YAKIN FAY YER HAREKETLERİNİN YÖN ETKİSİ

Öz

Performansa dayalı tasarımın temel amacı yer hareketine maruz yapılarda yapısal talebin belirlenebilmesidir. Yapısal talebin doğru belirlenebilmesi, yer hareketi özelliklerinin ve bunlarla yapısal talep arasındaki ilişkinin doğru tanımlanabilmesini gerektirmektedir. Son yıllarda faylara yakın bölgelerde elde edilen kayıtların diğer kayıtlara göre önemli farklılıklar içerdiği görülmüştür. İleri doğrultu ve ötelenme etkileri bu yer hareketlerini farklılaştıran ve hasar potansiyellerini arttıran temel özelliklerdir. İleri doğrultu etkisi fayın kırılma yüzeyine dik yönde meydana gelir ve bu yer hareketlerinin hasar potansiyelleri artırır. Ancak her kayıtın faya dik ve paralel yönlerini belirleyebilmek, fiziki imkansızlıklar nedeniyle, mümkün olmamaktadır. Bu nedenle etkili yönlerin belirlenebilmesi önemlidir. Literatürde maksimum hız yönü önerilen etkili yönlerden biridir. Bu çalışmada göreli kat ötelenmesi spektrum şiddeti ve spektral hızın maksimum yönlerinin de etkili yönlerden olduğu tespit edilmiştir. Maksimum hız yönünün etkinliği yer hareketinin atım periyodunun yapı periyodu oranına bağlı olduğu, bu oranın büyük olduğu durumlarda maksimum ivme yönü hasar potansiyelinin daha yüksek olduğu belirlenmiştir.

Anahtar Kelimeler

• Yakın Fay, yer hareketleri, ileri doğrultu etkisi, yön etkisi

DIRECTION EFFECT OF NEAR FAULT GROUND MOTIONS

Öz

The main objective of Performance Based Design is determining the structural demands for earthquake loadings. For a good estimation of structural demands, the relation between ground motion parameters and structural demands must be known. Near fault ground motions are significantly different from far field ground motions. Depending on the fault mechanism, ground motions may contain distinct pulse in velocity and permanent displacement in displacement records. These are increase the near fault ground motions damage potential. Forward directivity occurs in faults normal direction and damage potential of this ground motions are high. But for all records, psychically, it is not possible to determine the fault-normal and fault-parallel directions. In literature, to overcome this complexity the maximum velocity direction has been proposed. In this study in addition to maximum velocity direction two new directions, maximum drift spectrum intensity and maximum spectral velocity, were determined which are very effective as fault-normal direction. The efficiency of maximum velocity direction depends on ratio of pulse period to structural period. In the case of high value of this ratio, the maximum acceleration ratio is more destructive.

Anahtar Kelimeler

• Near Fault, ground motions, directivity effect, direction effect

Kaynakça

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