Simpson Gumpertz and Heger

Arlington, TX, United States

Simpson Gumpertz and Heger

Arlington, TX, United States
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Quinn B.H.,Simpson Gumpertz and Heger | Civjan S.A.,University of Massachusetts Amherst
Journal of Bridge Engineering | Year: 2017

For integral abutment bridge (IAB) design, there is no consensus on the preferable orientation of the piles supporting the abutment, although variations can affect overall bridge behavior and forces in the piles. This paper details a parametric study of steel girder IABs that used finite-element models to compare the effects of pile orientation on bridges of various lengths and skews. For this study, the bridge lengths investigated were 15.2 m (50 ft), 30.5 m (100 ft), and 45.7 m (150 ft) with skew angles of 0, 15, 30, and 45°. H-pile orientation of webs parallel and perpendicular to the abutment centerline were investigated and compared. The results apply to the thermal response of the models and report abutment and pile displacements, pile weak-axis and strong-axis bending moments, and ratios of maximum bending moments to yield moments. Results show that there is not one optimal pile orientation; rather, optimal orientation depends on other factors. Beyond the effects of length and skew angle, choice of orientation should consider expected temperature range, construction temperature, and backfill conditions. © 2016 American Society of Civil Engineers.

Richard M.J.,Simpson Gumpertz and Heger | Kassabian P.E.,Simpson Gumpertz and Heger | Schulze-Ehring H.S.,Buro Ehring
Proceedings of the Institution of Civil Engineers: Structures and Buildings | Year: 2017

In October 2013, the Philippines experienced a large (magnitude 7·2) earthquake and typhoon in a span of three weeks. As part of the rebuilding process, Simpson Gumpertz & Heger Inc. (SGH), working with New York architecture firm actLAB, consulted on designs to reconstruct two schools in the towns of Maribojoc and Loon. Designers and builders have given increasing attention to bamboo for engineered structures and are now using the material in a range of applications. Bamboo has good structural properties and can provide a sustainable construction material. Bamboo is a locally sourced material in the Philippines and was used for the structural columns and roof trusses in the school design while brick bearing walls provided the lateral force resisting system. SGH consulted on the overall structural design for the schools and focused on bamboo behaviour and details using its in-house materials laboratory. SGH also conducted a series of tests to investigate the strength of the bamboo connections in the roof truss. actLAB then used SGH’s recommendations to work with a local structural engineer and bamboo craftsman to finalise construction of the schools. The project brought together craftsmen, designers and engineers with local construction methods to re-engineer new classrooms and maximise structural resiliency. © 2017, Thomas Telford Services Ltd. All rights reserved.

Tumialan G.,Simpson Gumpertz and Heger
Key Engineering Materials | Year: 2017

This article provides an overview of ACI 440.7R - Design Guide for Strengthening of Masonry with FRP Systems. ACI 440.7R was developed by the American Concrete Institute (ACI) Committee 440 and published in 2010. ACI 440.7R has been recently revised to include new topics. This article provides an overview of the design methodologies recommended by ACI 440 for flexural and shear strengthening of masonry walls, confinement of masonry, and repair ("stitching") of cracked masonry with FRP systems. © 2017 Trans Tech Publications.

Phelps A.F.,Simpson Gumpertz and Heger | Horman M.J.,Pennsylvania State University
Journal of Construction Engineering and Management | Year: 2010

Traditional construction research methods have enabled focused but narrow advances in our understanding of industry phenomena. While contributing new insight, these methods are often not adequate to enable understanding of the complex interactions that lead to many of the industry's pervasive social and technical problems. One means of addressing these limitations is for the construction research community to complement prevalent quantitative and case study methodologies with qualitative theory-building methodologies, specifically ethnographic studies or those based on detailed and long-term observation of project environments. This paper identifies the critical need for theory-building methods and their methodological conventions, challenges, and opportunities. Specifically, the paper focuses on data collection in ethnographic studies and analysis of that data through the use of grounded theory. Through better understanding and more widespread use of theory-building methods, the construction research community can provide a needed complement to the current prevailing methods and greatly aid the maturation of our important field. © 2010 ASCE.

Catella N.D.,Simpson Gumpertz and Heger
Forensic Engineering 2015: Performance of the Built Environment - Proceedings of the 7th Congress on Forensic Engineering | Year: 2015

Finite element analysis can be a useful tool for structural failure investigation. It enables engineers to compare and quantify potential failure modes and it allows interested parties to visualize failure sequences. Finite element analysis is used less frequently for support of structural failure investigation than it is for design and there are several important differences. In design, it is typically sufficient to make conservative assumptions; in failure investigation, conservative assumptions may preclude potential failure modes. Therefore, it is important to characterize every aspect of the model as accurately as possible, thoroughly check assumptions, and understand the limitations of the model. This is especially true for nonlinear analyses, where models may be sensitive to small changes. For situations where the structure cannot be adequately characterized, finite element analysis may still prove useful by identifying trends resulting from variation in certain parameters that may have contributed to failure. Two case studies are presented to illustrate the advantages and pitfalls of finite element modeling in structural failure investigation: collapse of a mast-climbing scaffolding machine and deterioration of concrete railroad ties. © 2016 ASCE.

