scholarly journals Seismic performance comparison between force-based and performance-based design as per Canadian Highway Bridge Design Code (CHBDC) 2014

2016 ◽  
Vol 43 (8) ◽  
pp. 741-748 ◽  
Author(s):  
Qi Zhang ◽  
M. Shahria Alam ◽  
Saqib Khan ◽  
Jianping Jiang
Keyword(s):  
Seismic Performance ◽  
Time History ◽  
Performance Based Design ◽  
Performance Criteria ◽  
Highway Bridge ◽  
Reinforcing Steel ◽  
Earthquake Hazards ◽  
Design Code ◽  
Bridge Design ◽  
The Impact

Performance-based design (PBD) was first introduced in Canadian Highway Bridge Design Code (CHBDC) in 2014. Performance-based design is the design that meets multiple performance criteria under different earthquake hazards. To investigate the impact of changes in CHBDC 2014, a four-span concrete highway bridge is designed and evaluated using force-based design (FBD) and PBD methods as per CHBDC 2014, and FBD method as per CHBDC 2006. By incorporating soil–structure interaction (using p–y curves) nonlinear pushover and dynamic time history analyses are conducted to assess the seismic performance of these bridges. Maximum strains of concrete and reinforcing steel are compared among the three designs to determine their performance levels. It is concluded that PBD (CHBDC 2014) is highly conservative compared to FBD (for both CHBDC 2014 and 2006). For the three-level PBD approach, the design is governed by the criterion of reinforcing steel not yielding under the design earthquake (with 475 years return period).

Effects of column and superstructure stiffness on the seismic response of bridges in the transverse direction

2013 ◽  
Vol 40 (8) ◽  
pp. 827-839 ◽  
Author(s):  
Payam Tehrani ◽  
Denis Mitchell
Keyword(s):  
Seismic Response ◽  
Nonlinear Dynamic ◽  
Transverse Direction ◽  
Time History ◽  
Highway Bridge ◽  
Design Code ◽  
Bridge Design ◽  
Dynamic Analyses ◽  
Nonlinear Dynamic Analyses ◽  
Degree Of Irregularity

The transverse seismic responses of continuous 4-span bridges designed based on the 2006 Canadian Highway Bridge Design Code were studied using inelastic time history analyses. A total of 648 bridge configurations were considered in which the column heights, column diameters, superstructure stiffness and mass as well as abutment restraint conditions were studied. The maximum ductility demands obtained using elastic and inelastic analyses were compared to study the influence of the degree of irregularity. The effects of column stiffness ratios and superstructure to substructure stiffness ratios on the maximum ductility demands and concentration of ductility demands were investigated. A number of different regularity indices were compared to determine the suitability of these different indices in predicting the influence of irregularity. This study demonstrates the conservative nature of the 2006 Canadian Highway Bridge Design Code and provides some guidance on factors for determining the degree of irregularity and suitable regularity indices when carrying out nonlinear dynamic analyses of bridges.

scholarly journals Performance based seismic assessment of bridges designed according to Canadian Highway Bridge Design Code

2014 ◽  
Vol 41 (9) ◽  
pp. 777-787 ◽  
Author(s):  
M. Neaz Sheikh ◽  
Frédéric Légeron
Keyword(s):  
Seismic Performance ◽  
Seismic Design ◽  
Design Rule ◽  
Highway Bridge ◽  
Design Code ◽  
Bridge Design ◽  
Simple Method ◽  
Design Rules ◽  
Performance Based Seismic Design ◽  
Engineering Parameters

Recent research efforts have focused on the development of performance based seismic design methodologies for structures. However, the seismic design rules prescribed in the current Canadian Highway Bridge Design Code (CHBDC) is based largely on force based design principles. Although a set of performance requirements (performance objectives) for different return period earthquake events have been specified, there is no explicit requirement in the CHBDC to check the attainment of such performance objectives for the designed bridges. Also, no engineering parameters have been assigned to the specified performance objectives. This paper correlates seismic performance objectives (both qualitative and quantitative) with engineering parameters, based on the data collected from published experimental investigations and field investigation reports of recent earthquakes. A simple method has been developed and validated with experimental results for assessing the performance of bridges designed according to CHBDC. It has been found that the design rules prescribed in CHBDC do not guarantee that specified multiple seismic performance objectives can be achieved. An implicit seismic design rule in the form of performance response modification factor has been outlined for the performance based seismic design of bridges.

