STRUCTURAL APPRAISAL:
A CLASSICAL WAY FOR LEARNING
Joseph Michael Kelly, RA, CEng
Temple University
Architectural Program
1947 N. 12th Street
Philadelphia, PA 19122
USA
E-mail: jmkelly@temple.edu
ABSTRACT
Structural Analysis is an important subject in the Architecture
curriculum at Temple University. Structural appraisal projects help a
student understand architectural and structural integration, construction and
technology, and address practitioners concerns for preparing students for
practice. Projects incorporated in the Structural Analysis course typically
focus on the documentation of historic structures. Students field survey
neglected and/or abandoned historic buildings that are in danger of collapse or
demolition. The students are encouraged to appreciate the beauty in abandoned
structures rather than view them as eyesores. They are required to integrate
sustainable design and building conservation approaches in their
solutions. On specific projects, they
are required to 1) visually inspect the building and note damage, deficiencies
and overall condition; 2) perform analysis of the existing structural system;
3) identify necessary repairs; 4) perform analysis of the building for varying
stages of conservation, including associated cost estimates; and 5) determine a
new use for the building. The students are encouraged to follow both the
intuitive and mathematical paths in their analysis. Example projects include
the historic Baptist Temple (from which Temple University is named), farmhouses,
greenhouses, warehouses, barns and bridges. The goal of the projects is to
illustrate the significant impact of the integration of structure and
architecture and educating students about the significant contribution they can
make to protect historic structures.
1. PURPOSE OF THE WORK
Teaching structural
analysis to architecture students is simply not easy. The concepts are often
hard for the student to understand and there is often no simple solution. To help the students learn these concepts, they
are assigned a research project to provide a structural appraisal report on a
historical structure at the beginning of the semester. Structural appraisal is
the procedure of evaluating the capability of the structure for sustained use.[I]
The students in the class learn to efficiently organize, coordinate and
communicate information in order to convey data necessary for structural
analysis. In the field of architecture it is difficult to teach structural
analysis where the groundwork consists exclusively of a system of theoretical
concepts. Structural analysis is a problem solving activity. Authentic problems
are abundant in historic buildings to provide examples. Teaching structural
analysis to architecture students requires that the students must develop the aptitude
to deal effectively with problems, which occur in real circumstances. A
historic building with an exposed structure system provides an excellent case
study to directly involve the student in this learning experience. The course
emphasis is based on the concept of "how to learn how to learn" from
abandoned historic buildings in the built environment of Philadelphia. Temple
University architecture students are exposed to of the subject of structural
analysis through the class lectures, assignments and structural appraisal
project. The purpose of a building's structure is to offer a safe
and strong method of sustaining the loads imposed by the building’s
composition, the building's occupants and their property, and the forces of
nature, through a series of load paths down to a sturdy foundation.I The subject content addressed in the
course includes load determination and evaluation; resolution and equilibrium
of force systems; truss analysis, etc. The students learn how to calculate
centroids, moment of inertia, and shear and bending moment diagrams. In
addition, the students are taught basic beam, column and system design. The
course builds on the awareness of the theory of force equilibrium. Force
equilibrium stands for one of the most important concepts in the field of
structures for architects, and is the starting point for learning structural
behavior.II For equilibrium in a beam, the
externally applied bending moment has to be resisted by the internally produced
moment between the tension force and the compression force.I The
students gain first hand experience about force equilibrium while examining a
historic building. At the completion of this course, the students generally
have a good understanding of this concept and are able to utilize it in analyzing
statically determinate force systems.
The course is divided
into two parts consisting of statics and strength of materials. A principal
intention of strength of materials is to acquire an effective connection
between applied loads on a non-rigid body and the resulting internal forces,
and deformations induced in the body. The properties of a variety of structural
materials in resisting the applied forces are addressed. Upon completion of the
strength of materials section, students gain an understanding of the correct
relationship of material strength, stresses, section properties, and
deformation derived from the analysis of the load and different support
conditions of the structural member.III The
field observations conducted by students deal with the likely causes of
structural failure in the building under investigation and ways of strengthen
and repairing walls, piers, arches, roofs, etc.
