Tag Archive for: Critical Structures

TRU Compliance Equipment Testing Project Equipment Testing and Certification to Assess Risk

News & Views, Volume 50 | TRU Compliance Equipment Testing Project

EQUIPMENT TESTING AND CERTIFICATION TO ASSESS RISK

By:  Katie Braman

Using a risk-based approach derived from various seismic standards from the Institute of Electrical and Electronics Engineers, TRU and BC Hydro will develop a synthetic test motion in three axes, mount the equipment on a triaxial shake table at TRU’s testing partner’s facility, and test at increasing levels until various levels of damage are observed.

TRU Compliance Equipment Testing Project Equipment Testing and Certification to Assess RiskTRU Compliance, the accredited product certification body of Structural Integrity Associates, has been awarded a contract to assist BC Hydro in qualifying and better understanding the seismic vulnerability of critical equipment used to control its spillway gates.  As part of the larger efforts to seismically upgrade the John Hart, Ladore, and Strathcona dams along the Campbell River system on Vancouver Island, British Columbia, BC Hydro is procuring equipment that allows precise flow control of the water going over the spillway.  Reliable equipment is needed to prevent possible overtopping or having uncontrolled water flow through the spillway.

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Porting SI's ANACAP Concrete Model into LS-DYNA Advanced Structural Analysis

News & Views, Volume 50 | Porting SI’s ANACAP Concrete Model into LS-DYNA

ADVANCED STRUCTURAL ANALYSIS

By: Livia Mello and Shari Day

Porting SI's ANACAP Concrete Model into LS-DYNA Advanced Structural AnalysisOne of Structural Integrity Associates’ (SI) strengths is combining state-of-the-art software with material science expertise to solve difficult structural and mechanical problems. A notable example in recent years is the Aircraft Impact Analysis (AIA) performed by SI for NuScale Power, using the ANACAP concrete material model. With SI’s support, NuScale’s Small Modular Reactor (SMR) building design passed NRC’s comprehensive inspection, bringing NuScale’s SMR technology one step closer to market [N&V Vol. 47 p. 5].

SI’s success in AIA is due not only to our team’s capabilities but also due to the capabilities of our proprietary concrete constitutive model, ANACAP, developed by Joe Rashid, Robert Dunham, and Randy James of ANATECH, now part of SI. Modeling reinforced concrete, which is both nonhomogeneous and anisotropic, is often a challenge in advanced structural analysis. However, ANACAP has a long track record of accurately capturing nonlinear concrete response in structural systems subjected to static, impact, and seismic loads. Its application goes beyond AIA; it has also been utilized in several of SI’s commercial building, bridge infrastructure, nuclear plant, and hydroelectric facility projects.

ANACAP has the ability to account for cyclic degradation, multi-axial cracking, load-rate effects, aging, creep, shrinkage, crushing, confinement, concrete-reinforcement interaction, and high-temperature softening behavior. The combination of these features results in an exceptional representation of concrete intricate behavior. It also leads to more accurate results when compared to standard finite element “built-in” concrete material libraries, all the while being implemented within the same standard finite element formulation.

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American Society of Civil Engineers, ASCE

Structural Design for Physical Security

Structural Integrity’s Own, Andy Coughlin published by American Society of Civil Engineers, ASCE

American Society of Civil Engineers, ASCEAndy Coughlin’s work has been published in the ASCE Structural Design for Physical Security: State of the Practice. The Task Committee on Structural Design prepared the publication for Physical Security of the Blast, Shock, and Impact Committee of the Dynamic Effects Technical Administration Committee of the Structural Engineering Institute of ASCE.  Andy wrote Chapter 10 on Testing and Certification for Physical Security and assisted on several other chapters.

Structural Design for Physical Security, MOP 142, provides an overview of the typical design considerations encountered in new construction and renovation of facilities for physical security. The constant change in threat tactics and types has led to the need for physical security designs that account for these new considerations and anticipate the environment of the future, with flexibility and adaptability being priorities. This Manual of Practice serves as a replacement for the 1999 technical report Structural Design for Physical Security: State of the Practice and is intended to provide a roadmap for designers and engineers involved in physical security. It contains references to other books, standards, and research.

