Capstone Projects Focused on the Evaluation of Existing Structures

Paper ID #32683

Capstone Projects Focused on the Evaluation of Existing Structures

Jorge Tito is Assistant Professor of Engineering Technology. Dr. Tito received his Ph.D. and M.Sc. Degrees from the University of Puerto Rico, Mayag¨uez, Puerto Rico, in Civil Engineering with a major in Structures. He received the Civil Engineer Degree from the Pontifical Catholic University of Peru. Dr. Tito has experience in teaching, structural design, and construction management, and is a Registered Professional Engineer.

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Capstone Projects Focused on the Evaluation of Existing Structures

Abstract

Students of Structural Analysis and Design Engineering Technology of the University of Houston Downtown (UHD) are required to develop a capstone project covering the design theory and concepts developed in their courses. This paper presents the results of capstone projects that encompass the evaluation of existing structures, which were designed following building codes from more than 50 years ago.

The projects studied and discussed in this paper are the superstructure of the bridge “Travis St. over Buffalo Bayou”, located in Houston, TX; and the roof of the “Roberto Clemente” coliseum, located in San Juan, PR. Both have been in service since the early 1970s.

The bridge super-structure consists in three-span steel beams supporting the slab prepared for two traffic lanes and a pedestrian sidewalk. Students developed a numerical model of the bridge superstructure and studied the steel beam in detail. The roof of the coliseum is a dome with four truncated hyperbolic paraboloid surfaces, constructed with precast slabs supported by prestressed cables that becomesa rigid shell after grouting the space between slabs. The cables are anchored to four buttresses, a perimetral beam, and to diagonal steel trusses. Students developed a

numerical model of the roof and studied in detail the diagonal steel truss. For both projects, students presented a final report showing computer assisted drawings of relevant details, material take-off, structural analysis, and recommendations for additional studies.

These projects have multiple educational objectives in engineering, such as technical

communication through drawings, written reports, and oral presentations; practice with finite elements software; and use of building codes for structural design. Students express interest in these projects because they feel they are working on a problem whose solution is real and important to society.

Introduction

The American Society of Civil Engineers (ASCE) provides a comprehensive assessment of the major infrastructure categories in ASCE’s 2021 Infrastructure Report Card, showing that the average grade for the US infrastructure is a C-, in the typical A to F scales used by schools [1]. It is necessary to solve this deficiency with significant public and private investments, and by training engineers to be prepared for the evaluation, repair, and possible change of use of the existing infrastructure.

construction procedure and with a truncated hyperbolic paraboloid (hypar) surface. Both structures were selected because they are approximately 50 years in service, and because the availability of construction drawings and other literature related to their design and construction.

Travis Street over Buffalo Bayou Bridge

Texas Department of Transportation provided the drawings of the bridge at Travis street over the Buffalo bayou located in Houston, Texas, called Travis St. Bridge [2]. The superstructure of the bridge consists of three continuous spans, two of 67 feet at the ends, and a central span of 112 feet, for a total of 246 feet. The steel beams are vertically curved and receive a seven-inch concrete slab for two traffic lanes, a pedestrian sidewalk, and safety barriers, with an overall width of 37’-6”. The traffic is along one direction from south to north.

In this capstone project, the students are required to the following:

a) Form groups: The students formed two groups of five individuals. The groups started a logbook to annotate each activity during the semester.

b) Visit the site: The students observed the superstructure consisting in steel supports, steel beams, slabs, and protection railing. Also, part of the substructure (concrete beams and columns) can be observed. The bridge is close to the university campus and has safe access, allowing observation to verify and understand existing drawings.

c) Employ computer assisted drawing (CAD) software: This allows students to redraw the bridge structure based on the original drawings. The academic version of AutoCAD® [3] is used for this task.

d) Prepare a material take-off (MTO): The MTO corresponded to the substructure and superstructure.

e) Perform a structural analysis of the bridge superstructure: This was done using Finite Element Analysis (FEA) software.

f) Calculate the beam stresses due dead and traffic loads: They are compared with the steel capacity.

