Mehmet Baris Can Ulker

• PhD
• Visiting Professor at North Carolina State University

This study examines the prediction of the load-bearing capacity of closed and open-ended piles using machine learning (ML) methods. Full-scale load test results and CPT data are used to gather two comprehensive databases for such piles. ML models are developed employing input features associated with pile geometry and CPT resistances along with the...

Suction caissons are skirted foundations frequently used in offshore environments supporting various structures. Among those lie the offshore wind turbines (OWT), which are currently one of the most common renewable energy systems. In this paper we study the tensile capacity of caisson foundations of OWT in dense sands, where the generation of exce...

Doygun olmayan zemin davranışının başarılı bir şekilde tahmini, net gerilme ve matrik emmenin doygunluk derecesi ve boşluk oranı üzerindeki eşzamanlı etkisinin dikkate alınması gerektiğinden oldukça karmaşıktır. Hidromekanik davranışı yakalayabilmek için çok sayıda bünye modeli geliştirilmiş olmasına rağmen, bu modeller ya doygun olmayan zeminlerin...

In this study, a novel data-driven model is developed using boosting-type machine learning algorithms with the aim of predicting the ultimate load-bearing capacities of closed-ended piles. A comprehensive database is gathered using the full-scale load test data with four features. Special boosting type machine learning methods are trained and teste...

There are several constitutive models developed for understanding coupled hydromechanical behavior of three phase medium of unsaturated soils as well as models for explaining hydraulic hysteresis in water retention. However, very few attempts that merge the two aspects of behavior are available. This study develops a one-way coupled model for under...

Field pile load tests are fairly expensive experiments that can be applied to certain pile types required to be installed in full scale. Hence, it is neither practical nor efficient to perform a load test for every installed pile. While there exist many empirical relations for predicting pile capacities, such methods typically suffer from accuracy...

Factors affecting the cyclic response of seabed around offshore foundations are associated with soil structure, wave loading and drainage conditions. Constitutive theories proposed to account for these factors in the design of such soil-structure systems must be able to capture the essentials of seabed dynamics. In this paper, a combined theoretica...

Günümüze kadar pek çok çalışma kumların bünye davranışlarını modellemek üzere teoriler önermiş, klasik deneylerle bu teoriler belli ölçüde doğrulanmıştır. Kumların gözlenen tipik gerilme-şekil değiştirme davranışını yakalayabilen teoriler, sonrasında geliştirilen sayısal yazılımlara aktarılarak birçok geoteknik mühendisliği probleminin çözümünde ku...

The book has a total of 10 chapters divided into 3 main sections. The first section titled “Basic Mechanics” provides a review of the basics of continuum mechanics including states of stresses and strains as well as physical laws yielding the equations governing the static (or quasi-static) response of geotechnical engineering systems. In the secon...

In soil mechanics, it is of major interest to distinguish the soil behavior under cyclic or transient loads from that of monotonic ones. Here, it is necessary to provide modifications to general definitions of related constitutive models. Most cyclic plasticity models require accurate predictions of plastic irreversible strains computed through a f...

This paper proposes a semianalytical solution to the dynamic response of saturated-layered porous media under harmonic waves. The equations governing the dynamics of porous media are written in their fully dynamic form and possible simplifications are introduced based on the presence of inertial terms associated with both solid and fluid phases, ca...

In this paper, dynamic response of saturated-layered porous media under harmonic waves is evaluated through a semi-analytical solution. The coupled differential equations governing the dynamics of saturated or nearly saturated porous media such as soils containing all the inertial terms of solid and fluid phases are presented for a multi-layer syst...

Due to cyclic loading of water waves, the seabed soil may undergo a process called liquefaction where pore pressure counterbalances the effective stresses in the soil and disables the load bearing capacity leading to devastating consequences for coastal and offshore structures. This phenomenon has drawn much attention in the last four decades. Espe...

In this paper, the dynamic response of saturated and layered soils under harmonic waves is modeled using the finite element method. The numerical results are then verified by corresponding analytical solutions which are also developed by the author. The equations governing the dynamics of porous media are written in their fully dynamic form and pos...

A two-dimensional semi-analytical solution to the dynamic response of saturated porous media is presented considering a number of heterogeneous layers. The governing equations proposed by Biot are written in their fully dynamic form and possible simplifications of quasi-static and partially dynamic formulations developed in terms of the presence of...

In this study, solutions to the dynamic response of multi-layer soil under progressive waves are presented. Analytical solutions for a soil layer developed by the author are extended to multi-layers considering all the inertial terms. Problem is also solved with finite elements and numerical results are verified with the analytical counterparts. Dy...

In this paper, shear, effective stress and pore pressure distributions of two-layer porous soils subjected to harmonic waves are presented. The instability of the porous soil because of wave loading is investigated in terms of instantaneous liquefaction. The governing equations are written in their fully dynamic form, and possible simplifications a...

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In this paper, pore pressure distributions of two-layer porous soil under nonlinear harmonic waves are presented. The governing equations are written in their fully dynamic form and the possible simplifications are introduced. Finite element models are developed for each formulation and numerical results are verified with their corresponding analyt...

Instantaneous liquefaction of two-layer porous soil under nonlinear harmonic waves is presented. The governing equations are the poroelasticity equations accounting for the flow of pore water and the deformation of the soil skeleton yielding the coupled system. Possible simplifications to these equations are introduced in terms of including the ine...

In this study, standing wave-induced dynamic response and instability of seabed around a caisson breakwater are investigated. A seabed-rubble-caisson breakwater system is modeled using finite elements. The dynamic response of the porous seabed-rubble foundation is assumed to be governed by the Biot’s equations of coupled flow and deformation. Three...

The response of saturated porous medium is of significant interest in many fields ranging from geomechanics to biomechanics. Biot was the first to formulate the basic equations governing the process of coupled flow and deformation in porous media. Depending on the nature of loading vis-à-vis the characteristics of the media, different formulations...

In this study, a set of generalized analytical solutions are developed for the wave-induced response of a saturated porous seabed under plane strain condition. When considering the water waves originating in deep water and travelling towards the shore, their velocities, lengths and heights vary. Depending on the characteristics of the wave and the...

A finite element (FE) model is developed to study the breaking wave-induced dynamic response of the porous seabed and the rubble mound foundation under a composite caisson-type breakwater. The breaking wave impact pressure distributions on the front face of the breakwater are calculated using a recently proposed method. In this study the focus is o...

In this study, the problem of vehicular impact on a portable concrete barrier (PCB) is investigated. An available crash test is modeled and the impact response was simulated through a finite element (FE) model. On the basis of insight gained through this detailed FE analysis, a simpler rigid body model is then used to perform a comprehensive study...

Analytical solutions are developed for the response of saturated porous media under two-dimensional plane strain condition. Depending on the nature of loading vis-à-vis the characteristics of the media, different formulations (fully dynamic, partially dynamic, quasi-static) are possible. The solutions for these formulations are developed in terms o...

In this study the effect of cyclic loads on monotonic shear strength has been studied on torsional apparatus. Tests have been conducted on both reconstituted and undisturbed fine-grained hollow soil specimens. The plasticity index of soils is in the range from 2 to 33 for reconstituted specimens, prepared by dry pluviation, and from 5 to 13 for und...

In this study the effect of cyclic loads on monotonic shear strength has been studied on torsional, triaxial and simple shear apparatus. Tests have been conducted on undisturbed fine grained soil specimens. The plasticity index of soils is in the range from NP to 22 for undisturbed soil specimens. The existence of critical shear strain level, which...