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The paper describes load and resistance factor design (LRFD) calibration for the resistance factor used in the Stiffness Method internal stability soil failure limit state for geogrid mechanically stabilized earth (MSE) walls. The Stiffness Method was recently adopted in the current American Association of State Highway and Transportation Officials LRFD Bridge Design Specifications in the US, and will appear in the next edition of the Canadian Highway Bridge Design Code. The paper describes the details of the calibration of the soil failure limit state which is unique to the Stiffness Method. Calibration outcomes include consideration of the concept of level of understanding in the selection of nominal load and resistance values which is unique to LRFD foundation engineering practice in Canada. A practical conclusion from these calculations is that if product line-specific creep test data are available to estimate the reinforcement secant creep stiffness used for design, then a resistance factor of 1.0 is reasonable for US practice. If only minimum average roll value tensile strength data are available, then a value of 0.95 is recommended for US practice. For Canadian practice, the corresponding values for typical level of understanding are 0.90 and 0.85, respectively. [ABSTRACT FROM AUTHOR]

Copyright of Canadian Geotechnical Journal is the property of Canadian Science Publishing and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Copyright of Canadian Journal of Civil Engineering is the property of Canadian Science Publishing and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Copyright of Canadian Journal of Civil Engineering is the property of Canadian Science Publishing and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Copyright of Canadian Geotechnical Journal is the property of Canadian Science Publishing and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

The bridge over the Beauharnois Canal (BHC) is the main structure of the Nouvelle Autoroute 30 project, with a total length of 2551 m. It crosses the BHC and the Saint Laurent Seaway (SLS). This paper describes the development of the design and construction process of the Beauharnois Bridge carried out by a leading construction company in Montreal. It describes the construction procedures carried out to achieve the works in a schedule severely limited by the technical clauses of the contract and winter conditions. This paper emphasizes the different préfabrication systems employed in the construction of the bridge and the incremental launching technique used to erect the steel box-girders of the east part over the BHC and the SLS. The bridge superstructure is divided into two parts: the east part, formed by a closed composite structure with a steel box-girder spanning over 82 m, and the west part, designed with a concrete deck composed of five concrete prefabricated beams spanning a typical length of 45 m. The east part, with a length of 1456 m, was designed with no expansion joints. This side of the deck includes the main span of 150 m and was entirely assembled at the east abutment and erected in place using the incremental launching technique. [ABSTRACT FROM AUTHOR]

The New Champlain Bridge is a highprofile infrastructure project in North America due to its critical economic importance, the premature deterioration of the existing structure and its visibility throughout the metropolitan area. As the gateway into Montreal, significant architectural input is encapsulated in the project design criteria. Durability is a key aspect of the design with a 125 year service life specified. One of the most significant factors in the design, however, is the compressed construction schedule. The crossing is scheduled to open to traffic on 1 December 2018, with the notice to proceed announced in May 2015, permitting a total design and construction duration of just 42 months. Key elements of the design and construction which allow the project to be completed within the short timeframe, while meeting the challenges of environmental constraints, durability requirements and architectural considerations, are explored in this paper. [ABSTRACT FROM AUTHOR]

One option to mitigate the seismic risk of highway bridges in Quebec is to replace typical elastomeric bearings used there with natural-rubber seismic-isolator devices. To support this alternative, this paper assesses the seismic vulnerability of typical bridge classes retrofitted with seismic-isolator devices through the development of fragility curves. Retrofitted-bridge fragility curves provide a powerful tool to evaluate the impact of a retrofit measure on the performance of different bridge classes. The analytical fragility approach uses nonlinear time-history analysis with 3-D detailed models for typical configurations of highway bridges. Experimental results of square bearings with different sizes and shape factors are used to account for uncertainties related to the mechanical properties of seismic-isolators. Critical load tests are conducted on slender seismic isolation bearings and a finite-element model is calibrated with the test results to define the seismic-isolator limit states. The fragility curves of different key components of the bridge system are compared and the results reveal that seismic isolation is effective significantly in reducing the probability of damage to columns and foundations. Due to insufficient clearance between the superstructure and abutment wing walls, however, the probability of damage in wing walls is increased and the fragility of this component controls the bridge-system fragility for all bridge classes evaluated. Concrete-girder bridges are found to be more vulnerable than steel-girder bridges due to the larger superstructure mass involved in the seismic response. The results from this work can be used to evaluate and select bridge retrofits, and can form the basis for cost-benefit retrofit studies. [ABSTRACT FROM AUTHOR]

Copyright of Canadian Journal of Civil Engineering is the property of Canadian Science Publishing and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Copyright of Canadian Journal of Civil Engineering is the property of Canadian Science Publishing and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

The seismic performance of 15 continuous four-span bridges with different arrangements of column heights and diameters and designed using the 2006 Canadian Highway Bridge Design Code provisions were studied using incremental dynamic analysis (IDA). The seismic risk associated with exceeding different damage states in the columns, including yielding, cover spalling, bar buckling, and structural collapse (i.e., dynamic instability) was predicted. Some simplified equations were derived for Montreal, Quebec, Canada, to estimate the mean annual probability of exceeding different damage states in the columns using the IDA results. The results indicated that the probabilities of exceeding different damage states were reasonably low. [ABSTRACT FROM AUTHOR]