Material quantity estimation modelling of bridge sub- substructure using regression analysis

Abstract

In construction field, a time completion and an adherence to budget are two factors that mainly influence the successful of the projects. The adherence to the budget can be achieved when the estimated budget is closed to the actual cost. For the owners, cost estimation is necessary as a guidance in determining the amount of investment. Therefore, it is very important to know the estimation of the project cost by using the limited data before the detailed plans and specifications of the project are identified. However, in the case of bridge substructure preliminary cost estimation, there is a lack information about material quantity estimation models due to the difficulties of soil characteristic and hydrological conditions. Hence, this research aims to develop the estimation of material quantity models of the abutment and caisson of bridge, with the Presetressed Concrete I-Girder (PCI Girder) superstructure located in Sleman district, Yogyakarta province, Indonesia. The database used for developing model was obtained by conducting sub-structure structural analysis of 15 abutments and 45 caissons. The bridges have a various span length, abutment height, and caisson depth. Material quantity estimation models were analysed by the multiple regression analysis methods. The span length and the abutment height are determined as independent variables to predict the concrete volume, the reinforcing steel weight, the caisson concrete volume, the cyclops concrete volume and the caisson reinforcing steel weight. This research proposed 11 equation models to estimate the concrete volume and reinforcing steel weight of abutment and caisson.

On the Search of Models for Early Cost Estimates of Bridges: An SVM-Based Approach

“…When compared to the models proposed by other authors, some significant differences of the model introduced herein can be indicated. The previous works that aimed at modeling costs of bridges in the early stages of projects were focused on cost estimates of either parts of bridge structures [2][3][4] or specific types of bridges [5][6][7][8]. The model introduced herein offers cost predictions of bridges as a whole object (the substructure and superstructure together).…”

“…On the other hand, most of the previously proposed models are based either on regression analysis [2][3][4] or ANN [5]. The former requires a priori assumptions about the functional relationship binding bridge construction cost as a dependent variable with cost predictors as independent variables.…”

“…In this study, stepwise regression analysis was applied. Another work [3] reports analysis which aimed to develop material quantity models of the abutment and caisson as components of a whole bridge structure, with prestressed concrete I-girder superstructure. The research and application of multiple regression analysis resulted in a number of equations proposed for estimates of concrete volume and reinforcing steel weight of abutment and caisson as components of a whole bridge structure.…”

“…Moreover, several types of bridge structures are considered. Earlier works [2][3][4] focused mostly on estimates of either the substructure or superstructure. On the other hand, some works are limited to specific types of bridges [5][6][7][8].…”

“…On the other hand, some works are limited to specific types of bridges [5][6][7][8]. The application of the SVM-based regression method for the development of a cost estimation model allows overcoming some drawbacks of the models built on the basis of regression analysis [2][3][4] or ANN [5]. When compared to linear regression, the SVM method does not require a priori assumptions about the functional relationship for the developed model.…”