Cost Optimization of Reinforced Earth Walls

Abstract

This paper deals with optimum cost (objective function) design of geosynthetic reinforced earth retaining walls subjected to static and dynamic loading. The design restrictions are imposed as design constraints in the analysis. Choice of the initial designed length and strength of the reinforcement, which are the elements of the design vectors are made in a way that it forms an initial feasible design vector. Thus the problem is one of mathematical programming. The constraints and the objective function being nonlinear in nature, the Sequential Unconstrained Minimization Technique (SUMT) has been used in conjunction with conjugate direction and quadratic fit methods for multidimensional and unidirectional minimization to arrive at the optimal (minimum) cost of the reinforced earth wall. Optimal cost tables are presented for different combinations of the loading and the developed procedure is validated by taking up an example problem. It has been found from the typical example problem that saving of the order of 7-8% can be made over the conventional design of mechanically stabilized earth (MSE) walls with the aid of design charts.

CO2-Optimization Design of Reinforced Concrete Retaining Walls Based on a VNS-Threshold Acceptance Strategy

“…Wang and Kulhawy (2008) used a linear programming approach to minimize the cost of spread foundations. Badsudhar et al (2008) developed a sequential unconstrained minimization technique along with conjugate direction and quadratic fit methods to determine the optimal cost of mechanically-stabilized earth walls made with geosynthetically reinforced elements. Regarding the exact optimization of RC retaining walls, Saribas and Erbatur (1996) applied constrained nonlinear programming to a problem with seven geometric and reinforcement design variables, using the cost and weight of the walls as objective functions.…”

Optimization of Design Parameters and Cost of Geosynthetic-Reinforced Earth Walls Using Harmony Search Algorithm

“…HSA is used to run the optimization problem for walls of height 5, 7 and 9 m. The input parameters used to define the problem are presented in Table 5. Table 6 shows the summary of results, obtained by SUMT method, that has been referred to compare the results of this study with that of Basudhar et al [16]. The values for the total cost in Table 6 were obtained by applying the cost factors given in Table 2 and the spacing and length that were obtained by Basudhar et al [16].…”

“…Since the following analyses and associated results are compared to the results of Basudhar et al [16], similar parameters and geometry are considered. HSA is used to run the optimization problem for walls of height 5, 7 and 9 m. The input parameters used to define the problem are presented in Table 5.…”

“…the cost factors) are presented in Table 2. For comparison purposes, the same cost parameters, to that of Basudhar et al [16], have been adopted. The costs, applied per unit length of the wall, are as follows:…”

A nonlinear optimization model on the reinforcement length of a modular block wall by varying surcharge and soil strength parameters

“…Simulation is also utilized in [5] to assist in approximating the nonlinear optimum solution. [8] uses an optimization approach on cost. [9] introduces an advanced technique in finding a nonlinear optimization model for MSE wall design parameters.…”