WHO’S MINDING THE STORE? THE STRUCTURAL ENGINEER’S ROLE

Merle E. Brander, P.E., Member ASCE

Abstract

When we hear in the news about building failures that kill or injure people, the failures are often failures of buildings under construction and involve the means and methods of contractors, which traditionally have been out of the bounds of structural engineering. According to the following code, which is fairly typical of codes in general:

“No owner may construct or alter any building or structure, or portion of a building or structure, or permit any building or structure to be constructed or altered except in compliance with the provisions of chs. ILHR 50 to 64. Compliance with the provisions of this section does not relieve the owner from compliance with the administrative rules established in other related codes.” (ILHR 50.11 of the Wisconsin Administrative Code)

Since codes make building owners ultimately responsible, building owners should be able to control the risks that are brought onto their project sites, even those that result from contractor’s means and methods of construction. If the structural engineer is involved with the project from conception to completion, not only can project continuity be maintained, but also the structural engineer can help the owner by anticipating structural risks before they become part of the project and verifying that they have been appropriately addressed.

Current codes and standards offer some avenues whereby the structural engineer can control the risks that accompany the means and methods of construction. This paper discusses some of the reasons for involvement of structural engineers and some of the ways structural engineers can help control the risks of construction.

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Introduction

BUILT BUILDINGS SELDOM FAIL! – at least not in normal circumstances. Yet frequently we hear about sensational building failures that kill or injure people and result in years of litigation for people from popcorn vendors passing by on the street to the Structural engineer. What are reported in the news as building failures are most often failures of buildings-to-be – in other words, buildings being constructed. While the traditional interpretation of construction means and methods puts control of the construction-in-progress in the hands of the contractor, failures or accidents that occur during construction invariably involve the architect, engineer, building owner, and others incidentally in the vicinity of the construction. Although design professionals have traditionally adopted a “hands-off” approach to the contractor’s means and methods, it is clear that sometimes those means and methods carry risks onto the construction site that affect everyone involved in the construction process. Structural engineers need a way to control that risk for themselves, for the building owners who are their clients, and ultimately for the public. The question is, “Who’s minding the store?”

Some years ago, my wife and I went for an ice cream cone at a small shop in the town in which we lived. Behind the counter was a new employee, a young man who was a casual acquaintance of ours from our neighborhood. When he recognized us he immediately volunteered to treat us to ice cream cones. We declined, but wondered how many others were being treated to ice cream cones; and since he couldn’t have been earning enough to do all that treating, we suspected the treat was really on the shop owner. The young man had apparently learned the lesson about service and greeting customers with a smile- unfortunately he missed the part about earnings and profit. He clearly needed a manager minding the store who was able to see all aspects of the job.

In construction there are no ice cream cones being handed out, but there is a clear need for someone who can mind the store and see all aspects of the job. The structural engineer is the one who is the prime professional responsible for strength, stability, and durability of the platform on which the builders build and future occupants operation.

According to the BOCA National Building Code, which is fairly typical of codes in general:

“The construction documents for new construction, alteration, repairs, expansion, addition or modification for buildings or structures shall be prepared by a registered design professional. All construction documents required for a building permit application shall be prepared by a registered design professional consistent with the professional registration laws of the state in which the project is to be constructed·”

Codes require that buildings be designed by a structural engineer who has been trained in and understands the principles that govern the performance of building components in a constructed facility. Yet, though those same principles that apply to the performance of building components in a constructed facility apply also, and perhaps even more dramatically so, to components of the facility under construction, there is no such requirement for the construction process itself to be guided by the trained professional with the intellectual knowledge needed to determine the adequacy of materials for the use, determine the load paths, calculate strength requirements, etc. That we call the contractor’s means and methods. In the ASCE document “Quality in the Constructed Project” (Manuals and Reports on Engineering Practice No. 73) the submittal section includes references to the handling of temporary structures that fall within the means and methods of the contractor.

Construction bonding is as good a hint as any that there is a risk brought on a construction project by the activities of the contractor; but you can be sure the bond the contractor carries on the job site in no way indemnifies the engineer from personal injury claims resulting from contractor activity. It is up to the structural engineer to be watchful- to understand the general means and methods being employed on a project- and to make some reasonable effort to verify that the contractor is complying with whatever means and methods plans and specifications there are to achieve adequate construction that supports the project in progress.

The Role of the Structural Engineer

How can the structural engineer verify that the contractor is complying with means and methods plans and specifications and still avoid stepping on the sacred turf we call “means and methods”? First he/she must establish what it is that is expected from the project. The structural engineer should be involved from the beginning of the project to become aware of all the structural implications of actions proposed by various parties. Then structural engineers have to define the role of structural engineering, so it is clear to them and to others involved in the project where their responsibilities lie.