Nelson P.E.,Simpson Gumpertz and Heger
ASTM Special Technical Publication | Year: 2016

This paper reviews some of the pressing issues and challenges presented in papers from the first two ASTM exterior insulation and finish systems (EIFS) symposiums (ASTM STP1187-September 1992 and ASTM STP1269-March 1995) and compares them to EIFS today. What has changed, and what has not, over the last two decades? What pressing problems from 20 years ago have been addressed (e.g., absence of many options for drainable systems)? What new problems have emerged (e.g., additional code-mandated restrictions and concerns with combustible foam plastics as part of exterior wall assemblies)? What additional benefits of EIFS have emerged or been more fully appreciated in recent years (e.g., code-mandated emphasis on continuous exterior insulation)? © Copyright 2016 by ASTM International.

Taylor A.J.,Simpson Gumpertz and Heger
ASTM Special Technical Publication | Year: 2016

A drainable exterior insulation and finish system (EIFS), which is lightweight and improves enclosure thermal performance at a relatively low cost, is a valid option for over-cladding existing underperforming facades. This article describes a process for evaluating the suitability of a drainable EIFS for over-cladding an existing facade and, if it is suitable, the steps for successful design and installation of drainable EIFS over-cladding. This article also describes steps for existing facade investigation, code validation, and the thermal improvement benefit of EIFS over-cladding; design, detailing, and specifying; and quality assurance/quality control (e.g., mock-ups and testing) before and during construction. The article will also touch on the important design considerations of fire resistivity, designing for drift and drainage, and missile impact resistance. © Copyright 2016 by ASTM International.

Zarghamee M.S.,Simpson Gumpertz and Heger
Pipelines 2016: Out of Sight, Out of Mind, Not Out of Risk - Proceedings of the Pipelines 2016 Conference | Year: 2016

This paper details the procedure for pressure-induced thrust restraint design of concrete pressure pipelines with tied joints at elbows, tees, and end-caps through several examples following the current AWWA manual of practice M9. The paper discusses the problems that led to the development of the procedure, the design philosophy, and the development of a simplified approach for thrust restraint design. It discusses the assumptions embedded in the simplified approach. It presents the calculation flow diagram and describes the steps in the calculation for three different examples. These examples are selected for discussion in the order of their complexity: an end cap, a simple bend with welded joints, and a bend with mechanically harnessed joints. Through the use of examples, the paper shows how the calculation for each step is performed. Applicability of the procedure developed in the current AWWA Manual of Practice M9 to thrust restraint design of other pipes is briefly discussed. © 2016 ASCE.

Patel A.K.,Simpson Gumpertz and Heger
ASTM Special Technical Publication | Year: 2015

Water-resistant barrier requirements (i.e., code and industry guidelines) within portland cement-based plaster (stucco) wall cladding systems have changed over the past decade. Various types of water-resistant barriers have been developed, and different configurations for their use within stucco wall cladding systems have been implemented successfully. However, improper use or lack of a proper water-resistant barrier can lead to deterioration or corrosion of exterior wall components, including sheathing, framing, and insulation, and can eventually result in water leakage into interior spaces. This paper will review the changes in water-resistant barrier requirements for exterior stucco wall cladding systems. It discusses the mechanisms for failure and water leakage paths through stucco cladding systems and water-resistance barriers, presented through various case studies. Laboratory testing of various types of water-resistant barrier materials will also be performed. Comparisons of the results are explored along with examples of actual in-service installations. Copyright © 2015 by ASTM International.

Hamburger R.O.,Simpson Gumpertz and Heger
AEI 2011: Building Integrated Solutions - Proceedings of the AEI 2011 Conference | Year: 2011

In 2001, the Applied Technology Council (ATC) initiated the ATC-58 Project under contract to the Federal Emergency Management Agency (FEMA). Under this project, ATC is developing next-generation performance-based seismic design criteria for new and existing buildings that will be published as FEMA P-58. Unlike present-generation performance-based design criteria, which characterize structural and nonstructural performance in terms of standardized damage states, the P-58 criteria characterize structural performance in terms of the consequences of earthquake damage including: casualties; repair and reconstruction costs, expressed both in monetary and energy/carbon expenditures; and occupancy interruption time. The performance of nonstructural building components including architectural, electrical and mechanical components and systems is integrally considered with that of the structure. Following a methodology originally developed by the Pacific Earthquake Engineering Research Center, the P-58 procedures revolve around a building performance model that includes fragility and consequence functions for each of the damageable components and systems of significance. Monte Carlo simulation procedures are used to assess potential losses for: individual earthquake shaking intensities; scenario earthquake events, considering uncertainty in ground motion intensity; and, over a period of time, considering uncertainty in the magnitude and distances of scenario events that will occur. Project completion is scheduled for late 2011.

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