Land-subsidence relative to Pore-pressure and Effective Stress (Case study: Khorramabad Plain, southwestern Iran)

Phenomena of land subsidence, increasing the effective stress (σ1) of the body of aquifer sediments have not consolidated. Because the weight of the upper overburden aquifer sediments by the solid and the fluid contained in the pore space to be tolerated when the fluid pressure caused by drop in the water table the decrease in the effective stress increased this results in soil compaction and evidence of subsidence in the area, Such as tensile cracks, crack growth in civil structures tube wells in plain. The last few years Bagstrsh, Land subsidence caused major problems for the agriculture and can be civil structures near these gaps. In line with the international studies in this research area as a pilot scheme studied Khorramabad. In general it can be stated that decline in groundwater levels in Khorramabad plain area, increasing the effective stress in the alluvial plain water depths ranging from plain and prevent to avoid potential supply normal rainfall factors accretion phenomena Khorramabad plain island subsidence. Near the underground water, Thickness of clay and fine materials, the presence of active faults Khorramabad anticline and humanitarian intervention mechanisms developed in this area, because increased incidence of subsidence phenomenon in the area that will be output by the model is consistent with the content.