The first activity consisted of visiting the site; then the drawings are discussed in class by comparing some details with the pictures of the bridge and other annotations taken by the students. The visit is repeated by each group during the semester, mainly to understand some details of the drawings, and to measure the natural period using a dynamic test. One group used a drone for the field recognition. This activity was not part of this capstone project, but it demonstrated that students have the initiative to implement novel methods. Although not necessary in this case, the drone can be used to observe details that are difficult or risky to access. Figure 1a and 1b show pictures looking west and taken with the drone. Figure 1c shows the side view of the bridge looking east.

construction drawings. Redrawing the bridge structure in CAD is challenging for students, showing that they need more experience working with construction drawings, which can be remedied by including these exercises in previous courses syllabi. Figures 2 and 3 show some examples of CAD drawing using the student version of AutoCAD®.

Figure 2 shows the schematic of the bridge presenting the plan view, elevation, and a typical cross section of the superstructure. The bridge has three continuous spans, 67-ft at both end spans, and 112-ft at central span. The transversal section shows five steel beams receiving a 7.5-in slab with a sidewalk at the east side and safety rails at each edge.

Figure 3 shows the elevation of the steel beam and details of the splice, studs, and supports. The beams are continuous with variable cross section and symmetric with respect to the bridge centerline. Close to the ends, the section is W36x135; at the supports the section is W36x230 with a cover plate of 10”x7/8” welded at top and bottom flanges; the central section is a W36x150 with a cover plate of 10”x1” welded to the bottom flange. The continuous beam is supported by steel shoes that permit the bridge movement due to temperature changes.

The material take-off (MTO) is used to estimate the weight of the superstructure which is useful for its structural analysis. Table 1 shows the weight calculations corresponding to the

superstructure, which is 1381 kips, observing that students obtained similar values.

For the structural analysis of the superstructure, students use RFEM® software with a student license from Dlubal Inc., which provides access and training to the full version of their software [4]. Figures 4a and 4b show the model using RFEM® which consists in linear and plate finite elements. The steel beams are modeled using linear elements considering the geometry given in

Figure 1: Pictures of the bridge.

a. Top view (using a drone) b. North abutment (using a drone)

N

the drawings. The 7.5-in concrete slab is considered on top of the steel beams and modeled using the plate finite elements. The steel beams are modeled with the sections shown in the original drawings including the cover plates used as reinforcement at bent supports and at the

bridge centerline.

Table 1: Material take-off of superstructure – shoes, diaphragms, beams, slab, rail

Concrete: Slab Base Height Length Volume Weight Total

ft ft ft cf kip kip 2.5 0.5 257 321 48.2 4.5 1.125 257 1301 195.2 28 0.625 257 4498 674.6 2.5 1.125 257 723 108.4 1026.4 Concrete: Curbs 1 1 257 257 38.6 1 1 257 257 38.6 77.1

Steel: (left rail) Description Repeat Length Unit Weight Weight (ft) lb/ft kip Pipe 4" XS 2 257 12.5 6.4

Support 64 2.25 14.9 2.1

Base 32 26.80 0.9 9.4

Steel: (right rail) Pipe 6" Std 1 257 28.6 7.4

Support 64 2.25 14.9 2.1 Base 32 26.80 0.9 10.4 Steel: Beams W 36x135 2 35.7 135.00 9.6 W 36x230 2 54.4 230.00 25.0 W 36x150 2 33.0 150.00 9.9 Plate 10"x7/8" 4 16.0 29.77 1.9 Plate 10"x1" 2 15.0 34.03 1.0 Studs 7/8"x4" 2 54.0 0.87 0.1 Studs 7/8"x5" 2 42.0 1.09 0.1

Number of Beams 5 Total: 48 238.3

Diaphragms C15x33.9 2 30 33.9 2.0

W 14x34 11 30 34.0 11.2 13.3

Steel: Shoes E-80 10 151 1.51

E-225 5 490 2.45

F-225 5 450 2.25 6.21

Width Length Unit Weight (ft) (ft) lb/sf

Services: Piping+Electrical Estimated 2.5 257 10 6425 6.4 Total Concrete W eight: (kip) 1103 Total Steel W eight above shoes: (kip) 271 Total Steel W eight: (kip) 278 Total W eight of Services: (kip) 6 Total W eight Above Shoes: (kip) 1381

Comparison with Group Reports

Group #1 1346 Group #2 1317 Group #1 97% Group #2 95%

Figure 4c shows the dead load (DL) applied to the software consisting in the self-weight and a uniform linear load representing the railing, which is adjusted according to the ratio of the hand calculation vs RFEM® _{results. The structural analysis for the dead load considers some concrete} with very low elasticity because in this stage the beams receive fresh concrete. Figure 5d shows that the maximum deflection of the beams is 3.4”, which matches with the beam camber shown in the original drawings.

