jembatan, pemerintah mengeluarkan panduan untuk perencanaan jembatan gantung dengan judul Surat Edaran Menteri Pekerjaan Umum No. 02/SE/M/2010 tentang Pemberlakukan Pedoman Perencanaan dan Pelaksanaan Konstruksi Jembatan Gantung Untuk Pejalan Kaki. Jembatan gantung yang dirancang sesuai dengan panduan tersebut harus mampu menahan beban pejalan kaki sebesar 5 kPa. Dengan mengacu pada pedoman tersebut, direncanakanlah sebuah jembatan gantung dengan panjang total 127.34 meter. Agar dapat mengetahui perilaku jembatan terhadap beban yang direncanakan, dibuatlah pemodelan jembatan menggunakan software MidasCIVIL dengan menggunakan 4 variasi letak pembebanan dan 80 variasi beban mewakili bobot pejalan kaki dan kendaraan bermotor roda dua. Tujuan dilakukannya analisis ini adalah untuk mengetahui nilai keandalan struktur yang direncanakan dengan beban sesuai Surat Edaran Menteri Pekerjaan Umum No. 02/SE/M/2010 terhadap variasi beban pejalan kaki dan kendaraan bermotor yang sesungguhnya mungkin terjadi pada jembatan. Evaluasi struktur menggunakan metode probability based menghasilkan keandalan struktur jembatan sebesar 100% yang dianalisis terhadap lendutan, tegangan kabel, tegangan batang penggantung serta tegangan pilar. Sehingga dapat dikatakan bahwa beban 5 kPa yang disyaratkan oleh pedoman memiliki nilai yang konservatif dan akan menghasilkan struktur jembatan yang sangat aman.Kata kunci: : Jembatan Gantung, Variasi Letak Beban, Pejalan Kaki, Probability Based Design ABSTRACTTo support the establishment of bridge infrastructure, the government issued a guide for planning a suspension bridge with the title Surat Edaran Menteri Pekerjaan Umum No. 02 / SE / M / 2010 concerning the Implementation of Guidelines for Planning and Construction of Suspension Bridges for Pedestrians. Suspension bridges designed according to these guidelines must be able to withstand pedestrian loads of 5 kPa. With reference to these guidelines, a suspension bridge is planned with a total length of 127.34 meters. In order to know the bridge's behavior towards the planned load, a bridge modeling was made using MidasCIVIL using 4 position of loading and 80 load variations representing pedestrian weight and two-wheeled motorized vehicles. The purpose of this analysis is to determine the value of the bridge reliability that planned with load according to the Surat Edaran Menteri Pekerjaan Umum No. 02 / SE / M / 2010 against variations in pedestrian and motor vehicle loads that might actually occur on bridges. Structural evaluation using probability-based methods produces 100% bridge structure reliability which is analyzed for deflection, cable stress, hanger stress and pillar stress. So, it can be said that the 5 kPa load required by the guidelines has a conservative value and will produce a very safe bridge structure.Keywords: Suspension Bridge, Load Position Variation, Pedestrian, Probability Based Design

Evaluasi Keandalan Jembatan Gantung Pejalan Kaki Dengan Variasi Letak dan Jenis Beban Lalu Lintas

