How Arches Work! (with Diagrams!): Structures 2-2

[@ernestobetancourt3216]

I’m 19 years old and have realized how little I know about things that are around me and play a crucial role in my life. I’ve decided to learn so much about the structures around me and try to understand them a little better

[@SpannerAT34]

We are seeing the power of someone who can explain a topic so well

[@PaulKassabian]

Thanks!

[@KeyWestSaltLife]

I absolutely love this video series on structures. I think you do an amazing job explaining the topics and wish all professors had your skill and passion for teaching

[@lesterbrooker9421]

This was a wonderful video. I have pondered the 'thrust line' in an arch and have even tried to calculate it''s position from first principles. I soon realised I do not know enough on the subject to be certain of the placement of the thrust line. I was aware of this inverted chain method and its use by Gaudi and also it use in the checking of St Peter Dome but for some reason I never quite put the two together. Thank you for such a wonderful explanation. I hope that you continue your series of videos.

[@caryschainey]

Beautifully explained and demonstrated - thank you!

[@jeanettecook1088]

I'm a farmer living in New Hampshire USA. I'm fascinated by arches. I love to design small buildings, like chicken coops. I'm doing one now, with a roof that is a half arch, and having trouble finding a rigid structural material that will give the desired curve and strength, while being lightweight, streamlined and capable of receiving fasteners like nails and screws. I'm covering the roof with corrugated polycarbonate roofing panels... but I'd really like to know if one can get small arches commercially... or do I have to build my own? I'll probably have to make my own. Anyway, this was a great video, and it taught me a lot about designing with arches and partial arches. Thank you! 🎉 Edit: forgot to say, I'm a new subscriber!! 😊

[@fernandomingo3491]

Amazing explanation Paul. This video needs more publicity.

[@PaulKassabian]

Hey thanks! Doing my part to get structural engineering thinking out there...

[@PaulKassabianNumber1Fan]

Great video. You explain very well. I can tell that you love and know your subject.

[@ronchirayil4123]

Thanks so much for your videos Paul! They are so simple and vastly helpful!

[@PaulKassabian]

Glad you like them!

[@jitendrameghrajani4934]

The diagrammatic representation work is very good and easy to understand. Thanks!

[@jorgeojeda9338]

thanks for this video, i really love the explanation

[@arizona111]

Smashing video series! You certainly have a gift of explaining structural engineering to those without training! During the segment about the bridge that you worked on in England, "this is a steel arch so this can carry tension and compression" In Video 2.1, "arch carries compression only." Assume there is something here above my KZbin structural engineering certification. Can you explain "carry tension and compression?" Many thanks!

[@kumudeshhemachandra8408]

Wow! Super nice explanation , this is so helpful to me. Looking forward to more videos like this. Thankyou so much.

[@PaulKassabian]

You're welcome and glad to hear it!

[@tamarplotzker5231]

SO SO GOOD! Keep making videos to help us architecture students....

[@PaulKassabian]

That's the aim!

[@rumplestilskin007]

Love your wonderful and easy to understand video tutorials! Would have loved to be a student under your tutelage

[@syazwaniismail7171]

thank you for this video! i wish i found this sooner when i was still in engineering school

[@PaulKassabian]

You're very welcome!

[@mypropertyplan]

Great video, really enjoying the series. Also thank you for the millennium bridge, beautiful bridge. I have an apartment that looks right onto it.

[@PaulKassabian]

You're welcome! Video on Gateshead coming soon!

[@masteraccident4221]

I’m 12 and I’m here because I was confused how bridges work and it is satisfying to finally get the answer

[@yaminipurini8651]

Ur explanation is very clear

[@PaulKassabian]

thanks!

[@Yogimoon]

Wonderful video

[@PaulKassabian]

Many thanks!

[@joelhyer1929]

This is interesting! And powerful knowledge! Thank you so much!

[@PaulKassabian]

You're welcome!

[@hgblackshadowmaster]

Is there some sort of program for punching in start points, end points, and loads? That would be great!

[@birendrasilwal3075]

I loved the explanation

[@PaulKassabian]

Thanks for saying that - much appreciated!

[@HHHPedigrees]

Such an amazing explanation. I wish they taught students about arches in school.

[@PaulKassabian]

Thanks for saying that!

