Solutions for the Built World: Case Studies in Building Structures Investigations

Solutions for the Built World: Case Studies in Building Structures Investigations

This presentation was made to the Penn State AE 537 Class on Thursday Sept. 8, 2016.  Sonja Hinish, P.E., Senior Associate, WJE was the visiting practitioner who provided the talk.   Ms. Hinish discussed various categories of investigations that are customized and carried out appropriate to the type of problem to be solved or the need of the client.  Categories of investigations discussed included investigation for repair (PT inspections / repair), immediate response (failures / disasters /snow collapse) and the specialized investigation and testing techniques related to historic preservation and restoration.  Sample case studies of all these categories were discussed including the various tools and skills necessary for the particular situation ranging from industrial rope access to the use of specialized non-destructive field testing to the role of the testing laboratory.

An excellent follow up article that compliments this presentation was written by Robert T. Ratay, PhD, P.E. and published in Structure magazine titled Professional Practice of Forensic Structural Engineering.  Students are encouraged to review this article in conjunction with the content of the seminar by Ms. Hinish for inclusion in the discussion that follows.



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43 Responses to “Solutions for the Built World: Case Studies in Building Structures Investigations”

  1. YusufA
    September 15, 2016 at 9:07 am #

    Same common issues arise when looking at forensic engineering which hasn’t been answered just yet.

    Why do buildings fail?

    Is it because of lack of supervision or neglect during construction.

    I was particularly interested in the snow failure on the tensioned fabric roof collapse discussed in the presentation in class.

    However, I still believe that proper heating of the entire building roof system could help with snow drift failure.

    The thermal coefficient in the ASCE 7-05 also takes into account this phenomenon and I think more research could be done into figuring out the required amount of heat that would be needed to avoid the deposit of snow on roofs. This would also be relative to the region under consideration.

  2. Ommar E
    September 15, 2016 at 8:42 am #

    Some questions still linger on the topic of failure investigations;

    1- How are responsibilities shared among the different parties to a failure investigation
    2- Who , for example, responsible to secure the site where a collapse happened where no fatalities involved? is it the owner? insurance companies? local authority?
    3-Is there conflict of interest when the same company that investigate the failure perform the required construction work?
    4- Would the owner be liable if he does not get the investigation team to the site as early as possible when a incident happen ? Would that be seen as trying to hide or change the facts on the ground?
    4- What percentage of failures causes get figured out and the party responsible get held liable?
    5- Are out there well known mysterious cases that have not be resolved yet?

  3. Shubham
    September 15, 2016 at 1:58 am #

    The article by Mr. Robert T. Ratay provides a knowledge about Forensic Engineering. Few points, not covered in the talk, which I feel important are:
    1) Old copies of design codes, standards and manuals are important references on a forensic engineer’s bookshelf.
    2) Steps when – a) a Collapse occurs, b) a litigation is already in progress
    3) Dispute resolution.

    In Fig 2 of the article, is it the less clear cover provided? or is it something else the picture is trying to say?
    Article link mentioned in the second paragraph of this webpage.

    • Shubham
      September 15, 2016 at 2:03 am #

      Sorry about excuse the typo in first line.
      * The article by Mr. Robert T. Ratay provides an all-round information about Forensic Engineering.

  4. Joshua Z
    September 15, 2016 at 1:57 am #

    One topic that was prominent in our previous discussion post was the presence of neglect in many of the failures we looked at in the previous week. The Building Forensics industry exists to determine where something went wrong in construction, and often times it can be determined that neglect was a key factor in a failure. So, what happens when a forensics firm is not careful and it makes a mistake during analysis? I understand that sometimes, investigations are desired to be closed and settled quickly. In some cases of the building failing, the failure occurred because someone who was responsible during construction failed to complete inspections or properly assemble the building. This can also be a result of competitive bidding, as seen in the Save-On-Foods roof collapse case. Low prices led to failure to complete the required tasks. What if this were to happen with a forensics firm? If a settlement is reached based off of inaccurate information, does the investigation need to be reopened? How would the settlement change? Would a new firm be brought on to lead the new investigation? These are all questions that I was thinking about after the presentation.

  5. Shubham
    September 15, 2016 at 1:55 am #

    The lecture by Ms. Hinish was covered the basics, what Forensic Engineers do, to how do they do it? Especially, the use of industrial rope intrigued me.

    One important thing she mentioned, which cannot be overlooked: They do not read the contract documents (whether the client will have to bear the loss) so that they can have an unbiased judgement.

    In the case study of ‘Tensioned fabric roof collapse’, the overlooking of pre-existing connection during renovation is a good example of “Negligence”, where the basic cause wasn’t the obvious ‘Heavy snow load’. And is an good example of ‘sleuthing out the causes’.

