Sustainability and resilience in the rehabilitation of road infrastructures after an extreme event: an integrated approach

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2017, vol. 12, no. 3

The Baltic Journal of

Road and Bridge Engineering, 2017, vol. 12, no. 3

The Baltic Journal of Road and Bridge Engineering, 2017, vol. 12, no. 3

The papers published in The Baltic Journal of Road and Bridge Engineering are indexed/abstracted by:

• Science Citation Index Expanded (ISI Web of Science),

• INSPEC (Database of Institution of Engineering and Technology), • Current Abstracts, TOC Premier (EBSCO Publishing),

• TRIS (Transportation Research Information Services),

• VINITI (All-Russian Scientific and Technical Information Institute of Russian Academy of Sciences),

• SCOPUS (Elsevier Bibliographic Database), • ICONDA (The International Construction Database), • UlrichswebTM_, • IndexCopernicus. 9 7 7 1 8 2 2 4 2 7 0 0 9 ISSN 1822 - 427XISSN 1822-427X ISSN 1822-427X eISSN 1822-4288 ISSN 1822-427X eISSN 1822-4288 Contents

Juraj Chalmovský, Jan Štefaňák, Lumír Miča, Zdenek Kala, Šarūnas Skuodis, Arnoldas Norkus, Daiva Žilionienė

STATISTICAL-NUMERICAL ANALYSIS FOR PULLOUT TESTS OF GROUND ANCHORS 145

Marinella Giunta

SUSTAINABILITY AND RESILIENCE IN THE REHABILITATION OF ROAD INFRASTRUCTURES

AFTER AN EXTREME EVENT: AN INTEGRATED APPROACH 154

Rasa Ušpalytė-Vitkūnienė, Aliaksei Laureshyn

PERSPECTIVES FOR SURROGATE SAFETY STUDIES IN EAST-EUROPEAN COUNTRIES 161

Juri Ess, Dago Antov

ESTONIAN TRAFFIC BEHAVIOR MONITORING STUDIES 2001–2016: OVERVIEW AND RESULTS 167 Valentinas Šaulys, Oksana Survilė, Mindaugas Klimašauskas, Lina Bagdžiūnaitė-Litvinaitienė,

Andrius Litvinaitis, Rasa Stankevičienė, Aja Tumavičė

ASSESSING THE HYDRAULIC CONDUCTIVITY OF OPEN DRAINAGE FOR SURFACE

WATER IN ROAD SAFETY ZONES 174

Adam Zofka, Maciej Maliszewski, Ewa Zofka, Miglė Paliukaitė, Laura Žalimienė

GEOGRID REINFORCEMENT OF ASPHALT PAVEMENTS 181

Vytautas Dumbliauskas, Vytautas Grigonis, Jūratė Vitkienė

ESTIMATING THE EFFECTS OF PUBLIC TRANSPORT PRIORITY MEASURES

AT SIGNAL CONTROLLED INTERSECTIONS 187

Zhiyuan Xia, Aiqun Li, Jianhui Li, Maojun Duan

COMPARISON OF HYBRID METHODS WITH DIFFERENT META-MODEL USED

IN BRIDGE MODEL-UPDATING 193

Vaidas Ramūnas, Audrius Vaitkus, Alfredas Laurinavičius, Donatas Čygas, Aurimas Šiukščius

PREDICTION OF LIFESPAN OF RAILWAY BALLAST AGGREGATE ACCORDING

TO MECHANICAL PROPERTIES OF IT 203

ABSTRACTS IN LITHUANIAN I

ABSTRACTS IN LATVIAN II

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– road, railway and bridge research and design, – road construction materials and technologies, – railway construction materials and technologies, – bridge construction materials and technologies, – road, railway and bridge repair,

– road, railway and bridge maintenance, – road traffic safety,

– road and bridge information technologies, – environmental issues,

– road climatology, – low-volume roads,

– normative documentation,

– quality management and assurance, – road infrastructure and its assessment, – assets management,

– road and bridge construction financing, – specialist pre-service and in-service training;

besides, it publishes:

– advertising materials, – reviews and bibliography,

– reports abouit conferences and workshops.

THE JOURNAL IS DESIGNED FOR PUBLISHING PAPERS CONCERNING THE FOLLOWING AREAS OF RESEARCH:

The papers published in The Baltic Journal of Road and Bridge Engineering are indexed/abstracted by:

Science Citation Index Expanded

(ISI Web of Science) Thomson Scientific

INSPEC Database of Institution of Engineering and Technology Current Abstracts, TOC Premier EBSCO Publishing

TRIS Online Transportation Research Information Services (TRIS) Bibliographic Database

VINITI Database of All-Russian Scientific and Technical Information Institute of Russian Academy of Sciences

SCOPUS Elsevier Bibliographic Database

ICONDA The International Construction Database

UlrichswebTM _UlrichswebTM

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2017

12(3)

Editor-in-Chief Donatas ČYGAS

Vilnius Gediminas

Technical University Riga Technical University Tallinn University of Technology Baltic Road Association

Vilnius TECHNIKA 2017

ISSN 1822-427X eISSN 1822-4288

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THE BALTIC JOURNAL OF ROAD AND BRIDGE ENGINEERING http://www.bjrbe.vgtu.lt

2017, vol. 12, no. 3

International Research Journal of Vilnius Gediminas Technical University, Riga Technical University, Tallinn University of Technology,

Baltic Road Association

EDITORIAL CORRESPONDENCE including manuscripts for

submission should be addressed to Prof. Dr D. Čygas, Editor-in-Chief, Prof. Dr D. Žilionienė, Managing Editor

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All papers published in Journal “The Baltic Journal of Road and Bridge Engineering” are peer-reviewed by members of Editorial Board or by its appointed experts.

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15 September 2017. Printer’s sheets 10,25. Circulation 100copies Vilnius Gediminas Technical University Publishing House “Technika”, Saulėtekio al. 11, 10223 Vilnius, Lithuania, http://leidykla.vgtu.lt

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Editor-in-Chief

Prof. Dr Donatas ČYGAS Vilnius Gediminas Technical University,

Saulėtekio al. 11, 10223 Vilnius, Lithuania (Civil Engineering, 02T)

EDITORIAL BOARD

INTERNATIONAL EDITORIAL BOARD

Prof. Dr Hojjat ADELI,

Ohio State University, 470 Hitchcock Hall, 2070 Neil Avenue, Columbus, OH 43210, USA (Civil Engineering, 02T)

Prof. Dr Dago ANTOV,

Tallinn University of Technology, Ehitajate tee 5, 19086 Tallinn, Estonia (Geography, 06P) Dr Halil CEYLAN,

Center for Transportation Research and Education (CTRE), 482B Town Engineering Bldg.,

Iowa State University, Ames, IA 50011-3232, USA (Civil Engineering, 02T)

Prof. Dr Gianluca DELL’ACQUA,

Federico II University of Napoli, Via Claudio 21, I-80125 Napoli, Italy (Civil Engineering, 02T) Dr Mindaugas DIMAITIS,

PE “Road and Transport Research Institute”, I. Kanto g. 23, P.O. Box 2082, 44009 Kaunas, Lithuania (Transport Engineering, 03T) Dr Arvydas DOMATAS,

JSC “Kelprojekas”, I. Kanto g. 25,

44296 Kaunas, Lithuania (Informatics Engineering, 07T) Prof. Dr Alfredo Garcia GARCIA,

Polytechnic University of Valencia, Camino de Vera, s/n; 46071 Valencia, Spain (Transport Engineering, 03T) Dr Viktors HARITONOVS,

Riga Technical University, Azenes str. 20, 1048 Riga, Latvia (Civil Engineering, 02T)

Dr Inge HOFF,

Research Institute “SINTEF”, Hogskoleringen 7, 7465 Trondheim, Norway (Civil Engineering, 02T) Prof. Dr Siim IDNURM,

Tallinn University of Technology, Ehitajate tee 5, 19086 Tallinn, Estonia (Civil Engineering, 02T) Dr Vilma JASIŪNIENĖ,

Vilnius Gediminas Technical University, Saulėtekio al. 11, 10223 Vilnius, Lithuania (Civil Engineering, 02T) Prof. Dr Habil Gintaris KAKLAUSKAS,

Vilnius Gediminas Technical University, Saulėtekio al. 11, 10223 Vilnius, Lithuania (Civil Engineering, 02T) Prof. Dr Lev KHAZANOVICH,

University of Pittsburg, 3700 O’Hara str., 703 Benedum Hall Pittsburg, PA, USA (Civil Engineering, 02T)

Prof. Dr Habil Ivan LEONOVICH,

Byelorussian State Technical University, Pr. Niezavisimosti 65, 220027 Minsk, Byelorussia (Civil Engineering, 02T)

Assoc. Prof. Dr Dainius MIŠKINIS,

LRA under the Ministry of Transport and Communications of the Republic of Lithuania, J. Basanavičiaus g. 36/2, 03109 Vilnius, Lithuania (Transport Engineering, 03T)

Prof. Dr Juris R. NAUDŽUNS,

Riga Technical University, Azenes str. 20, 1048 Riga, Latvia (Transport Engineering, 03T) Dr Algis PAKALNIS,

PE “Road and Transport Research Institute”, I. Kanto g. 23, P.O. Box 2082, 44009 Kaunas, Lithuania (Transport Engineering, 03T)

Managing Editor

Prof. Dr Daiva ŽILIONIENĖ Vilnius Gediminas Technical University,

Saulėtekio al. 11, 10223 Vilnius, Lithuania (Civil Engineering, 02T) Assoc. Prof. Dr Ainars PAEGLITIS

Riga Technical University, Azenes str. 20, 1048 Riga, Latvia

(Civil Engineering, 02T)

Prof. Dr Andrus AAVIK Tallinn University of Technology, Ehitajate tee 5, 19086 Tallinn, Estonia

(Civil Engineering, 02T) Prof. Dr Alfredas LAURINAVIČIUS

Vilnius Gediminas Technical University, Saulėtekio al. 11, 10223 Vilnius, Lithuania

(Civil Engineering, 02T)

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Assoc. Prof. Dr Filippo Giammaria PRATICÒ, University Mediterranea of Reggio Calabria, Via Graziella-Feo di Vito, 89100 Reggio Calabria, Italy (Civil Engineering, 02T)

Assoc. Prof. Dr Virgaudas PUODŽIUKAS, Vilnius Gediminas Technical University, Saulėtekio al. 11, 10223 Vilnius, Lithuania (Civil Engineering, 02T)

Prof. Dr Habil Piotr RADZISZEWSKI, Warsaw University of Technology, al. Armii Ludowej 16, office 544, 00-637 Warsaw, Poland (Civil Engineering, 02T)

Prof. Dr Habil Valentin SILJANOV, Moscow State Technical University, Leningradskij av. 64, 125319 Moscow, Russia (Transport Engineering, 03T) Prof. Dr Habil Henrikas SIVILEVIČIUS,

Vilnius Gediminas Technical University, Saulėtekio al. 11, 10223 Vilnius, Lithuania (Civil Engineering, 02T) Assoc. Prof. Dr Juris SMIRNOVS,

Riga Technical University, Azenes str. 20, 1048 Riga, Latvia (Civil Engineering, 02T)

Prof. Dr Habil Dariusz SYBILSKI, Road and Bridge Research Institute, Jagiellonska str. 80, Warszawa, Poland (Civil Engineering, 02T)

Prof. Dr Audrius VAITKUS,

Vilnius Gediminas Technical University, Saulėtekio al. 11, 10223 Vilnius, Lithuania (Civil Engineering, 02T)

Prof. Dr Andras VARHELYI,

Lund University, P.O. Box 118, 22100 Lund, Sweden (Civil Engineering, 02T)

Assoc. Prof. Dr Janis VARNA,

Riga Technical University, Azenes str. 20, 1048 Riga, Latvia (Transport Engineering, 03T) Assoc. Prof. Dr Atis ZARINŠ,

Riga Technical University, Kaļķu str. 1, 1658 Riga, Latvia (Civil Engineering, 02T) Prof. Dr Habil Edmundas K. ZAVADSKAS, Vilnius Gediminas Technical University, Saulėtekio al. 11, 10223 Vilnius, Lithuania (Civil Engineering, 02T)

Prof. Dr Habil Adam ZOFKA,

Road and Bridge Research Institute, Instytutowa str. 1, Warszawa, Poland (Civil Engineering, 02T)

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doi:10.3846/bjrbe.2017.18 THE BALTIC JOURNAL OF ROAD AND BRIDGE ENGINEERING

ISSN 1822-427X / eISSN 1822-4288 2017 Volume 12(3): 154–160

1. Introduction

Construction, operation, and rehabilitation of road infra-structures result in significant environmental impacts. Air pollution, energy consumption, noise, land occupancy, ex-ploitation of natural resources, accidents are noteworthy impacts to take into account. On the other hand, during the service life, the capability of a road to withstand to a singular perturbation is a fundamental property to guar-antee the assigned functionality. In road construction and rehabilitation both the concepts of sustainability and resil-ience are becoming more and more relevant.

The sustainability in design and management is cur-rently dominating the research and the practical interests in the different topics of the road engineering. The concept of sustainability rose to prominence in the late 1980s and became a central issue in world politics. Brundtland et al. (1987) in the report Our Common Future defines for the first time the model of sustainable development, as “the development that meets the needs of the present without compromising the ability of future generations to meet their own needs”. Sustainability is a model characterized

by a holistic view and brings together three dimensions: ecology, economy, and society (Bocchini et al. 2013).

Another important concept, connected to the occur-rence of extreme events during the life cycle of an infra-structure, is the resilience. In general, the resilience is a mea-sure of the ability of a system to withstand an extraordinary event and to recover efficiently and rapidly the damage in-duced by such event. In the case of road infrastructures, the resilience refers to the ability to deliver a certain service level even after the occurrence of an extreme event and to recover their proper functionality as fast as possible.

Usually, the two concepts that account for two desired qualities of the infrastructures, are applied following sepa-rate approaches, few attempts to combine the two concepts can be found in the literature (Bocchini et al. 2013, Zinke

et al. 2012). However, an in deep analysis of the

sustain-ability and resilience demonstrates a significant number of similar characteristics. In fact, both concepts address a holistic view and deal with the assessment of an infrastruc-ture system, by using economic and social categories as a base for measurement. Further, the instruments and the

SUSTAINABILITY AND RESILIENCE IN THE REHABILITATION

OF ROAD INFRASTRUCTURES AFTER AN EXTREME EVENT:

AN INTEGRATED APPROACH

Marinella Giunta

Dept of Civil, Energy, Environmental and Material Engineering, Mediterranea University of Reggio Calabria, 89100 Reggio Calabria, Italy

E-mail: [email protected]

Abstract. For road infrastructures, the concepts of sustainability and resilience are becoming more and more relevant.

The sustainability is closely linked with the concept of development that meets the needs of the present without com-promising the ability of future generations to meet their own needs. The resilience is usually connected with the occur-rence of extreme events or unusual disturbances (earthquake, landslide, floods) during the life cycle of infrastructures and refers to their ability of recover the previous functionality. Usually, the two concepts that account for two desired qualities of the infrastructures are applied following separate approaches. Better choices in road design, maintenance and rehabilitation should lead to an improvement of both qualities. On the other hand, an in deep analysis of the sus-tainability and resilience demonstrates a significant number of similar characteristics. In the light of the above premises, in the present paper, the suitability of an integrated approach in the choice of the rehabilitation alternatives after an ex-treme event is evaluated. A method to assess the sustainability, based on life cycle costs, and to estimate the resilience is setup. It resulted that an integrated perspective can be pursued and both resilience and sustainability allow addressing an appropriate amount of technical, economic and environmental/social issues and can lead to identifying the most ef-ficient solution of rehabilitation.

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The Baltic Journal of Road and Bridge Engineering, 2017, 12(3): 154–160 155

calculation methods applied for the evaluation are simi-lar: Life Cycle Assessment (LCA), Life Cycle Cost Analy-sis (LCCA), Multi-Criteria AnalyAnaly-sis (MCA) can efficiently address both the concepts. Finally, both concepts have as-sumed in the recent years a great importance in research and practice. Better choices in road design, maintenance and rehabilitation should lead to an improvement of either these qualities.

In the light of the above premises, in the present pa-per, the suitability of an integrated approach in the choice of the rehabilitation alternatives after an extreme event is evaluated. A method to assess the sustainability, based on the assessment of life cycle costs, and to estimate the resil-ience is also proposed.

2. Sustainability: concept and approach

The sustainability is associated to the definition provided by the World Commission on Environment and Develop-ment, 1987: “... development that meets the needs of the present without compromising the ability of future gen-erations to meet their own needs ...”. However, there is no mathematical theory embodying these concepts, although one would be immensely valuable in humanity’s efforts to manage the environment. The idea of sustainability applies to integrated systems comprising humans and the rest of nature (Cabezas et al. 2005).

The idea of sustainability for the road should be ad-dressed not just in the design of infrastructures, but also in the rehabilitation, reuse or optimisation of existing in-frastructures. This way to operate complies with the prin-ciples of urban sustainability and global sustainable devel-opment.

Trustworthy design and management need to balance social, economic and environmental issues. Obviously, the sustainable infrastructures should lead to improving so-cio-economics.

The three dimensions or pillars, internationally ac-cepted as a well-established framework for the conceptual model of sustainability, are: economic, ecological, and social (Otto 2007). Economic viability concept relates to the public finance and is based on the financial and economic assess-ment of investassess-ments. Environassess-mental sustainability builds on the externalities framework. Social sustainability draws from public policy framework where service delivery, gov-ernance, and social equity are critical (Reddy et al. 2014).

Achieving sustainability on these three dimensions is a challenge.

Often in current practice, the economic decisions far outweigh environmental and social decisions in the con-struction industry where the choices are usually made to maximize both short and long-term profits. In the light of this evidence, the successful implementation of sustain-ability is highly dependent on the sustain-ability and facility to measure and estimate environmental, societal and long-term economic variables, and convert them into benefits and costs (Chong et al. 2007). Even if most practitioners are persuaded of the importance of the sustainability, the

deficiency of convincing data and calculations methods hamper its application during the decision-making stage. On the other side, it is also difficult to convince investors that increasing initial expenditure could benefit them in the long run.

In this context, LCA and LCCA are effective tools to assess the sustainability of road construction and rehabili-tation. In the following, a brief description of these tools is provided.

According to Set (1993) LCA allows:

1. to evaluate the environmental burdens associated with a product, process, or activity by identifying and qu-antifying energy and materials used and wastes released to the environment;

2. to assess the impact of energy and materials used and releases to the environment;

3. to identify and evaluate opportunities to affect en-vironmental improvements. The assessment includes the entire life cycle of the product, process or activity, encom-passing, extracting and processing raw materials; manu-facturing, transportation, and distribution; use, re-use, maintenance; recycling, and final disposal.

Typical life cycle assessment parameters include: − Material Usage, the amount of material used

ex-pressed in its mass and volume;

− Embodied Energy the amount of energy required for extraction, processing, manufacturing, trans-portation, and assembly of building materials; − CO₂ Emissions, the emission of carbon dioxide, that

contributes to global warming;

− Air Pollution, sulphur dioxide, nitrous oxides, methane, particulate and volatile organic com-pounds;

− Solid Waste Generation, the solid waste generated during manufacturing and construction;

− Water Pollution, the quantity of water use associ-ated with a material process, including the effluent deposited into water bodies;

− Environmental Costs, externalities connected with construction.

Life Cycle Costing (LCC) is one of the best tools available to assess the benefit and cost of the infrastructure construction. It involves financial forecasts of infrastruc-ture performance based on construction, operation and maintenance/renewal costs. This technique relies on the time value of money and expresses the infrastructure life cycle cost as a net present value. In other words, the total cost of construction, operating and maintaining the infra-structure is expressed as a single sum of money needed today to cover these costs over the study period selected for the life cycle costing exercise. Monetized externalities can be factored into this type of assessment to express the performance of the infrastructures in currency (Praticò, Giunta 2016a; Praticò, Giunta 2016b).

The main drawbacks of LCA, LCCA methods are the time and costs needed for the execution of a rigorous

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156 M. Giunta. Sustainability and Resilience in the Rehabilitation of Road...

assessment. In some cases, data referred to the parameters listed above are missing or incomplete. There are also dif-ficulties in the representation of environmental impacts among alternatives. For this last aspect, the use of Eco pro-file (Fig.1) can simplify the interpretation of life cycle as-sessments. However, there may be problems in achieving consensus on thresholds of sustainability. To construct an Eco profile, it should address the following aspects: select life cycle parameters, perform analyses to obtain impacts and then convert units of impact measurements (kg to

tonnes) to fit within the scale of Eco profile. The number of parameters selected determines the number of sides of the polygon (Peuportier 2001).

3. Resilience concept and measures

The concept of resilience accounts for eleven aspects: 1. four main properties (Robustness, Redundancy,

Re-sourcefulness and Rapidity);

2. four main dimensions (Technical, Organizational,

Social and Economic);

3. three main results (More Reliability, Lower

Socio-Economics Consequences, Fast Recovery) (Bocchini et al. 2014; Bruneau et al. 2003) (Fig.1).

As for the main properties:

− Robustness accounts for the reduced probability of degradation or loss of function in the event of dis-turbance or extreme event;

− Redundancy refers to the duplication of critical components or functions of a system with the aim of increasing reliability;

− Resourcefulness is the capacity to identify problems, establish priorities, and apply material (i.e. mon-etary, physical, technological, and informational) and human resources in the process of recovery to meet established priorities and achieve goals; − Rapidity is the capacity to meet priorities and

achieve goals promptly to contain losses, recover functionality and avoid future disruption.

Figure 3 graphically illustrates the properties of the resilience (Zhang, Wang 2016), and highlights the mutual interdependence, i.e. Rapidity in recovery the functionali-ty depends on Resourcefulness and Redundancy.

Regarding the dimensions of resilience:

− Technical dimension includes all the aspects related to the construction and other technological aspects and refers to the ability of the physical system to guarantee acceptable/desired level of performance post critical event;

− Organizational dimension considers the capacity of the organization that manages the infrastructure to make decisions and take actions useful to achieve greater Robustness, Redundancy, Resourcefulness, and Rapidity;

− Social dimension involves the impact on commu-nity and the mitigation measures;

− Economic dimension refers to the direct and indi-rect costs deriving from the reduction of the func-tionality and the rehabilitation.

Outcomes of resilience are:

− More Reliability: lower probability for the infra-structure to reach limit states;

− Fast recovery, namely the rapidity with which the functionality is re-established during a disaster; this is a paramount characteristic of resilient systems; − Low Socio-Economic Consequences, this outcome is

guarantee by both probabilities of low service level reduction and fast recovery.

Fig. 1. Example of Eco profile to represent Environmental

Impacts of Buildings (Peuportier 2001)

Fig. 2. Aspects of resilience (Bruneau et al. 2003)

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It should be noted that any resilience-based analysis and decision require a quantitative measure of the system performance (Zhang, Wang 2016). The performance of a transportation network can be measured by different me-trics, e.g. flow capacity (Nagurney, Qiang 2007), connectiv-ity (Chen et al. 2002; Clark, Watling 2005), and travel time (Asakura, Kashiwadani 1995; Chen et al. 2007). However, these metrics are mainly used to measure network perfor-mance under normal service conditions and are inadequate in reflecting the network susceptibility to disruptive, low-probability high-consequence natural and human-made hazards or its resilience (earthquakes, floods, terrorist at-tacks). More recently, other metrics have been proposed to measure the capability of the network after a disaster:

− used post-disaster connectivity and traversal cost among multiple origin-destination pairs in a net-work (Peeta et al. 2010);

− coverage and transport accessibility (Chang, No-jima 2001);

− pathway redundancy among all origin-destination pairs (Ip, Wang 2011).

4. Objective of the work

In the light of the above considerations, the aim of the pre-sent paper is the proposal of an integrated sustainability-resilience based approach in the assessment of different rehabilitation alternatives after an extreme event. The inte-grated perspective embodying both resilience and sustain-ability allows addressing an appropriate amount of tech-nical, economic and environmental/social issues and can lead to identifying the most efficient solution of rehabilita-tion. To this purpose a method to evaluate the sustainabil-ity, based on life cycle costs, and to estimate the resilience from the monetary standpoint is setup.

5. Integrated approach

The integrated approach sustainability − resilience in the rehabilitation of an infrastructure after an extreme event here proposed allows identifying which alternative, result-ing in the lowest total cost and high performance to per-turbation in post-event life, is the most suitable solution for the rehabilitation.

The approach is articulated in three main steps: − Step 1: Identification of the rehabilitation

alterna-tives;

− Step 2: Estimate of life cycle cost of each alternative; − Step 3: Estimate of the resilience, in monetary

terms, of a given infrastructure for each rehabilita-tion alternative.

Regarding the Step 1, for the identification of the re-habilitation alternatives, it is important to consider techni-cal, economical and time issues. As for the technical pro-blems, it is important to take into account the following aspects, if inherent to the solution of rehabilitation:

− horizontal/vertical alignment;

− type of embankment (materials, geometry); − type of tunnel;

− type of bridges (steel beams, cement precast beams, span);

− type of pavement, safety barriers, signs and other tools for safety.

The identification of the alternatives to putting in comparison should also consider the costs of construction and the time required to restore the functionality of the infrastructure (Praticò et al. 2011; 2013). Based on the pre-liminary consideration of these elements some solutions can be considered inappropriate as alternatives and thus excluded in the successive analyses.

In Step 2, for each alternative, an estimate of the su-stainability can be performed based on methods such as LCA and LCCA. In the proposed approach the LCCA is considered and applied. Life Cycle Cost Analysis is an en-gineering economic analysis tool that allows quantifying all the costs associated with a given option of the project (new project or rehabilitation project). Life Cycle Cost Analysis considers agency expenditures, for construction, operation, maintenance, disposal and user costs (delays produced by work zones, vehicle expenses) throughout the life of an alternative. A comprehensive LCCA analysis should also consider the environmental costs, for exam-ple regarding CO₂ emissions, energy consumption, Global Warming Potential.

By reviewing and estimating all costs during the life span, LCCA allows to determine and demonstrate the eco-nomic merits of design alternatives analytically and con-sequently helps transportation agencies to identify the most sustainable solution (Giunta 2016; Giunta, Praticò 2017; Praticò, Giunta 2016a; 2016b).

Regarding the evaluation of the resilience for the given rehabilitation alternative, Step 3, it is important to consider:

1. the need to monetize this property, for an easy con-sideration in the decision-making processes; 2. the consideration of the main events that can

cre-ate a perturbation and affect the functionality of the infrastructures;

3. the probability of occurrence of these events. Each infrastructure, based on its proper features (a type of alignment, type of embankment, type of bridge, type of tunnel), in the case of extreme events, be-haves differently regarding the loss of functional-ity and consequently regarding time and cost to re-store the previous level of functionality.

The cost to restore the functionality, namely the cost of reconstruction of the road infrastructures or its parts after an extreme event, and the time needed for recon-struction, which greatly affects the costs supported by the users, can be efficiently used to evaluate the resilience in monetary terms. It should be noted that the cost to re-store mainly considers inside two of the main properties of the resilience, Robustness and Redundancy, (the higher

Robustness and Redundancy, the higher the reconstruction

cost), while time to restore considers the Resourcefulness and the Rapidity.

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The rebuilding after an extreme event also produc-es environmental impacts that should be monetised for a comprehensive cost evaluation. These costs are different and additional costs concerning the ones related to the service life of the infrastructure in normal conditions.

Figure 4 shows a diagram of the proposed integrated approach. The model to estimate the costs for sustainabil-ity and resilience is explained in the following.

Based on the LCCA approach, the cost of the sus-tainability, C_sus, of a given rehabilitation alternative can be evaluated as:

sus ag us env

C =C +C +C , (1) where C_ag – the cost of the agency for construction, op-eration, maintenance, and disposal, C_us – refers to the ex-penditure of the user for delays produced by maintenance activities and C_env – the cost of environmental burdens due to the construction and maintenance activities.

These costs are related to different periods of the life of an infrastructure; therefore, to various alternatives at a given period, it is necessary to discount them. To this aim, the present value (PV) of the cost can be adopted. Present Value is calculated as follow:

1 1 n j j i PV C r +   = _ _ +   , (2)

where PV_j is the Present Value of the jth_{cost (C}

j), i is the

inflation rate, r is the interest rate, and n is the nth_{year of}

the service life.

Based on this assumption, the total present value (TPV) of sustainability is:

sus ag us env

TPV =PV +PV +PV . (3)

The total present value can be evaluated during the service life of an infrastructure. Life Cycle Cost Analysis enables to assess the trends of TPV during the time.

On the contrary, the evaluation of the resilience should emphasize the impact of the infrastructure dama-ge, failure, and recovery when subject to hazards charac-terised by a low probability of occurrence and potentially high consequences. In this sense, it is possible to associate to each considered alternative the cost of the total recove-ry of functionality in case of a later undesired event. The expenditure for recovering the functionality is disconti-nuous during the service life because it is related to the occurrence of an extreme event. A probability of occur-rence characterises each event. Consequently, the impact of an extreme event regarding the expenditure to recover the functionality of an infrastructure or its part should be evaluated as follow:

,

res i res i

i

C =

∑

PC , (4)

where P_i is the probability of occurrence of the event i; and

C_rec,i is the cost for the recovery of the functionality after the event i.

The cost for the recovery of the functionality encom-passed the three classes of cost considered for the sustaina-bility and namely, the agency cost for reconstruction of the infrastructure, the user cost, and the environmental cost.

, , , ,

res i rec i us i env i

C =C +C +C , (5)

where C_rec,i is the cost of reconstruction after the event ith_, C_us,i is the cost supported by the users for the loss of func-tionality and C_env,i is the environmental cost associated with the reconstruction. It should be noted that:

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− the cost of reconstruction depends on the level of resistance that it would achieve in the rehabilitated infrastructure (the higher the resistance, Robustness, and Redundancy, the higher the reconstruction cost); − the user costs are related to the delays for slow-downs or journey of alternative routes, and it should be addressed at the scale of the transporta-tion network. According to Bocchini et al. (2013), they can be evaluated as follow:

(

, ,

)

us car time car oper car truck

C =_N C +C +N

(

Ctime truck, +Coper truck,

)

_T trec delay, (6)

where N_car and N_truck refer to the daily number of cars and tracks affected by the limitation of traffic, C_time,car and C_time,truck, are respectively the time cost for cars and trucks; C_oper,car and C_oper,truck − operation costs per hour for cars and trucks; T_recis the time in days needed for the reconstruction and the recovery of functionality; t_delaysis the delay in hours supported by the users.

The activities connected to the rehabilitation of the infrastructures (material productions, transportation, and landfill) also produce environmental impacts that can be quantified for example regarding CO₂ emissions (Giunta 2016; Giunta, Praticò 2017; Praticò, Giunta 2016a; 2016b).

env kj kj

k j

C =

∑∑

Q UP , (7)

where Q_kj − the quantity of the jth_{impact due to the k}th

process and UP_kj − the unit cost of the impact.

The choice of the best solution of rehabilitation can be pursued based on the sum of the costs of sustainability (Equa-tion 3) and resilience (Equa(Equa-tion 4) using the monetiza(Equa-tion of the two most important aspects about each alternative.

, ,

k sus k res k

TC =TPV +C _{, (8)}

where TC_k − the total cost related to the kth_alternative

while TPV_sus,k and C_res,k are respectively the discounted costs related to the sustainability and the cost of resilience. The lower total cost could bring to identify the best rehabilitation strategy. Following the proposed approach, the most important aspects associated with sustainability and resilience assessment are considered at the same time and in the process of mutual interaction.

6. Conclusions

1. Resilience and sustainability are two qualities of the in-frastructure that should be pursued at the same time when decisions are made regarding the design, maintenance, and management of infrastructure systems even if in some case the pursuit of resilience can conflict with the pursuit of sustainability.

2. The consideration of these two qualities can help in the identification of the best strategy of the rehabilitation of an infrastructure or its part also after an extreme event. Nowadays natural disasters (earthquakes, landslides, floods) are getting more frequent importance, and thus the resilience assessment of the infrastructures and the selec-tion of the most effective recovery strategies is essential.

3. The main challenge in the evaluation of sustainabil-ity and resilience of a transport infrastructure is the quan-titative measure of these qualities.

4. In this paper, an integrated approach is proposed and a method to estimate in monetary terms the sustain-ability and the resilience of a given rehabilitation alterna-tive after an extreme event is set-up.

5. For the estimation of sustainability the Life Cycle Cost Analysis has been efficiently applied.

6. For the resilience, an accurate estimate of the costs of reconstruction, depending on the level of resilience that it would like achieved, of the user costs, due to the loss of functionality of the infrastructures, and of the environ-mental costs, related to the reconstruction activities, help to evaluate a given alternative from this standpoint.

7. The approach proposed seems useful to address a complete evaluation of different design/rehabilitation alter-natives. Practical applications of the approach are ongoing.

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THE BALTIC JOURNAL OF ROAD AND BRIDGE ENGINEERING

ISSN 1822-427X / eISSN 1822-4288 2017 Volume 12(3): I a–I c

ABSTRACTS IN LITHUALIAN

Juraj Chalmovský, Jan Štefaňák, Lumír Miča, Zdenek Kala, Šarūnas Skuodis, Arnoldas Norkus, Daiva Žilionienė. 2017. Grunto inkarų priėmimo bandymų statistinė ir skaitinė analizė, The Baltic Journal of Road and Bridge Engineering 12(3): 145–153.

Santrauka. Šiame straipsnyje pateiktas Mioceno amžiaus molio statistinių ir skaitinių metodų taikymas jėgos

ir poslinkių kreivių bei raunamų inkarų laikomajai galiai nustatyti. Pasinaudojus raunamų grunto inkarų bandymų duomenimis (jėgos ir poslinkių kreivėmis bei naudotų rovimo jėgų sklaida), atlikta regresinė analizė. Užtikrinant regresinės analizės tikslumą, atliekant statistinius skaičiavimus taikytas tiesinis regresijos modelis kartu su svertiniu mažiausiųjų kvadratų metodu ir patikimomis standartinių paklaidų metodikomis. Pagal tiesinės regresijos priklau-somybes nustatyta mažiausia inkaro viršaus apskaičiuojamų poslinkių patikimumo riba, kuri vėliau naudojama skai-tiniame modelyje. Sukurtasis baigtinių elementų modelis leidžia prognozuoti grunto inkarų, įrengtų smulkių dalelių gruntuose, elgseną. Šis modelis pagrįstas Moro Kulonu dėsniu, kuris įvertina inkaro, įrengto didelio slėgio srautine injekcija, skersmenį ir radialinius įtempius.

Reikšminiai žodžiai: baigtinių elementų metodas (BEM), grunto inkaro poslinkis, didelio slėgio injekcija,

skaitinė analizė, statistinė analizė.

Marinella Giunta. 2017. Tvarumas ir atsparumas atstatant kelio infrastruktūros objektus, įvykus ekstremaliam įvykiui, The Baltic Journal of Road and Bridge Engineering 12(3): 154–160.

Santrauka. Kalbant apie kelių infrastruktūros objektus, tvarumo ir atsparumo sąvokos tampa vis aktualesnės.

Tvarumas yra glaudžiai susijęs su plėtra, atitinkančia dabartinius poreikius ir neatimančia galimybės iš būsimųjų kartų tenkinti savuosius poreikius. Paprastai atsparumas susijęs su ekstremaliais įvykiais ar neįprastais reiškiniais (žemės drebėjimas, žemės nuošliaužos, potvyniai) naudojant infrastruktūros objektus ir su jų geba atkurti buvusį funkcionalumą. Dažniausiai abi sąvokos, nurodančios dvi infrastruktūros objektui reikalingas savybes, varto-jamos skirtingame kontekste. Geresni kelio projekto, priežiūros ir atstatymo sprendimai turėtų skatinti abiejų savybių pagerėjimą. Kita vertus, nuodugni tvarumo ir atsparumo analizė rodo daugybę panašių charakteristikų. Šiame straipsnyje įvertintas kompleksinis kelio infrastruktūros objektų atnaujinimo sprendinių pasirinkimo me-todas, įvykus ekstremaliam įvykiui. Sukurtas metodas leidžia pagal naudojimo laiko sąnaudas įvertinti tvarumą ir nustatyti atsparumą. Rezultatai parodė, kad naujasis kompleksinis metodas gali būti taikomas tvarumui ir atsparu-mui nustatyti, leidžia spręsti tam tikrus techninius, ekonominius, aplinkosaugos ir socialinius klausimus, surasti patį efektyviausią atstatymo sprendimą.

Reikšminiai žodžiai: ekstremalusis įvykis, naudojimo laiko sąnaudų analizė, atstatymas, atsparumas, kelias,

tvarumas.

Rasa Ušpalytė-Vitkūnienė, Aliaksei Laureshyn. 2017. Surogatinių eismo saugos studijų perspektyvos rytų europos šalyse, The Baltic Journal of Road and Bridge Engineering 12(3): 161–166.

Santrauka. Rytų Europos šalių kelių eismo saugos plėtra, kiek vėluodama, iš esmės remiasi Vakarų šalių

ten-dencijomis. Eismo įvykių mažėja, tačiau pažeidžiamų eismo dalyvių infrastruktūros plėtra yra mažiau įspūdinga, palyginti su kitomis kelių eismo dalyvių kategorijomis. Tradicinė kelių eismo saugumo analizė, pagrįsta nelaimingų atsitikimų istorija, turi daugybę apribojimų, susijusių su avarijų nepakankamumu, mažų ir atsitiktinių nelaimingų avarijų skaičiumi atskirose vietose ir trūkstamą išsamią informaciją, kuri fiksuojama policijos ar ligoninėse. Suro-gatiniai eismo saugos metodai grindžiami galimų eismo įvykių stebėjimu (o ne jau įvykusiomis eismo nelaimėmis), kurie vis dar stipriai susiję su eismo sauga. Tokie metodai dažnai yra veiksmingesni saugai vertinti. Straipsnyje apžvelgiama dabartinė eismo saugos analizės surogatinių metodų būklė, problemos ir galimybės, susijusios su šiuolaikinėmis miesto eismo sąlygomis, naujos efektyvesnio duomenų rinkimo technologijos. Metodas pateikiamas

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212 I b

Rytų Europos šalių kontekste siekiant sužinoti, kaip jis gali prisidėti prie tebesitęsiančio kelių eismo saugumo darbo ir geriau suprasti nelaimingų atsitikimų rizikos veiksnius, reikalingus veiksmingoms eismo infrastruktūros saugumo priemonėms kurti.

Reikšminiai žodžiai: Rytų Europos šalys, eismo sauga, surogatinės eismo saugumo priemonės, eismo įvykiai,

vaizdo analizė.

Juri Ess, Dago Antov. 2017. 2001–2016 m. eismo dalyvių elgesio tyrimas Estijoje: apžvalga ir rezultatai, The Baltic Journal of Road and Bridge Engineering 12(3): 167–173.

Santrauka. Gerai žinoma, kad vienas svarbiausių eismo saugą lemiančių veiksnių yra žmogus. Atkūrus Estijos

nepriklausomybę 1991 metais, eismo saugos situacija šalyje labai pagerėjo. Viena to priežasčių – pasikeitęs eismo dalyvių elgesys. Be to, kiekvienais metais buvo atliekami tyrimai, nustatomi tam tikri rodikliai, susiję su tuo, kaip ei-smo dalyviai laikosi kelių eiei-smo taisyklių. Tyrimų metu nustatytos ilgalaikės tam tikrų rodiklių, tokių kaip šviesoforo signalų nurodymų laikymasis, saugos diržų naudojimas, pėsčiųjų praleidimas nereguliuojamose pėsčiųjų perėjose, tendencijos. Šiame straipsnyje aprašytas eismo dalyvių elgesio tyrimas Estijoje, pateikta tyrimo rezultatų analizė ir aptartos aktualios problemos, sprendžiant eismo dalyvių elgesio klausimus. Tyrimo rezultatai parodė, kad visi eismo dalyvių elgesio aspektai turėjo teigiamų tendencijų, tačiau šios tendencijos buvo skirtingos. Kai kurie rodikliai, tokie kaip saugos diržų naudojimas, pasikeitė dramatiškai, tačiau kiti, tokie kaip šviesoforo signalų reikalavimų laikymasis, pasikeitė nedaug. Viena aktualiausių eismo dalyvių elgesio problemų – nenoras praleisti pėsčiuosius nereguliuoja-mose pėsčiųjų perėjose. Tai viena iš aktualiausių problemų, kuri turi būti sprendžiama Estijos eismo saugos strategijos kontekste.

Reikšminiai žodžiai: eismo įpročiai, eismo dalyvių elgesys, eismo dalyvių elgesio tyrimas, Estija, eismo saugos

rodikliai, eismo sauga, transporto eismo tyrimas.

Valentinas Šaulys, Oksana Survilė, Mindaugas Klimašauskas, Lina Bagdžiūnaitė-Litvinaitienė, Andrius Litvinaitis, Rasa Stankevičienė, Aja Tumavičė. 2017. Paviršinio vandens nuleidimo iš kelio juostos efektyvumo vertinimas, The Baltic Journal of Road and Bridge Engineering 12(3): 174–180.

Santrauka. Paviršinio vandens nuleidimo nuo drenuotų plotų tyrimai tapo aktualūs didėjant drenažo sistemų

plotams. Didelė dalis paviršinio vandens nuleistuvų yra įrengta šalikelės grioviuose ar šalikelės reljefo pažemėjimuose, kur kaupiasi atitekėjęs paviršinis vanduo. Kelių tiesimo ar rekonstrukcijos praktika Lietuvoje rodo, kad kiekviena nau-ja kelio atkarpos trasa dažniausiai kerta drenuotą plotą ir perskirsto ploto nuotėkio charakteristikas. Kiekviena kelio sankasa, kertanti paviršinio vandens vandentaką, yra lokali užtvanka paviršiniam nuotėkiui. Šalikelėje susikaupusį paviršinį vandenį reikia nuleisti, kad jis nepakenktų kelio konstrukcijoms ir nebūtų užliejami drenuoti pakelės plotai. Straipsnyje aptarta F-5 ar PN-42 konstrukcijos nuleistuvų vandens įtekėjimo angų būklė. 2017 m. tyrimų rezultatai rodo, kad tik 15,3 % nuleistuvų vandens įtekėjimo angos buvo visiškai švarios, o 45,2 % nuleistuvų rasta su visiškai užneštomis vandens įtekėjimo angomis, kitų 39,5 % nuleistuvų vandens įtekėjimo angos buvo pusiau užneštos. Aki-vaizdi nuleistuvų vandens įtekėjimo angų užnešimo gruntu ir užaugimo augalų šaknimis didėjimo ir ryški nuleistuvų su švariomis vandens įtekėjimo angomis mažėjimo tendencija. Rasta 22,6 % paviršinių vandens nuleistuvų, kurie yra pažeisti ūkininkų žemės dirbimo technikos.

Reikšminiai žodžiai: drenažas, nuleistuvas – vandens nuleidžiamoji drena, kelio juostos, paviršinis vanduo. Adam Zofka, Maciej Maliszewski, Ewa Zofka, Miglė Paliukaitė, Laura Žalimienė. 2017. Asfalto dangų stiprinimas geotekstilės tinklu, The Baltic Journal of Road and Bridge Engineering 12(3): 181–186.

Santrauka. Geotekstilinės medžiagos, panaudotos asfalto sluoksniuose, atitolina arba sustabdo atsikartojančių

plyšių susidarymą. Šio tyrimo rezultatai padės pratęsti dangos naudojimo laiką ir patobulinti sąnaudų ir naudos analizę. Daugelio nuo aštuntojo dešimtmečio atliekamų tyrimų rezultatai parodė asfalto dangų stiprinimo geotekstilės tinklu veiksmingumą, tačiau geotekstilės tinklai nėra plačiai naudojami kelių tiesimo praktikoje. To priežastimi gali būti didesnės pradinės sąnaudos, menkas supratimas apie jų veikimo mechanizmą gretimuose asfalto sluoksniu-ose ir standartinių projektavimo procedūrų trūkumas. Šiame straipsnyje aprašytas naujas tyrimas, siekiant nustatyti geotekstilės tinklo poveikį asfalto mišinių bandinių stiprinimui. Atlikti dviejų tipų laboratoriniai tyrimai, t. y. monoto-ninis (stiprumo ir trūkimo) bandymas ir ciklinis (nuovargio ir modulio) bandymas. Rezultatai parodė, kad bandinių stiprinimas geotekstilės tinklu yra labai efektyvus, nes tai patvirtina trūkimo energijos rezultatai ir galutiniai įlinkiai nuovargio bandymo metu. Straipsnyje pateiktas pavyzdys susiejant dangos įlinkius ir leidžiamąją ašinę apkrovą (taip pat žinomą kaip atsparumą nuovargiui) ir atskleidžiant praktinę stiprinimo geotekstilės tinklu reikšmę. Atlikta analizė parodė, kad, panaudojus geotekstilės tinklą, dangos įlinkių sumažėjo, o tai leidžia gerokai padidinti dangos atsparumą nuovargiui. Pabaigoje pateiktos rekomendacijos tolimesniems tyrimams stiprinimo geotekstilės tinklu srityje.

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The Baltic Journal of Road and Bridge Engineering, 2017, 12(3) 213I c

Vytautas Dumbliauskas, Vytautas Grigonis, Jūratė Vitkienė. 2017. Viešojo transporto prioritetą užtikrinančių priemonių veiksmingumo vertinimas šviesoforais reguliuojamose sankryžose, The Baltic Journal of Road and Bridge Engineering 12(3): 187–192.

Santrauka. Daugelyje Lietuvos miestų siekiama užtikrinti viešojo transporto prioritetą plėtojant viešojo

trans-porto juostas. Reguliavimo šviesoforais strategijos, kurios suteikia prioritetą viešajam transportui sankryžose, yra mažiau analizuojamos ir beveik netaikomos Lietuvoje. Šiame straipsnyje nagrinėjamos reguliavimo šviesoforais strate-gijos izoliuotose sankryžose ir strategijų įtaka viešojo transporto bei visų kitų transporto priemonių laiko sąnaudoms. Atliekant analizę buvo naudota gerai žinoma PTV VISSIM transporto srautų modeliavimo aplinka ir VisVAP grafinio programavimo aplinka. Ją naudojant sukurtos ir apibrėžtos viešojo transporto prioritetą užtikrinančios priemonės šviesoforu reguliuojamose sankryžose. Modeliavimo rezultatai rodo, kad viešojo transporto prioritetą užtikrinančios priemonės sumažina viešojo transporto laiko sąnaudas šviesoforais reguliuojamose sankryžose iki 60 % ir nesukelia didelių gaiščių visoms kitoms transporto priemonėms.

Reikšminiai žodžiai: viešojo transporto prioritetas, PTV VISSIM, VisVAP, reguliavimo šviesoforais strategijos. Zhiyuan Xia, Aiqun Li, Jianhui Li, Maojun Duan. 2017. Hibridinių metodų palyginimas su skirtingais

metamodeliais, atnaujinant tilto modelį, The Baltic Journal of Road and Bridge Engineering 12(3): 193–202.

Santrauka. Norint pagreitinti modelio atnaujinimo procesą ir patobulinti baigtinių elementų modelį, pasiūlyti

du hibridiniai (mišrūs) modelio atnaujinimo metodai integruojant Gauso mutacijos dalelių spiečiaus optimizavi-mo metodą, lotyniškojo hiperkubo atrankos metodą ir atitinkamai krigingo bei grįžtaoptimizavi-mojo ryšio neuroninio tinklo metamodelius. Taikant hibridinius metodus ir modeliuojant realaus padidinto pločio kabamojo tilto atnaujinimo procesą (nes tai buvo būtina remiantis vibracinio bandymo rezultatais), palyginti du pasiūlyti metodai. Rezultatai parodė, kad dažnio skirtumai tarp bandymo ir atnaujinto modelio rezultatų buvo nedideli, lyginant su bandymo ir pradinio modelio rezultatais atnaujinus modelį abiem metodais, nes visos reikšmės buvo žemesnės nei 6 %, kurios pradžioje būna 25–40 %. Be to, modelio kokybės užtikrinimo kriterijai šiek tiek padidėjo, o tai rodo, kad buvo gautos priimtinesnės modos formos, nes visi modelio kokybės užtikrinimo kriterijai buvo mažesni nei 0,86. Bendri tyrimo rezultatai parodė, kad, taikant abu metodus, galima gauti tinkamesnį ir veiksmingesnį baigtinių elementų modelį, neprarandant tikslumo. Tačiau abiejų hibridinių metodų palyginimas parodė, kad vienas jų su grįžtamojo ryšio neu-roniniu tinklu yra geresnis nei tas, kuriame naudojamas krigingo modelis, nes pirmojo metodo dažnio skirtumai dažniausiai yra žemesni nei 5 %, o antrojo – ne. Be to, pirmasis metodas yra efektyvesnis, nes jo konvergavimo greitis yra didesnis nei antrojo. Taigi hibridinis metodas, taikant Gauso mutacijos dalelių spiečiaus optimizavimo metodą ir grįžtamojo ryšio neuroninio tinklo metamodelį, yra tinkamesnis stambiam inžinerinio objekto modeliui atnaujinti.

Reikšminiai žodžiai: grįžtamojo ryšio neuroninis tinklas, Gauso mutacija, krigingo modelis, lotyniškojo

hi-perkubo atranka, modelio atnaujinimas, dalelių spiečiaus optimizavimas, kabamasis tiltas.

Vaidas Ramūnas, Audrius Vaitkus, Alfredas Laurinavičius, Donatas Čygas, Aurimas Šiukščius. 2017. Balasto ilgalaikiškumo prognozavimas pagal jo mechanines savybes, The Baltic Journal of Road and Bridge Engineering 12(3): 203–209.

Santrauka. Ilgalaikiškumas – pagrindinis balasto užpildo parinkimo ir geležinkelio kelio priežiūros planavimo

kriterijus, todėl svarbu nustatyti ryšį tarp dalelių atsparumo apkrovoms parametrų ir balasto užpildo darbo kon-strukcijoje ilgalaikiškumo. Balasto užpildo dalelių kokybės vertinimas, esant dinaminėms ir statinėms apkrovoms, parodo medžiagos patvarumą ir kietumą, o jie identifikuojami Los Andželo ir Devalio vertėmis. Kanados Ramiojo vandenyno pakrantės geležinkelių sudarytas modelis buvo pritaikytas galimoms suminėms kelio konstrukcijos ap-krovoms tonomis prognozuoti. Buvo atlikti bandymai su dolomito ir granito skirtingos granuliometrinės sudėties balasto užpildais. Nustatytas galimas bruto tonažas (apkrovos išreikštos milijonais bruto tonų) geležinkelio kelio naudojimo laikotarpiui, esant skirtingos rūšies užpildams. Tyrimo rezultatas – sudaryta geležinkelio kelio balasto klasifikacijos sistema ir nustatytos balasto medžiagos Los Andželo ir Devalio vertės reikalaujamam ilgalaikiškumui užtikrinti.

Reikšminiai žodžiai: balastas, ilgalaikiškumas, Los Andželo rodiklis, medžiagos parinkimas, mechaninės

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THE BALTIC JOURNAL OF ROAD AND BRIDGE ENGINEERING

ISSN 1822-427X / eISSN 1822-4288 2017 Volume 12(3): II a–II c

ABSTRACTS IN LATVIAN

Juraj Chalmovský, Jan Štefaňák, Lumír Miča, Zdenek Kala, Šarūnas Skuodis, Arnoldas Norkus, Daiva Žilionienė. 2017. Grunts enkuru izraušanas testa statistiski – skaitliskā analīze, The Baltic Journal of Road and Bridge Engineering 12(3): 145–153.

