Papers by Roumen A . Ivanov
Conference: VII International Scientific Conference „Machinery and Construction technologies in transport - 2024”, 09th -11th October, 2024, Sofia, 2024
Knowing the different geometry of the roadways and railways is of great importance for their desi... more Knowing the different geometry of the roadways and railways is of great importance for their design and reconstruction. Horizontal alignment, vertical alignment and cross-section are the three fundamental components of roadway and railway geometry. The geometry of the roadway can be of different types-horizontal and vertical curves. The horizontal alignment of the roads consists of straight lines, transition curves, circular arcs, etc. In practice, the geometry of roadways and railways is often a combination of different types of curves used in roundabouts and railway station tracks. Horizontal curves may be reverse, spiral, circular, compound, broken back, deviation, etc. Vertical curves are used to ensure a smooth transition between the tangents of the vertical alignment of roadways and railways. In transportation civil engineering a variety of curves are used. This research presents an approach to calculating the radius of a reverse curve. In the experiment described we show the difference between the officially used formulas and those proposed by the authors. The presented solution and example prove that it is necessary to improve the normative documents in the field of transportation infrastructure. The application of these formulas to an example shows that there is a difference between the two formulas applied for the calculation of the radius of the reverse curve.
Conference: Proceedings of the XI International Geomechanics Conference, 16 - 20 September 2024, Golden Sands Resort, Bulgaria, 2024
Monitoring and the analysis of the results from deformation surveys are important due to the risk... more Monitoring and the analysis of the results from deformation surveys are important due to the risk of landslides, structural movements, stability assessments of buildings, etc. The report reviews methods for finding stable points in geodetic networks. This research is concerned with the implementation in practice of the standards for deformation analysis and the number of reference points. The background for the analysis of the stability of points is presented together with the various criteria used in deformation analysis. The process for the detection of unstable reference points and the minimum number of reference points in deformation surveys are analyzed.
Only with geodetic and geotechnical methods we can interpret the mechanism, type, scope, duration... more Only with geodetic and geotechnical methods we can interpret the mechanism, type, scope, duration, dynamics and other characteristics of deformation processes of terrains around roads and railways. Geodetic and geotechnical monitoring is a system for monitoring, analyzing and controlling the steady state of the Earth's crust, terrains, buildings, and facilities. The monitoring shall be carried out before construction, during the construction period, and during the operation period, when there is a danger to the safety of the facility and buildings. The measurement accuracy depends on the minimum deformations to be recorded, the expected size, the speed of movement, etc. The appropriate measurement method is based on the accuracy with which the corresponding displacement of the observation point is determined. The chosen method is used without changes from the beginning to the end of defining the deformations, and the accuracy of the measurements in the individual epochs must be the same. The deformation survey of landslides and terrains with geodetic methods is of particular importance because it allows the identification of the minimum displacements that are critical to safety. Then according to those characteristics the appropriate methods-building a retaining wall, gabions, ground and cable anchors, covering the slope with steel mesh, etc., should be suggested by geotechnical engineers as geotechnical natural hazards protection systems and methods against the destructive natural process. Sometimes the geotechnical protection systems are not enough and it is necessary to build false tunnels. Different types of constructions for protection from natural hazards are discussed here. The article summarizes natural hazards, geodetic and geotechnical monitoring techniques and protection (prevention) systems.
Conference: VI International Scientific Conference „Machinery and Construction Technologies in Transport – 2022”, 05th-07th October 2022, Academic Journal “Mechanics, Transport, Communications”, vol.20, issue 3/3, 2022
In transportation civil engineering a variety of transition curves are used-cubic parabola, cloth... more In transportation civil engineering a variety of transition curves are used-cubic parabola, clothoid, Bloss, sinusoidal curve, etc. Knowing different geometry of the roadways and railways is from great importance for their design and reconstruction. When reconstructing roadways and railways it is necessary to carry out measurements to determine the length of straight sections and the radius of curves, etc. The results obtained from measurements can be filtered with digital filters and interpolated using splines. This work presents full classification of existing road and railway geometry.