    One question which I’m still stuck on, what measures are taken when a crack is observed in a structural member. How do we estimate the deteriorated capacity and decide the member is to be renovated or not? or What degree of renovation is required?

  6. Mehrzad
    September 15, 2016 at 12:54 am #

    It would be interesting to know if Ms. Hinish recalls a project in which an access equipment used to evaluate a building had to be relocated due to structural concerns of the influence of such equipment on its support and whether or not locating supports of a survey outrigger crane, for instance, to a more structurally sound area in a farther distance (it could be related to a project similar to our course project but with easy access to desirable locations) is more beneficial than usage of a less effective equipment on the floor slab.

  7. Prateek Srivastava
    September 13, 2016 at 8:17 am #

    It was a pleasure meeting Sonja in the class and to learn from her first hand experience in the field.

    The coursework is definitely gripping and is providing us with important factors as required while investigating a building from a structural forensic engineers point of view. I got to learn about the other important aspect of this field from Sonja’s presentation, ie, how to handle situation involving the owner/client, legal arbritations and insurance companies as its a tricky situation to whom to listen while providing your final investigation report while insurnace claim.

    Her presentation also made me realise that how well one need to be expert in the field to investigate as i might not have thought of sectional losses occuring at the wall plates due to continuos wetting and drying situation causing deterioration in Coors Grain Silo failure.

    One point as she mentioned while discussing ‘Tensioned fabric collapse’ Snow storm Jonas – January 2016 was that her firm WJE was called after 5 days of collapse and she reached the site on the 6th day after collapse. So, by that time most of the snow melted which made it relatively difficult to analyse the situation.

    My question being, ‘how to make a better judgement in such situations in general where the sources causing the event are no more present?

    Well, secondly the question being, how far one need to go while investigating to find the root cause or we just need to cater the needs of the client.

    • Yamile R
      September 14, 2016 at 9:13 pm #

      Those are very good questions.
      When a forensic engineer have a late arrival to the site after a collapse could be possible that external and especially natural causes, are no longer evidenced on the structure. What is left is estimate all loading and circumstances of that day. Ms Hinish mentioned on the example case of snow collapse that they investigated the weather records from NOHRSC, to try recreating the conditions of the moment of collapse. Other sources are equally available to all. Additionally, it is possible to look for traces on site and interviewing eye witnesses, depending on the case this could also be useful.

      • Ishan Uppal
        September 14, 2016 at 10:16 pm #

        Thank you Yamile for refreshing my memory regarding the weather records that were referred to, to recreate the conditions at the time of collapse.

        Answering Prateek’s second question, I believe as a Forensic Engineer, one definitely has to find the root cause that led to the collapse, regardless of the requirements of the client. I believe this because a Forensic Engineer has the responsibility of ensuring that a similar incident does take place again as it’s not just financial loss that one deals with but more importantly loss or injury to human life.

        • Joe H
          September 14, 2016 at 11:48 pm #

          I completely agree that the forensic engineer must focus on getting the right answer, not just pleasing the client. It’s interesting because this is different than structural design, where meeting the clients needs is the number one priority. Forensics offers a different set of obligations, which starts with the safety of the building.

          I was impressed with WJE’s take on ethics presented my Sonja. Their goal is to get the answer right, regardless of if it is the answer that the party who hires them wants. This practice has made them very reputable and respectable in the forensics industry. I understand that forensics is still a relatively industry (compared to design) so hopefully smaller or newer firms will see the reputation of firms like WJE and strive to match or exceed it. I think the companies can all push each other in a positive way to produce the most accurate results, which is the most we can ask for in an investigation.

        • Prateek Srivastava
          September 17, 2016 at 9:00 pm #

          Thanks for answering Ishaan.

          Even i second that thought, forensic engineers need to find out the root cause rather than just catering to their clients.

          As, it adds to their experience and they learn about certain other failures as well.

      • Prateek Srivastava
        September 17, 2016 at 8:52 pm #

        Thanks a lot Yamile for answering my question. Exactly, that’s what i am trying to say, if a forensic engineer reaches later on a failure site, he/she needs to rely on eye witnesses and traces left.

        Considering, eye witnesses how many are going to remember the exact sight its hard to say, secondly what an engineer would have looked if he/she would have been on time, would have been very different as they know what might would have got ’cause-effect relation’.

        That’s why its all very probabilistic in terms of finding evidences as you might or might not find the required things. It takes a very good eye for a forensic engineer and sound concepts to get to the conclusion.