Numerical Simulations of the Drifting Ice Sheets Collision with the Bridge Pier

2013 ◽  
Vol 368-370 ◽  
pp. 1383-1386
Author(s):  
Lian Zhen Zhang ◽  
Wei Xiong
Keyword(s):  
Numerical Simulations ◽  
Ice Sheets ◽  
Ice Sheet ◽  
Time History ◽  
Material Model ◽  
Bridge Pier ◽  
Bridge Design ◽  
Drifting Ice ◽  
Collision Force ◽  
The Impact

The drifting ice sheets impact with the bridge pier and other hydraulic structures in the rivers, which may damage even cause collapse of the structures. In this paper, the FEM software package LS-DYNA was used to performed the numerical simulations of the collision process of the ice sheets and the bridge piers to make clear the interaction between them and to understand the failure mechanism of the ice sheet. The elastic strain-stress model with von mises failure criterion was used to describe the ice material. The brittle damage material model was used to describe the concrete pier. Three types thickness of ice sheets were performed at various velocity of the ice sheet respectively. The impact process of every case were displayed and the time history curve of the collision force were given out. The simulations results show that the peak value of the collision force time history curve increases with the velocity of the sheet firstly and then decreases with the velocity of the ice sheet. There is one critical velocity which relate to the compressive strength of the ice sheet. The simulation result were also compared with the different bridge design code, which show that the code result is more conservative in bridge design.

Experimental Study for Seismic Performance of Confined Masonry Structure

2013 ◽  
Vol 353-356 ◽  
pp. 1826-1831
Author(s):  
Tie Jun Qu ◽  
Yan Ping Wang ◽  
Xian Yun Wang
Keyword(s):  
Seismic Performance ◽  
Dynamic Test ◽  
Hysteresis Loops ◽  
Structural Response ◽  
Time History ◽  
Design Code ◽  
Restoring Force ◽  
Static Test ◽  
Confined Masonry ◽  
Made In

A two-story masonry housing model was made in this paper. According to Intensity 7, adjusted Northridge record was selected to be the ground motion input in the pseudo-dynamic test. Pseudo-dynamic test and pseudo-static test were carried out to investigate the seismic behavior of the model structure. The time-history curves of the acceleration, velocity, displacement and restoring force of the structural response were obtained besides the time-history curves of the measuring points of the structure. Also the steel strain of the tie-columns and the hysteresis loops of the structure were obtained. The result shows multi-story confined masonry structures possess superior seismic performance if coordinated with the provision specified in the current compulsory design code and it can continue to use after appropriate dressing under the rarely earthquake.

Equivalent area of voided slabs

1998 ◽  
Vol 25 (4) ◽  
pp. 797-801 ◽  
Author(s):  
Leslie G Jaeger ◽  
Baidar Bakht ◽  
Gamil Tadros
Keyword(s):  
Simple Expression ◽  
Technical Note ◽  
Axial Stiffness ◽  
Highway Bridge ◽  
Slab Thickness ◽  
Design Code ◽  
Bridge Design ◽  
Equivalent Thickness ◽  
Simple Alternative ◽  
Equivalent Area

In order to calculate prestress losses in the transverse prestressing of voided concrete slabs, it is sometimes convenient to estimate the thickness of an equivalent solid slab. The Ontario Highway Bridge Design Code, as well as the forthcoming Canadian Highway Bridge Design Code, specifies a simple expression for calculating this equivalent thickness. This expression is reviewed in this technical note, and a simple alternative expression, believed to be more accurate, is proposed, along with its derivation. It is shown that the equivalent solid slab thickness obtained from consideration of in-plane forces is also applicable to transverse shear deformations, provided that the usual approximations of elementary strength of materials are used in both cases.Key words: axial stiffness, equivalent area, shear deformation, transverse prestressing, voided slab, slab.

Dynamic loading and testing of bridges in Ontario

1984 ◽  
Vol 11 (4) ◽  
pp. 833-843 ◽  
Author(s):  
J. R. Billing
Keyword(s):  
Dynamic Load ◽  
Dynamic Testing ◽  
Highway Bridge ◽  
Vibration Modes ◽  
Design Codes ◽  
Test Results ◽  
Design Code ◽  
Bridge Design ◽  
Strain Measurements ◽  
Bridge Testing

The Ontario Highway Bridge Design Code (OHBDC) contains provisions on dynamic load and vibration that are substantially different from other codes. Dynamic testing of 27 bridges of various configurations, of steel, timber, and concrete construction, and with spans from 5 to 122 m was therefore undertaken to obtain comprehensive data to support OHBDC provisions. Standardized instrumentation, data acquisition, and test and data processing procedures were used for all bridge tests. Data was gathered from passing trucks, and scheduled runs by test vehicles of various weights. Accelerometer responses were used to determine bridge vibration modes, and dynamic amplifications were obtained from displacement or strain measurements. The form of the provisions adopted for dynamic load and vibration was confirmed by the test results, subject to minor adjustment of values. Observations on the distribution of dynamic load, and its relationship to span length and vehicle weight, may provide a basis for future refinement of the dynamic load provisions. If the stiffness of curbs and barrier walls is not included in deflection calculations, bridges designed by deflection could be penalized. Key words: bridges, vibration, bridge testing, bridge design codes.

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