جستجوی مقالات مرتبط با کلیدواژه "پی سنگ" در نشریات گروه "زمین شناسی"

The effect of basement’s upper surface morphology on the accommodation development is investigated in this study, through a case study from the Asmari Formation in Dezful Embayment and Abadan Plain. Considering the depth of the basement’s upper surface, position of the studying formation’s bounding surfaces, its thickness and total thickness of basin fill sediments are calculated. Based on the available data from previous researches and data extracted from more than 200 drilled oil wells in the studied area, the maps of basement surface, the Asmari Formation bounding surfaces, isopach maps of the Asmari Formation and total basin fill deposits are created. Results from this study shows the minimum and maximum depth of the basement’s upper surface 7,000 and 15,000 meters respectively. The deepest level of the surface is in the north Dezful Embayment, while the shallowest level in the southern Dezful and Abadan plain. The maps of the formations bounding surfaces well correlates with the basement’s upper surface map, especially in the north Dezful embayment area. Similar results are achived from the correlation of created isopach maps with that of basement’s top. However, slight discrepancy in the correlations is observed in the south Dezful embayment. Results of present study clearly show that development of accommodation space of the Asmari Formation in the north Dezful embayment and Abadan plain was mainly affected by the basement upper surface during different sedimentation periods. The accommodation space in the southern Dezful embayment was most likely affected from the basement faults’ actvities. Highest rate of sediment supply was recorded in the middle part of the north Dezful embayment.

Ekbatan dam is a buttress gravity concrete dam. This dam is performed on Yalfan River in 5 km from south-east part of Hamedan, Iran. The purpose of dam is providing the drinking water of Hamedan city. It should be noted that more than 50% of dam capacity is filled by sediments. For this reason and in order to provide the drinking water of Hamedan city, it was decided to increase the height of old dam. The old dam was performed on the schisty rocks. Due to the heightening of dam and increasing of dam foundation, a main part of dam foundation is located on the karstic limestones. This caused to be worry about the bearing capacity, settlement and seepage problems in the new dam site. In this research, both labratoray and filed investigations have been carried out. Results show that rock mass properties are in medium category and they show potential of solubility. In this site, orientation of the main joint set is as same as Zagros zone orientation, which plays an initial role in distribution of karstic conduits. Recognition of karstic zones has been carried out using boreholes and water pressure tests data. Results show that karstic zones in the right abutment and also central part of the dam are located in the surface parts and maximum in 30m depths. Whereas, concentration of karstic zone in left abutment has been develop in 55-80 m depths. Because of dam heightening and in order to increase the bearing capacity of dam foundation and prevent the seepage problems, cut off design and grouting have been carried out. Consequently, their results have been analyzed.