بررسي اثرات تغيير مكان ناشي از گودبرداري بر سازه مجاور در مناطق شهري (مطالعه موردي شهر ايلام)

Investigation the Effects of Soil Excavation on Earth - Moving in Urban Areas (Case Study: Ilam City)

امروزه با توجه به كمبود فضا و گسترش فرهنگ آپارتمان نشيني در مناطق شهري، براي دسترسي به فضاي كافي و نيز بستر مناسب در بيشتر پروژه ­ها گودبرداري امري اجتناب ناپذير است. طراحي نادرست و عدم رعايت اصول ايمني در حفاظت از گود و ساختمان­هاي مجاور آن منجر به ايجاد خسارت جبران ناپذيري خواهد شد. در اين تحقيق اهميت در نظر گيري تغيير شكل­ ها در محيط اطراف محل گودبرداري و ميزان تأثير اين تغيير مكان­ها بر روي سازه­ هاي اطراف مورد بررسي و مطالعه قرار گرفته است. براي اين هدف اثر سختي سازه مجاور بر حركت زمين حاصل از گودبرداري لحاظ شده است. براي اين منظور از تقابل دو برنامه اجزاء محدود Etabs و Plaxis و مدل رفتاري خاك سخت شونده براي مصالح زمين استفاده شده است. براي لحاظ نمودن تأثير سختي سازه مجاور از يك ساختمان بتني با سيستم مهاربندي قاب خمشي استفاده شده است. نتايج نشان مي­دهد كه سختي سازه مجاور تأثير قابل توجهي در كنترل تغيير مكان زمين به علت گودبرداري دارد.

This study tried to investigate the importance of considering deformations in the surroundings of the excavation and the effect of these displacements on surrounding structures. In this context, the stiffness impact of adjacent structure on the ground movement resulting from excavation will be determinative because the fundamental problem of excavation in urban areas with old and even new buildings (including structurally weak buildings) is the impact of the various stages of excavation on adjacent structures and vice versa the interaction of excavation of adjacent structure. Several factors affect the behavior of excavation system such as modeling of structures adjacent to the excavation site which depends on the weight, geometry and stiffness of adjacent structure. Various studies have been conducted by various researchers in this field. Horodecki et al [1] have shown that in excavation done in urban areas, vertical displacement of soil level around the pit and adjacent structures can be seen better than the horizontal displacement of braced wall during the construction process. Accordingly, this study investigates this matter in various parts of the city of Ilam. For this purpose, after sampling the running projects in different parts of the studied areas (Ilam city) and conducting necessary tests and determining the behavioral parameters of soil in these areas (with the help of correlation equations), a set of finite element analysis is done. Behavioral model for soil is hardening soil model. To consider the stiffness impact of the adjacent structure the concrete building with moment frame system with real geometry and loading is used. Since the geotechnical software cannot model the structure with complete details, to achieve these goals, the interaction of two programs of Etabs and Plaxis finite element are used.