Figures 5a and 5b show the live loads (LL) from the design truck HL-93 according to AASHTO LRFD Bridge Design Specifications from 2017 [5], which differs from the design truck H20-44 used for the original 1967 design and specified in AASHTO 1961 [6]. Students did a

a. Plan View

Figure 2: Schematic of the bridge

67’-0” 112’-0” _67’-0” N o rt h A b u tme n t B en t 2 _Ben t 3 S o u th A b u tme n t c. Cross Section G-G 4 spaces @ 7’-6” = 30’-0” 2’-6” 6’-0” 1’-0” 2’-6” 1’-0” 2’-6” Concrete Slab 7 ½” 6” 6” 37’-0” b. Elevation

Figure 3: Steel three-span continuous beam and diaphragms. a. Beam elevation and details.

Figure 6 shows the design truck HL-93 consisting of a truck, a tandem, and a lane load. The analysis shows that for this bridge, the truck load produces higher stresses than the tandem load; therefore, for detailed structural analysis, the truck and the lane load applied simultaneously are studied in detail. Using the RFEM® load moving modules, students find the positions to

produce the largest beam stresses. The load combination required by the code corresponds to the Service Limit State, Strength I, as follows:

Qn <= 1.25DL + 1.33x1.75Truck + 1.75Lane Where:

 = 0.90

Qn: Nominal capacity DL: Effect of the dead loads

Truck: Effect of the truck load applied where produce maximum stress Lane: Effect of the lane load

The original drawings do not specify the steel grade of the beams; however, the 1962 “Standard Specifications for Road and Bridge Construction” from the Texas Highway Department indicates that the steel for beam construction must correspond to the designation ASTM A-373 [7].

However, ASTM specifies that steel type A-373 was withdrawn in 1966 and replaced by A-36 [8]. Since the bridge was built in 1968-1969, the steel is assumed to be A-36 for calculations, but this assumption must be verified. The steel A-36 has the following properties:

Yielding stress, Fy = 36 ksi . Then: Fy = 0.9x36 = 32.4 ksi Ultimate stress, Fu = 58 ksi

Figure 7a shows the stresses from the dead loads using the model consisting of the steel beams and fresh concrete. Figures 7b and 7c show the stresses due to the lane load and the truck load amplified by the impact factor of 1.33. The maximum ultimate stress is 38.7 ksi, which is 20% greater than the design stress.

To comply with AASHTO loads, the following tasks are necessary:

a) Investigate about the steel type used in the beams. A laboratory tensile test is necessary for this purpose. The sample must be obtained from a stress-free area.

b) Perform a deep search at the bridge owner's archives can help to find shop drawings and the type of steel used by the contractor.

c) Design the reinforcement of the critical areas of the bridge according to the type of steel and its internal forces.

The final student reports present the structural analysis, the interpretation of results, and the elaboration of recommendations. The details of the beam reinforcement are not part of the student report because it is necessary to know the type of steel for proper design.

Figure 4: RFEM® Model – geometry and dead loads.

a. Concrete slab modeling

b. Steel beams modeling

c. Dead load: self-weight & rail weight

Beam camber from original drawings

Figure 5: RFEM® _{Model – truck loads.}

b. Live load: Location for maximum negative moment. 16k 16k 16k 16k 4k 4k 16k 16k 16k 16k 4k 4k 0.064 ksf

8 k 32 k 14-ft @ 30-ft HL-93 TRUCK: ELEVATION 32 k 14-ft 6-ft

HL-93 TRUCK: PLAN VIEW

HL-93 TANDEM: ELEVATION

25 k 25 k

4-ft

HL-93 LANE LOAD

UNIFORM LOAD: 0.64 k PER LINEAR FOOT OF LOAD LANE (10-ft WIDE)

HL-93:

a) Effect of Truck + Lane Loads AND b) Effect of Tandem + Lane Loads

For maximum negative moment use 2 trucks spaced 50-ft and consider the 90% of the loads. Service Limit State, Strength I: Qn <= 1.25DL + 1.75LL

Impact Factor, IM=1.33 applied to the truck or tandem loads ➔ LL = Lane + IM (Truck or Tandem)

Figure 6: Live Loads (LL) from HL-93 loads.

