Tolga Y. Ozudogru

Istanbul Technical University · Department of Civil Engineering

This letter shows that the increase of heat exchanger pile capacity in response to heating, observed in several small-scale laboratory studies, cannot be directly attributed to the increase of contact pressure at the soil–pile interface. The main thermo-hydro-mechanical processes that influence the capacity and behaviour of heat exchanger piles inc...

In most analytical and numerical models of heat exchanger piles, strain incompatibilities between the soil and the pile are neglected, and axial stresses imposed by temperature changes within the pile are attributed to the thermal elongation and shortening of the pile. These models incorporate thermo-hydro-mechanical couplings in the soil and withi...

Heat exchanger piles utilize the constant temperature and the thermal storage capacity of the ground for heating and cooling of buildings. Sustainable use of the ground as a renewable energy source depends on the seasonal energy load balance. One of the critical factors for the sustainable operation of heat exchanger piles is that a constant temper...

Many offshore energy production and recovery structures such as wind turbines, offshore tidal turbines, and oil/gas platforms are built on carbonate sands, which predominantly consist of the skeletal remains of marine organisms. Particles of carbonate sands have highly porous grain structures with intra-granular voids. Such porous grain structure r...

Ground-source heat pump systems consist of heat exchanger boreholes, embedded with circulation pipes, buried in the ground and connected to a heat pump for heating and cooling of buildings. Due to the changes in seasonal energy demands of the building, sustainability of borehole heat exchangers depends on the seasonal load balance. As the soil can...

Zemin kesitinde yer alan tabakaların dinamik davranış özellikleri, depremler sırasında yapısal hasarı belirleyen önemli faktörlerden birisidir. Bu nedenle depreme dayanıklı yapı tasarımında deprem kaynak ve yapı özelliklerinin yanında yerel zemin koşullarının ve dinamik davranış özelliklerinin bilinmesi gerekmektedir. Zemin yapı ilişkisini inceleme...

This paper presents the non-uniform thermally induced strains and stresses that develop in the cross-sections of energy piles when subjected to operational energy demands. The thermal operation of energy piles depends on the thermal demands of the supported building. These thermal demands vary seasonally, daily and even hourly, which generates non-...

In this study, the authors investigated the feasibility of a ground-coupled system that utilizes heat energy harvested from the ground for deicing of bridge decks. Heat exchange is performed using circulation loops integrated into the deep foundations supporting the bridge or embedded within the approach embankment. The warm fluid extracted from th...

This paper presents the development of a 2D finite difference modelling approach and a 3D finite element numerical model for simulating vertical geothermal heat exchangers (GHEs), explaining the theory governing the thermal processes, element discretization and the selection of the appropriate boundary conditions. Both of these models provide fully...

Heat exchange capacity of an Energy Pile is a key parameter in the design of these elements as ground sourced heat exchangers. In most cases, field thermal conductivity tests are necessary to verify design assumptions similar to running a conventional pile load test to prove pile capacity. Current standards for measuring the heat exchange performan...

Highways are the most common and the most advanced means of transport compared to other transportation systems in Turkey. The embankment, subbase, base and pavement materials are provided from borrowed pits in traditional construction. During construction process; excavation, loading and transporta- tion costs of the material are the most important...

Low strain pile integrity testing which utilizes one dimensional wave propagation theory makes it possible to detect major discontinuities or defects (cavities, cracks, decrease and increase in cross-section) within a pile quickly and economically. In this study, pile integrity testing data of 187 piles in two close sites located in Buyukcekmece, I...

Bu araştırma, kazıkların imalat kalitesini belirleme yöntemlerini incelemekte ve uygulamadan iki örnek içermektedir. Araştırmanın birinci kısmında düşük deformasyonlu kazık süreklilik deneyi ile kazıklarda meydana gelen süreksizlikler ve imalat hataları ele alınmıştır. Burada bir arazideki 96 kazıkta uygulanan kazık süreklilik deneyi verileri değer...

Low strain pile integrity testing which utilizes one dimensional wave propagation theory makes it possible to detect major discontinuities or defects (cavities, cracks, decrease and increase in cross- section) within a pile quickly and economically. In this study, pile integrity testing data of 96 piles in a site located in Büyükçekmece are analyze...

Low strain pile integrity testing which utilizes one dimensional wave propagation theory makes it possible to detect major discontinuities or defects (cavities, cracks, decrease and increase in cross-section) within a pile quickly and economically. As the test data reflect the change in impedance, possible imped11ance diversity due to soil conditio...

Killi zeminlerin konsolidasyon davranışı ve gerilme geçmişinin belirlenmesi açısından, önkonsolidasyon basıncının saptanması önem taşımaktadır. Bilindiği gibi kohezyonlu zeminlerde önkonsolidasyon basıncından daha düşük veya daha yüksek değerlerde mukavemet ve sıkışma davranışları farklılık göstermektedir. Bu nedenle, önkonsolidasyon basıncının has...

This paper represents the results of various oedometer tests by using different size of samples to compare the pre-consolidation pressure. Pre-consolidation pressure is very important parameter that shows the stress history and the consolidation behavior of cohesive soils. In this research, five different types of high plasticity clay subgrades wer...

The pre-consolidation pressure is an important parameter for the stress history and the consolidation behavior of cohesive soils. This paper presents the evaluation of oedometer test results of several clay samples (CL and CH) in terms of the Unified Soil Classification System. Almost 30 soil samples were considerably selected, which had been taken...

The pre-consolidation pressure is a considerable parameter for the stress history of consolidation behavior of cohesive soils. This part of the main research embodies the results of various oedometer tests applied on several low plasticity clay samples according to the Unified Soil Classification System with a constant diameter size of 50mm. In ord...