Category Archives: Uncategorized

Simulation of a shake table test

LUAS replicated a shake table test experiment that was conducted at the University of Auckland to study the resilience of typical local masonry structures and the improvements by retrofitting measures. Blender and the BCB was used to remodel the shake table structure and expose it to the same seismic pattern that was used in the laboratory. This test showed interesting affinities but also deviations that are hoped to be addressed in a future joint cooperation. Discussions are going on how Auckland can contribute their distinct knowledge in masonry dynamics and to implement simplified strength formulation. This would extend the functionality of the BCB to enable the simulation of masonry building in addition to concrete structures. Eventually Blender and the BCB could be used to efficiently simulate the effects that a major earthquake has on large historical neighborhoods.


The collapse of the Morandi bridge

On August 14 the Morandi bridge in Genoa collapsed partially. A 200
meter long roadway section fell 15 meter on the below apartment houses.
In the course one of the massive pylons collapsed as well. The tragedy
claimed the lives of 43 people. This bridge was part of the A10 motorway
that is the main link between the Italian and French riviera. This
accident is one of the big tragedies that come unexpectedly and live
long in our memories. It it makes us ponder over the safety of similar
old structures that eventually would need urgent repair.

The reason of the collapse of the Morandi bridge is currently hotly
debated. Much hints to a lack of maintainance and a resulting failure of
structural member. But also the heavy weather conditions with a
Thunderstorm and a lighting impact are often blamed.

Most theories point to the failure of one of the suspension cables. The
BCB was used to systematically analyze the presumed collapse episode and
debris shape for the failing of each of the four suspensions. The
simulations were performed by Kostack Studio.

BCB-Tutorials for beginners and advanced learners

We have finally published a series of three tutorials that introduce the BCB. This series offers something for everyone: users without any Blender experience, people who want to take on the challenge to dive into the BCB methodology and for those who just want to see results fast.

1. Guide for BCB Installation & Simple Collapse Simulation
– installation instruction and introduction into a simple collapse simulation
2. Guide to Simulate a Multi-Family House with Standard Blender
– Introduction of the BCB fundamentals with standard Blender
3. Guide to Simulate a Multi-Family House with Fracture Modifier
– Introduction into a speed optimized variant with the FM

Have fun! And please post us your own simulation results.

Bridge collapse in Miami- Simulation with the BCB

Video: by courtesy of Kostack Studio

Blender and the BCB were used to model and simulate the bridge that collapsed in Miami in a speed modeling challenge. Due to the lack of precise technical drawings the Bridge was reconstructed on the basis of high resolution drone images. The element properties were estimated from close up photographs of the bursted reinforcement. The bridge was built and simulated in Blender in just 24 hours.

Even though the bridge model is only estimated and the BCB has not yet formulation for pre-stressed concrete it is interesting that the damage occurred about at the same location as it happened in reality. It is to be expected  that under evenly distributed loading damage happens at the truss diagonals with the biggest internal angle,  see image below.


Bridge collapse in Miami

On 15th of March 2018, a 53 m long recently-erected bridge section collapsed under its own weight. At the moment of the accident construction workers were working on the north end of the bridge section, re-tightening internal cables to strengthen the diagonal members- cracks in the structure were noticed short time before.
The bridge applied a new method, called “Accelerated Bridge Construction”, prefabricated bridge elements are hereby prepared in a factory, then shipped to the site and put together at the scene to minimize the impact on the local traffic. The exact reasons of the collapse are still being investigated.

Training game for fast victim sorting

This is the latest student assignment that has spun off INACHUS at Laurea University of Applied Sciences this year.  Our student Juha Penttinen took on the task to proof that an effective training tool for first responders that focuses on the fast pre-sorting of victims is possible. The pre-sorting is done based on the  popular smart triage sorting algorithm that was created to tag patience with a color code to direct the ambulance at first to the victims with the most severe injuries.

The special task in this educational game is to find victims deploying various search devices like phone finder, chemical trail detector, IR- and night vision etc. All the victims in the debris need to be found and tagged correctly in the shortest possible time.

The collapsed building structure used in this game is a result of the DEM simulations (performed by the BCB software) of the Vitruv building library.

The game can be freely downloaded from here: Training game for fast victim sorting

Second pilot in France

The second INACHUS field test was held on 31 May 2017 in Lyon, France. It focused on

merging data from wide area assessment tools and collapse simulations. In collaboration with

CARDEM, a French demolition company, INACHUS partners identified a three-storey factory

building in Saint-Fons that was scheduled to be demolished. A first scenario planned to weaken

key pillars and subsequently pull the building over by ropes. It then was decided to execute a

second scenario by gradually weakening certain pillars until collapse occurred, this procedure

was designed to mimic the impact of an earthquake.

Factory before and after collapse. Pillars were progressively weakened until collapse occurred

ASI visited the building in spring to record the construction technique in order to build the

virtual building model. The model was then simulated by ASI with the second collapse scenario.

Ground-based and airborne laser scans by FOI, ONERA and ITC created a textured point cloud

model of the building before and after the collapse. The image below shows the matching of

laser scan and simulation result.

The matching of laser scan and simulation result by ASI.

The Video below shows the simulation result performed by LUAS. The DEM model (provided by

courtesy of ASI) was simulated by applying the first collapse scenario where some pillars were

weakened and where the building was  then pulled over by ropes.