تحلیل عددی شمع کوتاه تحت بارگذاری کشش کج در خاک ماسه‌ای

نوع مقاله : مقاله پژوهشی

نویسندگان

دانشکده عمران، دانشگاه یزد، یزد، ایران .

چکیده

در موارد متعددی از شمع­ ها برای مقابله با نیروی کششی در پروژه‌های مهندسی مورد استفاده قرار می‌گیرد. در این مقاله، رفتار شمع کوتاه، با نسبت لاغری (λ=L/B) کوچک‌تر از 10، در بارگذاری کششی کج با زوایای مختلف و در محیط خاک ماسه‌ای با استفاده از مدل ­های غیرخطی نرم افزار Flac3D مورد تحلیل و بررسی قرار گرفت. معیار گسیختگی خاک از نوع موهر-کلمب انتخاب شد و تحلیل‌ها در محدوده تغییر شکل‌های بزرگ انجام پذیرفت. در این مطالعه شمع از مصالح بتن مسلح با مقطع 2/1×2/1 متر در خاک ماسه‌ای متراکم و عمق مدفون شدگی 10 متر در نظر گرفته شد. با توجه به نتایج تحلیل عددی، روابط داس و سیلی 1975 به چالش کشیده شد. منحنی­ های بار– جابجایی با زوایای مختلف برای بار کششی ارائه گردید، این منحنی ­ها نشان داد که با اضافه شدن مولفه افقی نیرو ظرفیت کششی شمع افزایش می‌یابد. به ­عنوان مثال در زاویه بار 60 درجه نسبت به خط افق ظرفیت کششی شمع 12 درصد نسبت به حالت کشش خالص بیشتر شده است. منحنی­های خیز و جابجایی قائم سرشمع در برابر زاویه اعمال بار، بر اساس نتایج عددی مدل‌ها ارائه گردیده است. همچنین رابطه معناداری بین ضریب β که توسط اسماعیل و ال سند 1994 معرفی شده است و نسبت لاغری شمع (λ) با توجه به نتایج عددی این پژوهش و مطالعات آزمایشگاهی محققان دیگر به ­دست آمد.
 

کلیدواژه‌ها

موضوعات


عنوان مقاله [English]

Numerical analysis of short pile under oblique pull out in sandy soil

نویسندگان [English]

  • Mohsen Ranji
  • R. Porhoseini
M. Sc., Yazd University
چکیده [English]

In many cases, piles have been used to counteract the pull-out force for engineering purposes. In this research, the behavior of short piles with a slenderness ratio (λ = L / B) less than 10, at oblique pull-out loading with different (inclination) angles in sandy soils was investigated using nonlinear models of Flac3D software. The Mohr-Coulomb behavioral model was selected for soil and the analyzes were performed in large strain conditions. In this study, a reinforced concrete pile with a cross-section of 1.2x1.2 m2 in dense sandy soil and buried depth of 10 m was considered. According to the results of numerical analysis, the relations provided by Das and Seeley (1975) were challenged. The load-displacement curves were presented with different uplift load inclination angles. These curves showed that the uplift capacity of the pile increases with the addition of the horizontal component of force. For instance, the load inclination angle of 60o, the uplift capacity of the pile was increased by 12% higher than the net uplift state. Furthermore, vertical displacement and pile deflection versus load application angle was plotted based on the numerical results. Also, a significant relationship has been found between the coefficient β introduced by Ismael and Al-Sanad (1994), and the slenderness ratio (λ) according to other laboratory studies and numerical results of this study.

کلیدواژه‌ها [English]

  • Oblique pull out
  • Sandy soil
  • Short pile
  • Numerical analysis
  • Lateral load
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