2. STRUCTURAL
DOCUMENTATION
A structure being
appraised is by description able to maintain the loads at the moment of
assessment.I At the beginning of the semester the
students do not have the knowledge or ability to undertake the structural
investigation work. However, as the semester progressives and the students
learn the basics of structural analysis, they gain confidence in their
abilities to carry out the appraisal. Particularly important is the
introduction of load tracing and how tributary loads act on structural members.
The field report is required and is to be supported by many annotated sketches
and calculations. The final documentation is approximately 2000 words in
length, excluding appendices. The students are taught in the weekly lectures
that as future architects they should be taking a leading role in sustainable
design, green architecture and building conservation. Through the lectures they
start to see the potential beauty in abandon structures that others see as
eyesores.
In summary, the scope
of the students’ research investigation includes 1) visually inspecting the
building documenting any damage, deficiencies and overall condition; 2)
analyzing the existing structural system to determine code compliance; 3)
recognize vital repairs to the existing building; 4) examine the building for
varying stages of conservation including associated cost estimates; and 5)
determining a new use for the building. The report is to clearly explain the
structural system of the building and the way loads, and forces are distributed
through the building to the ground. Using the extent and probable weights of the
building materials being supported, the students are required to estimate the
stress level in one element in each of the following categories: 1) a load
bearing wall; 2) a floor system, including joists, boards, any secondary
materials; 3) a structural component in the roof, such as a connection, rafter,
ridge beam or purlin; or 4) the foundations at one point where loads reach the
ground. Foundation performance is important to all buildings and the students
gain knowledge about the basic principles of soil and foundation behavior,
outline possible causes of problems including differential settlement. They
summarize alternative strengthening procedures in the report. The students are
asked to compare the stress level with the likely loadbearing ability of the
member concerned and comment on the occurrence of any visible deflection,
deformation, cracking or settlement, which might confirm the successful
operation of the existing structural system.
3. WORK ACCOMPLISHED
The structural
appraisal project is primarily about being familiar with how the structural
system of the building works.IV The
project includes field sketches representing elevations, sections, important
architectural/structural details, connections, roof framing, ceiling framing,
floor framing and foundation layout. Both transverse and longitudinal sections
through the structure are sketched, etc. All sketches are to be clearly
documented to show all necessary load paths and how loads transfer from point
to point. An understanding of the types
of loads and forces and the behavior of materials and components is a necessary
prerequisite for assessment of a building's present condition and for
consideration of engineering alternatives.V
Therefore, the students report on all structural items and conditions that
concerns them and makes suggestions for repair. This process allowed the 2002
class to save two historic buildings scheduled for demolition after presenting
their report to administrative officials. The 2003 class analyzed and built two
replica trusses of the transept trusses in the historical Baptist Temple. As
the contractor was making the field repairs, students gained first hand
experience by site visits. The students are encouraged to follow both the
intuitive and mathematical paths in their analysis. Each student normally has
to make several trips to the site to document and study the structure. They are
required to visit the library, city or county building permitting office to
obtain the history of the structure and other related information. They are
encouraged to obtain advice from consultants when required (i.e., from students
in landscape architecture, construction engineering technology, engineering,
architecture, etc.). In the fieldwork they utilize digital cameras, levels, lasers,
etc. as required. They are required to use structural terminology learned in
class when discussing the project and to explain that terminology in their
report or when called upon in class. Students take the assignment seriously and
gain a general understanding of the integration of architecture and engineering
in the process.
4. CONCLUSION
Structural appraisal
projects can be used to motivate students to learn about building structures.
By researching and investigating a historic building the students have a means
to assess what they have learned in the classroom and apply their knowledge to
a real project. Students thoroughly enjoy the fieldwork. They learn more
through this case study teaching and learning approach than in the traditional
lecture course. It is evident that significant progress was made through the
course of the semester. This observation prompts the question: how does a
student learn to bridge the gap between academics and practice?
5. VISUAL MATERIAL
5.1 Photographs
Fig. 1 Baptist
Temple Transept Truss Project
Fig. 2
Ambler Greenhouse Project Fig. 3 Ambler Greenhouse Project
Fig. 4
Footbridge Project
Fig. 5
Spring House Project Fig.
6 Spring House Project
6. REFERENCES