SciELO - Scientific Electronic Library Online

vol.19 issue1Detection of cavities in sandstone using gravity, resistivity and GPR methodsLinearized reflection coefficients for qP waves in anisotropic media author indexsubject indexarticles search
Home Pagealphabetic serial listing  

Services on Demand




Related links


Revista Brasileira de Geofísica

Print version ISSN 0102-261X


GALLAS, José D. F. et al. Shallow geoelectric methods and techniques to define an area affected by roof failure of an urban tunnel. Rev. Bras. Geof. [online]. 2001, vol.19, n.1, pp.33-46. ISSN 0102-261X.

This paper presents a case study where geophysics was successfully applied to solve a complex problem associated with a tunnel excavation accident in an urban area. It presents and describes the results obtained with geoelectrical methods applied in an emergencial task in a risky urban area in São Paulo City. It also compares the techniques and field arrays, ways to present and interpret the data. The employed methods were electroresistivity, induced polarization (IP) and self potential (SP). The objective of the survey was to delineate the extension of a roof failure of an urban tunnel under excavation beneath the Ibirapuera Park in order to orientate the volume of tunnel roof should be treated. Only two days (Saturday and Sunday) were available to carry out the survey and its interpretation. The results were considered satisfactory and brought a significant economy to the final cost of the tunnel. This economy was due to the decreasing of the remediation area from the initial 20 x 20 m (estimated by the engineers) to 3 x 5 m (estimated by the geophysical survey).

Keywords : Applied geophysics; Urban geophysics; São Paulo Basin.

        · abstract in Portuguese     · text in Portuguese     · Portuguese ( pdf )


Creative Commons License All the contents of this journal, except where otherwise noted, is licensed under a Creative Commons Attribution License