Experiments & Modeling of Steel Beam-To-Column Connections

"The study investigated five types of steel beam-to-column connections. The global rotational spring stiffness values of these connections were determined through laboratory testing and these values were used in the semi-rigid structural analysis where a rotational spring was introduced at the ends of the beams near the connection to the columns. A comparison between the semi-rigid elastic analysis the conventional rigid elastic analysis shows that moment-rotation and the load-deflection relationships as predicted using the elastic spring model are close to the experimental results. Therefore the study concluded that the rotational spring stiffness values obtained experimentally may be used to represent the degree of moment rigidity of the connections; thus improving the structural model." This is the abstract of the undergraduate research conducted by Angelo Lapuz, Christopher Camina and Danilo Baluyot, Jr. at DLSU-Manila.

Oreta & Lapuz (Rightmost) at the RSID2009 - Bangkok, Thailand

This research was presented by Engr. Angelo Lapuz in various conferences like the Regional Symposium on Infrastructure Development (RSID) held in Bangkok, Thailand last Jan 2009 and the Philippine Institute of Civil Engineers (PICE) National Convention held in Baguio City last Nov 2009.

Scholarships for future Earthquake Engineers & Seismologists

When I was a visiting scientist at the Tokyo Institute of Technology, Japan, I remember my host Prof. Kazuhiko Kawashima telling me about ROSE School - The Centre for Post-Graduate Training and Research in Earthquake Engineering and Engineering Seismology . It was my first time to hear about it. He was a visiting professor at ROSE School and he taught Seismic Design of Highway Bridges. I browsed the website and was impressed by the school's programs like the MEEES Programme which aims to provide higher-level education in the field of Earthquake Engineering and Engineering Seismology. I received an email from a colleague about Scholarships in Earthquake Engineering and Seismology. ROSE school seems to be the lead university in the scholarships. The Philippines is an earthquake country and needs specialists in this field. I hope our graduates - engineers and scientists - will grab this opportunity.

SCHOLARSHIPS FOR MASTERS IN EARTHQUAKE ENGINEERING AND/OR ENGINEERING SEISMOLOGY

Applications for the Masters in Earthquake Engineering and/or Engineering Seismology (MEEES), approved and financially supported by the European Commission under the framework of the Erasmus Mundus II programme, have just opened, with a deadline of 31st of December 2009.

The Masters is organised by a consortium of European University/Research Institutions, led by the Centre for Post-Graduate Training and Research in Earthquake Engineering and Engineering Seismology (ROSE School, www.roseschool.it) and featuring also the participation of the University of Patras (Greece), the University of Grenoble Joseph Fourier (France) and the Middle East Technical University of Ankara (Turkey).

The MEEES programme is an Erasmus Mundus Masters Course, that aims to provide higher-level education in the field of Earthquake Engineering and Engineering Seismology. Graduate students involved in this Erasmus Mundus Masters course have the possibility of following a 18-month MSc programmes on either Earthquake Engineering or Engineering Seismology. In addition, the proposed EM Masters course envisages also the possibility of students following a 18-month study programme that leads to the attainment of a Masters degree on Earthquake Engineering and Engineering Seismology.

A relatively large number of scholarships, ranging from 15000 to 38000 Euro, are available to applicants from all nationalities.

Full details on the programme, as well as online application procedure, can be found on its website: http://www.meees.org/

Jerry and his Mission

Dr. Jerry Velasquez, my classmate at Nagoya University (Japan) in the Master's and Doctoral programs is now the senior regional coordinator of the UN International Strategy for Disaster Reduction (UNISDR), based in Bangkok, Thailand. One of his mission is to promote Disaster Risk Reduction (DRR) in the Philippines and other developing countries to address the threats to life and property by climate change and natural disasters.

Here are quotes from his interview which appeared in the article in the Philippine Daily Inquirer (28 Oct 2009) entitled: "UN on RP Disasters: Worst Yet to Come."

• The Philippines was even worse than military-ruled Burma (Myanmar) in coping with natural calamities
• Studies projected a massive destruction of Philippine rice crops in a little over a decade owing to climate change, and severe flooding in Metro Manila affecting 2.5 million people by the year 2080.
• The Philippines ranked 12th among 200 countries at risk from tropical, cyclones, floods, earthquakes and landslides.
• In coping capacity to disasters, the Philippines ranks seventh among the 10 members of the Association of Southeast Asian Nations (ASEAN), just behind Laos, Malaysia and Burma.
• The coping capacity refers to a country’s capacity for hazard evaluation, structural defenses, early warning, emergency response, insurance and disaster funds, and reconstruction and rehabilitation planning.
• The “deadly trio” that worsen natural disasters were “poor urban government, unstable rural livelihood, and ecosystem decline.” So it’s not God who is doing it. It’s man who is at fault.
• A single event cannot be attributed to climate change because the climate system is in constant state of flux and has always exhibited natural fluctuations and extreme conditions.
• With the signing into law of the Philippine Climate Change Act of 2009, hopes are high that the new law’s focus on strong government-wide coordination, high-level leadership, links to science, and local level action, will be necessary ingredients to ensure immediate, comprehensive and sustained action by the Philippines in the face of this climate crisis. It is one of the most comprehensive and the most integrated legislation so far in the region. We now wait with breathless anticipation.