  8. Mehrzad
    September 13, 2016 at 7:36 am #

    Ms. Hinish’s lecture was very informative on the introduction of tasks and a glimpse of the work environment at forensic firms. The projects by WJE discussed in the lecture were self-explanatory of the engagement scenarios of forensic engineers in which non-technical and legal communications play a more significant role than the case of engineers of record (EOR) who mostly initiate contract documentation with less bonds to possible forthcoming legal involvement in case of the structure not performing as intended / expected. Complexities and unknown factors in the evaluation of a failed structure necessitates employment of experienced forensic firms in order to be able to estimate the most accurate account of actual failure occurrence causes and provide sound judgements for litigation, if applicable. Same EOR not from forensic firms sometimes work with clients such as owners or insurance companies that given the financial and legal aspects of a project are asked for their opinion summarized in a document. They may be asked for a report in favor of a certain party and this brings the ethical facet into play.

    I had the experience of dealing with owners requesting reports that would include causes of failure such as façade distortions under coverage terms of insurance companies. Another example was in a mall with a tenant of a large space that was a kids entertainment center. The tenant was concerned about floor slab cracks. The entire mall and possibly the neighbors, being close to a river, had major floor slab gradients. A portion of the slab resting on existing piles was re-designed and poured but the remaining portion of the slab revealed concerning top of slab elevation changes of multiple inches within 30-ft proximity. The large cost of slab replacement and modification of the structure underneath in the entire area and inability to secure coverage of repair costs from the insurer, the owner decided not to touch the existing condition justifying it had been there for a long period.

  9. Ommar E
    September 12, 2016 at 11:36 pm #

    Ms Sonja Hinish’s lecture shed the light on what is required of a forensic engineer. Especially on areas where conventional education and training in structural engineering might not be enough to do the job. Structural engineers are taught to structurally design buildings to ensure stability, soundness and high performance. However, when things go wrong, figuring out what went wrong calls for whole host of other skills set and many more tools in the box. On top of being a competent structural engineer, it requires the sophistication to navigate the world of conflicting interest when failures happen. It entails high ethical and moral judgment to not be swayed by clients’ needs and maintain integrity to the highest level. It also begs for knowing how to present the facts in a manner that they could be used to settle or provide sound bases for judicial matters. A good negotiation skill comes handy when parties to the failure case do not come to an agreement about the causes of failure. The uniqueness of every single case demands high degree of adaptability and ability to think out of the box. On a different note, forensic engineer should be able to improve the codes and the practice of structural engineering design by providing feedback from the experience they gain as a hands on practitioners leading to avoidance of many preventable failures. With the ever increasing complexity of the built world and its advance emerging technologies and material, the demand for forensic engineers to sharpen their tools and training is paramount.

  10. Ishan Uppal
    September 12, 2016 at 11:09 pm #

    Hi all,
    This course and the guest lecture by Sonja Hinish was really fascinating. The field of Forensic Engineering as introduced, is a side of engineering that basically “puts the puzzle back together” so to speak, and helps ascertain how and why structures fail.
    The moral responsibility of any engineer to build any product (building, machinery etc) by keeping in mind the safety of the user, was reinforced during this lecture for me. Especially when Ms Hinish discussed her Construction Crane Collapse case study.
    The Grain silo failure at the Coors factory was very interesting because the reason of failure of the structure was something I could have never anticipated! The area of the silo, where the hot spent grain hit the tank at entry, saw significant sectional loss and weakening which eventually lead to the collapse of the silo when it was filled to capacity. This was a classic example of how important foresight is to the Engineeing profession. As a structural engineer, the temperature of the liquid entering the silo would be one of the last things I would think of at the design stage. But the insights that I am getting with such case studies is now shaping my thought process while designing!
    The company that I worked with earlier had a Preservation and Renovations department. I wasn’t very familiar with the details of the work they did, but always thought the work was interesting. Ms Hinish’s lecture was a wonderful introduction into the conservation and preservation field. Especially the laser scanning, 3D printing work done by WJE at the Hotel Monaco in DC.

  11. Brendan B
    September 12, 2016 at 9:36 pm #

    I was certainly interested in Sonja’s comment about the legal process of forensics and what happens when firms are in disagreement. Similar to car insurance companies trying to reach an agreement after an automobile accident, forensics firms must arrange a meeting to reach an agreement. Over the summer I was involved in an accident where the other driver hit me from behind and tried to claim that they were not at fault, for whichever reason I still don’t understand. Fortunately, our respective insurance companies reached an immediate agreement that the other driver was at fault. However, cases are not always that easy.

    The Ratay article discusses the different ways to dispute damages such as settlement discussions (in my case), mediation, arbitration, and trial in court. Obviously settlement is the best/cheapest option as it doesn’t require bringing in a mediator/arbitrator, and it avoids court action. The article also mentions how some investigators choose to not get involved in the case because they may feel their credibility will be questioned on the grounds they are looking to profit from it. This leads me to question if there have been situations where the ethics of the investigator have been questionable.