ABSTRAKUntuk mendukung pembangunan infrastruktur jembatan, pemerintah mengeluarkan panduan untuk perencanaan jembatan gantung dengan judul Surat Edaran Menteri Pekerjaan Umum No. 02/SE/M/2010 tentang Pemberlakukan Pedoman Perencanaan dan Pelaksanaan Konstruksi Jembatan Gantung Untuk Pejalan Kaki. Jembatan gantung yang dirancang sesuai dengan panduan tersebut harus mampu menahan beban pejalan kaki sebesar 5 kPa. Dengan mengacu pada pedoman tersebut, direncanakanlah sebuah jembatan gantung dengan panjang total 127.34 meter. Agar dapat mengetahui perilaku jembatan terhadap beban yang direncanakan, dibuatlah pemodelan jembatan menggunakan software MidasCIVIL dengan menggunakan 4 variasi letak pembebanan dan 80 variasi beban mewakili bobot pejalan kaki dan kendaraan bermotor roda dua. Tujuan dilakukannya analisis ini adalah untuk mengetahui nilai keandalan struktur yang direncanakan dengan beban sesuai Surat Edaran Menteri Pekerjaan Umum No. 02/SE/M/2010 terhadap variasi beban pejalan kaki dan kendaraan bermotor yang sesungguhnya mungkin terjadi pada jembatan. Evaluasi struktur menggunakan metode probability based menghasilkan keandalan struktur jembatan sebesar 100% yang dianalisis terhadap lendutan, tegangan kabel, tegangan batang penggantung serta tegangan pilar. Sehingga dapat dikatakan bahwa beban 5 kPa yang disyaratkan oleh pedoman memiliki nilai yang konservatif dan akan menghasilkan struktur jembatan yang sangat aman.Kata kunci: : Jembatan Gantung, Variasi Letak Beban, Pejalan Kaki, Probability Based Design ABSTRACTTo support the establishment of bridge infrastructure, the government issued a guide for planning a suspension bridge with the title Surat Edaran Menteri Pekerjaan Umum No. 02 / SE / M / 2010 concerning the Implementation of Guidelines for Planning and Construction of Suspension Bridges for Pedestrians. Suspension bridges designed according to these guidelines must be able to withstand pedestrian loads of 5 kPa. With reference to these guidelines, a suspension bridge is planned with a total length of 127.34 meters. In order to know the bridge's behavior towards the planned load, a bridge modeling was made using MidasCIVIL using 4 position of loading and 80 load variations representing pedestrian weight and two-wheeled motorized vehicles. The purpose of this analysis is to determine the value of the bridge reliability that planned with load according to the Surat Edaran Menteri Pekerjaan Umum No. 02 / SE / M / 2010 against variations in pedestrian and motor vehicle loads that might actually occur on bridges. Structural evaluation using probability-based methods produces 100% bridge structure reliability which is analyzed for deflection, cable stress, hanger stress and pillar stress. So, it can be said that the 5 kPa load required by the guidelines has a conservative value and will produce a very safe bridge structure.Keywords: Suspension Bridge, Load Position Variation, Pedestrian, Probability Based Design

Evaluating seismic reliability of Reinforced Concrete Bridge in view of their rehabilitation

Considering in this work, a simplified methodology was proposed in order to evaluate seismic vulnerability of Reinforced Concrete Bridge. Reliability assessment of stress limits state and the applied loading which are assumed to be random variables. It is assumed that only their means and standard deviations are known while no information is available about their densities of probabilities. First Order Reliability Method is applied to a response surface representation of the stress limit state obtained through quadratic polynomial regression of finite element results. Then a parametric study is performed regarding the influence of the distributions of probabilities chosen to model the problem uncertainties for Reinforced Concrete Bridge. It is shown that the probability of failure depends largely on the chosen densities of probabilities, mainly in the useful domain of small failure probabilities.

Post-Tensioned Composite Bridge: Reliability-Based Optimization of Selected Design Parameters

In the paper small-sample double-loop optimization method is employed to find selected design parameters of a single-span post-tensioned composite bridge to ensure its reliability and load-bearing capacity. The selected approach consists in nesting the computation of the failure probability with respect to the current design within the optimization loop. The analyzed bridge is made of precast post-tensioned concrete girders, each composed of six segments that are connected by the transverse joints. Bridge spatial deterioration brings uncertainty into actual values of concrete strength in transversal joints and of actual loss of pre-stressing. Due to their significant effect on the bridge load-bearing capacity, both were considered as uncertain design parameters with the aim to find their critical values corresponding to desired reliability level and load-bearing capacity.