Troy Morgan

What are the limitations of the Mohr-Coulomb strength model? For an easy explanation read this excellent paper by Rodrigo Salgado.

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This paper (Open Access) was published today by the Journal of Earthquake Engineering and Structural Dynamics. Here I propose a methodology to minimally modify a ground motion time history to induce collapse in nonlinear single-degree-of-freedom systems. The metric used to characterize the modification is the Arias intensity. The methodology is presented as an alternative to incremental dynamic analysis (IDA) widely used in earthquake engineering.

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Our paper on enhancing the torsional performance of reinforced concrete beams has been published. https://rdcu.be/dMQpp

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I was pleased that my article reached 100 reads in ResearchGate. Achieved on April 16, 2024 Article: Analytical Performance Assessment of Deteriorated Prestressed Concrete Beams Dec 2023, International Journal of Concrete Structures and Materials 17(1) DOI: 10.1186/s40069-023-00624-1 Abstract: In this paper, a new approach is developed to numerically evaluate the structural performance of deteriorated prestressed concrete beams using the finite element analysis application RCAHEST (Reinforced Concrete Analysis in Higher Evaluation System Technology). A prestressing steel element was modified to represent the interaction between deteriorated concrete and prestressing steel. Considering the corrosion effects—as shown by the reduction of the prestressing steel section and loss of bond—a nonlinear material model was proposed for deteriorated prestressed concrete behavior. The modified damage index is intended to provide a numerical method for quantifying the structural performance of deteriorated prestressed concrete beams. The analytical procedure developed for the performance evaluation of deteriorated beams was validated by comparison with the credible test results, thereby enabling a more reliable and rational prestressed concrete beams design process. https://lnkd.in/gYtmVgxS

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Responsible Charge: I want to make a comment about a topic that arisen in several recent discussions. The NCEES model law defines “Responsible Charge” as the direct control and personal supervision of engineering work. The Board of Ethical Review has reinforced this definition throughout their case evaluations. Someone posted on LinkedIn about offering geophysical services in the state of California. California is the only state in the USA that explicitly licenses geophysics. The California California Board for Professional Engineers, Land Surveyors, and Geologists licenses geophysics in the state. To become a Professional Geophysicist (PgP) is a similar process to becoming a Professional Engineer (PE), Professional Land Surveyor (PLS), or Professional Geologist (PG). NCEES sets the national standards for PE and PLS and the National Association of State Boards of Geology (ASBOG) sets the national standards for PG, while each state administers the licensing process for their state. The sequence for any of these licensed professions is similar: get a four year degree in the subject, pass a fundamentals test, work for approximately four years under the responsible charge of a licensed professional, pass another exam, and then apply to the state licensing board for your license. After receiving your license, you are now a minimally competent professional who can be in responsible charge over work and sign or stamp reports. The concept of minimum competency means that a professional should keep learning throughout their career to expand both the depth and breadth of their knowledge. The professional should also have a good network of other similar professionals with whom they can discuss concepts when they are working near the edge of their skillset. For a company to offer geophysical services in California, either a senior employee or owner of the company must be a licensed Professional Geophysicist (PgP) in California. The company cannot use a subcontractor or consultant to be their PgP with responsible charge on projects as neither a subcontractor or consultant has the authority to tell people that don't work for them to immediately stop if something is being done incorrectly or poses a risk to the public. There are a lot of people who seem to misunderstand the concept of responsible charge, so I feel like I have to explain it often. If your company offers geophysical services in California and someone asks who your Professional Geophysicst(s) is/are, you should immediately share the names of the persons with responsible charge over that business area as not sharing it may cause people to think that you are offering a licensed service without a licensed professional in a position of responsible charge over the work. If you believe my understanding of this concept is incorrect, please share the law or statute that I need to read to correct my understanding.