Role of Civil Engineering in Poverty Alleviation

Poverty can be history if everybody helps in even a small way to alleviate it. There are many ways of eradicating or reducing poverty. Civil engineers, in particular, can contribute in building a better future of our society through the three of their majors tasks: Design, Construct and Maintain. KHRPN (Kahirapan) is a video by Joenel Galupino of De La Salle University, Manila - an entry to the PICE-LNM Chapter's Discover Ciivl Engineering @ You Tube Photo-Video Competition. Watch it and post your comments.

Green Buildings and Structural Engineering

The main theme of the 33rd IABSE Symposium at Bangkok (Sept. 9-11, 2009) is "Sustainable Infrastructure." The International Association of Bridge and Structural Engineers (IABSE) recognizes the important role of structural engineers in ensuring sustainability in their creations to ensure that energy and natural resources are still available for the future generations.

The keynote lecture on "Green Buildings and Structural Engineering" by Gene Corley (USA) highlights how structural engineers can contribute to sustainability by following the LEED Green Building Rating System - a framework for asssessing building performance and meeting sustainability goals. A rating of 40 points will earn a building a LEED Certification. Structural engineers, in particular, can earn LEED points in the category of Materials and Resources and the following subcategories:

(a) Building reuse - instead of demolition, the building structure or shell is reused.

(b) Construction waste management - diverting construction and demolition waste from ladfill into other uses

(c) Materials reuse - a portion of the materials of the project must be salvaged or recycled

(d) Recycled content - use of materials with "recyled content"

(e) Regional materials - use of local materials will reduce transport and energy cost

Structural engineers should design building which are adaptable to provide for ease of alteration or amendment in use. Buildings which consists of elements that can easily be deconstructed are preferrable for possible reuse. By proper planning and efficient design and knowledgeable of sustainability concepts, green buildings can be successfully built.

The author (center) with Filipino engineers infront of the IABSE booth.

Online MS/PhD Programs in Asia

The general consensus the world over is that online degrees are not as acceptable as their regular counterparts, but that perception is slowly changing as the face of academia itself undergoes a significant change. Today, even doctoral programs are being offered online and are accepted in all kinds of job settings as equal to those degrees that have been earned in traditional classrooms.

The situation in Asia is not that different from the rest of the world. People turn to online degrees for various reasons, the most significant of them being time. When it comes to a graduate program like MS or a doctoral degree like PhD, most of us prefer to earn them online because it allows us to continue with our work and study during our free time. The schedules are flexible enough to allow us to multitask with efficiency. We don’t need to take time off work and we get our regular salary as well. Besides, some employers are willing to sponsor their employees’ education, so this means you gain knowledge and are in a position to climb up the career ladder, all at no extra cost.

Various universities across Asia offer online MS and PhD programs, and some of the more prominent ones are The Open University of Hong Kong (China), University Sains Malaysia(Malaysia), University of the Philippines (Philippines), and the Indira Gandhi National Open University (India). While most of them do not require on-campus residency, some do mandate the same for a short period, either a few months or 15 to 20 days.

When you choose to study online, consider the discipline and the university rather than just the degree itself. For example, even a master’s degree from a prestigious university may hold more value than a doctoral degree from an unaccredited one. Or, a degree in a field that offers various job opportunities is infinitely more useful than one that is difficult or more interesting. Also, check the accreditation of the college you’re applying to and verify its credentials before you enroll. It’s best to talk to alumni of the college and discuss their experience before you decide that this is the university for you.

This guest article was written by Adrienne Carlson, who regularly writes on the topic of engineering degrees online. Adrienne welcomes your comments and questions at her email address: adrienne.carlson1@gmail.com

Genetic Algorithms in Optimum Concrete Design

Engr. Alden Balili, my graduate thesis advisee did a research on the application of genetic algorithms (GA) in the optimum design of reinforced concrete (RC) space frames considering seismic provisions of the code. The process of GA and its application to the optimization of space frames is in the figure below. Initially, the sizes of the beams and columns of the space frame are randomly selected which becomes the initial population. These sizes are then used by a separate Finite Element Analysis program to determine the member forces which are required in the design of the members including the amount of steel reinforcements. A database of the beam and column sections is used in the design process. The provisions of the National Structural Code of the Philippines (2001) are incorporated in the fitness evaluation of the solution or individual to satisfy the strength and serviceability requirements. The GA procedures of selection, cross-over, mutation and leader reproduction are then applied to generate a new population of solutions. He conducted GA simulations to determine the behavior of the optimization procedure using the different GA procedures like binary vs gray coding, leader reproduction and mutation. Based on his simulations, a new type of leader reproduction called modified leader reproduction was proposed. It was found out that this feature improved the effectiveness and efficiency of the concrete optimization algorithm to acquire the optimal values.

