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This article presents the application of two algorithms: heuristic big bang-big crunch (HBB-BC) and a heuristic particle swarm

ant colony optimization (HPSACO) to discrete optimization of reinforced concrete planar frames subject to combinations of

gravity and lateral loads based on ACI 318-08 code. The objective function is the total cost of the frame which includes the cost

of concrete, formwork and reinforcing steel for all members of the frame. The heuristic big bang-big crunch (HBB-BC) is based

on BB-BC and a harmony search (HS) scheme to deal with the variable constraints. The HPSACO algorithm is a combination of

particle swarm with passive congregation (PSOPC), ant colony optimization (ACO), and harmony search scheme (HS)

algorithms. In this paper, by using the capacity of BB-BC in ACO stage of HPSACO, its performance is improved. Some design

examples are tested using these methods and the results are compared.

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In this paper a discrete Big Bang-Big Crunch algorithm is applied to optimal design of reinforced concrete planar frames under

the gravity and lateral loads. Optimization is based on ACI 318-08 code. Columns are assumed to resist axial loads and bending

moments, while beams resist only bending moments. Second-order effects are also considered for the compression members, and

columns are checked for their slenderness and their end moments are magnified when necessary. The main aim of the BB-BC

process is to minimize the cost of material and construction of the reinforced concrete frames under the applied loads such that

the strength requirements of the ACI 318 code are fulfilled. In the process of optimization, the cost per unit length of the sections

is used for the formation of the subsequent generation. Three bending frames are optimized using BB-BC and the results are

compared to those of the genetic algorithm.

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Limitations in the design method used for the support systems of urban buildings make them vulnerable to damage by adjacent excavations. This paper examines a traditional system used to support excavation sites and adjacent buildings in which inclined struts are connected to the wall or foundation of the adjacent building. This method can be considered to be a type of shoring or underpinning. The performance of buildings and the criteria for deformation control during excavation are introduced. Next, a 2D finite element analysis is presented in which an excavation is modeled considering the parameters from the adjacent building and the inclined struts. The numerical model is capable of simulating the overall excavation and installation of the support system. The soil is modeled using an elastic perfectly-plastic constitutive relation based on the Mohr-Coulomb criterion. The finite element model is validated using Rankine earth pressure and in situ data was measured during an excavation. The effect of different variables on performance and acceptable limits for the inclined strut are discussed. The model used for the parametric study shows the influence of the characteristics of the adjacent building, soil parameters, geometry of excavation, type of excavation and effect of strut installation. It was found that one type of strut arrangement produced the best possible result. The results can be used as a primary approximation of small-to-medium depth excavations in which struts are used to reduce the deflections.