Investigation of landslide situation along the path of gas pipelines in Imamzadeh Hashem-Rudehen area of Tehran province, Iran

This article deals with the study of land slide situation on the proposed path of the gas pipe line from Imam zadeh Hashem to Rudehen in Tehran province, using geophysical studies with 3 geophysical methods of one dimentional geoelectrical method, 2 dimentional Geo electrical Induced Polarization and Resistivity (IP & RS) method, and Ground Peneteration Radar (GPR) method. For this purpose, geophysical studies were carried out in the study area (in 70 kilometers east of Tehran and near Rodhan) as follows. In order to measure the changes of Geoelectrical resistivity in the designated place, to check the ground conditions for the gas pipeline in the Imam zadeh Hashem project, to separate the underground layers based on their Geoelectrical resistivity and to diagnose possible fractures, the number of 20 electrical soundings in an irregular network were recorded in the land slide area along ten profiles. After the approximate identification of the land slide area, 2D study was done in two profiles with a pole - dipole arrangement of 380 meters with induction polarization and resistivity (IP-RS) method. In order to obtain more information near the surface at the same time and also to investigate the extension to the depth, 5-meter electrode intervals with a maximum of 8 jumps and 10-meter intervals from 4 to 13 jumps have been used The depth of investigation will be about 50 meters.  Moreover,  Ground Peneteration Radar (GPR) method was performed with the length of 1000 meters in 27 profiles. GPR studies have been conducted with the aim of investigating and determining the location of loosened areas and possible holes in the range. Data acquisition was done using 80 MHz antenna. The results of data acquisition for a total area of ​​1000 meters have been processed by professional software and interpreted by taking into account the environmental conditions and taking into account all the complications in the route of the conducted surveys.    Based on conducted studies, the land slide areas were determined and using Ground Peneteration Radar (GPR), underground cavities were located. With the help of the conducted studies, the range of the main land slide resulting from geophysical studies is determined and land slide prone surfaces are actually formed on the slope of land stratification and the mechanism of slides is planar movement. The main problem is related to the surface prone to upper slippage. Therefore, consolidation and stabilization of anomalous areas were investigated using stability analysis software.