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فرونشست خاک اطراف شمع تحت اثر بارگذاری سیکلی جانبی در خاک دانه ای | ||
نشریه مهندسی عمران امیرکبیر | ||
دوره 57، شماره 4، 1404، صفحه 551-570 اصل مقاله (1.22 M) | ||
نوع مقاله: مقاله پژوهشی | ||
شناسه دیجیتال (DOI): 10.22060/ceej.2025.21804.7829 | ||
نویسندگان | ||
جواد کشاورز؛ جعفر بلوری بزاز* | ||
گروه عمران، دانشکده مهندسی، دانشگاه فردوسی مشهد، مشهد، ایران | ||
چکیده | ||
در برخی از سازه ها همانند توربین های بادی از تک شمع ها در پی استفاده می شود. این سازه ها تحت اثر بارهای سیکلی همچون باد و امواج قرار می گیرند. بار سیکلی اعمال شده به پی باعث ایجاد جریان همرفتی در خاک اطراف شمع گشته و موجب پدیدار شدن فرونشست در اطراف شمع می گردد. هندسه فرونشست خاک تحت تاثیر فرکانس بارگذاری، طول مدفون شمع و تراکم خاک می باشد. مقدار فرونشست بر اساس تعداد سیکل در اطراف شمع و تاثیر بارهای سیکلی در ظرفیت باربری شمع و همچنین تغییرات فرکانس بارگذاری بر فرونشست اطراف شمع همواره از موضوعات مورد پرسش توسط پژوهشگران می باشد. در این راستا برنامه آزمایشاتی طراحی شد که بتوان به پاسخ این سوالات پرداخت. در این پژوهش شمع با طول های مدفون متفاوت تحت اثر بارگذاری سیکلی یک جهته قرار گرفته اند. آزمایشات در سه فرکانس مختلف در خاک ماسه ای سست و متراکم انجام شده است. نتایج آزمایشات نشان می دهد عمق و شعاع فرونشست خاک اطراف شمع با توجه به طول مدفون شمع، فرکانس بارگذاری و تراکم خاک متغیر است. بر اساس تحقیقات گذشته و نیز داده های آزمایشگاهی رابطه ای که بتوان فرونشست را تخمین زد ارائه و پارامترهای آن تعیین و کالیبره گردید. در نتیجه می توان با استفاده از این رابطه میزان فرونشت خاک اطراف شمع را در هر سیکل پیش بینی نمود. همچنین نتایج بارگذاری استاتیکی شمع قبل و بعد از بارگذاری سیکلی نشان می دهد ظرفیت باربری شمع می تواند افزایش یا کاهش یابد که به تراکم خاک در حالت اولیه و بازتوزیع ذرات خاک پس از بارگذاری سیکلی بستگی دارد. فرکانس بارگذاری نیز تاثیر چندانی در ظرفیت باربری استاتیکی پس از بارگذاری سیکلی ندارد. | ||
کلیدواژهها | ||
شمع؛ بارگذاری سیکلی؛ فرکانس؛ خاک ماسه ای؛ ظرفیت باربری استاتیکی | ||
موضوعات | ||
اندرکنش خاک و سازه | ||
عنوان مقاله [English] | ||
Soil Subsidence Around the Pile under Lateral Cyclic Loading in Granular Soil | ||
نویسندگان [English] | ||
Javad Keshavarz؛ J. Bolouri Bazaz | ||
Ph.D. student of Geotechnical engineering, Ferdowsi University of Mashhad, Mashhad, Iran | ||
چکیده [English] | ||
In many structures, such as offshore wind turbines, single piles are used in the foundation. These structures are subjected to cyclic loads such as wind and waves. The cyclic load applied to the foundation causes a convective flow of soil around the pile and also to appear subsidence around the pile. The geometry of soil subsidence is influenced by loading frequency, pile embedded length, and soil density. The amount of subsidence based on the number of cycles around the pile, the impact of cyclic loads on the pile's bearing capacity, and variations in loading frequency on the subsidence around the pile have consistently been topics of interest among researchers. To address this question, an experimental program was designed to provide answers. In this research, piles with different embedded lengths have been subjected to one-way cyclic loading. Cyclic tests have been performed with three various frequencies in loose and dense sandy soil. The results of the tests indicate that the depth and radius of the soil subsidence around the pile are various, according to the embedded length of the pile, loading frequency, and soil density. Based on past research and laboratory data, a relationship to estimate soil subsidence depth has been provided and the constant coefficients of this equation have been determined and calibrated. As a result, it is possible to predict the amount of soil subsidence around the pile in each cycle by using this relationship. Also, the results of static loading of the pile before and after applying cyclic loading show that the bearing capacity of the pile may increase or decrease, depending on the soil density in the initial state and the redistribution of soil particles after cyclic loading. In addition, the loading frequency has no considerable effect on the static bearing capacity after cyclic loading. | ||
کلیدواژهها [English] | ||
Pile, Cyclic Loading, Frequency, Sandy Soil, Static Bearing Capacity | ||
مراجع | ||
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