Abstract:
The qualitative ground improvement against the cost efficiency is widely discussed
topic in the construction industry. Since the inception of Southern Transport
Development project (STDP) in Sri Lanka in 2003 many ground improvement
applications have implemented along the highway trace form Colombo to Mathara.
The core aspects of ground improvement are cost, quality and process duration of the
application, which determined the success of the construction. Consequently, the
ground improvement techniques need to be defined that the most appropriated
application for a particular site conditions.
The first objective of this research was to evaluate complete cost analysis for Heavy
Tamping (HT) method application in STDP. Then the second objective was carried
out complete cost analysis for Compact Vacuum Consolidation (CVC) method as an
alternative ground improvement technique to the HT. Finally compare the both
methods financial aspects, process duration and quality as well as established
recommendation for selecting alternative technique by analyzing the key
performance indexes.
Research does consider specific site conditions which both methods are applicable to
improve the existing ground and the comparison limit where the sites have similar
range of ground properties.
Research was carried out through data collection and normalization of a trial
application in STDP and the cost estimation done according to the Bottoms-up
technique. The methods comparison was done by considering five main out lines:
time consumption, technology requirements, labor intensity, machine intensity and
total cost. These factors are determined which method is most appropriate to the
ground improvement.
Overall research findings evidenced that the CVC method has similar cost with
respect to the HT method. When compare the other key factors, the HT method has
less time, labor and technology requirement than the CVC but it is higher machinery
intensive. It can be stated two major recommendations for selecting ground
improvement technique; first is carried out feasibility study for listing out suitable
techniques and the second is compare the key performance indexes of that.
