IABSE presentation on slabs subjected to a combination of loads

At the IABSE spring conference in Rotterdam, I've presented a paper on slabs subjected to a combination of loads.

The abstract is as follows:

Previous experimental research at Delft University of Technology indicated an increased shear capacity of slabs under concentrated loads as a function of decreasing distance to the adjacent line support. Expressions have been derived for this increase, including the definition of an appropriate effective width. However, it is unknown if the uniformly distributed loads on solid slab bridges, e.g. due to dead loads, that act over the full width can be combined with the effects of concentrated loads acting only over the associated effective width at the support. To study this problem, additional experiments have been carried out at Delft University of Technology, in which a combination of loads consisting of a concentrated load close to the support and a line load over the full slab width are applied. The experimental results prove that the superposition principle applies to combinations of concentrated loads and distributed loads.

You can view the slides here:

Concrete slabs under a combination of loads from Eva Lantsoght

Presentation on Shear Assessment of Solid Slab Bridges

At the IABSE spring conference in Rotterdam, I've presented a paper on the shear assessment of solid slab bridges.

The abstract is as follows:

The capacity of reinforced concrete solid slab bridges in shear is assessed by comparing the design beam shear resistance to the design value of the applied shear force due to the permanent actions and live loads. Results from experiments on half-scale continuous slab bridges are used to develop a set of recommendations for the assessment of slab bridges in shear. A method is proposed allowing to take the transverse force redistribution in slabs under concentrated loads into account, as well as a horizontal load spreading method for the concentrated loads. For selected cases of existing straight solid slab bridges, a comparison is made between the results based on the shear capacity according to the Dutch Code NEN 6720 and from the combination of the Eurocode (EN 1992-1-1:2005) with the recommendations, showing an improved agreement.

You can view the slides here:

Shear Assessment of Slab Bridges from Eva Lantsoght

Writers' Lab: How much time does it take to write a dissertation?

As I've been keeping track of how I spend my time in ManicTime, I can now assess how much time writing my dissertation took me, and how much time rewriting and implementing comments took me.

When I finished my first draft, I thought the biggest chunk of work was done.

So. Wrong.

I spent a total of a little over 600 hours on my dissertation, over a time period from March 2012 to May 2013.

The following list shows you how my time budget breaks down:

Writing the first draft: 205 hours
Rewriting the first draft for approval by promotor and copromotor: 123 hours
Working on the comments of my committee: 255 hours
Final preparations on layout to get it ready for printing and publishing: 30 hours

As you can see: writing the first draft is only 1/3 of all the work. There's much more to be done afterwards...

If we break it down into time, the chronology of my dissertation looked like this:


Writing the first draft: March 2012 - November 2012

I delivered my first draft on November 14th. Most of my first 4 chapters as well as my 7th chapter were written in weekends and on the evenings, as I couldn't find the peace and calm for writing during the office hours, where regular research and teaching activities were in full swing. Over summer, I wrote a set of conference papers for the conferences that I was planning to attend in 2013, and in September and October I carried out the research for chapters 5 and 6.

Rewriting the first draft for approval by promotor and copromotor: early December 2012 - end of January 2013

As so many PhD students, I had to try rather hard to convince my busy supervisors to sit down, read the draft and provide me with their comments. As I had been working on my theory in silence, and not discussed it until I delivered the first draft, it took a number of meetings and significant rewriting of my chapter 5 to actually get my message across. In fact, this chunk of research was something I hadn't shown in a presentation yet, nor written down in a paper, so it naturally took me more time t crystallize my message.

Working on the comments of my committee: March 2013- mid April 2013

That was one hell of a busy time! The committee members get maximum 3 weeks for their feedback, I calculated a month, but the time it takes to pin a meeting with everybody added another 2 weeks. Working through the comments also added about 100 pages to the final document (also a number of extra Annexes).

Final preparations on layout to get it ready for printing and publishing: first half of May 2013

I found it very hard to stop proofreading, and to just let it go and accept that it can't be perfect. The final preparations were mostly related to fishing for typos, and getting my layout ready for the printer. Don't ask me about putting landscape tables on a portrait page - I spent three full days fretting away at that, and I still have a Table of Doom in my final dissertation.

How much time did you spend on rewriting as compared to writing? Do my results correspond to yours, or was your first draft an immediate hit?

Silver Linings: Study Yum

When your brain seems to need a little boost, and you feel ready to reach out for a candy bar or a cup of coffee with a shot of whatever-sticky-stuff, you can instead treat yourself to a delicious treat based on chocolate, nuts and dried fruits - with some powerfoods for an added bit of bazinga.

