Evaluation of the regulations used in colombia for the seismic vulnerability assesment of existing concrete structures

Student: Jaime H Gonzalez
Supervisors: Dr Lorenza Petrini

ABSTRACT

Colombia is a quite high seismicity country, but only starting from 1984 seismic forces were taken into account in structures design. It clearly indicates that the study of the behaviour of existing structures and the development of an effective seismic assessment code are extremely important topicsof investigation and should become urgent goals for Colombian government.

In this thesis, these investigations have brought to study several codes that present guidelines for th eseismic vulnerability assessment of existing structures (FEMA356, Eurocode-8 and the New Zealand Recommendation) and compare them with the regulations of the Colombian standards (NSR-98). Theoutcome of this comparison exhibits the weakness of the Colombian code and addresses possible modifications that could be performed in order to update it.

Among the limitations found in the Colombian Code, the main one is related with the use of a global ductility factor that depends on the structural system and detailing. This factor is defined entirely by the engineer judgement instead of the use of analytical local ductility factors as the one used by the other codes studied.

Other aspect considered has to do with the minimum requirements imposed by the NSR-98 for the collection of the required information of the structure which are not clearly established. It is concluded that this feature must be improved including levels of necessary information taking into account the type of structure analyzed.

It was also found that the NSR-98 does not include guidelines for the performance of non-linear analysis. This contradicts some considerations made by the other codes studied which state that these types of analysis produce more accurate and reliable results and that they must be compulsory for certain type of structures. According to this, the Colombian entities in charge of the development of the NSR-98 must make big efforts in this topic in order to incorporate the minimum requirements for non-linear procedures (static and dynamic).

You may download a digital version of this MSc dissertation here.