بررسي تاثيرپذيري عملكرد لرزه ‌يي ديوار خاك مسلح از پارامترهاي شاخص زلزله به‌منظور انتخاب زلزله‌ي طرح مناسب

Investigation into the Effect of Earthquake Index Parameters on Seismic Performance of Reinforced Soil Walls to Select an Appropriate Design Earthquake

در اين پژوهش، به‌منظور معرفي معياري مناسب جهت انتخاب زلزله‌ي طرح مورد استفاده در تحليل هاي ديناميكي مبتني بر تاريخچه‌ي زماني سازه هاي خاك مسلح، به بررسي تاثير پارامترهاي شاخص زلزله نظير بزرگا، شتاب بيشينه، سرعت بيشينه و ...، در عملكرد لرزه‌يي سازه‌ي خاك مسلح پرداخته شده است. در راستاي نيل به اين هدف، با بهره گيري از مدل سازي عددي تفاضل محدود و انتخاب 30 شتاب‌نگاشت با پارامترهاي شاخص معين، تاثير هر يك از پارامترهاي مذكور در عملكرد لرزه‌يي سازه در قالب تغييرمكان هاي افقي رويه بررسي شده است. نتايج حاصله نشان مي دهد كه از ميان تمامي پارامترهاي شاخص مورد بررسي در اين پژوهش، پارامتر CAV داراي بيشترين هم‌گرايي با عملكرد لرزه‌يي سازه‌ي خاك مسلح است. لذا اين امر مناسب‌بودن اين پارامتر را جهت انتخاب يك زلزله‌ي طرح مناسب محرز مي سازد.

The supremacy of reinforced soil walls, due to aspects of easy installation, flexibility and economic viability, in comparison with other stabilization techniques, has caused the widespread use of these structures. Through observation of these walls during earthquakes, and, also, by experimental study, their appropriate behavior and flexibility are shown. Since these walls have adaptable flexibility, their use in seismic areas has widely spread. Therefore, recognition of the seismic behavior of these structures is mandatory. The continuous expansion of even reinforced soil walls, as one of the most useful ways of stabilizing, and the lack of careful attention to routine procedures regarding dynamic analysis, both emphasize the necessity of using dynamic analysis on the basis of time history. On the other hand, the loss of a relevant criterion in choosing a design earthquake, in order to dynamically analyze soil structures, is always a challenge, on the basis of time history. In order to introduce a suitable criterion for selection of a design earthquake in dynamical analysis, on the basis of the time history of reinforced soil walls, the effects of seismic index parameters, such as magnitude, maximum acceleration, maximum velocity and etc., on the seismic performance of reinforced soil walls, are investigated. Moreover, in order to clarify this aim, a finite difference numerical modeling, choosing 30 time histories, with certain index parameters, was undertaken, and the effects of each parameter on the seismic performance of the system in horizontal displacement of the facing were investigated. The results show that among all selected index parameters, the CAV parameter has the most convergence with the seismic performance of reinforced soil walls. Thus, it seems that this parameter is suitable for a proper design earthquake selection. On the other hand, the magnitude does not have suitable convergence with the seismic performance of this soil structure. Thus, it seems that this parameter is not suitable for use in a proper design earthquake selection.