Figure 7: RFEM® Results – stress at beams.

a.Stress at beams due Dead Load (fresh concrete for s/w + hard concrete for railing)

b. Stress at beams: LaneLoad + 1.33TruckLoad @ Centerline

c. Stress at beams: LaneLoad +1.33TruckLoad @ Supports

Design Stress at Centerline (tension at bottom flange) = 1.25*15.1 + 1.75*(11.3) = 38.7 ksi

Design Stress at Supports (compression at bottom flange) = 1.25*14.5 + 1.75*0.9*8.6 = 32 ksi Note: The factor 0.9 is used because 2 trucks are considered to find the maximum stress at supports. Without amplification factors:

Stress at center = 15.1 + 11.3 = 26.4 ksi

Roberto Clemente Coliseum

The Roberto Clemente coliseum of San Juan, Puerto Rico, is a multifunctional building whose purpose is to host sport and entertainment events, and which, during recent years, has been used as hurricane shelter. The coliseum has capacity for 12,000 people and is fully air-conditioned. The structure consists of four reinforced concrete buttresses, a reinforced concrete perimeter beam that receives the roof system, which includes four main trusses, and prestressed concave and convex cables that support precast slabs grouted on site. The roof has a span of 314 ft that forms a rigid shell with a hyperbolic paraboloid (hypar) surface. The papers from the structural designers related to this structure [9], [10] and the construction drawings [11] are used by the students for this capstone project.

The goal of this capstone is to model the roof structure and the loads from ASCE 7-16 [12] using RFEM®, a finite elements software developed by Dlubal, Inc [4]. The structural analysis

provides the forces in the steel trusses which are used to evaluate strength. Due to time constraints, the analysis is focused on the structural evaluation of the trusses.

Additionally, students are required to re-draw the construction plans in AutoCAD® [3], and to obtain the material take-off of the trusses and concrete shell. These exercises help to understand the construction sequence, details, and to estimate the dead load that is used to verify the results from RFEM®_.

Figure 8 shows the balsa wood model of the structure, and Figure 9 shows the plan view of the roof structure, as presented by A. Costa [10]. The plan view is a square with 314-ft sides, cut at 72-ft from the corners. The roof is supported by four reinforced concrete buttresses L-shaped

with 100-ft height, one at each corner, and a perimetral reinforced concrete beam with variable cross section which has a maximum of 5-ft width and 14-ft height.

The roof consists in four diagonal steel trusses, convex and concave cables anchored to the buttresses, beams and trusses, and the precast slabs attached to the cables. The trusses also support the hanging gondola, and a cupola above the roof. All this system is modeled in RFEM®_.

Figure 10 shows the plan and elevation views of the main diagonal truss. Students used the original drawings shown in Figure 10a to make the free-hand sketch and re-draw in AutoCAD®, permitting a good understanding of this important structural component. The four diagonal trusses are coupled using a rigid steel box located in the center, making a spatial rigid X-shaped truss with 250-ft per diagonal and resting on the corner of the L-shaped buttresses. Students are challenged to read and interpret the existing construction drawings that represent a spatial structure. The drawings are from 1968; therefore, steel sections are specified and named

according to the corresponding steel code, which requires students to use the AISC 1961 Manual of Steel Construction [13], and the AISC database for historical steel sections [14]to enter the appropriate geometric properties into RFEM®.

Figure 9: Plan view of the roof [10]

a. Truss elevation from original drawings.

b. Hand drawing sketch of the truss elevation (done by students).

c. CAD drawings of the plan and elevation views of the main truss. Figure 10: Main diagonal truss elevation.

The shell of the roof are precast panels supported by prestressed cables and grouted joins. The panels are 1.5-in thick with 7.5-in depth ribs spaced at 4-ft, as shown in Figure 11. Most panels are 8-ft squares and others have triangular form to accommodate in the roof geometry. Each panel is installed hanging from the previously installed cables that form the truncated hypar surface. The cables are pretensioned to obtain the desired parabolic shape. After the panels are installed, the joints are grouted permitting the final configuration of a rigid shell. This method avoids the use of scaffolding to construct the roof.

