نشریه مهندسی عمران امیرکبیر

نشریه مهندسی عمران امیرکبیر

ارزیابی آزمایشگاهی پایداری آیروالاستیک عرشه Π-شکل پل کابلی دهانه بلند در حال ساخت: مطالعه تونل باد وابسته به پیکربندی سازه‌ای

نوع مقاله : مقاله پژوهشی

نویسندگان
مهدی ایزک محمدی
سعییدرضا صباغ یزدی
گروه مهندسی سازه، دانشگاه صنعتی خواجه نصیرالدین طوسی، تهران، ایران.
10.22060/ceej.2026.24445.8307
چکیده
در این پژوهش، رفتار آیروالاستیک یک مقطع کم‌عمق -Πشکل متعلق به عرشه پل کابلی دهانه بلند در دو پیکربندی «کامل» و «در حال ساخت» به‌صورت آزمایش مقطع الاستیک در تونل باد مورد بررسی قرار گرفت. با توجه به آن‌که در مرحله ساخت، عرشه بصورت طره‌ای و با کاهش سختی مؤثر و تغییر شرایط مرزی عمل می‌کند، ارزیابی مستقل پایداری آیروالاستیک آن ضروری است. مدل مقیاس‌شده با دو درجه آزادی قائم و پیچشی نصب شد و آزمایش‌ها در بازه سرعت باد 3.27 تا 7.72 متر بر ثانیه و تحت زوایای مختلف حمله اولیه انجام گرفت. هدف اصلی پژوهش، بررسی اثر تغییر پیکربندی سازه‌ای بر مرز واگرایی استاتیکی و دامنه پاسخ دینامیکی بود. نتایج نشان داد که در پیکربندی مرحله ساخت، پاسخ استاتیکی پیچشی و قائم به‌ترتیب حدود ۶٪ و ۱۰٪ افزایش یافته است. همچنین دامنه نوسانات دینامیکی پیچشی و قائم به‌ترتیب حدود 8.5% و 5.5% بیشتر از حالت کامل اندازه‌گیری شد. در برخی زوایای حمله، آستانه شروع ناپایداری در سرعت‌های پایین‌تری نسبت به پیکربندی کامل رخ داد که بیانگر جابجایی مرز پایداری آیروالاستیک در اثر کاهش سختی و تغییر شرایط مرزی است. نتایج این تحقیق نشان می‌دهد که تعمیم رفتار حالت بهره‌برداری به مرحله ساخت می‌تواند منجر به برآورد غیرمحافظه‌کارانه مرز پایداری شود؛ بنابراین انجام مدل‌سازی اختصاصی آیروالاستیک در این مرحله برای طراحی ایمن پل‌های دهانه بلند توصیه می‌شود.
کلیدواژه‌ها
آیروالاستیسیته
در حال ساخت
پل کابلی دهانه بلند
واگرایی پیچشی
آزمایش تونل باد
موضوعات

عنوان مقاله English

Experimental Investigation of Aeroelastic Behavior of a Shallow Π-Shaped Bridge Deck during Construction Stage

نویسندگان English

mehdi izakmohammadi
saeedreza sabaghyazdi
Department of Civil Engineering, Faculty of Civil Engineering, Khajeh Nasiruddin Toosi University, Tehran, Iran
چکیده English

In this study, the aeroelastic behavior of a shallow Π-shaped deck section of a long-span cable-supported bridge was experimentally investigated in both completed and construction-stage configurations using an elastically mounted sectional model in a wind tunnel. During the construction stage, the deck behaves as a cantilever system with reduced effective stiffness and altered boundary conditions, which may significantly influence its aeroelastic stability. The scaled model was allowed to oscillate in two degrees of freedom, namely vertical translation and torsional rotation. Wind tunnel tests were conducted within a wind velocity range of 3.27 to 7.72 m/s and under initial angles of attack from degrees. The primary objective was to evaluate the influence of structural configuration changes on the static divergence threshold and dynamic oscillation amplitudes. The results indicated that, in the construction-stage configuration, static torsional and vertical responses increased by approximately 6% and 10%, respectively, compared to the completed state. Furthermore, the dynamic oscillation amplitudes in torsion and vertical motion increased by about 8.5% and 5.5%, respectively. In certain angles of attack, the onset of instability occurred at lower wind velocities in the construction stage, indicating a shift in the aeroelastic stability boundary due to stiffness reduction and boundary condition modification. The findings demonstrate that extrapolating the aeroelastic behavior of the completed bridge to the construction stage may lead to unconservative stability assessment, and dedicated aeroelastic modeling is therefore recommended for safe design of long-span bridges during erection stages.

کلیدواژه‌ها English

Aeroelasticity
Construction Stage
Cable-Supported Bridge
Torsional Divergence
Wind Tunnel Testing
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نشریه مهندسی عمران امیرکبیر
دوره 58، شماره 4
1405
صفحه 511-530