پديد آورندگان :
پورحسيني ، رضا نويسنده استاديار دانشكده‌ي مهندسي عمران، دانشگاه يزد Pour Hosseini, R , سلطاني، نويد نويسنده دانشجوي دكتري دانشكده‌ي مهندسي عمران، دانشگاه شهيد باهنر، كرمان Soltani, N
كليدواژه :
ديوار زيرزمين , مصالح بنايي غيرمسلح , تحليل عددي , اندركنش خاك- ديوار
چكيده فارسي :
پايداري سازه‌هاي با مصالح بنايي به اندركنش خاك- ديوار زيرزمين وابسته است. استفاده از روش متداول شبه استاتيكي مونونوبه- اوكابه در تحليل لرزه‌يي ديوار هاي حايل دقت كافي ندارد. در اين مطالعه اندركنش خاك- ديوار بنايي زيرزمين در حالت دوبعدي كرنش صفحه‌يي و شرايط ژيوتكنيكي آن به روش اجزا محدود مدل‌سازي و رفتار ديناميكي ديوار حايل زيرزمين بررسي شده است. لنگر خمشي بيشينه‌ي ديوار به عنوان ملاك عملكرد ديوار انتخاب و اثر بسامد تحريك لرزه‌يي، نوع خاك، ارتفاع و ضخامت ديوار برآورد شده است. براساس نتايج عددي، سرعت موج برشي خاك و بسامد تحريك در تحليل ديناميكي ديوار نگهبان زيرزمين نقش به‌سزايي دارد، هر چند كه اين مشخصات در روش مونونوبه- اوكابه به حساب نيامده و به علت تعدد ساده‌سازي‌ها، نتايج اين روش در مواردي بسيار محافظه كارانه يا غيرايمن است. لذا براي طراحي ديوار نگهبان زيرزمين، رويكرد اندركنش خاك- ديوار ضروري به نظر مي‌رسد.
چكيده لاتين :
Fundamentally, the stability of masonry structures is dependent on the soil-basement wall interaction. Due to the ease of calculation and design of retaining walls by the quasi-static method of Mononobe-Okabe (M-O), this method has been widely used. However, the results of numerical models and experimental data have shown that this method is not very accurate, and the design is either very conservative or is unsafe. Since, in Iran, the use of masonry structures without reinforcement is predominant, in this study, the dynamic interaction between soil and masonry walls has been evaluated. This study has been conducted utilizing a 2D Plane Strain Finite Element Model. The behavior of the wall before cracking is idealized as elastic plate. After cracking, the strength of the wall drops very quickly, and, in this case, the remaining strength can be ignored, which can be assumed as having collapsed. Considering the geotechnical aspects that normally occur in practice, they have been simulated to produce the state of rest (ko) in backfill soil for a static situation. This state of stress has been selected for the initial condition in dynamic analysis. Dynamic displacement excitation is applied in a sinusoidal form at bed rock level by three cycles with different frequencies, but with the same peak acceleration in each case equal to 0.3g. The effect of excitation frequency, soil type, height, and the ratio of height to thickness in the wall was evaluated using the maximum bending moment of the wall (Mmax) as a criterion for the wall performance. The numerical results show that the effect of the shear wave velocity of the soil and excitation frequency on the dynamic response of the basement wall cannot be ignored. However, these factors are overlooked in the M-O method. This study has also demonstrated that the dynamic interaction of the soil and basement walls is necessary to consider parameters, such as: dynamic excitation frequency, soil type, and geometry of the wall.
