The use of Electrical Resistivity Tomography for Soil Sinking Investigation a case study in Satellite Town Langerpura Sub Himalaya Azad Jammu and Kashmir Pakistan

Abstract

Soil sinking is a major engineering concern need to be addressed through proper planning and investigation. Usually Engineers depend on borehole data or soil tests for designing the solution for such problems. In view of cost, time and less destruction, geophysical methods are best to probe such engineering and environmental problems. Therefore, Electrical resistivity tomography (ERT) method used to investigate soil sinking in Satellite town Langerpura, Sub Himalayas Azad Jammu and Kashmir Muzaffarabad Pakistan. Two profiles acquired overlap the zone under study with electrode spacing 5m and average depth of 40-50m. Three different geological zones are identified on the base of resistivity data. Low resistivity zone having resistivity 3.0 – 15Ωm is water saturated friable sandstone. Intermediate resistivity zone with resistivity range 100-1000 Ωm consists of alternate layers of sand, clay and river deposits. High resistivity zone with resistivity range 1000-4000 Ωm show cavities in subsurface. The room size cavity detected which cause the soil sinking at surface. Muck filling or compaction grouting recommended as engineering solution for stabilization of sink soil.