پديد آورندگان :
مظاهري، احمدرضا دانشگاه آيت الله العظمي بروجردي - دانشكده فني و مهندسي , كماسي، مهدي دانشگاه آيت الله العظمي بروجردي - دانشكده فني و مهندسي , ويسي، مجيد دانشگاه آيت الله العظمي بروجردي - دانشكده فني و مهندسي
كليدواژه :
كنترل ايمني , پايداري , تنش ها , نشست ها , GEO STUDIO , FLAC
چكيده فارسي :
كنترل ايمني و پايداري سدهاي خاكي در دوران ساخت، انتهاي ساخت، اولين آبگيري و بهره‌برداري آن بسيار حائز اهميت است. ارزيابي مقايسه‌اي نتايج تجزيه‌وتحليل‌ها براي ايمني ساختار و همچنين عمليات نگهداري منظم ضروري است. علاوه براين واضح است كه مطالعات دقيق مبتني بر چنين مقايسه‌هايي بـراي به دست آوردن تجربه براي طرح‌هاي آينده مفيد خواهد بود. در اين مطالعه سد خاكي دويرج از نظر پارامترهاي فيزيكي مانند، جابه‌جايي‌ها، تغيير شكل‌ها، تنش‌ها، فشار آب منفذي و پايداري آن در پايان ساخت و اولين آبگيري موردبررسي مقايسه‌اي قرار گرفت. مدل‌سازي عددي با استفاده از دو نرم‌افزار FLAC 2D و GEO STUDIO با مدل رفتاري موهر- كلمب (Mohr–Coulomb) انجام شد. نتايج بررسي‌ها نشان داد بيشترين نشست عمودي در تاج هسته رسي بعد از اولين آبگيري با مقدار 70 سانتي‌متر و همچنين بيشترين مقدار جابه جايي افقي در پايين‌دست سد برابر 12 سانتي‌متر رخ داده است. در بررسي تنش‌ها نيز مشخص شد كه مقدار بيشينه تنش‌هاي حاصل در مقطع هسته حدود 1000 كيلو پاسكال به‌دست‌آمده است.
چكيده لاتين :
Engineering and economic investigations in dam construction projects throughout the world indicate that, in many cases, rockfill dams with impervious clay cores are the best selection for the final design (Rezaei and Salehi, 2011). This approach makes the investigation of different issues affecting the stability of rockfill dams worthwhile. In general, dam safety is the first and foremost reason for controlling deformation and physical parameters in dams. Another reason is the importance of basic design concepts for engineers to apply in future designs as well as understanding the resistive and behavioral characteristics of soil and pebbles. One of the most effective approaches for interpreting the mechanical and hydraulic behavior of structures such as dams is to use data and compare the results with numerical modeling predictions. In the field of earth and rockfill dams, monitoring of typical physico-mechanical behaviors is a fundamental issue. Measurements of displacements, total stresses, pore water pressures, and arching ratio can be used to carry out a number of tasks (ICOLD, 1982), such as characterizing the dam’s overall behavior (Pagano et al., 1998), checking the behavior of specific zones, obtaining information about the in situ mechanical properties of embankment soils (Marsal and Resendiz, 1975), and finally, supporting the difficult task of evaluating dam safety and efficiency (Gould and Lacy, 1993). Justo (1991) and Naylor (1997) proposed methods for the incorporation of collapse settlement of rockfill into constitutive models. Naylor (1991) performed the finite element analysis for Beliche dam, a central core earth and rockfill dam, by considering the collapse settlement of the upstream rockfill in the modeling. The effect of pore water pressure dissipation in earthfill during construction was also considered by a number of authors including Eisenstein and Law (1977) and Cavounidis and Hoeg (1977), amongst others. For these cases, the incremental embankment construction was modeled as a two-stage process, the first stage modeling the new layer construction using undrained properties for the core and the second stage modeling pore water pressure dissipation. Zomorodian and Kuchi studied internal deformation, pore water pressure, and total vertical stresses in Masjed Soleiman Dam and compared it to numerical results, they also showed that the development of excess pore water pressure in the clay core of zoned earth dams during construction may lead to the onset or progression of hydraulic failure.
