The effect of hydrodynamic and morphologic conditions of Bahmanshir river on engineering geological properties of tidal deposits of Bahmanshir series

Bahmanshir river is a two directional tidal river in southwest Khuzestan province (IRAN). This river originates from Karun river near Khoramshahr city (upstream) and traverses downstream about 80 km before falling into the Persian Gulf. Holocene deposits along Bahmanshir river commonly consist of two clayey layers that have been separated by silty sand beds. These complexes have been known as Bhamanshir series which have deposited in tidal environment. Hydrodynamic and sedimentary environments studies of Bahmanshir river show that tidal currents flow upstream from Arvand River and downstream from Persian Gulf also in the middle part of river due to its meandered morphology, the intensity and energy of tidal currents reduces. The main aim of this research is, to investigate the effect of hydrodynamic and morphologic conditions of Bahmanshir river on engineering geological properties of tidal deposits of Bahmanshir series. The results of studies reveal that engineering geological properties of deposits are approximately the same for both upstream and downstream of the river but in the middle part due to its meandered morphology and reduction in energy intensity of flow, percentage of clayey minerals are more than upstream and downstream. This difference in percent of clayey minerals has caused the variety of engineering geological properties middle part rather than other region.