Topics include

  • Threat determination and available assessment and criteria documents,
  • Methods by which structural loadings are derived for the determined threats,
  • Function and selection of structural systems,
  • Design of structural components,
  • Function and selection of window and facade components,
  • Specific considerations for retrofitting structures,
  • Testing methodologies, and
  • Bridge security.

This book will be a valuable resource to structural engineers and design professionals involved with projects that have physical security concerns related to explosive, ballistic, forced entry, and hostile vehicle threats.

Of particular note is the publication of the process by which products can be tested and certified to achieve physical security performance in blast, ballistics, forced entry, and vehicle impact.  Often unclear or overly specific requirements hamper the application of quality products which protect people and assets from attack.  The certification process below shows how approved agencies, like SI’s TRU Compliance, play a role in testing, evaluating, and selecting products for use in critical physical security applications, rather than relying solely on the claims of the manufacturers.  TRU’s certification program is the first of its kind to receive IAS Accreditation for the certification of physical security products.Certification Process

News & Views, Volume 49 | Code Compliance and the Modular Construction Trend

News & Views, Volume 49 | Code Compliance and the Modular Construction Trend: What Manufacturers Need to Know to Comply with Building Codes

By:  Andy Coughlin, PE, SE

News & Views, Volume 49 | Code Compliance and the Modular Construction Trend

The modular construction industry is projected to grow globally at an annual rate of 6.9%, outpacing the growth of traditional construction.1  Modular construction has many advantages over traditional building methods, including improved quality control and shorter project durations. Factory-built systems are constructed in controlled environments with equipment and materials that are not feasible at congested job sites, and project schedules can be shortened when factory work and field work are performed in parallel.

However, modular projects may stumble without proper forethought: when fabrication takes place in a factory away from the jobsite, the building officials, inspectors, and engineers can have less oversight and less recourse to implement changes if issues are discovered in the field.  Code compliance may also be an issue when systems are designed by factory engineers rather than the engineer of record.  To mitigate these potential pitfalls, careful planning is required at the start of the project.

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News & Views, Volume 49 | The 4th Dimension- Lifecycle Assessment of Critical Structures

News & Views, Volume 49 | The 4th Dimension: Lifecycle Assessment of Critical Structures

By:  Dan Parker, PE

News & Views, Volume 49 | The 4th Dimension- Lifecycle Assessment of Critical Structures

By analytically simulating the steps in the construction process, including the sequence of concrete placements, and tracking the history of the material behavior starting from initial placement, the potential for cracking is evaluated by comparing the time dependent stress and strains to the concrete cracking resistance and capacity.

Aging Infrastructure Issues

The infrastructure in the United States is aging and, whether publicly or privately owned, significant resources are required to repair, replace, or modernize it.  Due to the high costs associated with these efforts, owners need to identify structures with high risk-of-failure consequences and find the most cost-effective solutions for rehabilitation.  High consequence infrastructure includes:

  • Highway and railway bridges,
  • Roadways for intra and interstate transportation,
  • Dams, locks, and levees for flood control and cargo transportation,
  • High rise business, apartment, and condominium towers, and
  • Power generation and distribution facilities for Nuclear, Fossil and Hydro utilities.
News & View, Volume 47 | TRU Compliance Expands into Physical Security | Testing and Certification Services

News & View, Volume 47 | TRU Compliance Expands into Physical Security – Testing and Certification Services

By:  Dan Zentner

This service coincides with the upcoming publication of the Structural Design for Physical Security Manual of Practice by the American Society of Civil Engineers, with TRU Compliance Director Andy Coughlin as coauthor.

News & View, Volume 47 | TRU Compliance Expands into Physical Security | Testing and Certification ServicesTRU Compliance’s testing and certification services is expanding into the dynamic field of Physical Security. This service coincides with the upcoming publication of the Structural Design for Physical Security Manual of Practice by the American Society of Civil Engineers, with TRU Compliance Director Andy Coughlin as coauthor.  TRU’s practice in this arena includes Blast, Ballistics, Vehicle Impact and Forced Entry services. This is possible through TRU’s partnerships with leading test laboratories such as Oregon Ballistics Labs, Stone-OBL, BakerRisk, Calspan, and others.  Physical Security certification by TRU is accredited by the International Accreditation Service and compliments TRU’s accredited Seismic and Wind Certifications.