  12. Shane M
    September 12, 2016 at 8:07 pm #

    Certainly I believe that every engineer, structural or not, should gain some experience in the study of failures and forensics. This is not an industry where you can just hope to learn from your own mistakes, because you should not risk making them in the first place. Unfortunately other people do make mistakes both big and small. Though it is not a common occurrence or if you do not work with failures at all, it never hurts to do some reading and investigations on your own. Ms. Hinish presented a variety of failure cases with different causes, and she really proved to me that you never know what to expect. It seems like her and her colleagues are always learning valuable lessons.
    The litigation advising side of forensic engineering seems to be half of the battle in closing any major case. I can see how complicated these cases can become; firms need to be quick and accurate in their investigations because of time and budget constrictions. Most, if not all, failures can be solved given enough time, but unfortunately this is not the case. With multiple firms involved in an investigation, its best to have mutual agreements and cooperation among all parties. Anything that keeps the case out of a trial in court is best for everyone.

    • Rebecca M
      September 14, 2016 at 6:45 pm #

      I think you’re absolutely right that engineers should gain experience in failures and forensics of structures. Starting out in this option, specific job opportunities like forensics and building enclosure science weren’t explained enough to fully understand it’s impact in this field. Studying forensic investigations gives a higher level of insight into the design process due to understanding the results of solved cases and the causes that played into the failures. With that knowledge, design professionals can go into a design with some of the more common factors in mind to mitigate repeat situations. One thing I understood through Ms. Hinish about WJE is that their engineers are constantly learning new things, which leads me to believe that the engineers of WJE would be less likely to fall into a repetitive rut, despite some engineers being known for doing one to two certain kinds of projects.
      As for the actual investigations, I wonder, on average, how long a firm is given to investigate the causes of a failure. Knowing that clients want or even need to know the why’s and how’s as soon as possible, what is the tradeoff between the amount of time an investigation takes versus the accuracy of the engineers in the project?

      • Brendan B
        September 15, 2016 at 12:06 am #


        It’s interesting how you bring up how clients want as much information as soon as possible. The building industry is always on a clock and budget, as owners and clients want everything to be completed as fast/cheap as possible. As we learned in the Save-On-Foods roof collapse, competitive bidding drove down contractor fees which made it difficult for them to perform the services to their standard. The decision to try to save some money with the contractor fees ultimately lead to a reduced quality of work.

        Regarding your comment about the tradeoff between the amount of time an investigation takes versus the accuracy of the engineers, one would hope the client values quality over time when investigating a failure. As you previously mentioned, engineers can use their knowledge of building failures to help prevent future cases. Forensics is a field where you never stop learning, and is essential to understand exactly why a failure occurred.

  13. Rebecca M
    September 12, 2016 at 6:57 pm #

    Like most others, I found Ms. Hinish’s presentation to be a great introductory explanation of a general day-to-day work style of a forensic structural engineer. One thing that didn’t surprise me about her presentation was the description of how much time she spends writing reports. During my internship this past summer, I went with another engineer to measure section loss of W27s in a leaking parking garage. While the actual measurements took only a few hours, the organization and creation of an understandable deliverable to give to the client took much longer.

    I also found, in the Professional Practice of Forensic Structural Engineering article, the phrase “reasonable degree of engineering certainty” that stood which connected very well to Ms. Hinish’s presentation. She explained that some engineers work on investigations that they’re not too familiar with to start. The article explains that the aforementioned phrase is a legal term in court and illustrates that the opinion of the engineer “does not have to be with one-hundred percent certainty.” To me, it seems as if this phrase keeps some of the blame off of the investigating engineer should he or she be incorrect about an assumption or cause of failure, perhaps due to an inexperienced approach.
    However, it is clear after Ms. Hinish’s presentation that the inexperienced engineers become much more knowledgeable about that specific topic due to copious amounts of time spent on research, before the final “verdicts” are given to the client. A few questions I’ve thought of after the fact is how many engineers work on an investigation together? Has there ever been a failures case where it was clear the engineers gave a bias opinion that went against a “reasonable degree of engineering certainty?”

    • Alec B
      September 14, 2016 at 11:51 pm #


      You mentioned a site survey performed during your summer internship. I performed a few similar site surveys during my summer internship, and I noticed how long it took to translate our findings on site and reproduce them as repair documents. I’d find it very interesting to read some of Sonja’s reports – I wonder what kind of level of detail she must include to properly convey all information. I’d imagine she must be very careful in the manner in which she words her reports such that information may not be misinterpreted or misleading.

