TY - JOUR ID - 54428 TI - Evaluation of Gradual Ground Linear Subsidence and Geotechnical Parameters Assessment in the Taleghani Site of Eshtehard JO - Scientific Quarterly Journal of Geosciences JA - GSJ LA - en SN - 1023-7429 AU - Rezaei, Fereidoun AU - Dadsetan, A. AD - Research Institute for Earth Sciences, Geological Survey of Iran, Tehran, Iran. AD - Geological Survey of Iran, Tehran, Iran Y1 - 2012 PY - 2012 VL - 21 IS - 83 SP - 3 EP - 12 KW - Linear Subsidence KW - Dispersive KW - Groundwater Hydrology KW - Eshtehard DO - 10.22071/gsj.2012.54428 N2 - Ground subsidence in eastern part of Eshtehard, built on the alluvial deposits, is linear and gradual. Preparing geological map and profiles; we studied the structural geology of the area. The sort and situation of aquifer, evolution of ground water levels and hydrochemistry were studied and the presence of ancient channel was detected by geoelectric method. The geotechnical studies suggest that the soils in the area (USCS Classification) belong to Lean clay (CL), Fat Clay (CH) and Silty Sand (SM). The maximum soil settlement is more than allowable settlements and soils recognized to be dispersive to semi-dispersive soils. The possible entrance of waste water from Eshtehard Industrial town into Eshtehard Qanat, from septic wells and transfer water system seems to provide necessary moisture for dispersive soils and have caused the subsidence in the area. Hydrogeology of alluvial aquifer was evaluated and indicates a negative debit. Although the hydrographs of pizometric wells are not compensated but it display any role in linear subsidence. Soils prone to dispersion by infiltration of water from septic wells and urban water system and the presence of ancient Qantas hidden in the depth of 15 meters caused linear ground subsidence. The results of this study show the development of ancient Eshtehard city and the selection of new site was not carried out on the geotechnical basis. Therefore it is recommended that before constructing any projects, geotechnical studies are necessary.  UR - http://www.gsjournal.ir/article_54428.html L1 - http://www.gsjournal.ir/article_54428_a9acf6bd1c29d5746929e917abcc2197.pdf ER -