In view of the challenges posed by the nature of expansive soil to
structural stability which makes it necessary in some cases to improve the
soils before structures can be placed on them, there is a need to investigate
modern trends in ground improvement techniques
in order to determine their reliability. This study is thus aimed at using the
reliability based approach to analyze theuse of polyvinyl alcohol (PVA) in combination with 1,2,3,4 Butane-tetracarboxylic acid
(BTCA) for ground improvement. This study is necessary given the challenges posed by the nature of expansive soil
to structural stability which makes it necessary in some cases to
improve the soils before structures can be placed on them. Simplex lattice
design was employed to build the design of experiment before experimental
investigations were carried out on the PVA-BTCA treated soft soils. Reliability
indices were computed on the basis of the 28th day unconfined
compressive strength (UCS) of the treated soil. Reliability index models were
developed using the Scheffe’s technique and optimized using excel solver. From
analysis of results, reliability model developed proved adequate at 5% level of
significance. PVA-BTCA combination provided a potential reliability or
probability of success of 99.936% at components combination of: 98.4256% for soil, 1.2352%
for PVA, 0.3392% for BTCA and 15.9934% for water. It was therefore recommended
that financial implications of using PVA-BTCA for stabilization be compared to
those of conventional methods, in order to compare their performance-cost
ratio.
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