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News & View, Volume 46 | Identifying Failure Mechanisms of Typical I-Section Floodwalls

News & Views, Volume 46 | Identifying Failure Mechanisms of Typical I-Section Floodwalls

By: Eric Kjolsing and Dan Parker

News & View, Volume 46 | Identifying Failure Mechanisms of Typical I-Section FloodwallsIn 2018, Structural Integrity Associates, Inc. (SI) supported the United States Army Corp of Engineers (USACE) in the structural assessment of the concrete-to-steel connection in typical I-Section flood walls. A representative flood wall section is shown in Figure 1. This effort was part of a broader scope of work in which the USACE is revising their guidance for the design of flood and retaining walls, EM 1110-2-6066.  The purpose of the structural assessment was to better understand the mechanics of load transfer from the reinforced concrete section to the embedded sheet pile. Three-dimensional finite element models of the connection were developed employing non-linear constitutive properties for the concrete, structural steel and reinforcement to achieve this goal.  A total of nine different I-Wall configurations with varying wall geometry, sheet pile embedment depth, and connection details were analyzed.  Hydrostatic load was applied incrementally to simulate the actual load distribution due to a rising water level. 

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News & View, Volume 46 | TRU Compliance Achieves Accreditation as a Product Certification Body

News & Views, Volume 46 | TRU Compliance Achieves Accreditation as a Product Certification Body

By: Andy Coughlin

News & View, Volume 46 | TRU Compliance Achieves Accreditation as a Product Certification BodyTRU Compliance, a division of Structural Integrity Associates, announced in March the achievement of accreditation from the International Accreditation Service (IAS) as a product certification body for seismic, wind, and blast/physical security performance of nonstructural components. According to the International Accreditation Service, TRU Compliance is the second company to be certified for Seismic performance of non-structural components and the first company to be certified for Wind and Blast/Physical Security performance.

“This is a significant milestone for Structural Integrity and our certification agency, TRU Compliance,” Chris Larsen, Vice President of Critical Structures at Structural Integrity comments. “The accreditation further validates our robust program as well as our comprehensive approach, which not only meets the stringent guidelines of the ISO standards but offers our customers a full scope solution for product certification”.

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News & View, Volume 46 | Assessing Prestress Losses in a Nuclear Containment Structure for License Renewal

News & Views, Volume 46 | Assessing Prestress Losses in a Nuclear Containment Structure for License Renewal

By: Eric Kjolsing

News & View, Volume 46 | Assessing Prestress Losses in a Nuclear Containment Structure for License RenewalNuclear power plants around the world are approaching the end of their original 40-year design life.  Efforts are underway to extend the operating license for these plants to 60 years or beyond.  As part of the license extension, it must be demonstrated that the reactor containment building remains able to safely perform its intended functions for the extended duration of operation.  Many of these containment buildings utilize a post-tensioned concrete design where the tendons are grouted after tensioning.  Since these grouted tendons cannot be re-tensioned, an assessment for the loss in prestress beyond the original design life must be performed.

This article describes a methodology to assess the structural performance of a containment structure over time as a function of confidence in the tendon losses and is split into three parts:

  1. A description of the methodology
  2. A representative probabilistic assessment
  3. Representative analysis results

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News & View, Volume 46 | Adding Value Through Test Informed Modeling- Hydro Structures

News & Views, Volume 46 | Adding Value Through Test Informed Modeling: Hydro Structures

By: Eric Kjolsing and Dan Parker

News & View, Volume 46 | Adding Value Through Test Informed Modeling- Hydro StructuresIn 2018, Structural Integrity Associates (SI) supported a utility in the structural assessment of a submerged concrete intake tower.  The tower is nearly a century old and was investigated as part of the utility’s periodic maintenance program. 

The assessment required the generation of an analysis model that accounted for both the structure and the surrounding water.  When accounting for fluid effects, a typical analysis approach is to develop a fluid-structure interaction (FSI) model that explicitly accounts for the interaction between the surrounding water and concrete tower.  However, this modeling approach is expensive both in terms of (a) cost, due to the increased effort needed in generating the model and (b) schedule, due to the increased analysis run time.  In lieu of developing an FSI model, SI implemented an alternative numerical approach to model the effects of the water and justified the approach through physical testing of the in-situ structure.

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