Abstract (EN):
This paper presents results of the deformability
parameters of municipal solid waste (MSW) determined
through laboratory (oedometer and triaxial tests) and in situ
tests [standard penetration tests (SPT) and cone penetration
tests (CPT)], as well as by a monitoring system including
topographic control marks, open-tube piezometers, earth
and pore pressure cells and inclinometer tubes with magnetic
settlement plates and spiders. The studied landfill is
located in a textile industry area, and was landfilled with
some direct waste (10 %) and mostly pre-treated waste
(90 %, from composting and triage). The influence of: the
waste age, construction phase of the landfill and confining
stress on the results of stiffness modulus, lateral waste
pressure coefficient at-rest (K0) and Poisson¿s ratio (m) are
presented, as well as an attempt to establish correlations to
estimate MSW stiffness modulus from SPT and CPT tests.
The results indicate the increases of K0 and m with the
average effective confining stresses during the first 2 years
of the post-construction phase, reaching maximum values
of 0.7 for K0 and 0.4 for m, and then decreasing gradually
until stabilizing at values of around 0.23¿0.48 for K0 and
around 0.19¿0.32 for m. The stiffness modulus values
determined by different methods are consistent with each
other and corroborate the fact that typical values for MSW
are low. These values are between 0.4 and 2 MPa for a
mean confinement stress of about 50 kPa, and tend to
increase linearly with the increase of the confinement
stress. The correlations established with SPT and CPT tests
are of the same type as usually proposed for granular soils;
however, the constant values are significantly lower than
the lowest values reported for normally consolidated sandy
soils.
Idioma:
Inglês
Tipo (Avaliação Docente):
Científica
Contacto:
lcosta@fe.up.pt
Nº de páginas:
15