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Deng Y.,Moffatt And Nichol Engineers
Structures Congress 2013: Bridging Your Passion with Your Profession - Proceedings of the 2013 Structures Congress | Year: 2013

Seismic issues are international interests. Non-linear Time History Analysis simulates the structure behavior under severe Earthquake movement more properly than other methods. In this paper, Non-linear time history analysis will be presented with one of the world famous project. Yerba Buena Island (YBI) West-Bound (WB) Ramps are portion of San Francisco-Oakland Bay Bridge Project. The Ramps are touched down to Yerba Buena Island (YBI) from YBI WB Widening by hinges. This project is located at a 0.627g Site Specific Response for Safety Evaluation Earthquake (SEE). YBI WB On-ramp is a highly horizontally Curved Bridge with radius of 127.3 feet (38.8 meters). Seismic behavior is very important for the project. In order to understand structural non-linear behavior, especially highly horizontally curved bridge behavior under severe earthquake events, YBI WB On-ramp stand-alone bridge is analyzed by non-linear time history analysis method. SAP 2000 with Hilber-Hughes-Taylor α direct integration method is used for Non-linear Time History Analysis (NL-THA). Seismic Modeling is discussed in this paper. Then six sets of acceleration time histories are used for NL-THA by SAP 2000. Open System for Earthquake Engineering Simulation (Open-SEEs) program developed by University of California-Berkeley is used to verify the SAP NL-THA accuracy in this paper. Site Specific Response Spectra ARS is also used for liner analysis and compared with results of Non-linear Time History Analysis and Open-SEEs Analysis. Non-linear push-over analysis is performed to determine the structural capacity and ductility under severe earthquake events. Finally, discrepancies between different program analyses are discussed and recommendations are presented. © 2013 American Society of Civil Engineers.


Heffron R.,Moffatt And Nichol Engineers
Ports 2013: Success Through Diversification - Proceedings of the 13th Triennial International Conference | Year: 2013

Waterfront infrastructure represents a significant investment and owners have a vested interest in maintaining and extending the service life of these aging assets. Exposed to the harsh marine environment, these assets are subject to degradation more than most non-marine assets. In addition, most owners are interested in protecting life safety and the environment through proactive and cost-effective maintenance. Recognizing these drivers, the ASCE/COPRI Ports & Harbors Committee's Waterfront Inspection Task Committee has developed a new manual to guide the inspection of waterfront assets. The new manual, "Waterfront Facilities Inspection and Assessment Standard Practice Manual," provides comprehensive guidance for the inspection and maintenance of waterfront structures both above water and underwater, as well as associated mooring hardware, fender systems, utilities, and appurtenant features. Eight inspection types are defined in the manual, with each inspection performed for a specific purpose using a tailored scope of work. Inspection types may also be combined and performed simultaneously. The eight inspection types include: Routine Inspection Structural Repair or Upgrade Inspection New Construction Inspection Baseline Inspection Due Diligence Inspection Special Inspection Repair Construction Inspection Post-Event Inspection The manual provides guidance on modeling service life using software such as STADIUM® to provide quantitative solutions to extending the life of waterfront structures. The manual covers every type of waterfront structure type commonly in use. Specific guidance is provided on the nuances of each structure type and the defects commonly found. The structure types covered include: piers (jetties), wharves (quays), bulkheads (quaywalls), seawalls, relieving platforms, gravity block walls, caissons and cofferdams, wave screens/attenuators, marinas, boat ramps, marine railways, floating structures, mooring buoys (SPMs, MBMs, etc.), and slope/shoreline protection. The intent of the manual is to provide owners and specifiers with guidance on what type of inspection to choose for a particular facility need, making the process simpler and more uniform since the scope of each inspection type is defined. The result is a standardized process that will assist owners in maintaining their waterfront assets and extending the service life proactively. © 2013 American Society of Civil Engineers.