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The latest issue of Geomechanics and Tunneling, Vol 17(2), features our publication: "A Framework to Demonstrate the Utility and Safety of the Observational Method (OM)." In this paper, we introduce a probabilistic methodology to assess how the Observational Method impacts structural safety, specifically examining changes in the probability of failure when the OM is applied. The full text is available here: https://lnkd.in/dCzJujvq

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Beam FEM Solver by prompting an LLM. For years I've been thinking of creating a simple FEM solver for beam structures but never really got myself to do it. Today I did and tried how good of an approach would the current state-of-the-art LLM's give. I used "im-also-a-good-gpt2-chatbot" model for it, which is one of the mysterious models recently found in LMSYS Chatbot Arena. Not many people know what it is, I've only heard rumors. It might be a GPT-4 with some new reasoning engine or something similar by OpenAI. Anyhow, what is worth mentioning is that I had a functioning FEM solver in 30 minutes from the first prompt. I used Rhino 8 and the new Code Editor in C# for the task and pretty much just pasted in what the AI model produced. Three errors debugging rounds later it was working just fine. I also tested it against Karamba3d, which I love, and found an excellent match in the displacements. I have some ideas what to do next and they might have something to do with a previously created (hand-written from scratch by me BEFORE the LLM era) cross-section analysis engine. That might lead to something like a GMNIA solver, but we'll see... Crazy times! By the way, can you spot what is wrong with the deformed shape in the video? It is a cantilever beam with a fixed support on the left and three members with a point load on the second node. #AI #Rhino #Grasshopper

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🚀 **Just Published!** 🚀 I’m excited to share my latest research paper titled **"Modeling Life Expectancy and Cost Effectiveness for UHPC Bridge Retrofitting Techniques"** published in the journal Advances in Bridge Engineering. In this paper, we explore how Ultra-High-Performance Concrete (UHPC) can be a game-changer for bridge maintenance and rehabilitation. 🌉✨ A major contribution of this paper is the life expectancy model for UHPC concrete. This is a matter of the quandary because life expectancy for concrete structures has been quantified by evaluating the corrosion or predicting the bridge condition index. In the paper, life expectancy modeling was performed based on the corrosion and inherent properties of the concrete. https://lnkd.in/evPaNB8G #engineering #bridgemaintenance #UHPC #construction #infrastructure #innovation #sustainability

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�� New Paper Alert 📣   Kindly check out our new study (co-authors: Abbie Liel and Ken Elwood) on the impact of failure mode uncertainty on seismic fragility and collapse risk of concrete structures. The study was motivated by physical evidence of failure mode variability between nominally identical test specimens and observed significant variability in the performance of neighbouring identical structures (both concrete and steel structures) in past earthquakes. Here, we present a methodology to identify structures susceptible to failure mode variability and propagate this variability in the probabilistic seismic assessment of RC structural systems, allowing for a more comprehensive evaluation of seismic risk. The presented case study demonstrates that failure mode variability can significantly affect the seismic fragility and collapse risk of RC structures. Please reach out for further discussions. https://lnkd.in/eVHuA3Jm #openaccess

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Presented By: Remy Lequesne, University of Kansas Description: ACI Committee 133 led a team of researchers and engineers to survey reinforced concrete buildings damaged in the Pazarcik (Mw7.7), Elbistan (Mw7.6), and Yayladagi (Mw6.4) earthquakes that struck Turkey and Syria in February 2023. The team, comprised of ACI members and collaborators from Turkey and the surrounding region, surveyed hundreds of buildings in ten cities in south-central Turkey. Most buildings surveyed were multi-story apartment buildings with reinforced concrete frame-wall systems, though the survey also included “tunnel-form” buildings that are comprised mostly of reinforced concrete walls and slabs. The presentation will describe reinforcement details that were commonly observed in damaged members, including widely spaced transverse reinforcement, “dog-leg” bends in longitudinal bars at the base of columns and walls, and lap-spliced column and wall longitudinal bars. The presentation will highlight reinforcement details in damaged members that are, or arguably are, permitted in ACI 318-19. These include inadequately confined beam and column longitudinal bars in joints when the members are not designated as part of the lateral force resisting system. https://lnkd.in/dbFH9ZKf

