Evaluation of Static and Dynamic Behavior of Rigid Columns

Year 2018, Volume: 2 Issue: 1, 17 - 26, 10.07.2018

Ayse Bengu Sunbul , Hüseyin Mungan Fatih Sünbül

Abstract

Construction on soft soils
often requires utilization of ground improvement techniques in order to solve
the problems associated with bearing capacity and stability. These techniques,
in addition to traditional preloading techniques, include various applications
to the ground based on rigid columns. Today, rigid columns can be modelled on a
computer using the finite element method (FEM) prior to the implementation in
the ground and complex ground-structure interaction mechanisms associated with
the applicability of a suitable soil improvement technique can be investigated.
In this study, rigid columns including rammed aggregate piers (RAP), jet
grouting (JG) and bored pile (BP), are tested in realistic finite element
models for both static and dynamic cases. Here, we consider 17 m uniformly distributed
load foundation in FEM modelling. Long term consolidation analysis is performed
in the numerical models to compute stress and deformation variations for static
case. The performance of  rigid columns
in the numeric model is also computed using real earthquake data. In the static
analysis, the settlement values prior to the ground improvement, was around
52.55 cm. After installation, the settlement values has dropped dramatically.
Following the RAP installation, the value has decreased to 26.04 cm. We have
also observed a decrease in other two installations where the settlement values
are 19.11 cm and 7.3 cm for the JG and the BP installations, respectively. Our
dynamic analysis also shows an improvement in the settlement values regardless
of any rigid inclusion ground improvement. It is worthy of note that these
installations considerably enhance building performance in the FEM models

Keywords

FEM, Ground improvement techniques, Static -dynamic analysis

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