I call it "Study Yum", because it is filled with elements that are beneficial for the brain, and it tastes amazing at the same time - and it's really easy to make, you only need a food processor (small quantities might work with a decent mixer as well).

Ingredients:
200 g dark chocolate, melted
500 g of dates, pitted and chopped
1 tablespoon of chia seeds
5 tablespoons of goji berries
50 g of melted butter
25 g of melted coconut oil (or more, replacing all of the butter)
5 tablespoons of almonds
5 tablespoons of walnuts
50 g of chopped apricots
warm water, if necessary for blending

Simply add all solid elements to a food processor, then add the liquid elements. Keep blending until it becomes a paste (add water if necessary for the texture). Scoop on a sheet of aluminum foil to make a roll out of it, then place in the refrigerator for a few hours so that it can harden out. Enjoy!

Presentation at fib Symposium 2013

Last April, I gave a presentation at the fib Symposium in Tel Aviv. The abstract of the paper and presentation is the following:

Existing solid slab bridges under a combination of wheel loads and distributed traffic loads sometimes do not fulfil the code requirements for shear. However, reinforced concrete slabs loaded close to the support are subjected to shear stresses which might result in a failure mode of combined punching and shear. This behaviour is studied in a first series of experiments on slabs under a concentrated load close to the support, and these experiments resulted in a set of recommendations. To verify if these recommendations can be used when assessing solid slab bridges under distributed and concentrated loads, slabs under a combination of a line load, representing the dead weight, and a concentrated load, representing a wheel load, are tested up to failure. The experimental results are used to assess the ultimate shear which can be carried at the support and the influence of the varied parameters is discussed. The results demonstrate how different types of loading such as dead loads and live loads can be superposed and how a stress check at the support can be carried out.

Here are the slides of my presentation:

Shear capacity of slabs under a combination of loads from Eva Lantsoght

Writers' Lab: Turning passive sentences into the active voice

Today, Ahmad Bilal shares a practical way on how to reduce your use of the passive voice. Ahmad is a civil engineer by profession from Pakistan, currently residing in Sweden. He received his bachelors in 2002 from NUST Pakistan and MS from Lund University, Sweden. His work experience revolves around structural design of buildings, tower foundations and design management. After about eight years of working experience, he felt the need to narrow his focus and selected Water Resources Engineering for his master's studies. One of the reasons to jump into water resources is his feeling that water related problems will the biggest challenge in the near future and that there are not enough experts available considering the magnitude of problems. His near future aims are to pursue a research related career or finding a suitable PhD position.
His life is a never-ending battle of "finding balance" and feeling guilty about what he is not doing at the moment. Besides struggling to look like engineer I also love traveling, enjoying nature, gardening and spending time with family. He writes at the following two blogs, about Water Resources and his previous experience .

Improved writing skills are one of the good things I have learned besides gaining professional knowledge during my masters. One writing mistake that I and other students often make, was excessive use of passive voice in our assignments. The use of passive voice is grammatically correct, but its overuse can make writing more prolix, mystifying and less appealing. A writer should use the passive voice when the object is to be given more importance than the subject.

One automotive way to check your use of passive voice in your sentences is to let your Microsoft Word check your writing. You can set your MS Word to always check for passive voice. The following instructions are based on MS Word 2010.

Consider the following sample paragraph, which heavily relies on the use of passive voice.

“Water resources are a lifeline to the human population and are being used for various competent purposes besides just drinking. With the advancement of technology, much artificial development has been carried out on natural water bodies to control and use water more efficiently. However, this has introduced mankind with some previously unknown and unforeseen problems. Sedimentation of dams is such a problem as it causes storage capacity of dam reservoirs being continuously reduced. “

If you have set MS Word to check for passive voice, it will automatically underline with a green line the parts of your text using passive voice. The procedure is simple, and consists of the following steps:
1. Click on ‘File’ in the menu bar
2. Click on ‘Options’, the penultimate choice from the file menu. A new window ‘Word Options’ will open.
3. On the left column go to ‘Proofing’
4. In writing style, from the dropdown menu, select ‘Grammar and Style’ and click on 'settings'. A new window ‘Grammar Settings’ will be opened.
5. Under ‘Style’ make sure that ‘Passive sentences’ is checked.
6. Click OK and from the ‘Word Option’ window, click ‘Recheck Document’.
Now when you will go back to your document, you will notice that sentences with passive voices are underlined in green.

Below is my version of rewriting the example paragraph. As compared to the previous option, the readability and ease of understanding the message for the reader have increased.