A paper on this study will be presented at the IABSE 2009 Conference at Bangkok, Thailand on Sept. 9-11, 2009.

A Neural Network Model for Shear of RC Beams

Experiments have shown that as the depth of the beam increases, the intensity of shear stress decreases especially in lightly reinforced beams. This phenomenon is referred to as “size effect”. Shear strength is not constant as given by some design codes like the ACI. To understand size effect, an artificial neural network (ANN) model was developed for RC beams without stirrups which fail under diagonal tension.

The ANN model consists of five input nodes representing (1) the compressive strength of concrete, f’c, (2) beam width, b, (3) effective beam depth, d, (4) shear span to depth ratio, a/d, and (5) longitudinal steel ratio. The output is the shear stress, Vu/bd. The graphical user interface of the Visual Basic program of the ANN model is shown.

The figure shows the simulation where the depth (d) was varied from 20 cm to 100 cm for two values of f’c and a/d and constant values for b at 15 cm and r at 2.75%. The size effect is obvious where the shear stress decreases with increasing depth. The experimental results by Kani shows a similar trend as the model. The shear stress also depends on the shear span to depth ratio – a shorter beam (a/d = 2.5) has a larger shear strength than a longer beam (a/d = 5.0).

How safe our our large RC beams with respect to shear failure? Structural engineers must take note of the decrease in shear strength of concrete for large beams so that they can provide adequate shear reinforcements or stirrups.

Reference: Oreta, A.W.C. (2004). "Simulating size effect on shear strength of RC beams without stirrups using neural networks." Eng'g Structures 26(2004) 681-691, Elsevier.

Collapse of a Building in Shanghai

"A 13-story under construction apartment building in Shanghai's Lotus Riverside complex fell to its side on June 27, 2009. During construction, a 4.6-meter-deep underground garage was dug on the south side of the building while a mound of soil heaped up to 10 meters high was located on the other side. This caused a difference in pressure on two sites of the building, which resulted in the collapse of a building in Shanghai" according to the China Daily. The lateral pressure caused the piles to snapped resulting in the foundation failure and tilting of the building.

Learning Lessons: The 1990 Luzon Earthquake

On July 16, 1990, an earthquake with magnitude 7.8 struck central Luzon. The human consequences were severe - at least 1200 people were killed and more the 3000 injured. Major destruction occured in Baguio City where hotels and school buildings collapsed like pancakes and Dagupan city where extensive liquefaction caused settlement of buildings and bridges. What lessons can we learn from this earthquake? This video - part of the "Understanding Earthquakes and Disasters: Photo-Video Presentations" highlights some lessons from the 1990 Luzon Earthquake. This video can also be viewed (full screen) and downloaded at YouTube.

A Neural Network Model for Confined RC Column

Artificial Neural Networks (ANN) are information – processing systems whose architecture mimic the biological system of the brain. Recently, civil engineers have utilized ANN for various applications especially in the modeling of civil engineering systems.

In my case, I developed an ANN model for predicting the confined compressive strength and strain of a circular reinforced concrete column. The model has seven input nodes: (1) unconfined concrete cylinder strength, f’c; (2) concrete core diameter, d, where the core is the part of the section enclosed by the centroidal axis of the hoop or ties; (3) column height, H; (4) yield strength of lateral reinforcement, fyh; (5) volumetric ratio of lateral reinforcement; (6) tie spacing, s ; and (7) vertical steel or longitudinal reinforcement ratio. The two output nodes, on the other hand, represent the peak stress or compressive strength of confined concrete circular column, f’cc and the strain, ecc , at peak stress. Shown below is the GUI of the Visual Basic program of the ANN model.

The predictions of the compressive strength or peak stress, f’cc, of confined concrete columns and the corresponding strain, ecc, have been a subject of various researches, both analytical and experimental. The values of these two parameters are usually used in the analytical models developed for describing the stress-strain relationship for confined concrete.

You may run the ANN model at http://mysite.dlsu.edu.ph/faculty/oretaa. Go to the Software section. Papers on the model can also be downloaded from this site.

The World Without Engineers

What will the world might look like if there were no engineers like civil engineers, electronic engineers, mechanical engineers, etc. You may download from the website of Agilent Technologies' Educators Corner a poster or screensaver on "The World Without Engineers." Here is my favorite - The World Without Computer Engineers.

Indeed, the advancements and innovations in computers have changed our ways of computing and data prcessing. In my case, I experienced using some of the computing tools shown in the image above. I still remember when I was a kid, my father taught me how to use the abacus. During my high school days, we were taught how to use the slide rule in our chemistry class. Then the scientific calculator was born just before I graduated in high school. During my college years, we used computer cards in our computer programming classes using the FORTRAN language. Then I also used a programmable calculator using BASIC language. My first computer was an Apple Computer whose memory is in kB. Today, we have computers which are fast and with almost unlimited memory space in terabytes.

