STRUCTURAL ENGINEERING CONSULTING AND THE IMPACT ON CONSTRUCTION EXECUTION

THE IMPORTANCE OF ENGINEERING IN CONSTRUCTION DESIGN

The role of the structural engineer is a key component in the construction process. As part of the wider discipline of civil engineering, structural engineering is concerned with the design and physical integrity of buildings and other large structures.  Structural engineering is one of the most fundamental engineering disciplines because it deals directly with the structural integrity and strength of a building or structure. Thus all construction projects must utilize the principles of structural engineering in order for the new building or structure to bear its own load and to be able to withstand the demands that will be placed upon it.

Design of the Structure – Structures must be designed so that they can withstand their own weight as well as the loads and pressures that will be placed upon them. Structural engineers provide crucial information about roof types, foundations, floors, steel beams, material quality, retaining walls, and more. A structure that does not consider structural engineering in its design runs the risk of collapsing under its own weight or under the environmental pressures placed on it.  In both design and construction, numerous operational tasks must be performed with a variety of precedence and other relationships among the different tasks.
Analysis of the Structure – A thorough analysis of the structure according to the principles of structural engineering will ensure that the new building or structure is up to all necessary design codes. Careful analysis also yields information about the load the structure can bear, the wind velocity it can withstand and the overall capability and utility of the building.
Let’s take a closer look at what structural engineering is, why it is so important, and how Alexander and Davis Consulting assists its clients with this service.  Structural engineering is founded on the principles of physics and mathematics. It involves applying knowledge of physical laws as well as empirical research into the strength of different materials as well as the necessary geometry and calculations required for a structure to be sound. Some key ways that structural engineering affects projects include the design of the structure and an analysis of the structure.
In the planning of facilities, it is important to recognize the close relationship between design and construction. These processes can best be viewed as an integrated system. Broadly speaking, design is a process of creating the description of a new facility, usually represented by detailed plans and specifications; construction planning is a process of identifying activities and resources required to make the design a physical reality. Hence, construction is the implementation of a design envisioned by architects and engineers. Several characteristics are unique to the planning of constructed facilities and should be kept in mind even at the very early stage of the project life cycle. These include the following:

• Nearly every facility is custom designed and constructed, and often requires a long time to complete.
  
• Both the design and construction of a facility must satisfy the conditions peculiar to a specific site.
  
• Because each project is site specific, its execution is influenced by natural, social and other locational conditions such as weather, labor supply, local building codes, etc.
  
• Since the service life of a facility is long, the anticipation of future requirements is inherently difficult.
  
• Because of technological complexity and market demands, changes of design plans during construction are not uncommon.
  

In an integrated system, the planning for both design and construction can proceed almost simultaneously, examining various alternatives which are desirable from both viewpoints and thus eliminating the necessity of extensive revisions under the guise of value engineering. Furthermore, the review of designs with regard to their constructibility can be carried out as the project progresses from planning to design.
For example, if the sequence of assembly of a structure and the critical loadings on the partially assembled structure during construction are carefully considered as a part of the overall structural design, the impacts of the design on construction falsework and on assembly details can be anticipated. However, if the design professionals are expected to assume such responsibilities, they must be rewarded for sharing the risks as well as for undertaking these additional tasks. Similarly, when construction contractors are expected to take over the responsibilities of engineers, such as devising a very elaborate scheme to erect an unconventional structure, they too must be rewarded accordingly. As long as the owner does not assume the responsibility for resolving this risk-reward dilemma, the concept of a truly integrated system for design and construction cannot be realized.
It is interesting to note that European owners are generally more open to new technologies and to share risks with designers and contractors. In particular, they are more willing to accept responsibilities for the unforeseen subsurface conditions in geotechnical engineering. Consequently, the designers and contractors are also more willing to introduce new techniques in order to reduce the time and cost of construction. In European practice, owners typically present contractors with a conceptual design, and contractors prepare detailed designs, which are checked by the owner's engineers. Those detailed designs may be alternate designs, and specialty contractors may also prepare detailed alternate designs.
Structural engineering is crucial because it directly impacts the safety and durability of buildings and structures. For example it is structural engineering that allows for an accurate estimation of safe weight maximums on bridges, the storm force winds a warehouse or facility can withstand, or the magnitude of tremors a skyscraper can endure during an earthquake.
 
A Structural Engineer provides a key link for the Contractor during construction, but the Structural Engineer role and connection with construction of the project starts well before the first shovel hits dirt.  Coordination of a well-planned and detailed set of construction documents is a critical first step.  Unforeseen site conditions are costly enough, however, without this first step, a project can get lost in request for information (RFI’s) or confusing drawings.  A well-coordinated set of documents includes coordination among the many design disciplines.  This involves checks between different consultant drawings and collaboration of design team members during meetings to resolve challenges during design and before construction.
On many projects, a general contractor may be involved early in a pre-construction role or on a Design-Build project.  This provides a great opportunity to coordinate and collaborate during design with the entity that is going to build the structure.  There are many different ideas on the best methods to construct and working together during design should greatly enhance the ability of the project to be built.
There may be no more critical time period for a project schedule than during construction and within the construction period one could argue that completion of the building structure is quite possibly the most critical.  While other phases of construction may allow for multiple trades to be working on site, the building structure physically supports all other elements and must be completed first before others begin.  Keeping the structure schedule on track is critically important and the SE needs to keep up with the pace of the Contractor.  Beyond responding to RFI’s and submittals as quickly as possible (which should go without saying) and at most no more than the time allotted by the project specifications, projects that allow for regular site visits with the Contractor to answer questions and provide clarification go a long way to keeping job sites busy and productive.
This last item is a key and critical point to providing construction administration for the Structural Engineer.  Site visits and Code required Structural Observations are necessary for the success of virtually all projects.  Below is the description of Structural Observation from the City of Los Angeles DBS Structural Observation Form:
“STRUCTURAL OBSERVATION means the visual observation of the structural system, for general conformance to the approved plans and specifications, at significant construction stages and at completion of the structural system.  Structural observation does not include or waive the responsibility for the inspections required by Section 108, 1701 or other sections of the code.”
Site visits and observations go hand in hand with other disciplines and help to provide checks and balances during construction as noted above.  Inspections by third party inspectors provide specific review of the contractor's work and provide the SE with information on the quantity and quality of constructed material.  The SE works in conjunction with the inspection team and the Contractors to verify the structure is being constructed in conformance with the approved construction documents.
With a strong team of Owners, Contractors, and Designers, construction of a project can and should go smoothly.  The Structural Engineer plays a critical role in its success and this responsibility starts early in design and extends into and through construction.  Only when construction is done can we truly say, “On to the next project!”
Our engineers understand the critical nature of developing cost effective structural solutions while considering all aspects of the design through the final piece of the structure being placed.   And do not hesitate to contact any of our offices should you have a need for a structural consultant that works diligently through the completion of your project.
Structural engineering is also tasked with ensuring that materials and resources are used efficiently. For example structural engineers must be able to determine the optimal material grade that ensures safety and function without unnecessarily raising costs. Structural engineers must also be able to work within the design aesthetics called for by the project. Thus structural engineering plays a crucial role by marrying visual appeal, practical function, and budgetary resources in a way that satisfies all needs.
Alexander and Davis Consulting offers structural engineering as one of our core services. We will conduct evaluations and inspections of the foundation and design, perform all necessary calculations, conduct rigorous structural testing, inspections, investigations, and studies, and even assist with acquiring building permits. We are proud to offer this fundamental, important engineering service to our clients and we strive to deliver nothing but the best, strongest, and safest results for our community.

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