rockfall BLOG

Rockfall simulation program Rockyfor3D

The presentation describe the rockfall trajectories analysis realized with Rockyfor3D software from Ecorisq

Rockyfor3D - Rockfall simulation program from The Incline

 

Thomas

New full scale test on rockfall embankments

From INCLINE this interesting video. 

 

Thomas

 

 

New full scale test on Tecco -Geobrugg

Full scale test in October 2014 in Winterthur, Switzerland on high bearing capacity stell nettings.

A slope inclination up to 85° was simulated in this test and the system restrained the gravel successfully. 

 

Thomas

Painting system for rockfall reinforcement

In some areas of high naturalistic or historical value will be used rockfall systems/components treated with epoxy paint; these paintings ensure good camouflage of structures on slopes and provide a limited visual impact.

The painting method  can be applied on these systems:

- nettings

- plate

- rope

- foot concrete foundation

Below some picture

High capacity nettings brown painted - detail view (Courtesy www.rockfalldefence.com)

High capacity nettings brown painted - frontal view (Courtesy www.rockfalldefence.com)

Foot concrete reinforced with anchors light pink painted (Couretesy www.theincline.it)

 

Lucky and unlucky trees

Thomas

Probability vs fate

Is more probability calculus or fate....???

 

 

 

Thomas

Old anchors system of rockfall barriers

We were in the 70's and the early pioneers in Italy built the first rockfall barriers.When the drills were not  developed the anchors were made in this way....see the photo below.

Big foot, not drilled anchors and connection with large steel handles ropes and thimbles.

 

 

 

 

New Skyline in San Leo (Rimini) - Italy

Last year there was a big landslide in  San Leo nearst of Rimini -Italy.

 Probably this (belowe) is a most knowed view of rock landslide in San Leo.

 And this the most poupolar video on Youtube

 

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In recent months, I went to see the landslide and I tried to compare a side photo I took douring my trip with a photo archive from Google Street View....and the effect is interesting because it show the volume collapsed.

This is the lateral view with with old and new skyline

 Thomas

 

Rocex 2014 in Lecco -IT

As a member of the organizing committee, I welcome all interested on rockfall at the Rocex 2014 in Lecco - IT
https://sites.google.com/site/rocexs2014/home

Thomas

History of a mega blast after rockfall in South Tirol

Phone call from a blast:

Hello Thomas I'm Giacomo and on 21 January, a large rockfall occurred about 3000 cubic meters and impact a farm nearst of  Bolzano in South Tirol -IT.

On the cliffs in high above the farm was (in precarious balance) a large pillar of about 500-600 cubic meters.

On January 22, we carried out flight with helicopter to verify the situation with the geologists of the Geological Survey of Bolzano and we approved the demolition plan.

In terms of urgency we have obtained licenses for explosives in a single day.  

The dimension of pillar was:height of about 14m; width 10.5m and thickness 3.5 m; the base of the pillar was compromised and therefore it was decided to break up it to avoid the fall of  large volumes .  

The day 23 was prepared the site at the top of  pillar with scalig operation and at the same time the climbing company has started to develop holes for blasting. Since the instable volume was big we decide for small diameter holes (51mm) made ​​with portable drilling machine and depth of 4 m .

The day 24 was performed the first blast which was conducted with a strong overdose of the explosive in order to compensate for the small drilling that in some points appeared deficient for obvious safety problems (to limit the vibrations).   Around the zone was made ​​a security fence guarded by about 50 volunteer firefighters groups of Termeno (BZ) of about 400 m from the blasting point; at he end of slope we have realize a rockfall earth dam for protection of a pylon of high voltage ( interrupted at the time of the blasting ) and the farm .  

The demolition was then completed on January 27; after the first blasting we could get with more security at the bottom of pillar for load the last part of blast and explosion.

This is all...in next days will send to you some video of events

Thank you Giacomo

 By - By Thomas

Giacomo (www.geologico.it)

 Large scale video

 

Detail scale video

http://www.stol.it/Media/Videos/Intern/Tramin-Erste-Sprengungen-an-der-Grauner-Wand

 

Thomas

Big Rockfall Event in South Tirol - Italy

Unit size: firefighter

 

Thank you Mauro for information

Thomas

Articulated Concrete Block Mattresses (ACBMs)

 

From the experiences in submarine environment, this technology from Maccaferri could be applied to protect against natural risk in mountain?

In many cases the pipeline (water, sewers, it cable, ets..) pass nears rock slopes with rockfall problem; in some cases for my point of view this solution could be applied with a little layer of covering granular materiel (only aesthetic).

Thomas

 

Wood lateral anchor

What do you think of this lateral anchor to connect the lateral cable with rigid post of a rockfall barrier?

Thomas

IAEG XII 2014 Congress on Rockfall risk assessment

News, congress IAEG XII 2014 inTourin on Rockfall risk assessment and management - current practice and developments.

Link the web site

Thomas

Rockfall Characterization and Control

Thank you to John D Duffy from DOT of California (USA) for this interesting news. The book published form Transportation Research Board (TRB).

Here for buy >>>>>>  http://www.trb.org/Main/Blurbs/167065.aspx

Thomas

You moved ?

From my friend in north west Italy.

Thomas

Test 1:1 on P650 Maccaferri (6500kJ) in Fonzaso (IT) 24.10.12

I attended in october 2012 the full scale test organized by Maccaferri Spa and Risp Srl in the field test facility of Fonzaso - IT.

The test on rockfall barrier (RMC P650) with 6500kJ energies, post height 6.5m, impacted by boulder of 17666kg dropped from a height of 38.25m.

The video beolwe granted from Risp Srl, describe the event.

 

 In the last 10 years I have seen a lot of 1:1 test on rockfall barriers but this was impressive for two reasons:

1. easy and symmetric behavior of the barrier during the deceleration of boulder
2. elastic rebound of boulder during impact.

My point of view regarding the symmetric behavior is due to large number of brakes elements (with short eleongation, aprx 1.0m, ) distributed on the structure RMC P650 that guarantees an optimal distribution on forces in space and time of deceleration.

The bounce of boulder indicates (for my opinion) that rockfall barriers still has many structurals reserves....this is positive because the technical limits on rockfall barriers must and can still be reached.....good work to the producers...

What do you think?

Thomas

Tecco Full Scale test in Winterthur(CH) 09.10.12

I was invited by Geobrugg to attend a revolutionary test 1:1 in Winterthur (CH) October 9, 2012. It was a full-scale test to verify/ceck the behavior of the flexible steel mesh on a platform that simulates a slope landslide. Video procedure are linked belowe.

 

 

I seem to be back at the beginning of 90’s with the first full scale tests on rockfall barriers organized form Tubosider in France, Igor in Italy and Geobrugg in Switzerland. After 20 years of test 1:1 on rockfall barrier could be organize a “Technical Guideline to 1:1 test on felxible nettings” to standardize the procedure to test in full scale the nettngs on slops? What do you think?? Thomas

Deviation lower lateral cable on rockfall barrier

In many cases the rockfall protection barriers must adapt to the conditions of the terrein. One of the points that require greater attention and detail to guarantee the structural strength of the rock barriers is te deviation on lower lateral cable. In the drawing belowe you can see two  typical case but not the only one. You may need to resolve deviations elevation (as in drawings) and planimetric.

Case n°1: lateral lower cable deviation

Case n°2: intermediate lower cable deviation

In many cases it is the experience of the engineer on site or installation company that allow you to solve the problem...but....

....after the Guideline ETAG027/2008, the variation of geometry of the rockfall barriers respect to the tested barrier will be guaranteed by the manufacturer with special calculation as as described in chapter 4.3:

"If for local reasons of the natural site it is necessary to have a different geometry from the test site geometry a specific design shall be provided. Forces acting in the structure should be evaluated to demonstrate the fitness for use of the falling rock protection kit. The producer, under its own responsibility, shall provide geometric tolerances in the installation book with special references to the spacing of the posts and the inclination of the main ropes".

I don't understand if the responsibility to define what forces act on the modified structure are in charge of the manufacturer  or designer???

And today for my experiences I've never found a manual with described tolerances permitted for the deviation of lower/lateral cable.

Who can clarify this issue?

Thomas

 

 

Attenuators Barriers or Hybrid Barrier

In last years, expecially in United States and Canada a new type of rockfall protection system has developed.

These new barrier are usually called "rockfall attenuator" or "hybrid barrier". The reason for these two definition are:

• the new system don't stop the block in movemnt but slows it and guiding it during the slope
• the new system is a combination of two tecnologies, rockfall protection barrier and drapery systems on rock cliff

For my point of view is better the terms "attenuator barrier" is a more intuitive terms to explain the behavior of structure.

Where the zone to protect has before a sufficent area of possible accumulation of block, the AB (attenuator barrier) will be interesting; with this system the block are not stopped but guiding down along the slops and accumulated at the foot of slops. Another interesting aspect of this barrier is the reduction of maintenance and the capacity of auto cleaning.

In this drawings belowe are be explained the behavior.

Here you can find some detail directly from the web:

• Sperimentation from WSL and Axel Volkwein

• Video impact on this barrier

 

• Some technical details from producers
  • Link1
  • Link2

Others contributors will be appreciated

Thomas F.