The role of a structural engineer might be defined differently by different people, depending on the impact structural engineering has on the activities of the various parties involved in a project. In some cases, the contractor might see the presence of the structural engineer on the job site as a hindrance to the steady progress of work as the contractor has determined it should be. The building owner might be viewing the structural engineer as the owner’s representative not only in matters structural, but as regards the project generally. The architect might see the structural engineer as a competitor for the right to make critical decisions about the nature of the construction proposed. One thing structural engineers have to keep in mind is that their role has already been defined to some extent by the expectations inherent in the title Professional Engineer.

The Preamble to the “NSPE -Code of Ethics for Engineers” contains the followed admonishment:

“Engineering has a direct and vital impact on the quality of life for all people. Accordingly, the services provided by engineers require honesty, impartiality, fairness and equity, and must be dedicated to the protection of the public health, safety, and welfare.”

The fundamental duty of engineers to “hold paramount the safety, health, and welfare of the public” is repeated more than once later in the Code of Ethics. That seems somewhat contradictory to the statements in the General Conditions of the contract, which suggest:

“Engineer’s visits and on-site observations are subject to all the limitations on Engineer’s authority and responsibility ·particularly·Engineer will not supervise, direct, control or have authority over or be responsible for contractor’s means, methods, techniques, sequences or procedures of construction, or the safety precautions and programs incident thereto.”

In other words, structural engineers are to hold paramount the safety, health, and welfare of the public, as long as it doesn’t interfere with the contractor’s course of activities. Well, engineers may try to distance themselves from the means and methods and all the practices during construction that cause the public and the building owner to be at risk, but in lawsuit after lawsuit, when things go wrong, structural engineers still are held liable by the public- sometimes even by the contractor’s employees- for the problems that arise. The fact is that, when construction practices jeopardize the structural integrity of buildings under construction or of structures temporarily in place during the construction process and make them vulnerable to failure, structural engineers become involved; and even if they wanted to, they cannot escape responsibility for withholding the unique knowledge they have as structural engineers because a litigious public won’t let that happen. With any structural failure, or failure of strength, stability, or durability of means and methods construction occurs, the structural engineer, whether actively involved or not, will be challenged for an explanation, as will the owner for allowing the risk to exist without being appropriate addressed by a structural engineer.

Lest anyone question whether the risk I am talking about is real or not, you should know that, in an OSHA 1926 Construction Manual published in 1996, the 25 most frequently cited OSHA Part 1926 Construction Regulations were listed. Of those 25, 10 of them were related to activities directly related to the adequacy of structures during construction. Those 10 ranged from missing, inappropriate, or improperly installed scaffolding, to insufficient protection from the hazards related to excavations.

Implementation

How can structural engineers improve the delivery of projects to reduce the risks introduced by those whose activities, by accepted contracts and long-standing tradition, they do not control? I am not ready to suggest a total revision of the entire system of construction project delivery, but I know the system that already exists can more effectively be used to allow broader input from structural engineering.

The first thing structural engineers must do is identify the situations in the construction process that demand structural engineering and include in the specifications references to codes and code referenced documents that require the contractor demonstrate that those situations have been addressed by a structural engineer appropriately trained for the task. That does not mean that the structural engineer for the project must be directly responsible for all the incidental structural items, like scaffolding, shoring during construction, walkways, etc.; it just means that the structural engineer should specify that the contractor must have a structural engineer- someone on the contractor’s staff, the project engineer, or another consultant hired by the contractor- appropriately address the items and the structural engineer should specify that the contractor submit documentation that indicates that the items have been appropriately addressed.

To incorporate requirements for incidental structural items into the project documents, the engineer has some already established avenues at his disposal. The first is the Supplementary Conditions section of the specifications. Even though the General Conditions, that clearly limit the role and responsibility of the engineer during the construction, are used as a standard part of the project manual, there is the opportunity to insert into that manual Supplementary Conditions that can amend or expand items included in the General Conditions. As indicated in the Standard Form of Agreement Between Owner and Engineer for Professional Services:

“The duties and responsibilities of ENGINEER during the Construction Phase as set forth in this paragraph 2.5 are amended and supplemented as indicated in Exhibit A.”

So while engineers may continue to accept the idea that they “will not supervise, direct, control or have authority over or be responsible for contractor’s means, methods, techniques, sequences or procedures or construction, or the safety precautions and programs incident thereto”, a supplementary condition can be added that requires the contractor to indicate how and by what authority he/she intends to carry out the construction activities that have structural implications. In that setting the structural engineer will not be telling the contractor how or in what sequence the contractor’s work is to be done. The engineer will be merely requiring that the contractor verify that the responsibility for all structural aspects of those means and methods have been taken by a structural engineer for construction unique to the project or by others when using preengineered components, such as shoring trusses.