  14. Yemi O
    September 12, 2016 at 4:45 pm #

    Sonja’s presentation was very refreshing for me in particular. Being able to thoroughly understand the behavior of structures and their interaction with the environment to the smallest detail encompasses what forensic engineering is to me, and this involves going out into the field and having that hands-on interaction with the structure

    It was particularly interesting to see the uniqueness of each building failure problems and the different approaches used to solve them. One thing to point out as Yamile also pointed out, was Sonja talking about how soon they get to a building after it has failed in some way. This can be problematic, I think, because it can lead to a case where the forensic engineers may not be able to come up with a logical conclusion for a particular type of failure. Furthermore, this can in turn lead to some legal issues in the future.

    Another thing to note are the advancement of technologies when it comes to the forensic science and investigation of buildings/structures. Does WJE work closely with a particular firm/firms to help in the improvement of their forensic analysis of structures through the use of a software or an on-site equipment? It will be interesting to know how far these processes have progressed over the last decade.

    • MichaelB
      September 12, 2016 at 8:11 pm #


      I think you bring up an interesting point. I’m am also curious what different technologies are available today for forensic engineers to use. I think it is especially interesting how you check for existing reinforcement in reinforced concrete non invasively. I know it is common to use GPR along with exposing a small section. From my limited exposure to this process it seems much more useful if the GPR is performed directly by the investigating structural engineer. If the GPR is done by a third party they do not know what to look for as far as what strips the engineer is interested in.

      I was also intrigued the method mentioned in the article Professor Parfitt referenced that involved using X-rays to determine reinforcement for delicate structural features. I would be interested to read about what the differences between X-raying an area of interest and using GPR; in addition what situations would benefit more from X-raying compared to GPR

      • ErikS
        September 13, 2016 at 6:48 pm #

        Yemi and Michael, WJE and similar investigating firms use many techniques and technologies to perform investigations and assessments, and not all of these are highly technical or advanced. Many of the more technical non-destructive tests (NDT) or techniques utilized are:
        • GPR or X-ray to determine presence and configuration of internal steel reinforcing,
        • Ultrasonic and pulse-velocity (a physical wave is created from knocking/banging on the surface and the wave is timed through the material) techniques are used to determine if voids or cracks are present in concrete,
        • Ultrasonic testing is used to determine steel (or other material) thickness for pipes or tanks,
        • Infrared cameras are used to look for hot-spots in electrical or mechanical equipment but also for potential roofing or facade water or air leaks.

        And there are many more. And often these NDT are followed up with a destructive, or minimally-destructive, technique such as partial demolition of a slab to confirm reinforcing bars, taking a coupon (sample) of a steel section, removing finishes from the interior of a wall or cladding from the exterior, removing bricks, or cutting an inspection opening in a roof – all in an effort to confirm the findings of the non-destructive test. These openings can be created by the investigating firm or with the assistance of a specialty contractor, usually trained in the specific materials to be cut through.

        Generally, if possible, the investigating firm has the capability and experience to perform the NDT and analyze the results. This is generally the most effective and efficient for as you mentioned this keeps the search for information with the engineer/architect (I will stick with engineer) that is actually looking for the information so that if something else comes to light the engineer can assess this new lead and determine if it is valid and whether it needs to be incorporated in the remaining investigation. There are occasions when it is advantageous for a third party to perform tests when either the equipment is cost prohibitive, the extensive knowledgebase/training required is not available in-house, etc. Often times the investigating firm has a working relationship with the subcontractor and trusts the techniques performed and data provided, but still often follows up with destructive confirmation testing.

        With regards to software there are many programs that are utilized for structural analysis. The data points and material properties are input into the program and the engineer and software analyze the data output. The output is only as good as the input and the engineer setting up the model.

        For facade assessment work the investigation may include water testing, which includes spraying water on the building from calibrated nozzles in a specific configuration or spacing. Software for this work often includes CAD or other structural analysis programs, depending on the type of facade failure. Having a good understanding of CAD (note CAD and not Revit or BIM) is important as building the detailed interfaces of a building facade is not [currently] possible or at least practical with Revit.

        As for X-ray vs GPR it often depends on the thickness of the slab, the density of the reinforcing mats, I believe the substrate, if you are looking within the slab or through the slab, etc. I am not as familiar with these two techniques and hopefully Sonja or Paul will speak to this.

        • MichaelB
          September 14, 2016 at 9:00 pm #


          Thank you for providing a detailed response. I definitely agree about using CAD over Revit for drafting complex details. Revit has gotten pretty good in some respects as you can install an add on to freeze a view section to break it into drafting lines so you don’t have to start a detail from scratch.

