A Comparison of Three and Two-Dimensional Analyses of Rockfill Dams in Narrow Valleys (A Case Study: The Vanyar Dam)

A two-dimensional analysis of the largest cross-section of earth dams may generate appropriate results provided that the dam is located in a U-shape valley. The Vanyar dam has been constructed in a narrow valley. With regard to the geometrical consideration of the valley, there is no plane strain condition throughout the long side of the dam. In this research, the results of three and two dimensional numerical analyses of the Vanyar dam are compared in terms of settlement, pore water pressure, and total vertical stress. These analyses were carried out by a finite difference method through FLAC-3D and FLAC-2D softwares. In order to verify the results of the analyses, the settlement data recorded by the instruments in the body of the dam are compared to those provided through the numerical analyses. The results of the three and two dimensional analysis show that the settlements in the upper half of the height of the dam have a suitable adaptation. Moreover, the two- dimensional analysis shows the settlements in the lower half of the height of the dam more than those shown by the three-dimensional analysis. Furthermore, in terms of total vertical stress and pore water pressure, the two-dimensional analysis shows the values throughout the height of the dam more than those shown by the threedimensional analysis

The Investigation of Salinity Effects on Behavioral Parameters of Fine-Grained Soils

The present paper aims at investigating the effect of water salinity on engineering properties of fine-grain soil. Saline water used in this study was obtained from half saline water of Ajichay River (with TDS more than 1877 ppm) and saline branch of Korchay (with TDS more than 97000 ppm) located in Northwestern of Iran. Fine-grain soil studied is from Korchay dam core. Due to the high hardness of water in this river, the feasibility of using saline water as the water required in clay core of the dam process has been studied in this research. The experiments were performed including Atterberg limits, standard compaction, consolidation, direct shear and dispersion. These tests were performed by using distilled water, half saline water and saline water on reservoir materials. Due to low percentage of clay minerals in the soil, the changes in engineering soil properties as salinity increases are negligible. However, the use of saline water reduces Atterberg limits, compression index (Cc), swell index (Cs(, coefficient of compressibility (av), coefficient of volume compressibility (mv) and causes slight increase in soil shear strength parameters. Despite the high percentage of sodium in half saline and saline water, dispersion degree of soil is ND2 in pinhole test

The Outcomes of Superior Cavopulmonary Connection Operation: a Single Center Experience

Abstract Introduction: The superior cavopulmonary connection operation is one of the stages of the palliative surgical management for patients with functionally single ventricle. After surviving this stage, the patients are potential candidates for the final palliative procedure: the Fontan operation. Objectives: This study aimed to analyze the outcomes of superior cavopulmonary connection operations in our center and to identify factors affecting the survival and the progression to Fontan stage. Methods: The outcomes of 161 patients were retrospectively analyzed after undergoing superior cavopulmonary connection operation in our center between 2005 and 2015. Results: The early mortality rate was 2.5%. Five (3.1%) patients underwent takedown of the superior cavopulmonary connection. The rate of exclusion from the Fontan stage was 8.3%. Statistical analysis revealed that elevated mean pulmonary artery pressure preoperatively and the prior palliation with pulmonary artery banding were risk factors for both early mortality and takedown; however, the age, the morphology of the single ventricle and the type of operation were not considered risk factors. Conclusion: The superior cavopulmonary connection operation can be performed with low rate mortality and morbidity; however, the elevated mean pulmonary artery pressure preoperatively and the prior pulmonary artery banding are associated with poor outcomes

The Outcomes of Superior Cavopulmonary Connection Operation: a Single Center Experience

<div><p>Abstract Introduction: The superior cavopulmonary connection operation is one of the stages of the palliative surgical management for patients with functionally single ventricle. After surviving this stage, the patients are potential candidates for the final palliative procedure: the Fontan operation. Objectives: This study aimed to analyze the outcomes of superior cavopulmonary connection operations in our center and to identify factors affecting the survival and the progression to Fontan stage. Methods: The outcomes of 161 patients were retrospectively analyzed after undergoing superior cavopulmonary connection operation in our center between 2005 and 2015. Results: The early mortality rate was 2.5%. Five (3.1%) patients underwent takedown of the superior cavopulmonary connection. The rate of exclusion from the Fontan stage was 8.3%. Statistical analysis revealed that elevated mean pulmonary artery pressure preoperatively and the prior palliation with pulmonary artery banding were risk factors for both early mortality and takedown; however, the age, the morphology of the single ventricle and the type of operation were not considered risk factors. Conclusion: The superior cavopulmonary connection operation can be performed with low rate mortality and morbidity; however, the elevated mean pulmonary artery pressure preoperatively and the prior pulmonary artery banding are associated with poor outcomes.</p></div