“Water resources are a lifeline to the human population. We use them for various purposes besides just drinking. In order to control and use water more efficiently, we have created many artificial control and diversion structures by making use of the advancement of technology. However, this has introduced us with some previously unknown and unforeseen problems. Sedimentation of dams is such a problem as it continuously reduces the storage capacity of dam reservoirs.”

Silver Linings: Flowing through Conference Travel

Conference travel can be exhausting, and I for one always notice how tired I am after a conference because suddenly I need an alarm clock to wake up.

After preparing months for a conference, you shouldn't just shoo away from the place of action because you feel that it becomes taxing and overwhelming. Instead, try to support yourself as much as possible through these extra-busy days, so that you can benefit from it as much as possible.

Instead of wearing yourself out by placing extra stress on your body, make a few conscious choices that make you go those few extra miles before your gas tank runs dry:

1. Go well-prepared

Don't arrive to a foreign airport in a frenzy, trying to remember your hotel name and trying to figure out how to reach the hotel. Avoid late nights in your hotel room to finish up your presentation. Instead, just make sure you have all prep-work out of the way so that you can focus your concentration and energy on learning and networking.

2. Prioritize

Make a realistic schedule - you can't be sitting in lecture sessions from 8 am to 10 pm, meet people AND visit the exhibition. Before the start of the conference, take a few moments to list your priorities: Who do you want to meet? Which company should you visit on the exhibition? Which sessions should you attend? When should you hang out in the hotel lobby and catch up with your acquaintances.

3. Make a few conscious food choices

If possible, try to select a few extra nutritious meals from the buffet. Replace a coffee by a green juice or smoothie. Try to stock up on nutrients in a healthy way before you load up your plate at the dessert buffet. And then indulge in your favorite foods - a conference is not the place to put yourself on a strict diet. Just make sure you get what you need before you start with coffee, alcohol and sugar.

4. Exercise

Bring your sports clothes, and exercise! After sitting an entire day, the best treat you can give yourself is exercise: running in the city you are visiting, trying out the hotel gym or pool or practicing a yoga sequence in your room - just try to make time for movement, at least 15 minutes every day.

5. Find some quiet time to read or relax

If you feel that fatigue and overwhelm are starting to creep up, then try to withdraw from the noise and business for half an hour to read, sit in the sun, take a nap or whatever feels right for you at that moment. Taking this one small action might be just what you need to keep going again, and might work better than a double espresso.

What do you do to avoid crashing down with exhaustion by the end of a conference? Please share your tips in the comments below!

Defending tomorrow!

Defending in Delft's spaceship tomorrow!

Tomorrow, on June 14th of 2013, at 12:30 I will defend my PhD thesis and propositions in the Aula of Delft University of Technology.

This is what my day will look like:
11:45 arrival to the Senaatszaal
12:00 presentation for friends and family, without the committee
12:30 Committee enters, and the defense/interrogation starts
13:30 end of the defense, the committee leaves
13:45 graduation ceremony (if all goes well)
14:00 reception at Aula
18:00 dinner with friends and family to celebrate

I'm almost finished!

Writers' Lab: Writing your acknowledgements

Your acknowledgements might be the only part of your dissertation that your friends and family will ever read (and probably some other researchers in your field too).

While acknowledgements typically have a lighter tone than the rest of the dissertation, it doesn't make writing them something you finish within 20 minutes.

So when you are planning to write your chapters, you need to understand that compiling everything into the entire dissertation might take some additional time. You'll need to add not only your acknowledgements, but also your CV and make sure everything is in the same layout.

Sometimes I open an old dissertation from my research group, and I can really feel the despair of the final weeks of writing and getting everything finished speak through in the acknowledgements. While I can totally relate to those feelings, I don't think it is necessary to show these in your dissertation. The feelings will pass once you defend, but those words will remain there.

My colleagues told me to write my acknowledgements early on, and I followed that advice. I wrote my acknowledgements in November, as I was preparing my first draft. And I'm very glad I did so before getting sucked into the frustrations and anger/sadness that can arise at later stages in the writing/editing process.

I've restated a few sentences, and I've added some people that I forgot to name, but the core of the text hasn't been altered since November.

Therefore, if you are writing your chapters, don't forget to write your acknowledgements!

Silver Linings: Listening to your inner circadian rhythm

Too often in graduate school we are running around as sleep-deprived, stressed-out zombies that just can't juggle all the tasks we have to fulfill and drop a ball here and there.

What if I tell you that I have never worked after 10pm in my entire PhD career (provided that you don't count a conference dinner as "work")? I've been tired and sleep-deprived at times, but eventually I have learned to honor my circadian rhythm and give my body the rest it needs. By now, I wake up early in the morning without needing an alarm clock, and I feel rested and refreshed.

