BİR TÜNELDE PORTAL VE TÜNEL STABİLİTESİ İLİŞKİSİ (ANKARA-SİVAS YÜKSEK HIZLI DEMİRYOLU PROJESİ, T3 TÜNELİ)

Öz Son yıllarda hızlı bir gelişim gösteren ulaşım ağı projeleri kapsamında inşa edilen tünellerin en çok karşılaşılan sorunlarından biri portal şevlerinin duraylılığıdır. Portal şevlerinde meydana gelen yenilmeler zaman zaman tünelde de duraylılık problemlerine sebep olmakta ve sorunu büyütmektedir. Bu çalışma kapsamında, buna tipik bir örnek olan Ankara-Sivas Yüksek Hızlı Tren projesi kapsamında inşa edilen T3 Tünelinde meydana gelen yenilme incelenmektedir. Tünel kazısı devam ederken, çıkış portal kesimi şevlerinde çatlaklar meydana gelmiş ve aynı zaman da tünel gövdesinde de göçük meydana gelmiştir. Bu çalışma kapsamında hem göçen kesimin güvenle tekrar kazılması için sayısal analizler ile önerilen yeni destek sistemleri değerlendirilmekte, hem de portal kesiminde şev duraylılığının sağlanması için gerekli analizlerin yapılması ve sonuçların performansı tartışılmaktadır. Buna ek olarak, çalışmada genel olarak tünel portal kazısı ile tünel içi tahkimat sistemlerinin etkileşimi tanımlanarak, bu tür tünel çalışmaları için bir prosedür önerilmektedir.

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