DOLGU BARAJ GRANÜLER ZEMİNLERİNDE İÇSEL STABİLİTE POTANSİYELİNİN DEĞERLENDİRİLMESİ

Year 2024, , 1169 - 1176, 22.04.2024

Sadettin Topçu , Evren Seyrek

https://doi.org/10.31796/ogummf.1362774

Abstract

Dolgu barajların uzun dönemli güvenliği, sızma akımının gerçekleştiği zeminlerin içsel stabilitesine bağlıdır. Sufüzyon/sufozyon, kohezyonsuz zeminlerde görece ince malzemelerin, iri malzemelerin arasındaki boşluklardan sızma akımıyla taşınması olarak tanımlanır. Sufüzyon/sufozyon mekanizmasına bağlı olarak gerçekleşen içsel stabilite bozulmasıyla, granüler filtrelerde geriye doğru erozyon(borulanma) veya boşluk suyu basıncındaki artışa bağlı olarak statik stabilite kaybı gözlemlenebilir. Sufüzyonun gerçekleşebilmesi için iki koşul vardır: Sızma akımının yeterli hidrolik eğime sahip olması ve malzemenin granülometrisinin danelerin taşınmasına elverişli olması. Granüler filtrelerin tasarım ve planlanmasında sufüzyon mekanizmasının önceden belirlenebilmesi için bazı yaklaşımlar geliştirilmiştir. Bu çalışmada, dane çapı dağılım eğrisini kullanarak içsel stabilite potansiyelini belirleyen Istomina, Kezdi, Kenney ve Lau ile Burenkova metotları karşılaştırılmıştır. Eskişehir ili sınırları içerisinde yer alan Gökpınar Barajı’nın yarı-geçirimli malzeme sahasındaki plastik olmayan zeminler üzerinde yapılan çalışmaya göre, yöntemlerin uygulama esasları birbirine benzedikçe aynı değerlendirme sonucunu bulma oranları artmaktadır.

Keywords

Dolgu baraj, Sızma, İçsel erozyon, Sufüzyon, Granüler filtre

ASSESSMENT OF INTERNAL STABILITY POTENTIAL IN EMBANKMENT DAM GRANULAR SOILS

Abstract

The long-term safety of embankment dams depends on the soil's internal stability where seepage occurs. Suffusion/suffosion transports relatively fine materials through the voids between coarse materials by seepage flow in cohesionless soils. Backward erosion (piping) or a loss of static stability can be observed due to increased pore water pressure in granular filters with internal stability deterioration due to the suffusion/suffosion mechanism. There are two conditions for suffusion to occur: The seepage flow must have sufficient hydraulic gradient, and the granulometry of the material must be suitable for the transport of the grains. Some approaches have been developed to predetermine the suffusion mechanism in designing and planning granular filters. In this study, Istomina, Kezdi, Kenney-Lau, and Burenkova methods that determine the internal stability potential of soil using the particle size distribution curve have been compared. According to the study carried out on non-plastic (N.P) soils in the semi-permeable material field of Gökpınar Dam, which is located within the borders of Eskişehir province, the rates of finding the same evaluation result increase as the application principles of the methods are similar.

Keywords

Embankment dam, Seepage, Internal erosion, Suffusion, Granular filter

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