Once I understood that my body functions differently over the course of a day, my productivity increased so much that I could go home most days before dinner, having ticked off all my tasks for the day from my to-do-list.

It takes some experimenting.

It takes some time to learn to actually listen to your body. If you're a researcher, chances are that you live from your shoulders upwards. But baby, there's a whole lotta wisdom programmed inside the rest of you.

It takes some guts to go against the flow and decide you are not going to live on tall coffees and little sleep anymore.

It takes some major prioritizing as well.

But if you're willing to take the leap, then start to tune in with yourself by paying attention* to the following:

1. Alertness during the day

When do you feel sluggish? When are you performing at your best? How can you schedule your tasks around these moments of the day?

2. Sleeping and waking times

If you don't put an alarm clock, when do you wake up - how much sleep do you really need? If you are completely sleep-deprived, it might take some time before your sleeping and waking times regulate themselves. But try sleeping earlier for a while - larks and owls are pretty much half/half of the world's population, but in graduate school, it looks like everyone is an owl. There are too many larks trying to fit themselves into an owl schedule!

3. Response to stimulants

Once you're clean with possible caffeine, sugar and fatty junk food addictions, you can tune into yourself and see how you really react to these stimulants. Most likely, you'll experience the rush and the dip that come with the change in blood sugar levels.

4. Response to exercise

If you've been in the lab until 10pm, is it a good idea to go for a run and then crash down into your bed? Most people get too energized from exercise, so experiment and see when you get the best results: early morning, in the afternoon, in the early evening or late at night?

*If you want to learn something from your body, you'll need to take it very very easy on the caffeine and sugar. Otherwise, you'll only see/feel the results of those spikes and drops in your blood sugar levels.

Five Key Elements to Consider when Applying for a PhD

Recently, a reader posted me the following question:

Hi I am thinking of doing PhD and have just come acrossed some scholarships possibiities as well. But before applying I need to contact a potential supervisor and required to do communication about possible phd topic etc. However I am reluctant as to how to start and what should I need to care about during first communication phase. I will be glad if you or someone reading it would provide some useful advice for this stage.

The requirements are different for every school, but there are a few general guidelines that should be helpful for every student who is planning to apply for a PhD (and apply for funding).

Here are the five key elements to consider when applying for a PhD:

1. Familiarize yourself with the work of prospective supervisor(s)

To get a grasp of the style of your prospective supervisor, or a professor you might be interested to work with, start reading a few of his papers. You shouldn't aim at understanding the deep details of these papers, but just familiarize yourself with the topics he works on, the main ideas, his writing style, and his publication venues of preference.
Depending on your goals for graduate school, you might prefer to work with a supervisor who publishes mostly conference papers, as this can signify he/she has a strong network. Also, check if the professor publishes together with his PhD students, or if he publishes most of the research as first author and the students as workslaves on "lower" positions in the author list.

2. Write your autobiographical essay and letter of purpose and rewrite, rewrite and rewrite it again

Your autobiographical essay is your little stage, where you can give your prospective supervisor and institution an idea of what kind of person you are, and what your extra skills are besides your excellent academic qualifications. Don't be afraid to mention all other extra-curricular activities that keep you busy, as these elements will help sketching a more complete profile of who you are as a student.

3. Explore the coursework

Have a good look at the courses that are offered, and examine if these courses can fit into your plan of study. If you want to specialize for example in seismic design, apply to a program that offers plenty of courses in this field of study. If you apply to a research-only program, you can still see if there could be courses that can fill the gaps in your knowledge - and you can mention this in your letter of purpose. You can show your prospective institution that you have seriously looked into their program.

4. Try to go for a personal visit

If traveling to your future institution is an option, absolutely try to carve out some time and budget to go for a visit. You will get an impression of your future supervisor, the facilities, the atmosphere and the town the institution is located in. You'll be living in the same city for a decent number of years, so go and explore and wonder if you would feel at home in that place.

5. Prepare for possible tests in time

Depending on the program you apply to, you will need to take some standardized tests. Delft does not require any tests to be taken, but US institutions require you to take tests such as the TOEFL, GRE etc. If you take standardized tests abroad, try to take them at least a year before your intended start of study. There are not that many options for taking standardized tests in most European countries (once or twice a year for the GRE, for example), so make sure you plan ahead.

What would you advise someone who is planning to start applying for a PhD program?

Writer's Lab: How to stay motivated when writing an entire dissertation

That very beginning of writing your dissertation - chapter 1, the introduction - and then nothing but the flashing cursor in your writing software... This situation is probably the beginning of 99% of all dissertations.

