Structural Engineering Expert Witness Opines on Bridge Construction Dispute

Jared Firestone

Written by
— Updated on December 20, 2017

Structural Engineering Expert WitnessCase: Scott Bridge Co. v. Gresham Smith & Partners, 2015 U.S. Dist. LEXIS 139604 (M.D. Ala. Oct. 14, 2015)


Plaintiff filed this action in tort against Defendant alleging professional negligence, gross negligence, and/or wantonness. Plaintiff’s claims relate to designs that Defendant prepared for use by Plaintiff in constructing “deep water” piers 7, 8, and 9 of the B.B. Comer Bridge in the Tennessee River.

Defendant described the relationship between it and the Plaintiff and the B.B. Comer Bridge as follows:

“In March of 2001, Defendant … contracted with the Alabama Department of Transportation (ALDOT) to serve as the design engineer for the B. B. Comer Bridge Replacement Project … which involved the replacement of the B. B. Comer Bridge on State Route 35 crossing the Tennessee river in Scottsboro, Alabama. The bridge project was divided into three phases. Phase II included the section of the bridge crossing the main channel of the Tennessee River and involved Piers 7, 8 and 9 of the bridge. ALDOT contracted separately with Plaintiff … as the contractor for Phase II of the bridge project.”

Plaintiff asserts that while preparing its cofferdam design for the construction of the piers, its engineers noticed a potentially inadequate concrete seal designed by Defendant and notified ALDOT of the problem in early October 2009.

Plaintiff further described the dispute that arose between it and Defendant as follows:

“ALDOT directed [Defendant] to evaluate its defective design and then develop a re-design to solve the problem. In its first evaluation, [Defendant] concluded its original design was “not good’ and so informed the ALDOT. Several weeks of re-designs and uncertainty over the ultimate solution ensued until Scott Bridge was finally able to implement the re-designed work at the end of November 2009.”

Plaintiff alleges that Defendant’s redesigns “caused considerable construction damages and costs to Plaintiff, the balance of which Plaintiff now seeks recovery in this action.”

Expert Witness:

Plaintiff retained Dr. Richard Hartman, P.E., an engineer, to offer various opinions regarding [Defendant’s] designs of Piers 7, 8, and 9, along with opinions regarding Plaintiff’s construction practices. Dr. Hartman graduated with a degree in Civil Engineering in 1965 and a Master of Science degree in 1966 with a focus on structural engineering. He obtained a doctorate in 1972, with a focus on structural engineering and minors in material science (metallurgy) and elasticity. He has been in the construction industry for over forty years, and he is a licensed professional engineer in 38 states. He has experience with cofferdams, bridges, foundations, and foundations and designed cofferdams for a deepwater bridge in Georgia.

Dr. Hartman reached the following conclusions in his expert report:

  1. The means and methods used by [Plaintiff] to install the drilled shafts and the cofferdam were consistent with accepted construction practices.
  2. The foundation designs for Piers 7, 8, and 9 as shown in the original Contract Drawings were unstable relative to uplift.
  3. All foundation redesigns for Piers 7, 8 and 9 were stable relative to uplift.
  4. The first redesign of the Pier 7 foundation was not feasible to construct.
  5. [Defendant] did not meet [the] generally accepted standard of care and was negligent when preparing the original designs of Piers 7, 8 and 9.

Defendant retained Dr. Ted Thomson, P.E., a licensed professional engineer, to analyze whether Defendant’s designs for Piers 7, 8, and 9 sufficiently resisted the buoyancy force that would have been created when the cofferdams were dewatered, and to render an opinion regarding whether or not GSP’s foundation designs ultimately met the standard of care. Dr. Thomson obtained a Bachelor’s degree in Civil Engineering from the University of Delaware in 1993. He subsequently obtained his Master of Civil Engineering degree (concentrating in structural engineering) from the University of Delaware followed by a Ph.D. (concentrating in geotechnical engineering) from the University of Massachusetts in 1998. He is a licensed professional engineer in six states. Dr. Thomson is also a member of several professional organizations and specialized in geotechnical and structural design and instrumentation, and insitu geotechnical testing. He has also worked on projects involving cofferdams in water, and was engineer of record on a marine project in Wilmington, Delaware that involved a jetty with a cellular cofferdam that ‘behaves a similar way (to the case at bar) when it’s subjected to the forces.

Daubert Challenge:

Defendant challenged both Dr. Hartman’s qualifications to offer testimony in this case as well as his methodology. Defendant argued that Dr. Hartman was unqualified on the following bases: (1) Dr. Hartman is not a geo-technical or structural engineer; (2) while he is qualified to testify regarding cofferdam design and construction, his expertise in cofferdams and retaining walls does not qualify him to testify regarding the standard of care for the design of a marine bridge foundation involving concrete; (3) Dr. Hartman has no experience designing a marine bridge with a concrete foundation and cannot testify as to the standard of care for designing the same; (4) Dr. Hartman has never testified in a case regarding the standard of care engineers should use in designing a bridge; (5) Dr. Hartman has never been involved in the construction or oversight of a bridge with drilled shafts like the subject bridge; and (6) Dr. Hartman did not conduct any specific research regarding the proper methodology for drilled shaft installation before formulating his opinions in this case.

Defendant also argued that Dr. Hartman’s methodology was unreliable. Defendant first argued that Dr. Hartman’s understanding of methodology is derived from his discussions with contractors and past review of reference materials as opposed to specific research regarding the proper methodology for drilled shaft installation. This argument was not supported by testimony and other evidence of record as to the source of Dr. Hartman’s methodology.