Kotulak P.W.,Moffatt And Nichol Engineers
Ports 2013: Success Through Diversification - Proceedings of the 13th Triennial International Conference | Year: 2013

As a component of the Masonville Dredged Material Containment Facility (DMCF) project, the Maryland Port Administration (MPA) was required to develop a compensatory mitigation package to offset impacts associated with filling approximately 130 acres of open water in the Patapsco River, which is a major tributary to the Chesapeake Bay. The mitigation approved for the project is a comprehensive package of inwater and upland environmental restoration projects totaling over $20 million, primarily located adjacent to the DMCF in 90 acres of open water and 54 acres of uplands that comprise Masonville Cove. The projects serve to enhance the environment and provide improved habitat and increased wildlife use of the area, in addition to remediating contamination from historical industrial usage and dumping. The projects discussed in this paper include over 2 miles of shoreline restoration and stabilization using created fringe marshes with sandy beaches and living shorelines behind offshore rock breakwaters, 90 acres of reef creation and substrate improvement, 15 acres of creation and enhancement of tidal and non-tidal wetlands, and 30 acres of upland capping of contaminated soil. Design development concepts for these projects are presented along with reports on the completed construction that describe practical measures used to achieve the goals of the restoration. © 2013 American Society of Civil Engineers.


Srivastava S.,Moffatt And Nichol Engineers
Ports 2013: Success Through Diversification - Proceedings of the 13th Triennial International Conference | Year: 2013

This paper presents the results of a parametric study performed to investigate the seismic response of nonstructural components such as marine loading arms and gangway towers supported on pier and wharf structures. The existing seismic code provisions have included empirical equations for calculating an effective seismic force for nonstructural components which are more applicable to a multi-story building than to a waterfront structure. Moreover, the empirical equations do not account for the inelasticity of the supporting structure. To study the seismic interaction between a nonstructural component and a supporting pier structure, time history analyses are conducted using a set of twenty-eight ground motions at different performance levels. Nonstructural components considered in this study can be idealized as a single-degree-of freedom system, and their seismic mass is small compared to the total mass of the supporting pier structure. This paper reviews the influence of key parameters that affect the seismic response of the nonstructural component, such as the ratio of the time periods of the component and the supporting pier structure, the effective damping of the component and the effective damping of the supporting structure. A comparison between the results of this parametric study and the code-based empirical equations is also presented. © 2013 American Society of Civil Engineers.


Jaradat O.,Moffatt And Nichol Engineers
Ports 2013: Success Through Diversification - Proceedings of the 13th Triennial International Conference | Year: 2013

The United States Coast Guard (USCG) is challenged by aging infrastructure that has reached a point where many of the existing structures need to be replaced or repaired within constrained timelines or even while still operational. In recent years, a tremendous amount of work has gone into the development of Rapid Bridge Construction (RBC) methods. Rapid Pier Construction (RPC) is analogous to RBC in many ways, as bridges share similar structural elements and operational considerations as marine structures. In 2009, the USCG commissioned a study of RPC focusing on streamlining the construction process by accelerating the critical path steps and minimizing interruptions to operations. RPC has many potential benefits over typical pier and wharf construction, including potential overall cost savings, increased lifespan, higher durability, and reduced maintenance. RPC has a focus on the use of large precast components in modular construction, saving time on formwork and concrete curing. This paper addresses the applicability of RBC methods to the development of waterside infrastructure, piers and wharves. It also includes a review of literature related to RBC methods and materials, the development of an RPC concept, and recommendations for future applicability of RPC to construction in the marine environment. © 2013 American Society of Civil Engineers.


Dinh H.H.,Moffatt And Nichol Engineers | Parra-Montesinos G.J.,San Francisco Oakland Bay Bridge East Span Seismic Safety Project | Wight J.K.,University of Michigan
ACI Structural Journal | Year: 2010

