Source: Scott Roberts Memories from 2007 back in Durban, building a 2010 World Cup Stadium; we hit a problem with the diaphragm wall excavation, when the grabber got stuck in the bedrock about -20m down. So we sent commercial divers down through the bentonite slurry to fix a new steel cable to the grabber so we could retrieve it and keep the project going. Those boys were hardcore.
Demir et. al. 2024 — Nordhavnstunnel.pdf
It started with ITA (International Tunnelling Association) WG 11’s catalogue of immersed tunnels. The third one (and also the fourth) in the list is from Copenhagen. Actually, the culvert is located in the most photographed region of the country - under Nyhavn. In this excellent catalogue prepared by Nestor Rasmussen (DK) and Walter Grantz (USA), the S.3 tunnel has been described as shown below. Then, search is started. With the help of people from Reddit, we found the location of the tunnel in the HOFOR database. The possible location is under Nyhavn’s connection to the sea - which shown with blue dashed line. In one of the documents, it says “Den dykkede ledning i Nyhavn blev nu også lagt. Den gik fra Kvæsthusgade til Havnegade.” which translates to “The submerged pipe in Nyhavn was now also laid. It ran from Kvæsthusgade to Havnegade.” Afterwards, I contacted the Københavns Museum, and Jakob Ingemann Parby, Senior Researcher and Museum Inspector, has reached out to me to provide more resources. In one of the resources online, Københavns Energi A/S’s (previous name of HOFOR) book called “Fra stinkende rendestene til computerstyrede kloakker” (in English “From smelly gutters to computerized sewers”) had more information on the topic. This beautiful image shows the lowered steel pipes: Let’s zoom in a little bit. I think they used barrel as ballast to sink the pipes. Pipe may look like very flexible, but it’s not actually, the design of the pipe is with bent corners as shown in the image. Actually, we even have a construction drawing. We can see the backfilling and longitudinal profile of the pipe. They had gate valves to periodically flush the pipes that accumulate dirt and sediments. Another construction stage photo is coming from Københavns Museum archive - Jakob Ingemann Parby. You can see the cranes and same shape: ...
The beauty of Streamlit with Plaxis is the simplicity of the UI and how minimalistic it looks. Also, the 2x2 output figure for a retaining wall is the most compact output you can imagine. Everything you need to show for all these stages is inside one figure. Moreover, this tool can deliver a really detailed excel sheet to share with other designers. Watch the video to see it on action: Also fixed-end anchors and node-to-node anchors! And lastly, how to start the Streamlit directly from Plaxis as shown in videos: ...
Introduction Table of Content Last month, we had an interesting and long discussion over the email with the creator of PCTempflow, a widely used software for fire analysis, and others like PCSheetPileWall and Framework: Gerrit Wolsink. Over the course of the many emails, we have agreed that there is something wrong (or incompatible) in the Eurocodes. This brief article is our joint effort on clarifying our views on this problem. If you have any input, please feel free to reach out. ...
Another couple nights to experiment on the parametric design with FEM-Design and Grasshopper. No problem with geometry and load definitions except couple of small bumps. The load combinations require more than couple nights, so I just move to the GUI if I need. I
Note that when the apps are not used for a while, you might need to “wake” them. It might take up to a min. https://bdem-hb.streamlit.app/ https://bdem-hs.streamlit.app/
During 2019 Plaxis User Meeting in İstanbul, I have presented a detailed discussion on Hardening Soil Model. The presentation was really welcomed by the audience and in fact, later on, I have been invited to two other companies for the same presentation. This short post will be a summary of that presentation. Hardening Soil model (will be called HS from now on) was presented in an excellent conference for 10th year of Plaxis in a paper called The hardening soil model: Formulation and Verification by Schanz, Vermeer and Bonnier. However, HS is tightly bonded to previous studies on the literature such as Lade, Tatsuoka and Ishihara, Cam-Clay model, Kondner and Zelasko, Jardine, Duncan and Chang, Al Tabbaa, Simson et. al. ...
I have just published a new tool and this post will detail the methods that are being used in this tool. What it does: Performs Hoek-Brown analyses for rock and recommends additional parameters based on the inputs. https://berkdemir-bd-hoek-brown-bd-hoek-brown-vsh6i6.streamlit.app/ Theory Introduction The Hoek-Brown material model is the most widely used rock mechanic model due to its simplicity and ease-of-use in continuum based numerical models such as finite element or finite difference models. Hoek-Brown model is published in Hoek & Brown (1980) and after that, it is constantly updated. Latest update was published in 2019. ...
Introduction By now, everything should have been settled about modulus of subgrade reaction. We all know some typical statements about it: It depends on the soil properties It depends on the foundation size It depends on loading type, temperature, bitcoin prices and others. However, let’s think about a weathered rock with E=500 MPa and a foundation to be built on top of this rock with 20 x 50 m dimensions. You can say it depends on many factors as much as you like, everybody has a rough idea already: 100,000 kN/m3. So, if you are a fancy engineer and dare to make some calculations, you can find much lower values. Will they believe you or will they think that you are being too conservative (if lowering the subgrade reaction means being conservative)? Let’s start with simple terms. The equation that everybody knows and nobody wants to use: $$ K=\frac{q}{s} $$ So, the subgrade reaction is equal to a spring stiffness distributed under the foundation. If you divide the pressure by the settlement, you will find the subgrade reaction, amount of deformation for unit pressure. If we think about how we calculate settlement (how it depends on many factors), we can see actually how complex this modulus is. ...