The students modeled the roof using the coordinates provided by the drawings. Plate finite elements and linear elements are used to model the precast slabs with the nerves. The process is simplified considering that the roof is symmetric. Figure 11 shows the RFEM® modeling of the rigid shell, noting that the cables are not modeled because for permanent loads the roof behaves like a rigid shell.

Figure 12 shows the RFEM® _{model of the main trusses and the secondary trusses #9 and #10,} which are used to support the cupola, gondola and provide lateral support to the main trusses. The trusses are joined using the rigid steel box, which is modeled using finite element plates.

Another important element is the hanging gondola, which is supported by the main truss. Figure 13 shows the drawing and the RFEM® modeling of the gondola, which consists in trusses of different sizes that are supported using tubes and cables hanging from the main trusses. The students modeled the gondola independently from the main trusses and used the reactions as applied forces to the main truss, reducing the number of elements for the computer final analysis.

Figure 14 shows the complete roof, including the gondola, cupola and shells. The walls and the perimetral beams receive the cables to make the roof but are not modeled to reduce the computer time for analysis eventually replacing them by simple supports. The model of the roof and walls is shown in Figure 14c, it is used to calculate the wind loads using the numerical wind tunnel included in RFEM®_.

Figure 12: Main trusses and secondary truss #9 and #10

Model of the rigid steel box used to receive the trusses at center.

Martinez et al [9] reported that the weight of the gondola is 400 kips, uniformly distributed on its surface, which makes 50 lbs per square foot (psf), and the weight of the cupola and shells is 30 psf. The project used lightweight concrete for the precast panels, which helps to reduce the dead loads. The self-weight of the steel is computed by the software. The live load considered for the roof is 20 psf, and for the gondola is 50 psf, as considered in the original design.

Figure 14: Roof from the RFEM® _model a. Upper view

b. Bottom view

The wind and vertical earthquake loads are calculated from ASCE 7-16 using the local

coefficients published by ATC Hazard by Location [15] for risk category IV. Such a high rating is necessary because the structure is used as shelter for hurricane events.

The design wind velocity is 178 mph, according to the Puerto Rico Building Code 2018 [16]. ASCE 7-16 [12] is used to calculate the wind pressures applied on the roof. Figure 15 shows the design uplift pressures at three roof areas, that is, 88 psf at windward edges, 59 psf at center, and 30 psf at leeward edges. The wind pressures computed with the numerical wind tunnel and using the model shown in Figure 14c, compare well with the pressures computed with ASCE 7-16, as observed in Figure 15c. The wind pressure used in the original design is 36 psf [9], that is calculated using service wind loads, which is equivalent to 58 psf if computed with ultimate wind loads, as used by ASCE 7-16.

a. Location of the Coliseum and wind velocity from ATC Puerto Rico

b. Design wind pressures

Figure 15: Wind Pressure

F = 32’ h D = 55’ V=178mph q_A = 88 psf D = 314’ A C B q B = 59 psf q_C = 30 psf

The vertical earthquake calculated is 15% of the dead loads, calculated according to Puerto Rico Building Code 2018. The technical papers and the construction drawings do not mention that the structure was designed against earthquake loads.

The loads are input to the model and combined according to ASCE 7-16. The scope of this capstone project is limited to the study of the steel trusses, then it is possible to reduce the model by 50%, including the tributary shell and a main diagonal truss, as Figure 16 shows. This

reduced model is convenient for the students because they can run the software in significantly less time than for the complete roof model. Several runs are required to refine the model eliminating modeling errors, like distorted finite element mesh, discontinued elements,

duplication of elements, etc. RFEM® helps with a tool to find errors, but the larger the model the longer the time required.

The RFEM® module for steel design is used to verify that the truss sections comply with the steel code ANSI/AISC-16 [17]. In general, the elements of the main truss have a stress ratio (s/r) less than 1.0, meaning that they pass the code checking, except for a W14x48 steel sections located at top of the truss and close to the supports that have a stress ratio of 1.51. However, Figure 16b shows that the high stress ratio is localized close to the node and dissipates quickly; therefore, it is not considered a critical condition that requires reinforcement.

The material take-off of the trusses and shells is part of this capstone project; it is used to compute the weight of the roof and to compare with the results of RFEM® to ensure that the model is correct. Also, it is used to verify some statements of the technical papers, like the weight of the precast slabs and of the gondola.