          I am not too familiar with how GPR works either but I believe it outputs a chart like this from Wikipedia: It seems GPR may require more training to interpret the results when compared to an X Ray as it is not a clear cut image. I would assume you have to take more safety precautions using X-Ray equipment to avoid exposing yourself to radiation.

        • Shane M
          September 15, 2016 at 1:45 am #

          Erik, thank you for this informative reply. I never knew how much equipment could have use in these investigations. I am intrigued by the innovative uses of the equipment you talked about. I am curious as to which NDT is the most commonly used by WJE. Some of the tests sound like they might require some additional training in order for an engineer to be performing them in the field. Does WJE train all of their engineers for field testing/analysis or is that more of a specialized sector of the company?

  15. Joe H
    September 12, 2016 at 4:09 pm #

    My interest was especially sparked when Sonja was talking about having multiple forensics teams investigating on the same job site. Initially, my thoughts were that these companies would be rivals who did not want each other to find the same information as the other team in hopes that they would be the first to accurately determine the failure. I was surprised when she said that it was a very friendly, interactive atmosphere during these investigations.

    This poses the question of what are the rules of sharing information for these investigations? Do it vary company to company or do copyright laws apply? I know that working for a design company, everything you create is their property and you cannot use or share it. How do forensic findings differ? I know that the end goal of design and forensics are much different, and I’m sure that changes the rules.

    I would personally believe that it is much more important to find the correct answer than to have your firm be the first to finish. If sharing info benefits the investigation but shares credibility with another firm, I believe it should still be shared. I’m sure there are many more factors than that, but I am curious what all they are and how they affect the investigation and collaboration.

    • Joshua Z
      September 12, 2016 at 5:03 pm #


      I was also curious about the rules pertaining to sharing information. One thing that also piqued my interest was how if there were multiple firms investigating a failure, are they all being hired by the same employer or are they hired by different employers? In the event that they are hired by different employers, does this make the rules for sharing information different from if they were all hired by the same entity?

      Another note that I was curious about was payment. If two firms were hired to perform the same scope of work, would they be paid the same? Obviously quality and quantity of work come into play, but I was curious as to how payment might differ.

      In terms of sharing work, I think competition might also be discouraged as multiple firms may also be brought on to investigate different areas of failure. Therefore, if one firm found information that may be helpful with the investigation that another firm is leading in a different area, it only makes sense that they would share said information. I’m not certain, but it is just my take on the situation.

      I agree with you wholeheartedly that finding the correct answer is much more important than finding the answer first. This way, it is possible to make progress and more thoroughly conduct an investigation, as well as pave the way for future investigations.

      • philr
        September 14, 2016 at 2:55 pm #

        When it comes to information sharing, I submit that any information gathered during an investigation is the property of whoever is paying for the information….with the exception of “make safe” requirements and any legal reporting / safety obligations.

        If I was doing an investigation for company A, and an investigator for insurance company b was looking at the same pile of rubble, then I think there would be some natural sharing of facts and observations. However, I would suspect my client would want me to independently verify any facts that I got from that other engineer, and any conclusions I reach would be privileged info only for the person that is paying me for that opinion.

        • Yingzhe You
          September 14, 2016 at 11:36 pm #


          I agree with you. If different forensic companies are hired by different clients or by the same client, there must be a reason for that. Sometimes information provided by others may influence your judgment, especially when you are still doing your investigation. I think that our clients want is the results from different views, and that’s why different engineers are hired.

          Investigation in the field may be kind of tough work, so certain kind of help from other company can reduce the unnecessarily physical work and time.

          That’s to say, cooperation of certain level can be helpful but we should not share all our information to others.

  16. Di W
    September 12, 2016 at 12:58 am #

    Both this course and Ms. Hinish’s speech have been leading me to a whole new world of the buildings and structures. Since I have been a structure engineering student for ages, I was always considering how to successfully build up something rather than how do buildings fall down. However, from a brand new angle in this course, I started to think about the reasons that caused building collapse and from which I could see where most mistakes happened during design and finally I could avoid those mistakes in my design.

  17. Yamile R
    September 10, 2016 at 2:04 pm #

    The talk by Sonja Hinish on “Solutions for the Built World” was very interesting. We learned about building forensics from an industry point of view. I found myself very curious about the engineers’ first approach to a building failure, and Ms Hinish, with example cases was able to respond to it. She always emphasized that each case is particular, that some are more difficult to access, and that others may need more initial investigation work than others. Also, that the timeframe between a collapse and the engineer’s first visit is very influential, since part of the “evidence” could no longer exist.
    To complete this idea, and as part of the process of forensic work, Ratay’s article includes a list of activities that engineers on each case should accomplish, whether is a structural condition, a collapse case or a litigation. The scope will vary according to this and to the client’s requirement, but is a good general idea of the process.

