GEM Engserv Pvt. Ltd is an ISO 9001:2015 certified organization, certified by TUV India in accreditation with National Accreditation Board for Certification Bodies (NABCB).
GEM Engserv Pvt. Ltd is an ISO 9001:2015 certified organization, certified by TUV India in accreditation with National Accreditation Board for Certification Bodies (NABCB).
Building construction projects are becoming more and more cost and time sensitive. Especially with several redevelopment projects starting up concurrently in a vicinity, the decisions taken on one’s project is no longer based on static information. We have also seen developers opt for unique configurations to optimize the building footprint and maximize the yield from each project, given the heightened competition within each micro-market. A combination of these factors is making peer reviews of structural design a growing need to prevent a delay or worse rework after proceeding on a project.
This article explores scenarios that we have recently observed that warrant peer reviewing structural designs and how this activity can pre-empt large impact to time and cost at a later stage.
The impact of delays is no longer localized. Developers (especially in the redevelopment sector) operate in a hyperlocal, closely knit community, often building multiple projects at once. Word about a stalled project travels fast and may impact the community’s confidence about the brand’s other projects within the micro-market.
Extremely tight plot boundaries leave no margin for design assumptions
Redevelopment projects in Mumbai typically operate with minimal setbacks, leaving little tolerance for inaccuracies in load transfer, foundation layout, or lateral movement predictions.
Complexity due to deep basements
Construction below ground level in congested urban plots significantly increases risks related to excavation stability, groundwater control, and retaining systems. Assessment of geotechnical parameters and earth-retention structures become critical and design oversights can lead to ground movement or distress to neighbouring structures.
Dynamic neighbouring conditions increase uncertainty during design and construction
In redevelopment zones, adjacent plots are often undergoing parallel excavation or demolition, meaning boundary conditions assumed during design may change over time. We have received several requests for performing peer review as an after-thought i.e. after realizing that there has been a change in the environment in which the project is being built.
Load concentration near plot boundary may increase structural vulnerability
A project’s commercial feasibility drives the need to maximize the built area which has given rise to some ingenious space planning. Many project layouts now include discontinuous columns (parking layout), structures such as multi-level car parks, services areas beyond the main building footprint and often very close to the plot boundary. As a result, foundation eccentricities increase, load paths become less intuitive and differential settlements and rotations become more critical.
When structural elements sit very close to plot edges, there is little or no tolerance for construction deviation and retrofitting / strengthening options are limited. Imagine this compounded by adjacent demolition, excavation and other construction activities in the substructure – this often escalates the uncertainty.
Overloaded structural designers
It should be evident to all that the number of structural designers in the industry have not grown in the same proportion as the explosion in number of projects that are being undertaken. Isn’t it strange that the same set of people are churning out twice or thrice the workload that they were managing a couple of years ago? In our assessment, it is possible that designers are either generating “plug and play” designs which are over-safe or may be sacrificing a thorough internal review process which means that some of these critical vulnerabilities might get overlooked.
The risk is often hidden and may surface later. Such issues manifest not as failure of the structure but as an impact elsewhere – cracking, latent defect, tilt, deflection – and it may become difficult to identify the actual root cause.
To offset this risk, structural designers have found an easy way out – load the structures with a skewed factor of safety. Then again, this threatens commercial feasibility which was the starting point in this endeavour anyway.
Even if we consider the structural engineer to be a highly skilled specialist in their domain (similar to a physician, surgeon or oncologist), a second opinion is more warranted than ever, given the context in which we are operating today.
Often, a developer’s team includes a technical coordinator who is also responsible for coordination across various disciplines, reviewing validity of design calculations and providing feedback when necessary. This is not ideal considering the risks highlighted in the previous sections. Peer review is ideally conducted by an experienced and independent team of professionals who have come across a variety of scenarios across their career.
Expertise and effectiveness
Peer reviews must be performed by qualified and experienced structural engineers, preferably not be a single individual (project coordinator). The benefit of having a team of engineers to review, brainstorm and critique builds a level of confidence which cannot be expected from a single in-house engineer coordinating as well as peer reviewing design calculations.
Independence and objectivity
Peer reviews introduce independence and objectivity in the design process. The intention is a critical review of the design intent, assumptions and analytical models to identify points of failure. The structural engineer reviews the design afresh without prior involvement, commercial pressure or confirmation bias, allowing identification of whether the chosen structural system appropriately considers all dynamic inputs such as loading scenarios, soil conditions and construction methodology.
Recommendation of alternatives and best practices
A peer review team may be able to make recommendations of possible ways to resolve conflict, optimize the design and offer a fresh perspective on design assumptions and analytical decisions related to material properties, boundary conditions and soil-structure interactions. They may also suggest alternatives based on their experience on other projects and recent trends in contemporary practice.
In our experience, peer reviews can add immense value to a construction project if introduced at the appropriate stage. However, success of the peer review is often more a people issue than a question of technical competence. A good fit between the principal structural consultant and peer review consultant can be a force multiplier. In this context, selection of the peer review consultant becomes critical.
Notably, while the peer review consultant may offer value engineering recommendations, the intent of the exercise is not to be mixed up (as it usually is). We have explored value engineering in previous articles – links given below: