Advanced method to control the safety factor of a civil structure after a collision

Collisions in civil structures are till today not so common and of course the hope is that it will not become common. However, these collisions can happen in an internal or in an external way. The negative effect of collisions to structures in the road or railway infrastructure of a country can be very large. Especially in a country like the Netherlands with a high density of people with a lot of infrastructures. Missing a structure in a important road or railway link can be a great problem for the traffic stream every day again.

A second order effect by collisions is the impact on the safety of a structure. When the structure has been demolished, it will be reconstruct, when the structure is still needed. Mostly a part of the structure will be demolished and not in total. So the structure will partly be used. An example is for instance a block on two lanes of a six lane fly-over. At that moment an reanalyses has to be made to get an idea of how many lanes have to be blocked with a sufficient reliability for the rest of the lanes.

In the design stage of a structure, the common way to get a safety factor for a structure is to check the results of an analysis with the current checking code. This can be the EURO code or a National code. These checking codes can be changed during the lifetime of the structure. However, after a lifetime of some years the structure can be changed too. It is also very common that some structure parts have been added. A digital form of geometry data of the structure is not always available. To get the as-built configuration of the structure drawings can be checked in relation to the current situation, but is very time consuming. The elapse time of this process is large, so looking to some alternatives should reduce the total elapse time.

Scanning technology is a rather new product in the field of civil engineering. However, this technology which is coming originally from the land surveying and the petrol industry is a very handsome tool to get a 3D model of an ‘as built’ structure. The civil engineering division in the Netherlands maintains a lot of structure. A large part of these structures are constructed in the pre-digital period. So, the CAE models of these structures are not kept on a disk or a CD in a digital way as a backup.

The paper describes the scansytem itself, the process of scanning, transforming the clouds of points to surfaces and from surfaces to a basic geometry. Additional to this paper items, some general possibilities of the new technology, dedicated to a civil structure (a steel structures) in detail will be described.

• SUMMARY

• 1. INTRODUCTION

• 2. PETROCHEMICAL INDUSTRY

• 3. ADVANCED SCAN SYSTEM

• 4. ACCURACY TESTS

• 6. RESULT OF THE SCANNED IMAGES

• 7. AN DEFORMED MAIN GIRDER AFTER A COLLISION

• 8. CONCLUSIONS

• 9. ACKNOWLEDGEMENTS

• 10. REFERENCES