ANÁLISE DO COMPORTAMENTO DE FUNDAÇÕES RASAS FRENTE À GÊNESE DE UM SINKHOLE

Resumo

Sinkholes are depressions on Earth's surface due to underground cavities collapse, and they
are commonly found in karstic fields in which soil is susceptible to erosion and leaching, because, both
erosion and leaching can create tunnels and galleries in carbonatic soil due to dissolution process. By
this sense, unstable caves can be formed below structures or infrastructures, and it can cause economic
losses and generate dangerous situations for human beings, as these caves can collapse, plus lead field
deformations of about 5 cm/year. Following this motivation, the present work aims to present the
influence of a construction with vertical stress equivalent to 15 MPa over a shallow foundation on a
karstic field through numerical modeling. In the first scenario, the structure is represented by a
distributed equivalent load, simulating a raft foundation, and in the second scenario, the structure is
represented by equivalent load distributed by strip footings. By analyzing the numerical modeling, it
was possible to evaluate the influence of both hallow foundations on the behavior of the field, which
allowed to verify that on the surface the footing scenario presented subsidence higher than 1.21 meter,
approximately 3 times the subsidence of the raft scenario, 0.37 m. It was also observed that shear zones
near karst and construction were more intense in the second scenario. In this way, this work alerts to
careful evaluation of cave stability and buildings safety in karstic environments.