Identification and evaluation of mechanical behavior collapsible soil (case study in north eastern of Iran)

Collapsible soils, when saturated, without any change in applied stress or any vibration, undergo large settlements. This will cause damages to the building foundations, roads, rail road, dams, pipelines which may lead to fracturing and collapsing. Collapsible soils are scattered all over the world. In Iran they can be found in central and eastern part of the country. In the present research, the North Eastern of Mashhad has been studied in order to identify the collapsibility potential of soil in this area. This was necessary since new buildings construction such as subway of underground transportation system is in process. These buildings are commonly affected by vibration forces transmitted from this system. Physical and mechanical parameters of the collapsible soil in this area have been evaluated and various collapsibility criteria are compared. The laboratory test results indicate the collapsibility of the soil potential. Also field tests were performed to evaluate the mechanical properties and collapsibility potential of soils. The results have confirmed the possible collapsibility of sub-soil in this area, which may lead to unavoidable damages to the buildings and rail way system.