Figure 16: Half roof model: trusses and slabs a. Half roof model

b. Half main diagonal truss

Lessons Learned

The evaluation of existing structures is appropriate for students of the Structural Analysis and Design Program because it gives students the opportunity to successfully reach the learning outcomes of the capstone course. During the project execution, the students applied material covered in different undergraduate courses related to technical skills, like concepts of structures, construction, and drafting, and soft skills like oral presentations, team working, and writing a report.

The redrawing of detailing using AutoCAD® _{and the development of a material take-off (MTO)} are useful to verify the geometry of the numerical model and the results from the structural analysis software. Additionally, these tasks challenge students to develop a better understanding of the construction process.

The Travis St. Bridge drawings show several details of the supports, steel beams, slab, and safety railing, along with the design truck used. However, the steel type is not shown, requiring

students to make a bibliographic research to find the technical specification applied during construction. This then allowed an estimate of the type of steel used. In the case of the coliseum, students have the construction drawings and some technical papers written by the structural designers, which significantly help to understand several details and the construction process of the roof, which is a truncated hyperbolic paraboloid that is a non-traditional structure.

In both projects, because the structures were built 50+ years ago, some of the drawings are blurry and difficult to read. Thus, the exercise of re-drawing some details in AutoCAD® is important for a better understanding of the project. This is a good intermediate step before initializing the input in the structural analysis software.

To develop both large projects, it is important to have access to software based on Finite

Elements Analysis, and with the appropriate technical support. For this reason, the students used the software RFEM®_{, developed and owned by Dlubal, Inc. This company provides the student} license of the full professional version of their software. In addition, the company has

demonstration videos, webinars, and personalized technical support that significantly help students to model the project structures.

Typical undergraduate courses do not include working with construction drawings and the intensive use of professional software whose implementations would help the students in the workplace. Thus, this dynamic needs to be complemented with the continuous support from the instructor during the different phases of the projects.

The project related to the coliseum was developed during the Covid-19 pandemic, which included additional and new challenges for the instructor and for the students. Students used different online tools to permit proper team coordination, which is not as effective as in-person meetings, but thanks to the efforts of everyone, the project was executed according to schedule.

Academic Assessment

Figure 17 shows the results of surveys that measure the compliance of the course learning outcomes (LO) during the semester according to student perception. In both projects the percentage of students that agree or strongly agree that the projects covered the course learning outcomes is 96%, which corresponds to a ‘high’ student satisfaction.

Students appreciate working with the evaluation of existing structures, principally because they feel that the project scopes have practical applications in their engineering career, and because they feel that it is important for society. The main comment is respect to the steep learning curve required to master the software application for structural analysis.

Figure 18 shows the results of a survey about teamwork. The survey consists in questions about the group performance resulting in answers of 88% and 92% as ‘always’ for the different

questions, permitting a conclusion that the students are well prepared for team working and they used this skill for the projects with positive results. The Program emphasizes this soft skill in different courses; therefore, students developed different methods to work together. Also, the Program is relatively small, and students had previously worked together in other courses.

As the instructor, the author noted that students need more previous exposure to construction drawings to permit visualization of details, and to obtain valuable information for different engineering objectives. The practice of AutoCAD® _{to re-draw the existing old drawings and the} elaboration of Material Take-Off grant experience in reading and interpreting drawings. The students enjoyed this type of practical experience.

Conclusions and Recommendations

The students are required to use current codes to evaluate the structural performance of existing complex structures constructed approximately 50 years ago and designed following old codes and procedures. Additionally, students need to use AutoCAD® _{to re-draw some structural} details, and they need to calculate the weight of the structure from the material take-off. Continuous support from the instructor is important to ensure the correct interpretation of the construction drawings and to review the different stages of the numerical model.

The software RFEM® is used for the numerical models. This is an advanced tool with a steep learning curve, but it also has intense technical support from the developers. From this project, students thus received valuable lessons in using technical support provided by software

developers to answer any questions, a useful skill to have in industry. The results for dead loads are compared with those obtained from the material take-off to verify the numerical model.

For the bridge, the students concluded that it is necessary to perform laboratory tests to define the type of steel of the beams and, according to the results, design the reinforcement to resist satisfactorily the design truck HL-93, specified by AASHTO-2017. For the coliseum, the technical conclusion is that the main steel trusses can support the loads of ASCE 7-16 without additional reinforcement.