[@FoxRiverBridge]

I know very little so this is a very open question, but in the case of the single load off to the side, would you find the weakest point on the arch by using a differential equation to figure out at what point the area between the thrust line and the upper arch is the greatest?

[@MxdicG]

I have a question. At 4:31 say you wanted to improve the strength of the arch in the scenario, what would you have to do to prevent it from failing?

[@PaulKassabian]

Good question! Remember this plot doesn't have the self-weight of the masonry itself, so that helps. Other options for masonry arches is to add more distributed weight above so the effect of the point load is reduced, or reduce the point load itself somehow. Lastly, make the arch in a material that can take tension.

[@colepopovic4659]

Love this!!!

[@thoughts7085]

Teacher you said that the arc gets destroyed if the weight gets changed. Now imagine a live load in the form a truck moving on that compression arch. How does it deal with that continuously moving load?

[@rameshingale9395]

Nice.

[@ahmadsharifshajib116]

Wonderful explanation, really it is very helpful.

[@PaulKassabian]

Glad it was helpful!

[@muhammadsalmankhattak2352]

Hi plz make more such videos.these are really helpful for us.thank you very much

[@PaulKassabian]

Just posted the most recent and more on the way!

[@earthfirstarchitecture]

What if the arch was the exterior of a building, and you attached a second story floor to the interior edges half way up the arch. How would that affect the forces on the arch?

[@cscsamsung9749]

ขอบคุณ สำหรับการเรียนรู้วิชา เรขาคณิตที่เรียนในระดับประถม สามารถสร้างสิ่งมหัสจรรย์ โดยอาศัยค่าสมมาตรในวิศกรรมศาสตร์.

[@madhurjyakeot7743]

There can be many arches between two points. Am I correct? If yes, how to choose the one for my design?

[@mastersamurai7683]

I'm a bricklayer and I'm wondering what the strongest arch is. I've heard segmental, catenary or triangular? What is the answer? And does a triangular arch still count as a true arch?

[@mastersamurai7683]

I was taught segmental but have also heard triangular yet Google says catenary?

[@av_naturasmr]

If arch(catenary) bridges requires forces acting on them to be balanced in order not to fall down, how does it deal with varying loads like moving vehicles on the deck of the bridge.

[@rolandfisher]

Announcer: "Sorry, folks! You must leave. The thrust line has left the building!"

[@lannycrockett6571]

can you design a 3 centered arch drawn with a square, that can use a built up wooden arch truss? span say 60 feet? maybe out of 2x6's ?

[@iam5085]

Interesting, superb videos. Where could I build my own mini bridge, maybe in small scale first. Would I be able to calculate the max weight and size of things? Food for thoughts, if I had the time...but I find this subject refreshing among all these Ukraine this and that news (I wish Putin would give up).

[@OutThereEquipped]

Hi Paul, I have the original master betacam footage of the millennium bridge being installed. It’s been sat in my loft for maybe the last 20 years. Perhaps it would be a nice keepsake for you? I would be delighted to send it your way as a gift. Let me know if you would like it, if so you can find my email on my channel ‘about’ page. Thanks for making the series, it’s a great watch 👍

[@PaulKassabian]

Thanks and glad we connected by email!

[@robertingersoll5289]

I was hoping you would have discussed the buttress and flying buttresses here Maybe another video??

[@pawanacharya2915]

great videos!!! can you please explain mathematically, why the parabolic shape are better than semi circular arches ?

[@nicolasramirez3944]

Look up a derivation for the shape of a cable under uniform loading. The curve turns out to be parabolic. In an arch under uniform loading, the thrust line will be parabolic (anti-funicular form based on the cable). A semi circular arch is different than a parabolic curve, and that deviation will introduce bending moments!

[@PaulKassabian]

Great response...

[@USER-jo7yz]

If the arch is an inverted catenary do you get horizontal shear at the supports?

[@greggsenne1268]

Break the force vector at the supports into two vectors, one of which is in the shear direction.

[@mohammedlasmi649]

Thanks too much

[@gebremeskelgebrekorkos8642]

many like

[@bouzoukistudent8180]

and that is how we build wooden roofs .

[@saithadutoglu6287]

sorry Mr Paul parabola or hyperbola?