The Little DVD of Civilisation

Take a look at at the amazing ways civil engineers overcome the challenges of creating and maintaining our infrastructure for us, and for future generations. This video, "The Little DVD of Civilisation", which was created by the Institution of Civil Engineers promotes the importance of how civil engineers build the quality of life like supplying clean and safe drinking water in Ethiopia, reducing flooding in London, construction of man-made island for the new airport in Hong Kong, development of sustainable housing community and preserving historical structures like Leaning Tower of Pisa. Civil engineers play various specialized roles in creating a safe and sustainable built and natural environment. Watch this video because "when you understand civil engineering, you see the world differently."

Play BEAT THE QUAKE

What precautions should you do to protect people from harm and reduce damages to property in case an earthquake occurs? Test your knowledge on earthquake preparedness and safety by visiting http://www.dropcoverholdon.org/ and play "Beat the Quake." In this game, you are challenged to make your home a safe place during an earthquake. You click on each object shown in the room and you choose an option on how to secure it. But you must hurry, because the earthquake may happen any time. After the quake, you will see how the objects responded to your design. This is both fun and educational especially to kids. Are you ready to play "Beat the Quake"?

On Shaky Ground

On Shaky Ground (5:55 min). This is a presentation of various types of earthquake geotechnical hazards and their effects on structures. These hazards include ground ruptures, soil liquefaction and land slides. Since a geotechnical hazard can cause a serious effect on a community, reducing the impact of these hazards must be addressed. This video is part of the "Understanding Earthquakes and Disasters: Photo-Video Presentations for Public Awareness and Education."

Bridges are falling down!

Bridge superstructures and substructures have been damaged in recent earthquakes like the 1994 Northridge earthquake and 1995 Hyogeken-Nanbu earthquake in Japan. Bridges are Falling Down ( 5:52 min) is a photo-video presentation that shows the different types of damages in bridges and some retrofitting techniques. This video is part of the "Understanding Earthquakes and Disasters: Photo-Video Presentations for Public Awareness and Education."

Buildings: Shake, Rattle and Roll

In past earthquakes, many buildings have collapsed or were damaged due to ground shaking or foundation failures. The presentation shows the common types of failures of buildings like soft stories, short columns, torsion, poor detailing and ductility in reinforced concrete columns and beams, and irregular structures. The importance of seismic retrofitting and strengthening of existing structures is also highlighted.

This video is part of “Understanding Earthquakes and Disasters: Photo-Video Presentations for Public Awareness and Education, ” a project funded by the DLSU-Manila University Research Coordination Office (URCO).

Preparing for the BIG ONE

The key to reducing the impact of earthquake hazards is disaster preparedness and mitigation. Since the Philippines is an earthquake country, it is important to prepare against seismic hazards. This video poses some questions and tips to consider with regards to design and construction of structures, seismic assessment and retrofitting and community disaster preparedness. PHIVOLCS tips before, during and after an earthquake are also presented.

This video is part of the author's photo-video, "Understanding Earthquakes and Disasters: Photo-video presentations for public awareness and education", a project supported by the University Research Coordination Office (URCO) of DLSU - Manila.

Visual Basic Games in Civil Engineering

In the laboratory course on Computer Methods in Civil Engineering at DLSU-Manila, aside from computer applications in civil engineering, I required the students to create game applications related to civil engineering. The randon number generator function is a very useful function in game simulations. These game applications may be used to review the students on their understanding of the concepts and equations in civil engineering. Student competitions may be conducted using the software to make the class more interesting and enjoyable. Through these activities, the students’ understanding and retention of the concepts hopefully may be improved. Here are the GUI's of some of the game applications created by the students.

Hangeneering by J.P. Sy and D. Baluyot. Based on the game, "Hangman", this is a game to test the student’s mastery on solving reactions in statically determinate beams. There is a time limit which varies from 30 seconds to 90 seconds depending on the level of difficulty. The program chooses randomly the figure and the beam parameters. There is a formula for getting the score of the player. The game will be over when the user answered incorrectly three times or when the time has run out. This game can be played in the Engineering Mechanics (Statics) or Strength of Materials class.

Jeopardeng by C. Fabie and R. Masa: This is an adaptation of the famous American game Jeopardy. The game has four different categories that cover various topics about civil engineering. Each category has four objective questions. There is a data base of questions which are selected randomly. The user answers all questions under the four categories in any order, aiming to bag a high score. After all questions have been answered within the time limit, the user is prompted to the “Final JeopardENG Round”; wherein a computational question will be asked to the user worth 5000 points.

This game can be played in class to review the students about civil engineering terms, concepts and definitions. A competition among students can be done with the student having the highest score declared as the winner.

You may play some games at http://mysite.dlsu.edu.ph/faculty/oretaa.

CPE Seminar on Computer-Aided Modeling, Design & Analysis of Bridge Structures

Bridges are important structures in infrastructure projects such as highways, elevated expressways, flyovers and water crossings. The effective and efficient design of bridges requires a good understanding of bridge engineering principles and usage of modern computing tools. The objectives of the seminar are (a) To provide an overview of the theoretical and practical background on analysis & design of various types of bridge structures with a special focus on RC bridges, and (b) To introduce the use of up-to-date computing tools for the modeling, analysis, and design of bridge structures.

