Biography Kermin Chok is currently a Technical Director in the Civil and Structural division at Meinhardt. He is a
member of the firm’s Global Design Group, which is responsible for accelerated concept development,
internal quality control and knowledge sharing. In his role, he helps advance the technological edge as it
relates to engineering and design collaboration. He leads the development, deployment and integration
of custom and off-the shelf workflow solutions tailored to the firm’s needs.
Kermin’s research interests center on digital design as it relates to architectural-engineering collaboration,
workflow compression and structural optimization. His work in these areas has been previously published
in the journal of the Association for Computer Aided Design in Architecture (ACADIA) and the
International Journal for Architectural Computing (IJAC).
Previously, Kermin worked at Skidmore Owings and Merrill (Chicago) and Halvorson and Partners
(Chicago). In his past roles, he has contributed to many large scale projects such as the Burj Dubai,
Trump Tower (Chicago), Infinity Tower (Dubai) and Central Market Development (Abu Dhabi). Exposure to
these large projects has shaped his thinking on the future of design collaboration and engineering.
He holds a Bachelor of Science (Civil Engineering) with Honors from Northwestern University and a
Master of Engineering (Civil Engineering) from MIT. He is currently based in Singapore.
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The building industry is currently awash in a plethora of digital design tools. Each tool seeks to address
a specific need in the design process starting from light conceptual modeling to detailed building
information modeling (BIM). For example, in larger architectural projects, conceptual studies are often
undertaken with a mix of physical models and rapidly evolving parametric models. This rapid adoption of
digital tools have allowed for a new mode of architectural expression previously impossible where in
architects can digitally mold their designs instantaneously. In the delivery phase, BIM is a key tool in
order to effectively deliver these increasingly complex projects. In this evolving design environment,
software vendors routinely update their products yearly with an ever growing list of features. While
compatibility within their own design platforms has increased, the linkages between platforms utilized by
industry specialist are often insufficient to keep pace with evolving design practices.
Software innovation in the building industry has typically been targeted at the architectural and
contracting industries due to their commanding size. The time required for architects to reshape a
building for a client’s input and approval has minimized. The structural engineering industry has
typically lagged with software innovation and has not kept up with the current speed of architectural
innovation. The problem is exacerbated by attempting to fit a traditional structural engineering approach,
better suited to simple building geometry, to projects that involve geometric complexity. If the
structural engineer does not keep up with the current innovations in the architectural digital domain,
they risk becoming marginalized in the conceptual and schematic design processes. The conventional
means of concept collaboration, wherein an engineer uses their judgment to converge on efficient
architectural and structural solutions, followed by initial design checks to confirm the suitability of the
proposed concepts, may become obsolete in the digital frontier.
This paper explores how the structural engineering process might be re-thought to provide collaborative
solutions that the traditional engineering process lacks. The paper explores challenges and solutions
ranging from working with architectural geometry in the fluid conceptual phase, internal process
efficiency to communication and collaboration with different members of the design team.
Types of Collaboration
In the building design process, project participants include, but are not limited to, the client/developer,
project management team, architectural design team, engineering consultants and contractors. Every
party has different, sometimes competing, priorities. In addition, different parties have different preferred
mediums of communication and software platforms, which can complicate project execution.
For example, the client may desire an iconic but cost effective design and their preferred medium of
communication may be reports or emails. Meanwhile, the architectural team may be seeking to deliver a
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project that pushes the edge of design while adhering to the design brief. Their primary medium of
communication is usually visual which may include sketches or detailed renderings. On the other end of
the spectrum is the PM and contracting team who has safety, constructability and cost on the forefront
of their mind. Their communication and project execution platform may be detailed BIM.
In this fragmented communication environment, design intent and project requirements can be easily
misinterpreted. This paper proposes that the smarter leveraging and linking of existing software
platforms, rather than the use of more software platforms, as a solution to this challenging design
environment.
In order address such challenges, the paper frames proposed solutions in three radiating spheres of
innovation: efficiency, communication and collaboration. This is illustrated conceptually in Figure 15.
Figure 15: Spheres of Innovation
Internal Efficiency Internal efficiency is the first step for any member of the design team to effectively contribute to the
design process. Digital design tools, while allowing un-paralleled architectural freedom, has the
additional characteristic of accelerating the design process. Architectural design iterations occur in ever
compressing time scales, and engineering consultants must accelerate their internal process to provide
timely feedback to the design team. If the design team continues with the conventional fragmented
internal processes, the engineering studies can easily be two or three design iterations behind,
subsequently resulting in “forced” solutions further along the design process.