Shop Drawings

In the ASCE document “Quality in the Constructed Project” (Manuals and Reports on Engineering Practice No. 73), there is the following discussion about Shop Drawings for Temporary Construction (item 16.11):

“Temporary construction shop drawings depict components that will not be part of a completed structure, but are to be used temporarily during construction, such as sidewalk slabs, temporary lifts, temporary buildings, shoring reshoring form work, bracing, scaffolding, dewatering, or temporary power, The constructor has full authority and responsibility for these shop drawings, including design, preparation, review, and approval, since he or she develops the construction plan and has control of the construction process of which the temporary construction is a part. Construction or erection -procedures, shoring, bracing for excavations, or other temporary construction requiring engineering analysis or design requires the seal of a qualified professional engineer affixed to the drawings and specifications.

The role of the design professional or engineer of record is to evaluate the effect of temporary structures on integrity of the completed structure. From this viewpoint, he or she may indicate in the construction contract documents how long such items as temporary bracing, shore-up, reshoring, and similar items need to remain in place. If a non-self-supporting frame is involved, and needs special treatment during construction, or if the design concept of the structure limits the construction sequence, he or she will also include this information. The design professional usually does not review temporary construction shop drawings except when necessary to determine compatibility with the design of the completed structure.”

As stated earlier, shop drawings must demonstrate the structural adequacy of the construction, something that can only be done by a structural engineer. The Structural engineer requests shop drawings for many aspects of a construction project. The shop drawings are submitted to demonstrate to the owner by way of the prime structural professional that the owner’s risks are being addressed by qualified persons. The project documents should clearly state that the review does not confer on the prime structural engineer responsibility nor absolve the contractor of responsibility for proper construction of items shown. The review is done to detect any departure from the original project intent and thus reduce the risk of improper construction. Considering that, the Structural engineer can request shop drawings for any scaffolding, temporary structures, walkways, etc. that will be used to implement the contractor’s means and methods of construction. The request for shop drawings for aspects of construction is not considered interference by the engineer because it is intended to give the engineer the opportunity to verify that the contractor has understood and complied with project requirements. In the same way, shop drawings for the structural items that can impact structural adequacy for personnel and the public would let the structural engineer verify that the contractor understands and has addressed the implications of those items. The request for shop drawings could be accompanied by a request that the party responsible for addressing structural aspects of the contractor’s means and methods submit a statement verifying substantial completion with whatever he/she has specified to make the scaffolding, walkways, temporary structures, etc. structurally adequate. Since the owner and Engineer are subject to the effects of risky action by the contractor, they have the right to demand that the contractor submit whatever documentation is required to allow them to judge for themselves whether risks have been adequately addressed.

Observations During Construction

The structural engineer makes observations during construction to verify that the construction is in general compliance with the plans and specifications. Why can the Structural engineer not also observe the temporary structures, scaffolding, etc. in place to verify that they are in compliance with the documentation that the contractor himself submitted prior to the start of work.

It is understandable that the structural engineer feels compelled to run away from the structural risks that accompany the contractor’s means and methods, rather than insist that those risks be appropriately addressed by the contractor before the engineer comes on the project site. The standard general conditions are written to avoid action on an isolated site, but there really are no isolated sites, particularly with projects that interface with existing construction or interact with existing operations. For example, an insurance company has a claim in a case that alleges a person was emotionally injured as he stood on the sidewalk, well away from a project site, and observed scaffolding fall with workers on it. It is better to anticipate structural risks by all parties to the project and deal with them ahead of time through the specifications than to allow the risks to be brought into the construction process unaddressed by the appropriate theoretical person.

Concluding Remarks

Since various persons are counting on there being structural integrity from the beginning of construction to the completed structure, to control the risks inherent to construction it is important that there be continuity from project concept, in which project needs are identified, to project completion. The structural engineer is the one who should understand the entire construction process and the delivery of the construction project through the five phases of construction listed in the Standard Form of Agreement Between Owner and Engineer for Professional Services:

1. Study and report

2. Preliminary design

3. Final design

4. Bidding or negotiating

5. Construction.

It is essential, therefore, that the prime structural engineer be selected early in the project, even before the study and report phase of the project begins. Then the structural engineer will be the one with the knowledge and understanding of the project and the implications to the structural integrity of the various construction activities that occur to appropriately mind the store during construction.

April 28, 1997