Dr. Naveed Anwar is the Associate Director of ACECOMS and an Affiliate Faculty of the School of Engineering and Technology of the Asian Institute of Technology, Bangkok, Thailand. Dr. Naveed is the principal author of several engineering software including SDL, GEAR, SYSDesigner. He is also a consultant of CSI, the developer of ETABS, CSI Col, SAFE and SAP2000.

For more info. about the program and fees: Go to the PICE-LNM Website.

Visual Basic Applications in Civil Engineering

Innovative approaches in teaching can be introduced in the classroom using the computer. In the author’s laboratory class on Computer Methods in Civil Engineering, students develop simple computer software applications and computer-based games on topics related to civil engineering using Visual Basic. By creating their own software applications, the students demonstrate their creativity and integrate concepts, methods and skills in mathematics, basic engineering and specialized civil engineering subjects. These software applications and games can be introduced in the classroom to motivate learning and to facilitate retention and understanding of engineering concepts. Here are examples of the Graphical User's Interface of the students' projects.

Beam Deflection Application: This is a software application for solving the elastic deflection and slope of a beam. The inputs to the program are the cross-section dimension and properties of the I-section and the beam loadings and lengths. The outputs include the moment of inertia of the I-section, the beam deflection and slope at specified point X from the left end. This application may be used in the course on Mechanics of Materials or Structural Analysis to demonstrate the effect of section properties, beam loading and lengths on the elastic deflection and slope of a beam. By computing the deflection of the beam at different values of X, the shape of the elastic curve can be drawn.

Open Channel Flow: This software application determines the normal depth of an open channel using Manning’s Equation. In this program, the user first selects the shape of the cross-section: (a ) rectangle, (b) trapezoid, or (c) triangle. The system of units have to be chosen also. The inputs to the program are the dimensions of the cross-section and Manning equation parameters, S, n and Q. The output of the program is the normal depth of flow. This software application can be used in the courses, Fluid Mechanics or Hydraulics. The values of the various parameters, such as dimensions of the cross-section, slope of channel bed, coefficient of roughness or flow rate, maybe varied to study the effect on the normal depth of flow.

You may download and try these programs at my website at http://mysite.dlsu.edu.ph/faculty/oretaa.

Per Tveit's Network Arches

Prof. Emeritus Per Tveit, Dr. Ing. of Agder University, Norway, visited De La Salle University, Manila a few years ago to share his knowledge and expertise about Network Arches. "When I was a student over 50 years ago, I got the idea of the network arch. Optimal network arches are arch bridges where some hangers cross other hangers at least twice. When the arches are less than 18 m apart, the tie should be a concrete slab with partial longitudinal prestress. The arches should be universal columns or American wide flanges. Network arches are best suited for spans between 80 m and 170 m, but will compete well in a wider range of spans. This results in attractive bridges that do not hide the landscape behind them. A network arch bridge is likely to remain the world’s most slender tied arch bridge, " he says. Indeed, Tveit can be considered the "father of network arches." He traveled around the world using his own resources spreading the information about network arches - the basic components, analysis, design and construction. His website has detailed information about network arches.

If you want to know more about Network Arches, contact:

Per Tveit, Dr. Ing. dosent emeritus Agder University N-4876 Grimstad, Norway

E-mail: per.tveit@uia.no

Website: http://pchome.grm.hia.no/~ptveit/

Here is a YouTube video of Mangamahu network arch bridge - the first of its type in New Zealand.

9-11 Twin Towers Attack Simulation

I just viewed this very interesting 3D simulation of the airplane crashing into the World Trade Center twin towers.

Popsicle Stick Bridges Slideshow

Popsicle Stick Bridge Building Competitions have become a popular activity for students here and abroad. This blogsite had many visitors who "googled" about popsicle stick bridges. Here is a slide show of the popsicle stick bridges that competed in the 5th DLSU Bridge Building Contest.

Toys for Creative Minds

If you want to develop children's creativity, patience and imagination, give them a Lego or MegaBloks. Lego or MegaBloks consist of colorful interlocking plastic bricks, beams, axles and minifigures which can be assembled and connected in many ways to contstruct various types of objects such as vehicles, buildings and even working robots. Anything constructed can then be taken apart again, and the pieces used to make other objects. Lego and MegaBloks pieces are compatible.

My two kids especially my son, Geof enjoy creating objects using Lego and MegaBloks bricks. Geof designed his own Lego twin tower almost similar to the Petronas twin towers with perfect symmetry in design and colors. He creates cars, airplanes and buildings. He usually watches Lego creations in You Tube and gets inspiration from these movies. When inspired, he will diligently and painstakingly assemble the structure from his imagination. My daughter, Julia (4 yrs old), also creates her own cars and structures.

