مصالح و سازه های بتنی

مصالح و سازه های بتنی

مطالعه آزمایشگاهی توزیع کرنش بتن در یک دیوار برشی بتنی مسلح خمیده تحت بارگذاری جانبی چرخه‌ای

نوع مقاله : مقاله پژوهشی

نویسندگان
1 دانشکده مهندسی عمران، دانشگاه صنعتی شریف، تهران، ایران
2 استاد، دانشکده مهندسی عمران، دانشگاه صنعتی شریف
چکیده
این مطالعه آزمایشگاهی به بررسی روند توزیع کرنش ایجادشده در بدنه یک دیوار برشی بتنی مسلح خمیده تحت بارگذاری چرخه‌ای و در غیاب بار محوری می‌پردازد. در ابتدا، یک نمونه آزمایشگاهی در مقیاس یک‌سوم در آزمایشگاه دینامیک سازه کف قوی دانشگاه صنعتی شریف ساخته شده و تحت بارگذاری چرخه‌ای تا جابه‌جایی جانبی نسبی هدف 2 درصد قرار گرفته است. به منظور بررسی روند توسعه ترک‌ها در سطوح داخلی و خارجی دیوار، در مجموع 34 کرنش‌سنج بر روی بدنه دیوار نصب‌ شده و تغییرات کرنش در طی بارگذاری چرخه‌ای که در هشت گام اعمال‌شده، اندازه‌گیری و بیشینه مقدار آنها تعیین شده است. مقادیر ثبت‌شده از کرنش‌سنج‌ها نشانگر نحوه رشد و گسترش انواع ترک‌های ایجادشده روی بدنه دیوار بوده که متأثر از سازوکار خرابی حاکم در هر مرحله از بارگذاری است. در ابتدای بارگذاری، ترک‌های افقی سرتاسری روی بدنه دیوار تشکیل شده که متأثر از لنگر خمشی و اعوجاج پیچشی بوده و به تدریج ترک‌های قطری و ضربدری شکل با ماهیت برشی تمامی سطوح داخلی و خارجی دیوار خمیده را بصورت تقریباً متقارن در برگرفته است. همچنین، بسته به موقعیت قرارگیری، کرنش‌سنج‌ها حداکثر تا حدود 8000 میکرواسترین کرنش را تجربه‌ کرده‌اند و در نهایت، شدت خرابی در نواحی ابتدایی و انتهایی پای دیوار منجر به خرابی نمونه و جداشدگی و قطع‌شدگی برخی از کرنش‌سنج‌ها شده است. با توجه به مطالعات آزمایشگاهی محدودی که پیرامون دیوارهای برشی بتنی مسلح خمیده صورت گرفته است، نتایج این آزمایش می‌تواند به-منظور صحت‌سنجی مدل‌های تحلیلی و عددی بکار گرفته شوند.
کلیدواژه‌ها

موضوعات


عنوان مقاله English

An experimental Investigation into the Strain Profile Measurements of a Curved RC Shear Wall Subjected to Lateral Cyclic Loading

نویسندگان English

Hatef Abdoos 1
Alireza Khaloo 2
1 Department of Civil Engineering, Sharif University of technology, Tehran, Iran
2 Distinguished Professor, Department Civil Engineering, Sharif University of Technology
چکیده English

This paper aims to experimentally investigate how the strains are distributed within the panel of a curved reinforced concrete shear wall (CRCSW) due to the lateral reversed cyclic loading. In this regard, an experimental testing program is designed and conducted, in which a one-third scale CRCSW is fabricated. In total, 34 strain gauges are affixed to the wall panel, at the target locations, in order to capture the strain variation along as well as across the wall panel. During the loading process, the strain values are monitored within the eight phases of the applied loading and the peak response is reported as the representative of each phase. Thereafter, the variation of the strain profile corresponding to the measured responses are plotted, which indicates the strain evolution process in the tested CRCSW. The strain variations also demonstrate the cracking pattern and damage sequence of the CRCSW subjected to the applied loading. Within the initial stages of the loading, the simultaneous action of bending moment and warping torsion is responsible for the horizontally aligned cracking surfaced at both faces of the wall panel, and then the inclined diagonal cracking pattern was developed and propagated all the wall panel. Moreover, due to the severe localized damages concentrated at the bottom of the wall tips, in some cases, strain gauge debonding was detected. The findings of this study can generally be employed as a benchmark for future studies regarding the calibration of the analytical and numerical investigations.                    

کلیدواژه‌ها English

Experimental Investigation
Curved RC Shear Wall
Cyclic Loading
Strain Gauge
Strain Profile
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  • تاریخ دریافت 29 اسفند 1402
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