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I was pleased that my article reached 600 reads in ResearchGate. Achieved on June 26, 2024 Article: Seismic Performance Assessment of Deteriorated Two-Span Reinforced Concrete Bridges DOI: 10.1186/s40069-022-00498-9 Abstract: This paper presents a nonlinear analysis procedure for the seismic performance assessment of deteriorated reinforced concrete bridges using a modified damage index. A finite-element analysis program, RCAHEST (Reinforced Concrete Analysis in Higher Evaluation System Technology), is used to analyze deteriorated two-span simply supported reinforced concrete bridges. The new nonlinear material models for deteriorated reinforced concrete behaviors were proposed, considering corrosion effects as shown in a reduction in reinforcement section and bond strength. A modified damage index aims to quantify the seismic performance level in deteriorated reinforced concrete bridges. Several parameters of two-span simply supported deteriorated reinforced concrete bridge have been studied to determine the seismic performance levels. The newly developed analytical method for assessing the seismic performance of deteriorated reinforced concrete bridges is verified by comparison with the experimental and analytical parameter results. https://lnkd.in/giY8-JiM

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Published research article at Geosciences with the title: The estimation of shear wave velocity for shallow underground structures in the Central Himalayan region. https://lnkd.in/dVTqNGG7

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Test your knowledge of engineering ethics.

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Ritika S. Kundu, Ph.D., P.E. will be presenting on Design and Construction Challenges at the Piney Branch CSO 049 Storage Tunnel in Washington, DC on Monday, June 24 at 10:25 a.m. at next week’s North American Tunneling Conference. The Piney Branch CSO 049 Storage Tunnel (PBST) will be the last major project for the DC Clean Rivers Program. The project includes construction of a 2,200-foot-long, 18-foot internal diameter storage tunnel; two connections to combined sewer infrastructure; and two shafts. Major challenges include excavation underneath an existing live outfall that must remain in service; excavation of the tunnel through several areas of low rock cover and mixed-face conditions; and negotiations with a variety of federal, regional, and local stakeholders to address project impacts. This presentation describes the overall project scope, geotechnical conditions along the alignment, design and construction challenges, and construction procurement. https://lnkd.in/gcuXxqEP   #delveunderground #NAT2024 #NATunneling2024

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This one is our recent article published in ASCE-ASME Journal of Risk and Uncertainty in Engineering Systems, Part A: Civil Engineering. I would like to thank the co-authors Professor Subrata Chakrborty and Professor Sudib Kumar Mishra for their constant support in this research work. It can be accessed from the link given 👇 https://lnkd.in/gs47Mxwp The work proposed a new error model in effectively implementing heteroscedasticity in Bayesian framework for an effective structural health monitoring using limited available modal data. #SHM #FEMU #Bayesian #UncertaintyQuantiification #ASCE

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I know many of us struggle with burnout, and I am thankful for these tools that help us overcome the struggles. I get so frustrated when people tell me I just need a spa day (like I don't have enough to juggle without trying to budget and schedule a spa day!) If you face similar frustrations, and you haven't registered yet, sign up for our webinar May 21 on Battling Burnout Beyond Bandiads.

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Practice Periodical of ASCE wants papers on infrastructure!

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I am pleased to share our latest paper published in the ACI Structural Journal titled ‘Structural Behavior of Low-Carbon and Functionally Graded Concrete One-Way Slab Strips’, co-authored by my wonderful supervisors: Dr. Josh Woods, PhD PEng, Dr. Evan Bentz, and Dr. Neil Hoult! You can read it at the following link: https://lnkd.in/eqYhhmAa This study investigates the structural performance one way slab strips made of lower carbon concrete and different types of functionally graded (layered) concrete in comparison to conventional concrete. Results indicated little to no structural behavioural differences between lower carbon and conventional concrete, as well as slight enhancements in stiffness from functionally graded concrete.

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If you have an interest in earthing design then please read our recent article on "State of the Art Distribution Earthing Design" by Matthew Bale and Gordon McMurray: https://lnkd.in/gf6BJqvN The article discusses typical situations where standard (common) earthing designs result in unacceptable safety risk, and modern methods available to unravel and solve design complexities. #earthing #electricaldesign

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