The Lack of Textbooks in Civil Engineering

One of the challenges to an engineering professor here in the Philippines is choosing the main textbook of his courses. Before I recommend a textbook as the main reference, I first go around bookstores specifically National Bookstore or Goodwill bookstore to check what textbooks are available. Recently, I noticed the lack of textbooks in civil engineering in commercial bookstores. What you will see are Board exam reviewers and the old edition of textbooks like Strength of Materials by Singer and Pytel. Would you believe that even if we want to replace the textbook by Singer and Pytel in Strength of Materials with a new one, we can’t – because we can’t find a replacement. In our Engineering Mechanics course, we have to write our own textbook in Statics.

I know there are new and better textbooks like those written by R.C. Hibbeler. I usually use Mechanics of Materials and Structural Analysis by R.C. Hibbeler as my main textbooks in my two courses in structural analysis. And usually I recommend the latest edition. However, I observed that these books have become scarce. Even if I inform the local distributor to make the textbooks available, the situation remains the same – NO TEXTBOOKS. Why should I recommend a textbook which is NOT available for the students to purchase?

I would like to call the attention of book publishers and distributors in the Philippines to make their textbooks in Engineering Mechanics (Statics & Dynamics), Mechanics of Materials, Structural Analysis and Structural Design (Reinforced Concrete and Steel) available in commercial and university bookstores so that the faculty can choose their main textbooks in their courses. I raised this problem also to the Commission on Higher Education (CHEd) - Technical Panel in CE during their evaluation visit at our university. Well the CHEd representative doesn’t have an answer to this ..... Ironically CHEd requires a minimum number of books and references per subject - what are they going to do about this ? Your guess is as good as mine.

On TecQuipment Structures Teaching Apparatus

The Department of Civil Engineering (De La Salle University-Manila) will introduce a laboratory component in the undergraduate courses in the Theory of Structures and the TecQuipment’s (TQ) structures teaching apparatus will be used. Among the TQ apparatus purchased were for Frames (Deflections and Reactions), Beams Deflections, Pin-jointed Frameworks, Shear center, Unsymmetrical Bending, Beam Shear and Bending Moments. We are presently being familiarized on the use of the equipment by a local representatvie of TQ. There were some problems initially during the demo but the TecQuipment Ltd (UK) Engineering Manager, Andrew Darby BEng (Hons) immediately responded to the problems encountered. I can see a great potential for the TQ Structures Teaching Apparatus in enhancing the understanding of structural analysis concepts. I am looking forward to using these equipment in our laboratory class in structural analysis. As a matter of fact, I plan to write a teaching and learning manual using these equipment.

Two Popsicle Stick Bridges from DLSU

I would like to feature two popsicle stick bridges submitted by my undergraduate students at the 5th DLSU-CES Bridge Building Competition. Bridge No. 09 by Morgan Say and Jet Tugado is a Warren-type truss bridge. It actually ranked no. 4 in both the Strength and Design category. The bridge has the properties, L = 626 mm, W = 1073 g (quite heavy). It's deflection at P = 10 kg was only 3.2 mm but at failure, it posted a very large deflection D = 19.20 mm. Again the arrangement of the diagonal members may have contributed to the large deflection. The diagonal members in this bridge are under compression. If only the weight and the deflection were reduced, it may have joined the top 3. Actually it is ranked no. 1 based on the P/W ratio only.
The second bridge (Bridge 16) by Jefron Gaw, Allan Mariano and Lex Alviar was withdrawn from the competition because its depth D exceeds the limit, making it impossible to test the bridge using two point loads. The bridge has an arch shape. The bridge is quite heavy W=1425 g. It is a well designed bridge and it may have performed well in the competition, if it only passed the specifications. The bridge was actually tested upto failure using the UTM and observe the failure mode - a bending failure at midspan.

I would like to commend the participants for creating the nice popsicle stick bridges. You are all winners!

GRASP Analysis of the Top 3 Popsicle Stick Bridges

In the strength category of the 5th DLSU-CES Bridge Building Competition, the bridges with weight W were subjected to two-point loads using a UTM (Read the blog on bridge testing). The values of P and D at failure were noted to get the Strength rating S=P/(D*W). The bridge with the largest S wins the competition.

The value of S depends on the stiffness (P/D) of the bridge and the weight W. The competition measures how efficient the materials were used to obtain a structure with large ratio of stiffness to weight.

Using the GRASP software, the top 3 winning bridges (B13, B03 and B06) in the strength category were analyzed . Observe the very interesting deflected shapes of the models. The figure also shows the members with axial tensile forces (labeled T). Why did the top bridges perform better than the others? What are the factors that contributed to the large stiffness (P/D) of the bridges? One major factor is the material property of popsicle sticks - the tensile stress capacity is larger than the compressive stress capacity in popsicle sticks. It would be easier to break the popsicle stick due to compression than to tear it due to tension. Hence, if you want to efficiently use the strength of popsicle sticks, design your bridge such that tensile forces not compressive forces are developed in most of the members. In the top 2 bridges - B13 and B03 - relatively large tensile forces were induced in the diagonal members compared to the compressive members.