    Also, it was interesting to learn that a forensic investigation do not always gets to a final conclusion, as Ms. Hinish pointed out about the warehouse roof collapse, that the parts settled before the engineers could find the cause. Settlement is one of the commons dispute resolutions according to Ratay, together with mediation, arbitration and trial in court. We have seen that the legal process can be tedious, but is important to understand the involvement and requirements from the engineer for each step.

    • mkev
      September 11, 2016 at 4:17 pm #

      It is not uncommon for a client to stop the work before a cause is found or before a cause is confirmed (usually there are theories but more time is needed to confirm or eliminate them). Several years ago I was asked to investigate an arena in PA where shortly after the placement of a new roof (roofing, not structure) snow slid down the roof, hit the parapets and peeled off a large section of the facade.

      I was asked to investigate on behalf of one of the insurance companies. After making several trips to the site, the investigation was suddenly called off. The reason was that as coincidence would have it, the same insurance company insured all of the primary parties that were involved in the project. As a result, there was no need to pursue a claim since they would be just going after themselves (albeit perhaps different accounts or divisions) so it was not worth the added expense to determine the exact cause.

      Did I know what happened? Yes, and it was fairly obvious in “my opinion” but technically the investigation was never completed nor were any reports made public.

  18. Alec B
    September 8, 2016 at 11:56 am #

    I’d like to begin by saying that Sonja’s talk was very insightful and provided a first-hand approach to forensic engineering. Hearing Sonja’s personal experience in stepping through the process of arriving at a conclusion to some of her case study examples demonstrates some challenges encountered that are unique to every project. After re-thinking Sonja’s talk in preparation for this discussion, additional questions came to mind that some of you may be able to answer by sharing your thoughts on the matters:

    One question that came to mind is: when is “enough, enough” in investigating a building failure? Much like any timeline in the building industry, the timeline of an investigation can’t go on forever, and I’m sure clients are in demand of answers sooner than professionals may be capable of providing them. Sonja mentioned how some cases are settled even before a cause is unsurfaced and continued investigation stops before ever determining the main reason for the failure. When does a team of forensic engineers eventually come to a conclusion even if one or two components/details of the investigation don’t necessarily add-up to the cause or exist as expected based on the believed reason for failure? I understand the answers to these questions vary from project to project, but what I’m getting at is: are there certain metrics or matrices developed that help determine when “enough is enough” or is it mainly the engineers’ judgement?

    Something else I found interesting in Sonja’s talk is the legal process behind the forensic engineering. Sonja answered my question in relation to what legally happens when firms disagree on the main cause of failure; she mentioned that most often meetings take place and the main cause is agreed upon or at the very least legal matters are settled based on the differing opinions of the involved forensic engineering teams. Of course, sometimes not all disputes may be settled and then a court order needs to be involved as “a last resort.” The related article linked to this post gets into more detail behind the legal matters that exist behind the forensic investigation which I found to be quite interesting. What it seems to boil down to is that professionals must provide unbiased answers that are uninfluenced by their clients and pre-existing ideas in order to promote the desired and ethical outcome of any legal matter surrounding a building failure.

    • Yamile R
      September 10, 2016 at 2:15 pm #

      As you and Phil pointed out from Ms. Hinish talk, the most important legal and ethical role of a forensic engineer is to give their impartial opinion based on their findings.

    • Yemi O
      September 12, 2016 at 4:49 pm #


      I completely agree with your question of knowing when enough is enough. Personally, I think structural failures are a culmination of many factors and because of that, you can’t exactly point out the “main” cause of a failure. However, it is evident that there will be some cases where it is very apparent but I feel it is also important to know how to bridge the gap between intuition and facts in cases where the causes are not that obvious.

    • Yingzhe You
      September 13, 2016 at 12:55 am #

      What you talked about enough is really interesting. As Sonja mentioned in one of her cases, different engineers came up with different reasons for the same building failure case. I’m wondering is that because of the different judgments of “enough” made by different engineers. Some of them might just stop after finding important evidence and took it as the crucial one.

      And one more question about “enough”. Engineers need plenty of time for their investigation, but with the time passing by, not all evidence will remain the same at the time of collapsing. Snow is a good example. It may melt after collapse, so we can’t get the snow load if we can’t weight the snow on the roof on time. So is there a certain time after the collapse that we may stop gathering information? I think that may be one of the answers for “enough investigation”.