Defendant further argued that Dr. Hartman failed to use sufficiently reliable methodology in evaluating whether the foundation designs met the standard of care because the value he used in his calculations regarding resisting forces was unreliable for the following reasons: (1) the value of the friction force between the steel and surrounding soil was pulled “off the shelf” from a Minnesota Department of Transportation manual and was neither site- nor region-specific; (2) Dr. Hartman failed to consider friction between the drilled shaft and the rock socket because the Minnesota manual did not assume friction in that area; (3) Dr. Hartman used a value for the friction between the seal concrete and the steel casing/cofferdam steel that was more conservative than the standard of care; and (4) Dr. Hartman did not use an accurate value for the weight of the cofferdam steel because he ignored a resistive force that would have increased the total weight. In support of those arguments, Defendant referred the court to the methods and conclusions of its own experts.

Defendant also argued that Dr. Hartman used unreliable methodology in evaluating whether the first redesign for Pier 7 was constructable because he offered only his opinion that the revised design was impossible to construct.

Finally, Defendant argued that Dr. Hartman’s opinions regarding whether the foundation designs met the standard of care and whether the first redesign of Pier 7 was constructable are irrelevant and would not assist the trier of fact because the uplift calculations he used were not sufficiently related to the site-specific conditions in this case.

Plaintiff contested the sufficiency of Dr. Thomson’s qualifications to testify as to the same. Specifically, Plaintiff argued that: (1) Dr. Thompson’s experience is primarily in geo-technical projects, construction, and observation testing projects and that his reliance on a staff engineer to perform critical calculations is evidence of his lack of experience and expertise; and (2) Dr. Thomson has no experience in performing engineering analysis involving a marine bridge with drilled shafts, seal concrete, and cofferdams.


The Court denied both motions made to disqualify Dr. Hartman and Dr. Thomson.

Firstly, the Court found that both Dr. Hartman and Dr. Thomson are qualified to testify as experts based upon their respective qualifications. Dr. Hartman and Dr. Thomson possess the necessary “knowledge, skill, experience, training, or education” to testify in this matter. (F.R.E. 702). The arguments made against their qualifications are properly characterized as being related to the weight and credibility of their testimony, but do not undermine their qualifications to testify on the subjects they offered their testimony for.

Secondly, the Court found that both Dr. Hartman’s and Dr. Thomson’s testimony was reliable and relevant.

Defendant’s challenges to Dr. Hartman’s methodology were based on the fact that Dr. Hartman’s methodology and conclusions were different from those reached by Defendant’s experts. There is an acceptable range of differing methodologies and conclusions within which different expert witnesses may operate, and this case presents that range. Asserting that an opposing party’s expert uses methods that do not conform with one’s own expert’s method does not demonstrate the unreliability of the opposing expert’s methods. The Supreme Court recognizes that experts may reasonably differ on issues of methodology and conclusions, but that those differences should be admitted assuming they each meet the reliability and relevance requirements to assist the trier of fact in deciding often complex issues.

One of the material calculations in this case has to do with “uplift,” and the value for the “factor of safety” (i.e., the ratio of the resisting forces to the driving forces, or uplift) differs between Dr. Hartman’s and Dr. Thomson’s testimony. Dr. Hartman utilized the Minnesota Department of Transportation manual in his analysis, Dr. Thomson used values contained in the Florida Department of Transportation manual, and the parties concede that the Alabama Department of Transportation manual does not contain the necessary standards for the issues at hand. While the parties argue over soil and ground compositions in Minnesota, Florida, and north Alabama, the geographic proximity of those two states to Alabama, skin friction between the drilled shaft and the rock socket, and the friction value between the seal concrete and the steel casing / cofferdam steel, the evidence of record taken as a whole, and especially the deposition testimony by Dr. Hartman and Dr. Thomson, convinced the court that, for purposes of a reliability and methodology determination, the Minnesota and Florida manuals’ friction force values are appropriate, and that Dr. Hartman’s and Dr. Thomson’s overall analyses, including the factors of safety used by each individual, met the baseline requirements of admissibility.

As discussed above, Defendant also challenged the methodology and reliability supporting Dr. Hartman’s testimony regarding constructability and standard of professional care, specifically with designs as to aspects of Pier 7. Again, the record as a whole, which has been subjected to careful and close scrutiny, and Dr. Hartman’s qualifications and areas of specialization are sufficient to satisfy the admissibility requirement of Rule 702 as to Dr. Hartman’s testimony on these points. Defendant’s assertions speak to the weight Dr. Hartman’s testimony arguably should be given by the trier of fact, but are not persuasive that his testimony is inadmissible.

The opinions and findings of Dr. Hartman and Dr. Thomson were precisely the sort of testimony that should be weighed and decided by the trier of fact, in this case the trial judge at a bench trial, but does not cause the testimony to be inadmissible.

After reviewing the parties’ briefs and the evidentiary submissions, the Court found that Dr. Hartman and Dr. Thomson based their testimony on sufficiently reliable methods. Even if the parties argue that they disagree with their opponent’s expert’s opinions, the parties can argue against any opinions reached by an opposing party’s expert as well as present evidence of their own theories at trial, which is in keeping with the notion that “[v]igorous cross-examination, presentation of contrary evidence and careful [attention] to the burden of proof are the traditional and appropriate means of attacking … admissible evidence[,]” (Daubert) and “the weakness in the underpinnings of the expert’s opinions go to its weight rather than its admissibility.” (Jones v. Otis Elevator Co., 861 F.2d 655, 663 (11th Cir. 1988)). The parties will have the opportunity to cross-examine Dr. Hartman and Dr. Thomson at trial to test their credibility and differing opinions before the trier of fact.

The testimony these expert witnesses offer is relevant to issues raised by Plaintiff’s claims and Defendant’s defenses, and they are likely to assist the trier of fact in reaching the ultimate issues.

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