Results from a comprehensive investigation aimed at studying the behavior of steel fiber-reinforced concrete (SFRC) beams in shear, as well as the possibility of using steel fibers as minimum shear reinforcement, are presented. A total of 28 simply supported beams with a shear span-to-effective depth ratio of approximately 3.5 were subjected to a monotonically increased, concentrated load. The target concrete compressive strength for all of the beams was 41 MPa (6000 psi). The studied parameters included beam depth (455 or 685 mm [18 or 27 in.]), fiber length (30 or 60 mm [1.2 or 2.4 in.]), fiber aspect ratio (55 or 80), fiber strength (1100 or 2300 MPa [160 or 330 ksi]), and fiber volume fraction (between 0.75 and 1.5%). In total, three types of steel fibers were considered, all with hooks at their ends. The behavior of beams failing in shear prior to or after flexural yielding was also investigated by varying the longitudinal reinforcement ratio (1.6, 2.0, and 2.7%). Test results showed that the use of hooked steel fibers in a volume fraction greater than or equal to 0.75% led to multiple diagonal cracking and a substantial increase in shear strength compared to reinforced concrete (RC) beams without stirrup reinforcement. All SFRC beams sustained a peak shear stress of at least 0.33√ f′c MPa (4.0√f′c psi). The results also indicated that the hooked steel fibers evaluated in this investigation can safely be used as minimum shear reinforcement in RC beams constructed with normal-strength concrete and within the range of member depths considered. Copyright © 2010, American Concrete Institute.


Cox N.,Moffatt And Nichol Engineers | Dunkin L.M.,Airborne | Irish J.L.,Virginia Polytechnic Institute and State University
Coastal Engineering | Year: 2013

Idealized computational simulations with the nearshore model XBeach were carried out for a series of barred beach configurations in order to quantify the impact of nearshore bars on infragravity swash. Results show that nearshore bar systems reduce infragravity swash energy at the shoreline. The amount of swash reduction was found to correlate with both bar depth and rip width, when a rip channel is present. In order to develop a generalized empirical model for significant infragravity swash for barred beaches, the simulations were used to extend the empirical swash model of Stockdon et al. (2006) to include bar characteristics. The developed empirical model relates significant infragravity swash to incident wave conditions and nearshore bar depth. With respect to Stockdon et al. (2006), this new model improves predictive skill by reducing root-mean-square error by 50% for the computational simulations and by 15% when applied to a range of field data. © 2013 Elsevier B.V.


Heffron R.,Moffatt And Nichol Engineers
Ports 2016: Port Planning and Development - Papers from Sessions of the 14th Triennial International Conference | Year: 2016

Waterfront infrastructure represents a significant investment and owners have a vested interest in maintaining it and extending the service life of these aging assets. Exposed to the harsh marine environment, these assets are subject to degradation more than most non-marine assets. In addition, most owners are interested in protecting life safety and the environment through proactive and cost-effective maintenance. Recognizing these drivers, the ASCE/COPRI Ports and Harbors Committee's Waterfront Inspection Task Committee has developed a new manual to guide the inspection of waterfront assets. The new manual, entitled "Manual of Practice 130-Waterfront Facilities Inspection and Assessment Manual", provides comprehensive guidance to owners and practitioners for the inspection and maintenance of waterfront structures both above water and underwater, as well as associated mooring hardware, fender systems, utilities, and appurtenant features. © ASCE.


Matson C.B.,Moffatt And Nichol Engineers
Ports 2016: Port Planning and Development - Papers from Sessions of the 14th Triennial International Conference | Year: 2016

Offshore wind energy (OSWE) is often considered as more than simply a way to reduce carbon footprint. It is also viewed by many coastal municipalities as a source of new jobs and economic growth. This paper explains the reality of these expectations and presents five critical design considerations that must be applied in the development of a successful U.S. wind turbine logistics port. These design considerations have been developed through years of planning, analysis and design of offshore wind turbine facilities, general cargo terminals, and offshore oil and natural gas structures. To achieve the economies required by the U.S. market, innovative terminal handling methods and vessel loading technologies must be implemented. These technologies have already been applied in Europe and are doing much to drive down the levelized cost of offshore wind energy. © ASCE.


Trademark
Moffatt And Nichol Engineers | Date: 2012-04-04

Computer software, namely, software for use in database analysis; computer software for extracting, viewing, and analysis of data and information contained in governmental infrastructure-related databases.

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