Papers by Michael Doubrovsky
Vìsnik Odesʹkogo nacìonalʹnogo morsʹkogo unìversitetu, Mar 24, 2024
One of the ways to reduce piling expenses is decreasing volume of piling works. It can be provide... more One of the ways to reduce piling expenses is decreasing volume of piling works. It can be provided by shortening either the piles length or the number of pipes. These results may be achieved if each shortcut pile is improved and bears the same loading as a pile of normal length or if each pile of normal length is improved and bears larger axial force in comparison with its initially designed capacity. Presented study clarified possibilities to regulate the pipe pile's bearing capacity using an internal rigid diaphragm (closure) placed inside the pile's shaft. It increases the bearing capacity of the tubular pile due to additional soil reaction under the closure. Pressing the pipe pile's model into sand box was assumed as the most gentle and precise method to study considered driving process. Besides results of such approach may be good adapted to predict pipe behavior in case of Press-in method of the pile installation. Some conclusions were made clarifying the diaphragm's positive contribution to pile bearing capacity, the effect of the closure's location along the pipe shaft, and the influence of the diaphragm's design (flat, conical, and cylindrical closures). Numerical analysis of the gained experimental data gave the possibility to apply approximating functions with good correlation indexes.
Advances in Science, Technology & Innovation/Advances in science, technology & innovation, 2024
Journal of shipping and ocean engineering, Jun 27, 2023
Journal of shipping and ocean engineering, Jun 28, 2015
Some new innovative constructions and piling technologies for improvement of offshore and port be... more Some new innovative constructions and piling technologies for improvement of offshore and port berthing structures are worked out and discussed. The aims of innovations are to decrease required power of construction (in particular, piling) equipment and, correspondingly, to improve environmental situation at the construction site. Another achieved goal is providing long tubular piles installation in hard soils conditions without application of very heavy and powerful driving machines. Worked out solutions are based on two approaches. One of them provides separate loading of driving force on pile's shaft and pile's tip concentrating the whole driving force on one of the mentioned parts of the pile. Another approach is focused on prevention of soil plug formation inside of the tubular pile tip facilitating the pile installation process. Also improved anchorage system for sheet piling seafront walls is presented and discussed. All considered innovations are patented and can be used in wide range of marine, offshore, coastal and harbor structures.
Journal of shipping and ocean engineering, Mar 28, 2019
In order to provide short construction period and to avoid bulky technologies in maritime conditi... more In order to provide short construction period and to avoid bulky technologies in maritime conditions some rational structures and installation methods are worked out. These methods may be applied for erection of temporary (seasonable) near-shore constructions; they are comparatively cheap and do not involve heavy construction equipment and mechanisms.
Journal of shipping and ocean engineering, Aug 28, 2017
Some new approaches to designing and calculation of maritime structures made of sheet piling with... more Some new approaches to designing and calculation of maritime structures made of sheet piling with staggered toe are considered and discussed. Obtained results allow determination of piles spacing efficiency in staggered embedment wall. The specificity of interaction of piles in "comb" with the soil foundation regarding transition from continuous to "comb" wall is investigated. Practical application is illustrated by example of calculation.
Japanese Geotechnical Society Special Publication, 2016
The Continuous Flight Auger (CFA) technology has evolved especially in recent decades. Using of C... more The Continuous Flight Auger (CFA) technology has evolved especially in recent decades. Using of CFA technology has expanded all over the world. The article deals with geotechnical design of pile foundations, especially by static load tests and by calculation using numerical models. Results of static load tests which were performed in and in Slovakia are analysed and compared with numerical modelling. The technology of CFA has been used due to the advantages of this technology in comparison with driven and bored piles in local geotechnical conditions. Plaxis 2011 was used for CFA piles analyses by FEM. Advanced constitutive hardening soil model was used for soil layers. Comparison of load-settlement curves, ratio of pile base and pile shaft resistance and distribution of unit shaft friction are presented in the paper. The best geoengineering solution in this case is the use of new pile technology CFA (continuous flight auger), FDP (full displacement piles), DDS (drilling displacement system), that lead to increased bearing capacity.
Proceedings of the Second International Conference on Press-in Engineering 2021, Kochi, Japan, 2021
The paper discusses an interaction model that allows to take into account kinematics factors of t... more The paper discusses an interaction model that allows to take into account kinematics factors of the considered system and to use it when designing and calculating variable values of main system parameters, corresponding to its current deformed and stressed states. Main result of the model development and its applied aspects are presented. In particular, possibility and efficiency of consideration not only horizontal components of displacement but also rotations are invesigated.