Another factor is buckling failure in the compression members. If you want to increase the capacity of the members against buckling, then provide braces. The top 2 bridges have horizontal braces at the top and bottom preventing lateral buckling of the members. Bridge B06 which is 3rd in the competition has relatively larger compressive forces in the top chord and diagonal web members. Observe the buckling failure of the top chord. If only horizontal braces were installed at the top, the bridge may have developed a larger capacity and less deflection before failure.

Another factor which increased the stiffness of the bridges, particularly the top 2 bridges is the use of a deep box girder. This results to a relatively light-weight bridge but effective against bending. Sticking together popsicle sticks forming stiff griders like in the bridges shown result to very heavy and not very efficient bridges. They may carry a larger load (P) before failure but the ratio with weight may be smaller because of the large bridge weight.

Modeling your bridges and analyzing them using a software like GRASP before the actual construction will guide you on how to improve the bridge designs. You can redesign the arrangement of the truss members, increase the depth or know the location of braces to prevent buckling failure.

Best Popsicle-Stick Bridge Designs

In the recently concluded 5th DLSU-CES Bridge Building Competition last 7 Feb 2009, the bridges made from popsicle sticks competed for the Best Bridge Design based on the following criteria:

• Creativity and Innovativeness in the design and form: 30%
• Application of bridge design principles: 30%
• Practicality and implementability: 20%
• Neat and well-polished bridge: 20%

Four judges examined and evaluated the bridges. After about an hour of evluation, the scores were tabulated. It was a tight race for the winner. The winning bridge from Don Honorio Ventura College of Arts and Trades (DHVCAT) won by a hairline against the bridge entry from the Technological Institute of the Philippines (TIP), Manila. The 3rd placer is the bridge from the Technological Institute of the Philippines (TIP), Quezon City. Building popsicle-stick bridges using glue takes a lot of planning, patience and ingenuity. Cutting the popsicle sticks to fit the form of the bridge, gluing the sticks and polishing involves a lot of time. In general, the popsicle-stick bridges submitted were impressive. Many of the bridges were unique and may serve as models for future bridges. The students have demonstrated their skills and understanding about bridge construction.

DLSU CES 5th Bridge Building Contest

The 5th DLSU Bridge Building Contest was held on Feb 7, 2009. Seventeen bridges made from popsicle stick bridges were submitted from various engineering schools - Don Honorio Ventura College of Arts and Trades (DHVCAT), Technological Institute of the Philippines (Manila and QC), FEATI University, Far Eastern University (FEU) , Pamantasan ng Lungsod ng Maynila (PLM), University of the East (UE-Manila) and De La Salle University (DLSU-Manila). The bridge must span a distance of 560 mm and must have a width not more than 140 mm, height not more than 200 mm, depth not more than 100 mm, weight not more than 1.50 kg. There were two categories in the competition: Bridge Design and Bridge Strength. In the Bridge Design category, the criteria used were creativity, innovativeness, application of bridge design principles, practicality, implementability and neatness. The winner for this categroy is one of the entries from DHVCAT. In the Bridge Strength category, the bridges were tested using the UTM and the load P and deflection D at failure and the bridge weight W were used to get the Strength Rating (see blog on bridge testing). The winners in this category were 1st: PLM, 2nd: TIP-Manila and 3rd: DLSU-Manila.

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Introducing Structural Engineering

At DLSU-Manila, we hold a forum promoting the various specializations in civil engineering - Hydraulics and Water Resources (HWR), Transportation Engineering (TRE), Construction Technology and Management (CTM), Geotechnical Engineering (GTE) and Structural Engineering (STE). I was tasked to present the STE specialization. To introduce the STE specialization, I created a short video using Power Director and presented this during the forum.

So you want to be a structural engineer? Watch the video and explore the world of the structural engineer and how he changes the world.

Tales of Disasters: Earthquake!

Here is another film made by No Strings for programmes in South East Asia and funded by Trocaire. The movie is about Badu and the Little Girl who experienced an earthquake. It is a movie on earthquake preparedness and response. Watch this with your kids.

This video was accessed at http://cogssdpe.ning.com/.

ASEP 14th International Convention - Call for Abstracts

The Association of Structural Engineers of the Philippines, Inc. (ASEP) on its 47th year is hosting the 14th ASEP International Convention with the theme, “Structural Engineering: Coping with the Global Crisis” on May 21-22, 2009. In this regard, you are invited to submit an abstract and full paper (later) for presentation during the convention.

Topics of papers on structural engineering which address innovative approaches of coping with the global crisis and problems - financial, political, environmental, climate change, natural disasters, terrorism, poverty and sustainability - are welcome.

Specific topics include: Performanced-based design, Retrofitting and Strengthening, Structural Failures, Structural Risk, Natural Hazards and Disaster Rsis Mitigation, ISO Standards and Codes of Practice, Earthquake and Wind Engineering, Value Engineering, Engineering Ethics, Urban Planning and Infrastructure Development, Fire, Impact and Blast Loads, Case Studies on High-Rise Buildings and Long-Span Bridges, Prestresses and Pre-cast Construction, Foundation and Geotechnical Issues.