After receiving the student input about their experience working with these capstone projects, the Department decided to split the course in two semesters, permitting a better preparation to learn the tools needed for the project, and to obtain more technical conclusions. Also, the theory of matrix analysis will be implemented in courses of structural analysis including more application of advanced software.

The surveys about team working shows that the students expressed interest in the topics, mainly because of the practical applications and importance for society. Also, students show high performance working in teams, which is reflected in the quality and timing to complete the capstone projects. The capstone related with the coliseum was done during the Covid-19 pandemic and students used different online tools to permit a successful coordination of their tasks, which also reflected their high team working skills.

This type of project permitted the application of topics covered in previous courses of the Structural Analysis and Design Program, including reading and interpretation of technical literature and communication through drawings, reports, and presentations. Additionally, the academic evaluation of the projects makes it possible to recommend improvements in the study plans of the Program, such as including the study of existing structures through construction plans and advanced software for structural analysis.

Acknowledgement

The author would like to thank the Texas Department of Transportation for providing the

original drawings of the Travis St. bridge, and the consulting firm H2A of San Juan, Puerto Rico, for providing the original drawings of the coliseum Roberto Clemente. Also, thanks to the 2019 and 2020 capstone course students for their hard work.

References

[1] American Society of Civil Engineers, ASCE. “2021 Infrastructure Report Card, A Comprehensive Assessment of America’s Infrastructure”.

Available: https://infrastructurereportcard.org [Accessed May 20, 2021]

[2] Texas Highway Department - Houston Urban Project & City of Houston - Department of Public Works. Federal ID Project I-10-7(168)777. Proposed State Highway Improvement – Houston Urban Expressways - Travis and Milam Street Connections to I-45 North. “Travis Street Buffalo Bayou Bridge”. Final Plans, drawings No 43-47. Design by Bernard Johnson Engineers, Inc., March 1967.

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Available: https://www.autodesk.com/education/edu-software

[Accessed Dec. 10, 2020]

[5] American Association of State Highway and Transportation Officials, AASHTO. LRFD Bridge Design Specifications, 8th Edition. Washington, DC. September 2017.

[6] American Association of State Highway Officials, AASHO. Standard Specifications for Highway Bridges, 8th Edition. Washington, DC. June 1961.

[7] Texas Highway Department. Standard Specifications for Road and Bridge Construction, pp 564. January 1962.

Available: https://www.txdot.gov/business/resources/txdot-specifications/historic-bridge.html

[Accessed Dec. 10, 2020]

[8] ASTM Standard A373. Specification for Structural Steel for Welding, withdrawn in 1966 and replaced by ASTM Standard A36. ASTM International, West Conshohocken, PA.

[9] M. R. Martinez, A. Costa, and A. C. Scordelis. "Cable Suspended Precast Concrete Shell Roof for the New San Juan Municipal Coliseum." ACI Journal 70.11 (1973): 749-56.

[10] A. Costa. "The San Juan Roberto Clemente Municipal Coliseum: A Design and

Photographic History of Its Roof Structure Installation”. First Edition. Sir Speedy Vazquez and Vazquez Enterprices, Inc. Hato Rey, Puerto Rico. April 2010.

[11] City of San Juan, Puerto Rico. Municipal Coliseum. Final Plans. Design by Pedro A. Miranda & Associates – Martinez & Costa Structural Engineers. Santurce, Puerto Rico, 1968.

[12] ASCE/SEI 7-16. Minimum Design Loads and Associated Criteria for Buildings and Other Structures. American Society of Civil Engineers, Reston, VA, 2017.

[13] AISC 1961. Manual of Steel Construction. American Institute of Steel Construction, New York, November 1961.

[14] American Institute of Steel Construction, AISC. “v15.0H Historic Shapes Database” from year 1873 to 2010.

Available: https://www.aisc.org/publications/steel-construction-manual-resources/#37584

[Accessed Dec. 10, 2020]

[15] ATC. Hazards by Location.

Available: https://hazards.atcouncil.org/#/wind?lat=18.41619686018695&lng=-66.07543726696777&address= [Accessed Dec. 10, 2020]

[16] Puerto Rico Government. Puerto Rico Building Code 2018.

Available: https://up.codes/viewer/puerto_rico/ibc-2018 [Accessed Dec. 10, 2020]