      • Di W
        September 14, 2016 at 11:56 pm #


        The example of SNOW LOAD you mentioned shed light on the word of “enough”. Besides, I have a little different point. If the Snow Load is the mainly reason that causes failure, engineers could still find some evidence from the local observatory stations. Data will exist even the snow has gone by the time that engineers arrive. Thus, engineers can estimate the snow load according to the data

        On one hand, experience is a good way to overcome the problem of “enough”. Investigation in different building collapse cases can help firms accumulate data and improve their database. With a highly developed database of building failure, engineers can find the real factors much easier that lead to the building failure. For example, if they know that most of the factors that caused building failure in a certain area was snow load, they can directly go to the snow part. On the other hand, we really do not expect that our database gets larger and larger because that means more and more buildings failed. Isn’t it very controversial?

  19. philr
    September 8, 2016 at 11:42 am #

    I enjoyed the presentation today. I especially resonated with the message that the company does not cater the desired outcome of the client, which I would hazard to guess is essential to long term survival this industry. I also noted her comment that occasionally there are evaluations required for materials and technology that she is unfamiliar with, so the first task may be to learn more about what is being evaluated.

    In the Ratay article, I found the following statement curious.

    “All of the parties on a construction project have legal responsibilities as defined by their contracts, and by state and federal laws. But professionals performing “value engineering” and “peer reviews” generally do not have liability for the safety of the constructed facility.”

    I find the statement that an engineer performing “peer review” does not have liability for the safety of the facility is curious. Yes, they may not be the engineer of record, but any significant mistake in peer review would likely catch the attention of an attorney, should he get wind of it.

    • Alec B
      September 12, 2016 at 2:23 pm #

      You bring up an interesting point about engineers not typically being held responsible or liable if they were contracted to perform a “peer review” or “value engineering.” An engineering contact of mine once told me a story about how his firm was hired by the contractor to occasionally visit the construction site to help identify any areas that may be improved upon from a value engineering perspective or from an overall constructability standpoint. A tragic accident occurred that resulted from the lack of sufficient shoring for concrete planks being installed. Though my engineering contact had nothing to do with the design (or even the supervision) of the project, he was still brought into court because he visited the job site on a regular basis. As it turns out, his company actually had to pay a settlement for even being involved with the project at all – granted, it wasn’t even close to the settlement some other companies had to pay, but I found it interesting that his company had to pay anything at all since they were only on-site occasionally to help with value engineering and constructability.

      • ErikS
        September 12, 2016 at 4:09 pm #

        Phil and Alec, in follow up to your comments regarding liability of architects/engineers performing “peer reviews” or “value engineering”, specifically peer reviewing which I have more experience with – the reviewing engineer does have liability for the safety of the constructed facility; however, in a limited capacity. Generally a reviewer’s notes on drawings and specifications are “suggestions” or “considerations” for the Architect or Engineer of Record. The reviewer is not designing nor providing designs for the AOR/EOR, but merely providing comment for consideration to improve the air/moisture barrier, roofing, structure, etc. It is up to the AOR/EOR to accept or decline the suggested improvements.
        If the reviewing party saw an oversight that could be detrimental to the integrity/safety of the structure the reviewing party has a professional obligation to state the issue. Again, it goes back to the AOR/EOR to accept the comment and act upon it. Should the reviewer not comment on an item of concern and a failure occurs there is the possibility the reviewer could be held liable, at least to a minimal extent, if not for simply not adhering to their engineering ethics and speaking up.
        With regards to your engineering contact, Alec, it would be interesting to go back through that litigation to find how they accessed liability upon your contact/contact’s company. It is generally difficult to determine what someone assessed or observed on site, especially when not contracted specifically to perform such assessments, unless the contact has photographs or written notes indicating the issue(s) that later lead to the collapse had been observed and not commented on, and that assumes the contact had a background sufficient enough in that field to have recognized and commented on the potential concern.

        • Mehrzad
          September 15, 2016 at 12:48 am #

          Standard of Care to be implemented by the AOR/EOR and defined in Ratay’s article and literature as the quality and soundness of services by “normally competent practitioner of good standing in the same field” is of major importance in mitigation of failure causes. In a similar situation as Alec’s contact’s, a firm I worked at was responsible for design of a large cold-formed metal framings project of modifications to an existing building. The firm, as the CFMF’s subcontractor’s engineer was called to the site multiple times by the design team of record due to strictness of the EOR on numerous CFMF connections to the main framing, CFMF welds, bracings, etc. In case of failures initiated in elements other than the CFMF and affecting the CFMF, and in the absence of enough evidence for what triggered the failure, I imagine the firm could still be claimed accountable. As failures have more occurrences in miscellaneous framing and cladding/facades than the main framing, it is vital for contractors’ engineers, similar to AOR/EOR, value and peer review engineers, to conform to the Standard of Care.

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