Deadline of Submission of Abstracts: 14 February 2009

Deadline of Submission of Full Papers: 24 March 2009

Send abstracts to: asep14aic@gmail.com

Disasters and Development

One of the videos in "Understanding Earthquakes and Disasters: Photo-Video Presentations for Public Awareness and Education" is entitled "Disasters and Development."

Natural disasters occur if society is highly vulnerable to the hazards. When a disaster occurs, the development and the economy of the country and local community is affected. As a country develops, the population increases and more infrastructures are constructed, and these may increase vulnerability to the hazards. . Understanding the relationship between disasters and development is important in designing a comprehensive disaster risk mitigation program.

Tales of Disasters: Tsunami!

I joined a social network - Coalition for Global School Safety & Disaster Prevention Education and learned of the various initiatives around the world in promoting disaster awareness to the public especailly in schools through the world wide web. I found interesting videos created by No Strings, a group of puppeteers who use colorful and engaging adventure films to teach life-saving messages to children.

Here is the first video on Tsunami. The story centers on Badu, a likeable but lazy villager who teaches by negative example and a Little Girl who is aware of natural hazards and disasters and their signs and effects. Watch this video with your kids as this is really very informative.

Designing for Safety & Stability Leads to Sustainability

Today, there is an increasing demand for engineers to focus their efforts on the protection and preservation of the environment. The civil engineering community, which includes structural engineers, plays a major role in maintaining the balance and harmony between the built and existing natural environment. The built environment, which includes infrastructures such as residential houses, high-rise buildings, long-span bridges, roads and expressways, and large civil structures like dams and reservoirs, provide for a livable atmosphere for all. However, the impact of these infrastructures on the natural environment especially in natural hazard-prone countries like the Philippines should be a concern. Richardson (2002) summarizes the realities of infrastructure impact on the environment as follows: It is said that 50% of the world population lives in cities today and this may grow to 75% by 2030. Cities are said to cause 75% of the world’s pollution and consume 75% of the world’s energy. Buildings are reported to produce 40% of the world’s CO2, consume 50% of the energy derived from fossil fuels, consume 3 billion tons of raw materials in construction each year and consume 75% of all energy used through artificial lighting, heating and cooling every day. 25% of all wood harvested is used in building construction.

The negative impact of infrastructures on the environment aggravates especially when natural disasters occur. Natural disasters like earthquakes, floods, typhoons, tsunamis and landslides spoil both the built and natural environment. Aside from causing numerous deaths and injuries to people, natural disasters had caused the destruction of important infrastructures such as buildings, bridges and roads and devastation of nature which contributed to environmental degradation. The 1999 Chi-Chi earthquake in Taiwan caused 2,415 deaths, 1,441 severely wounded, US$9.2 billion worth of damage, 44,338 houses completely destroyed and 41,336 houses severely damaged. The 2001 Gujarat earthquake in India was the most devastating earthquake in India in recent history. The quake destroyed 90 percent of the homes in Bhuj, several schools, and flattened a hospital. Gujarat's commercial capital and a city of 4.5 million, as many as 50 multistory buildings collapsed and several hundred people were killed. In the July 16, 1990 earthquake in the Philippines, damage to buildings, infrastructures, and properties amounted to at least P 10B. The Hyogo-ken Nanbu earthquake in Japan which hit the city of Kobe and surrounding areas in Hyogo prefecture on January 17, 1995 cause the collapse of nearly 55,000 houses in the city of Kobe. The cost of reconstruction of buildings alone was roughly estimated at between US $61-70 billion.

As a consequence of the destruction brought about by natural disasters, the natural resources, materials and energy that have been utilized in constructing these infrastructures have been put to waste. Moreover, the large amount of disaster-caused waste and debris poses another environmental problem. The most severe natural disasters generate debris in quantities that can overwhelm existing solid waste management facilities or force communities to use disposal options that otherwise would not be acceptable.

How may structural and civil engineers contribute towards the reduction of these negative impacts in a region where natural disasters like earthquakes, typhoons, tsunamis and landslides are prevalent? Structural and civil engineers have significantly contributed towards the protection and conservation of the natural environment especially when we consider the impact of natural disasters. on infrastructures and the environment. Civil and structural engineers, when they properly design structures and foundations for safety and stability, are actually contributing significantly to the preservation of the natural environment. Proper analysis, design and construction of structures will minimize damage or collapse. Refined modeling, testing and analysis of soil may prevent foundation failures. Strengthening and improvement of unstable slopes will control the occurrence of landslides. When structures are strengthened or retrofitted, the usable life of the structure is extended reducing end-of-life waste. These primary responsibilities of structural and civil engineers regarding safety and stability, in the end, leads to the reduction of non-renewable natural resources consumption and minimizing the accumulation of construction waste and disaster-caused debris waste. The responsibility of structural and civil engineers in designing for safety and stability and the role they play concerning the maintenance of environment especially in disaster-prone countries must be appreciated by everyone including the so-called “environmentalists.”

This article was published at the Philippine Star, Star Science Column, 6 March 2008