Quay, jetty, coast protection and offshore structures for use in variety soil conditions are prod... more Quay, jetty, coast protection and offshore structures for use in variety soil conditions are produced. All elaborations are applied in designs and some of them are realised in construction. Several new gravity masonry wall designs are suggested. They resulted even settlement of the structure under the external load and fast erection procedure. Some new designs based on perfection of sheet-piling walls (with curvilinear semi-rings cross-section) and piled structures (piles of high bearing capacity, combined gravity-piled structures, etc.) are shown.
The paper describes the principles of technical policy concerned with the actual problems of the ... more The paper describes the principles of technical policy concerned with the actual problems of the technical operation of shallow water ports in modern conditions. Some new ideas to improve the design and construction process of ports hydrotechnical structures are presented. They are based on the principle of functional dividing of constructive elements of the structure and on the possibilities of a port achieving construction by its own forces. Development of some traditional port structures as well as some new constructions and technologies are proposed. New designs and "know-how" of gravity structures (massive retaining walls and their improvement), sheet piling walls and effective mixed type structures are considered. Some results of their application are investigated and an example of reconstruction of the shallow-water Ukrainian ports is given.
Development of Scientific Schools of Odessa National Maritime University, 2020
船舶与海洋工程 英文版, 2011
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IABSE Congress Report, 2000
Soils and Foundations, 2015
This paper considers the problem of the determination of the real parameters of the cross-section... more This paper considers the problem of the determination of the real parameters of the cross-sectional values of sheet piling walls made of U-profile piles (moment of inertia and section modulus) and their drivability with regard to interaction of piles through soil. Among the main factors which influence this are the soil friction in the interlocks and the transmission of longitudinal shear forces in the interlocks of the sheet piles. In the field, the soil-interlock interaction depends mainly on the installation method and the soil properties. The aim of this research was to study the dependencies between the applied forces and the friction in the interlocks by full-scale physical modeling during press-in by taking the pile-pile and interlock-soil interactions into account. The results of the on-site full-scale tests as well as the laboratory physical modeling of Uprofile piles in different soil conditions are presented in the paper. Using the data obtained, "force-displacements" diagrams were constructed to assess the influence of soil friction and resistance in the interlocks. The calculation model was improved based on the results to provide a more reliable numerical modeling and design of the "sheet pile-soil media" system. The physical modeling clearly shows the influence of soil behavior on the interlock between sheet piles, especially in the case of saturated sand.
Osnovaniâ i fundamenty, Dec 17, 2020
Lecture Notes in Civil Engineering, 2022
Increase of water depths, use of new huge vessels, essential loads and toughened operational requ... more Increase of water depths, use of new huge vessels, essential loads and toughened operational requirements stipulate rise in construction cost of coastal, port and marine structures. So, development of innovations for these structures at the stages of design, construction and operation is actual to decrease erecting cost, time of building and maintenance expenses. This book of two leading researchers in port, coastal and geotechnical engineering in Ukraine presents innovations and improvements both in theoretical and applied aspects of marine structures and related construction technologies. Proposed developments relate to all types of such structures: quay walls, piers, breakwaters, retaining walls, port and offshore berthing facilities, etc. Innovative solutions improve design approaches (both static and dynamics) for systems “structure-soil-water” as well as construction methods for their implementation. Practical aspects of their implementation are considered for conditions of di...
Bases and Foundations, 2020
Modern marine structures (berths, breakwaters, offshore platforms, etc.) often include steel tubu... more Modern marine structures (berths, breakwaters, offshore platforms, etc.) often include steel tubular piles of essential length (80-100 m and more) that should provide high bearing capacity in case of external axial loads application. Interaction between elements of the system “piled structure – soil media” is not yet studied sufficiently. It relates also to the bearing capacity of the long steel tubular piles of large diameter. One of the interesting peculiarities of long tubular piles’ behavior is the formation of soil plug at the piles’ tip. There are a lot of suggestion and methods aimed to increase piles bearing capacity under static pressing load. One of them relates to use of the additional structural element, i.e., the internal diaphragm welded to the internal surface of the pile’s shaft. Such approach has been applied in some practical cases of marine construction and demonstrated its effectiveness. At the moment there are no researches focused on study of the peculiarities ...
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Papers by Michael Doubrovsky