Leveraging architectural geometry
A critical first step in closing the gap between architectural and structural design is being able to use the
surface massing model that is generated at the early stages of the design process. In the initial stages of
the design project, the design team is primarily concerned with overall geometry and massing and its
relation to floor areas, rough environmental studies and feasibility of the structural system.
Illustrated in Figure 1 is an example massing model that the structural team might receive from the
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architectural team. These forms are usually generated parametrically using software such as Rhino-
Grasshopper or Bentley Generative Components. Working with such surface geometry using traditional
structural engineering drafting platforms such as AutoCAD can be very challenging, due to program
limitations and incompatibilities. The loss of geometric information during import/export procedures
between different software platforms only compounds the challenge.
Figure 16: Example Architectural Tower Massing
In order to address this challenge, custom digital design tools in Rhino-Grasshopper have been built
which allow the quick and easy extraction of structurally relevant information. While the architectural
design team might be primarily concerned with floor areas and the sensitivity of the proposed massing
to the site, the structural team is looking for key information such as the total gravity load, base shears
and overturning moments due to lateral loads. Illustrated in Figure 17 are two custom components that
compute the relevant code specific wind pressure for the site and key structural information derived
from the architectural surface geometry.
Figure 17: Custom Rhino-Grasshopper Components
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Figure 18: Typical Structural Information Layered on Tower Massing
Illustrated in Figure 18 are key structural information such as wind pressure, story shears and overturning
moments along the tower’s height. In addition to computing structural information, other custom
components that allow direct linkages to structural analysis have been implemented by the author.
Working within a single geometry environment has the advantages of preserving data integrity and also
accelerating the design and analysis process. An accelerated process allows for the structural implications
of geometry modifications to be understood in almost real time. This allows the structural engineer to
provide efficient structural solutions relevant to the current design iteration.
Figure 19: Direct Linkages to Structural Analysis
Structural Morphology
During the design cycle of most projects, geometry is constantly adjusted due to changing design
requirements or design exploration. This is especially true in the schematic design phase of projects,
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where rapid evaluation of structural performance is necessary. The architectural team may be exploring
parameters such as building height or subtle adjustments in tapers or other architectural expressions. In
the structural realm, engineers seek to understand the influence of varying structural member properties
such as wall thickness or beam sizes on critical structural performance such as total building drift or
inter-story drift. These studies have traditionally been performed with manual point-and-click operations.
While such manual manipulation of structural models is adequate for projects of moderate size,
buildings of larger scale and increasing complexity can quickly render this process unworkable.
Furthermore, more value is added to the design process by studying the geometry of the primary
structural system rather than focusing on the member level performance contributions. Nonetheless, the
affects to individual members can also be realized.
In order to efficiently accomplish structural geometry studies, custom programs that automate this
process have been developed by the author. The program morphs the structural analysis model
according to parameters, runs selected analysis (e.g. Linear Static, Natural Frequency, Spectral Response)
and generates a report that documents the sensitivity of the performance measure (e.g. drift, natural
periods, base loads) to the geometry parameter. Illustrated in Figure 20 is a screenshot of the custom
program.
Figure 20: Custom Structural Morphology Program
Illustrated in Figure 21 is an example parametric study of varying the core geometry of a tower. The core
is morphed in 1m increments along the y-axis. Over the course of six runs, the core has a y-direction
depth ranging from 7m to 13m. In this situation, the effect of the geometry modification on the building
natural periods is documented.
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In tandem with the tools to explore a structure’s geometry, optimization techniques are another critical
tool that can accelerate structural analysis and design. Structural optimization is a mathematical
approach to satisfy a set of deflection and strength constraints while minimizing the amount of material
used. Another custom program developed by the author interacts with a finite element solver and
determines the optimum distribution of structural material to walls and beams. See Figure 22 for a
screen shot of this custom program.
Figure 22: Custom Multi Constraint Optimization Solver
Illustrated in Figure 23 is a simple three span truss with two cantilevers. In this example, control of
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deflection at the mid span and two cantilever tips are sought while meeting imposed minimum and
maximum size constraints on the structural members. Such custom optimization tools can greatly
accelerate the structural exploration process and minimize the often tedious trial and error approach to
structural sizing. Furthermore, member size constraints can be collaboratively established by soliciting
architectural and constructability concerns.
Figure 23: Example Optimization Model
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In all firms, communication occurs both internally and externally. In most structural design groups, junior
level engineers are tasked with analysis and design while more senior engineers are responsible for client
contact and management of numerous projects. Due to the differing responsibilities, preferred mediums
of communication can vastly differ. Furthermore, different aspects of the project can have different level
of importance to the different levels within a firm.
For example, senior managers might be primarily concerned with schedule, material quantities and
overall structural behavior. However, design engineers might be mainly concerned with detailed analysis
and design involving individual member forces. Communication between the layers can be hindered by
failing to understand the differing concerns of each team member.
