Variation analysis effects of square and rectangular columns section with different longitudinal reinforcement rates in the main reinforcement two pile caps analysis

F S Munhoz,J.S Giongo

doi:10.1590/s1983-41952017000300011

Abstract

ABSTRACT The transition between the columns of building and foundation had been used the pile-cap structural elements. The most appropriate method for the pile caps design is the Strut and Tie model. In most cases in the structural project is not considered the influence of certain parameters: the columns cross section and the amount of longitudinal reinforcement columns. This paper studies the effect of the variability of the geometric section of square and rectangular columns, with different longitudinal reinforcement rates, in the main reinforcement traction two pile caps. The basis for study was development experimental program in the Structures Laboratory of EESC-USP . The traction reinforcement bars strains are reduced the pile-caps central section to pile-caps sections that approximate cutting axis shows the experimental results. In models with columns of elongated rectangular section and with great reinforcement rates this reduction is smaller.

Highlights

The pile caps “are volume structures used to transmit foundation forces for the piles” is defined by the NBR 6118: 2014 [1]
This paper studies the effect of the variability of the geometric section of square and rectangular columns, with different longitudinal reinforcement rates, in the main reinforcement traction two pile caps
According to Fusco [3] when there are different reinforcement ratios in columns force is transmitted for the pile caps at different heights, which can change the height of the truss changing forces in the tensile reinforcement bars

Summary

Introduction

The pile caps “are volume structures used to transmit foundation forces for the piles” is defined by the NBR 6118: 2014 [1]. In Brazil, the most common method for pile caps design is is based on research Blévot & Frémy [2]. These authors recommend an application of the Strut and tie model based on experimental models tested by them. The method Blévot and Frémy [2] is recommended for forces centered on the columns and all piles need to be spaced from tthe centre column. In this research was chosen do an experimental analysis of models with different sections of columns and different reinforcement ratios, were not found in literature studies with pile caps which varied these parameters

Objectives

Methods

Results

Discussion

Conclusion