The report reviews different methods for building underground gas storages, their role for ensuri... more The report reviews different methods for building underground gas storages, their role for ensuring seasonal unevenness in consumption and advantages over other methods for gas storage. Case study shows that several countries in Southеast Europe have big possibilities for becoming gas distribution centers. Mentioned new underground gas storages will increases the geopolitical role in the energy sector of Southеast Europe. Geodetic survey methods are the most commonly used instrumental methods for monitoring the natural hazard. Only with geodetic and geotechnical methods we can interpret the mechanism, type, scope, duration, dynamics and other characteristics of deformation processes of terrains.
Reports on Geodesy and Geoinformatics 5(60), 2001
Contributions to Geophysics and Geodesy Vol. 36/4, 2006
The systemic and technological aspects in derivation of the national/regional integrated geodetic... more The systemic and technological aspects in derivation of the national/regional integrated geodetic system are set out. Here, instead of consistency of three independently derived reference systems, the procedures are suggested which integrate networks, technologies, data and models connecting elements from different reference systems. The proposed procedures should be applied to the following areas 1) the design of layers of the complex basic geodetic network, 2) the measurement technologies in building of network, 3) the consistency of datums, 4) the modelling of inhomogeneous data, 5) the comparison and concordance of results, obtained by different methods. In order to analyse these procedures a term "integrating process" is introduced. The different elements, stages and varieties of these processes are set out. Two technological schemes for determination of the consistent parameters of geodetic system by means of integrating processes are proposed. The procedures for derivation of an integrated system with corresponding to it geocentric 4D integrating geodetic datum are outlined. It is suggested the materialization of the system to be realized by integral basic geodetic network. The network's structure and the possibilities of integrating technologies for determination of quasigeoidal deviation parameters are discussed. The integrating model for adjustment of 1D heterogeneous (leveling and GPS) height data with evaluation of the basic quasigeoid and the national/regional vertical datum is proposed.
Bulgarian Geophysical Journal, V. 28, 1-4, 2002
The dynamic interactive network design for derivation of an optimal observational scheme of a new... more The dynamic interactive network design for derivation of an optimal observational scheme of a new Gravity Basic Network for Bulgaria is proposed. This design has been obtained by a special case of sequential optimization. As a result a homogeneous network with minimal variances of the gravity values is suggested. The absolute gravity stations are included in the modeling by the establishment of national Gravity Datum and scale. The optimizing procedure is applied to the existing Bulgarian gravity network.
Conference: International Symposium on “Modern Technologies, Education and Professional practice in the globalizing world”, 6-7 November 2003, Bulgaria, 2003
This paper reviews different possibilities for combination of GPS and classical measurements. A m... more This paper reviews different possibilities for combination of GPS and classical measurements. A model based on transformation of GPS and terrestrial data measurements in Local System has been presented.
Conference Proceedings of the Second International Conference, European Polytechnical University, 2012
This report investigates how GPS receiver react to harmonic emissions from low-power transmitter.... more This report investigates how GPS receiver react to harmonic emissions from low-power transmitter. There is made experiment of the influence of sinusoidal electromagnetic radiation, on functionality of civil GPS receivers with C/A code. There are represented the main methods for increasing the reliability of the GNSS navigation.
Books by Roumen A . Ivanov
Monograph, Publisher: HST "T. Kableshkov", Sofia, ISBN: 978-954-12-0272-2, 2020
This monograph defines the place, role, and importance of engineering surveying in the field of d... more This monograph defines the place, role, and importance of engineering surveying in the field of deformation monitoring, deformation surveys, and geotechnical monitoring. Тhe monograph represents the author’s experience in this field-the presentation of deformation ellipsoid in a topocentric (local level) coordinate system for deformation analysis, strain analysis, common processing of GPS and terrestrial measurements, determining the tilting of buildings and facilities, and preliminary and optimal design of deformation monitoring schemes.
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Papers by Roumen A . Ivanov
Books by Roumen A . Ivanov