A structural assessment is a procedure utilized to check the adequacy, structural integrity and soundness of structures and their components. An assessment is made to evaluate a structure’s current and future use and conformance to current building codes.
As structures are aging, the assessment of buildings, bridges, tunnels, dams and industrial structures is becoming increasingly important. and all these require periodical inspection to ensure structural safety, strength and stability under normal/actual loads as well as reducing the possibility of disproportionate collapse under unanticipated or accidental loads.
The main task of assessment is to ensure that the structure or parts of the structure do not fail under loading. The assessment is carried out for ultimate limit states, which are:
− loss of equilibrium of the structure or parts of it as a rigid body (e.g. overturning)
− attainment of the maximum resistance capacity
− transformation of the structure or part of it into a mechanism
− instability of the structure of part of it
− sudden change of the assumed structural system to a new system (e.g. snap through)
A reduction of serviceability may lead to a limitation of use and therefore serviceability assessment might become necessary. Serviceability limit states include :
− local damage which may reduce the working life of the structure
− unacceptable deformations which affect the efficient use
− excessive vibrations which cause discomfort to people