External communication can also suffer from a similar lack of alignment of priorities and mediums of
communication. Architectural teams might be more visually inclined while project management teams
might tend towards written communication.
Automated Post Processing of Structural Analysis
In order to bridge the gaps in communication both internally and externally, tools which are interactive,
easy to use and highly visual are implemented. To this end, a custom program was developed by the
author to automate the post processing of structural analysis results. The program reads information
directly from the structural analysis model and generates interactive web pages displaying information of
interest.
Information ranging from story loads to drifts to material quantities can be quickly reported. This frees
the design engineer from tedious manual manipulation of data and allows them to concentrate more
value added tasks such as design exploration or architectural collaboration. Illustrated in Figure 24 is a
screenshot of the custom program which allows for easy post processing of structural analysis.
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Figure 24: Custom Program for Structural Analysis Result Reporting
Figure 25 shows the interactive, easily shareable, web page reporting relevant structural information. This
democratizes and distills the wealth of information that structural analysis produces. It also allows all
members of the design team who may not be directly involved with the management of the analysis
model, to understand, at their selected level of detail, structural behavior and performance.
Figure 25: Web Based Reporting of Structural Analysis
Common 3D Modeling Platform
In order to communicate geometry variations and schematic structural sizes, utilizing a common 3D
modeling platform with the architectural team is crucial. A common lightweight modeling environment
allows easy visualization of structural members and its impact on the architectural design. This also
provides a fast way to generate traditional 2D plans, elevations and sections as the design rapidly
evolves.
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Figure 26: Bi-Directional Linkage of Structural Analysis and Rhino
Collaboration
Internal efficiency and communication are the crucial first steps in delivering greater value to our clients.
The key differentiator in the future for design and project delivery will be how the skills and experiences
of the team can be effectively leveraged. Digital design tools have opened up previously inconceivable
possibilities for architectural expression. In the previous two sections, this paper has shown the
possibilities of using these same tools in custom ways to accelerate and communicate structural design.
In this section, the paper explores ways to collaboratively explore the design space so that client’s needs,
architectural intent and structural requirements are fulfilled simultaneously.
Floor Plate Geometry Exploration
A simple example of leveraging digital design tools for architectural collaboration might be the exploring
the location of corner columns in a typical floor plan. Usually, corner conditions want to be
architecturally expressed for occupant views. This can be achieved by sliding the columns away from the
corner. However, this creates a cantilever condition which might lead to excessive slab deflections which
can complicate the façade design.
The structural design team might explore the variation of the columns away from the corner and its
effect on slab deflections. Illustrated in Figure 27 is a range of corner slab conditions with the
supporting columns moved away from the corner.
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Leveraging bi-directional linkages to structural analysis, these geometries can be analyzed quickly and
deflection performance obtained. Moving beyond linear modes of collaboration where geometries are
traded back and forth between architect and engineer, custom tools allow the engineering team to
proactively explore a range of geometries which might satisfy both architectural and structural
considerations. Illustrated in Figure 28 is the result of structural analysis. With such quick analysis
available, the design team can converge towards a mutually satisfying outcome in much shorter time
frames.
Figure 28: Floor Plate Displacement
Force Trajectory Exploration
Tracing force trajectories along a design surface is another potential avenue for design exploration
leveraging digital design tools. In Figure 29, some common design spaces where force trajectory
exploration might be illustrative are shown. The first situation is a core and outrigger lateral system,
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which is often preferred due to its reduction of core size and limited impact on the architecture. Another
commonly encountered structural situation is the design of transfer beams.
Figure 29: Trajectory Studies Loading Profiles
A custom component was written by the author to dynamically interact with external finite element
software and trace principal force trajectory lines given a set of seed points. Figure 30 shows the raw
principal force vectors in the finite element package and the final result from the custom tracing
operation. Thus, in more complicated structures with multiple loads paths, where basic structural
intuition might be misleading, this operation can be used to show stress concentrations and primary
load flow.
Figure 30: Filtered Trajectory Lines
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Digital design tools have significantly advanced within the architectural design community. The design
community now has the opportunity to explore innovative, iconic designs that before only resided in the
imagination of the designers. This paper has explored areas of innovation which might allow the
structural community to collaborate more effectively with their architectural design clients.
The paper began by exploring innovations in the internal efficiency realm. This area provides the
foundation for effective project execution. Building upon this, the paper explored innovations in
communication that are built upon a base of automation that aid the production of highly visual and
interactive documentation. Finally, the paper explored digital design technologies from the perspective of
provoking new possibilities for design exploration. These technologies will serve continue to serve as the
foundation for innovative and iconic design projects in the future.
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