Table 1: The key concept and parameters of the ACO model corresponding with the arch dam.

Concept

Define corresponding with the arch dam

Parameter discrete

Each group of concrete or rock mechanical parameters corresponds to a group of displacements and these displacements are defined as computed data. As the value of each parameter is continuous, some discrete points are chosen within the range.

Ant

An ant is an agent which moves between parameter discrete points. Each ant can choose a group of parameters during each search.

Objective function is expressed as the sum of the squares of the errors between the computed displacements and the field monitored displacements. is the vector of the mechanical parameters to be analyzed.

Pheromone update

The object of pheromone updating is to study the influence of material parameters on the modified ACO algorithm.

Inversion parameter

To find a group of parameters that contains every parameter and minimizes the value of .

Edge

Relationship of the discrete points between two adjacent parameters, for example, each of 50 discrete points of two adjacent parameters, there are 2,500 edges between parameters.

One cycle

Including two searches: “moveahead” and “moveback,” and output is two times parameters

One tour

A group of parameters, the tour is optimized depending on , average value of all the relating to ants choosing edge (, )