The end is also quite the same for most of us: compiling a list of notations, adding the references if you haven't used an automatic importing system, and compiling the table of contents.

What happens in between those moments can be a bit messier. You might just sit down and write it all out, or you might come across gaps in your work and spend a few more weeks to figure things out.

Even though you might be able to write your dissertation quickly, chances are still that you will hit a rough patch at some point in the process. If you want to stay motivated when working on such a large project, here are 7 ideas to try out when you need to pick up your motivation again.

1. Reread an important paper

If you want to get your inspiration flowing again, then try to remember which work inspired you in the first place. When you are stuck somewhere, reread an important paper that was essential to your work. Or read a new publication in your field. Remember how we discussed earlier how reading sparks creativity?

2. Edit a previous chapter

Do some work that doesn't require much of your hard thinking deep working capacities, but that needs to be done to move forward. You can for example edit a chapter that you wrote earlier, and wait until your bad mood drifts away.

3. Think about your propositions

If you need to defend both your dissertation and 10 propositions as in the Netherlands, you might like to take your thoughts and worries away from your dissertation and look for good citations or ideas to use for your propositions.

4. Take some time off

You know yourself best - when you need a break, take some time to recharge and refuel. That doesn't need to be an entire holiday, but you can simply take an evening off and indulge in some things you love, or you can take a weekend to yourself and try to watch some inspiring documentaries or read some thought-provoking books.

5. Have a discussion with your supervisor

If you're really stuck and you are doubting the quality of your work, then don't suffer in silence. Speak up and ask for a meeting with your supervisor to discuss the difficulties that you are facing.

6. Don't stress over it

Friction and creative blocks are inherent parts of the entire process of creating something - and a 100k word thesis is certainly "something". So be prepared: you will run into some creative blocks, but that is just fine! That does not mean that something is wrong with you as a PhD candidate.

7. Set boundaries

At incredibly busy times in the lab and with my funding agency, I've ran on an 8am to 10pm schedule to get all the measurements done and all the simulations run. For writing, that just doesn't work (or at least not, to write an entire thesis). Set office hours for yourself, even if you work as a part time PhD. Know when you can work on your dissertation, and make a realistic planning of what you can achieve.

How did you get from the flickering cursor to compiling your table of contents? What challenges did you face along the way, and how did you resolve them?

Silver Linings: Getting started with meditation

He often joins my meditation

Over the past two years, I've regularly written about my explorations in meditation and mindfulness on this blog. By now, I consider meditation as important for my mind as exercise for my health. Over time, I've developed this habit, and by now I simply meditate every single day.

The practice of meditation has made me calmer and more focused and productive, and it has had tremendous benefits for my research.

I understand that you might think that you don't have the time for it. But believe me, the additional mental clarity you build up will help you regain those 10 or 20 minutes that you spend in meditation very easily.

My path towards daily meditation has been on and off. Many times I've fallen of the wagon, but I've always come back and tried again. If you want to get started with meditation, these are my five essential points:

1. Try out different times during the day

Different people prefer different times of the day to meditate. You might like to try it out as first thing in the morning, during your lunch break, right when you get home or at night before you go to sleep.
It took me quite some time to understand that for me, meditating first thing in the morning (after brushing my teeth and washing my face to wake up), is the best way to make sure I make it a priority.

2. Try out different styles of meditation

Don't say "I don't like meditation, it's not for me". For sure, there will be some kind of meditation that you enjoy. Try out different styles (gradually, don't try to master everything at once), such as: body scan, breathing meditation, mindfulness meditation, walking meditation, visualization, guided meditation, meditation using binaural audio,... There are so many varieties that I am sure there will be something out there that suits you.

3. Start small

If you want to get started without getting discouraged, start small. Leo Babauta advises you to build the habit by starting tiny: 2 minutes a day. As long as you start building the habit, you will improve and start to enjoy. If you practice a sitting meditation without guidance nor mindfulness bell, then listen to your inner urge to get up. Resist this urge twice, and get up at the third time the urge surfaces.

4. Log your progress and process

Whether you make a wall chart to track your progress, tick it off from your to do list in your planner or use a habit-building app, tracking your progress and journaling about your observations and the entire process will help you ease into your new habit.

5. Be gentle on yourself

If you fall of the wagon, don't beat yourself up. Just start over and over again. I did my first meditation trials 13 years ago. Ever since then, I've been picking it up, trying to make it stick, and lose it again. It's an iterative process in the end, and its purpose is not to stress you out, but to help you grow into a more focused version of yourself.

Do you meditate? Would you like to start? Share your experiences in the comments section!