Kopsavilkums. Rakstā atainots statistisko un skaitlisko metožu lietojums spēka – pārvietojuma līknes un

izraušanas pretestības noteikšanai Miocēna mālā iestrādātiem iepriekšsaspriegtiem grunts enkuriem. Pieņemšanas procesa gaitā iegūtie grunts enkurus raksturojošie dati apstrādāti ar regresijas analīzi, iegūta pārbaudīto enkuru spēka – pārvietojuma līkne, kas atbilst pārbaudēs lietotajām slodzēm. Lai sasniegtu minēto mērķi, par ticamu statis-tisko metodi izvēlēts lineārās regresijas modelis, kas balstīts uz mazāko kvadrātu un stabilu standartkļūdu metodēm. Atklāto lineārās regresijas sakarību lietoja par kontroles zemāko robežu enkura galvu pārvietojumiem, kuri, savukārt, bija aprēķināti ar skaitlisko modeli. Ar nolūku prognozēt smalkgraudainās gruntīs iestrādātu enkuru darbību, tika izstrādāts galīgo elementu modelis. Izstrādātais skaitliskais modelis, kas izmanto Mohr-Coulomb stiprības kritēriju, novērtē augstspiediena iestrādes gaitā papildus veidojošos radiālos spriegumus un fiksētā diametra palielināšānos.

Atslēgvārdi: Galīgo element metode (GEM), grunts enkuru pārvietojums, augstspiediena iestrāde, skaitliskā

analīze, statistiskā analīze.

Marinella Giunta. 2017. Autoceļa infrastruktūras ilgtspējības un izturības rehabilitācija pēc ekstrēma notikuma: integrāla metode, The Baltic Journal of Road and Bridge Engineering 12(3): 154–160.

Kopsavilkums. Ilgtspējības un izturības koncepcijas autoceļa infrastruktūrai kļūst aizvien nozīmīgākas.

Ilgtspējība ir cieši saistīta ar attīstības koncepciju, kas atbilst šodienas vajadzībām un bez kompromisiem attiecībā uz iespēju nākošajām paaudzēm īstenot savas vajadzības. Izturība parasti ir saistīta ar infrastruktūras spēju sava darbmūža gaitā pēc ekstremāliem notikumiem (zemstrīces, nogruvumi, plūdi) saglabāt savu iepriekšējo funkcionalitāti. Parasti abas šīs koncepcijas, kas raksturo vēlamo infrastruktūras kvalitāti, apraksta ar atšķirīgām metodēm. Labākajiem autoceļa projektēšanas, uzturēšanas un atjaunošanas risinājumiem jānoved pie abu kvalitāšu uzlabošanās. No otras puses padziļināta ilgtspējības un izturības analīze demonstrē būtisku vienādu raksturlielumu skaitu. Dotajā rakstā, ņemot vērā augstāk minētos apsvērumus, novērtēta integrālas metodes piemērotība rehabilitācijas alternatīvu izvēlē pēc ekstremāla notikuma. Balstoties uz darbmūža izmaksām, izstrādāta metode, kas novērtē ilgtspējību un izturību. Tā norāda, ka perspektīvā integrālā pieeja, kas izskata ilgtspējības un izturības kritērijus, ļauj izskatīt atbilstošu tehni-sko, ekonomisko un ekonomisko/sociālo jautājumu skaitu, lai izvēlētos visefektīvāko rehabilitācijas risinājumu.

Atslēgvārdi: ekstrēms notikums, darbmūža izmaksu analīze, rehabilitācija, izturība, autoceļš, ilgtspējība. Rasa Ušpalytė-Vitkūnienė, Aliaksei Laureshyn. 2017. Aizvietojošo satiksmes drošības pētījumu perspektīvas austrumeiropas valstīs, The Baltic Journal of Road and Bridge Engineering 12(3): 161–166.

Kopsavilkums. Satiksmes drošības attīstība Austrumeiropas valstīs seko vispārējām attīstības tendencēm

rietumvalstīs, lai arī ar kavēšanos laikā. Bojā gājušo skaits samazinās, lai gan mazaizsargātajiem satiksmes dalībniekiem paredzētie uzlabojumi ir mazāk iespaidīgi salīdzinot ar citām satiksmes dalībnieku grupām. Tradicionālajai sa-tiksmes drošības analīzei, kas balstās uz ceļu sasa-tiksmes negadījumu vēstures izpēti, ir daudz ierobežojumu, kas saistīti ar nepilnīgu informāciju par negadījumu skaitu, mazu un izkliedētu negadījumu skaitu atsevišķās vietās, kā arī detaļu trūkumu policijas un slimnīcu atskaitēs. Aizvietojošās satiksmes drošības analīzes metodes balstās uz dažādu situāciju novērošanu, kas nav ceļu satiksmes negadījumi, bet tomēr tās raksturo satiksmes drošību. Drošības novērtēšanai šādas metodes bieži vien ir efektīvākas (un pro- aktīvākas). Rakstā aplūkots aizvietojošo satiksmes drošības analīzes metožu eksistējošais statuss, izaicinājumi un iespējas, kas saistītas ar modernajiem apdzīvoto vietu satiksmes apstākļiem un jaunajām tehnoloģijām, kas ļauj efektīvāk vākt datus. Metode ir izmantota

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Austrumei-The Baltic Journal of Road and Bridge Engineering, 2017, 12(3) 215II b ropas valstu kontekstā ar nolūku izvērtēt tās nozīmi satiksmes drošības uzlabošanas darbā un labākai ceļu satiksmes negadījumu cēloņu noskaidrošanai, lai varētu izstrādāt rezultatīvus pretpasākumus.

Atslēgvārdi: Austrumeiropas valstis, autoceļu drošība, aizvietojošās satiksmes drošības analīzes metodes,

satiks-mes konflikti, video analīze.

Juri Ess, Dago Antov. 2017. Igaunijas satiksmes dalībnieku uzvedības monitorings 2001–2016: pārskats un rezultāti, The Baltic Journal of Road and Bridge Engineering 12(3): 167–173

Kopsavilkums. Ļoti labi zināms, ka viens no satiksmes drošību visvairāk ietekmējošajiem faktoriem ir cilvēka

faktors. Salīdzinot ar 1991 gadu, kad Igaunija atguva neatkarību, tā ir dramatiski uzlabojusi ceļu satiksmes drošību. Viens no iemesliem, kas ļāvis sasniegt šo uzlabojumu ir satiksmes dalībnieku uzvedības izmaiņas. Iespējams, ka vienlaicīgi ir bijuši ikgadējie pētījumi, kuros mērīti atsevišķi indikatori, kas raksturo Ceļu satiksmes noteikumu prasību ievērošanu. Rezultātā ir iespējams noskaidrot ilglaicīgas attīstības tendences par tādiem indikatoriem kā satiksmes signālu ievērošana, drošības siksnu lietošana, gājēju prasību ievērošana neregulētos ceļu mezglos utt. Dotā raksta mērķis ir aprakstīt Igaunijas satiksmes dalībnieku uzvedību, analizējot rezultātus un definējot aktuālās problēmas, kurām nepieciešami risinājumi. Pētījuma gaitā noskaidrots, ka visi uzvedības aspekti ir uzlabojušies, bet to attīstības tendences ir atšķirīgas. Atsevišķi indikatori, piemēram, drošības jostu lietošana ir dramatiski mainījušies, kamēr citi, kā piemēram, satiksmes signālu ievērošana uzrādījuši tikai viduvējas izmaiņas. Noskaidrots, ka galvenā satiksmes dalībnieku uzvedības problēma ir ceļa nedošana gājējiem neregulējamās gājēju pārejās. Tas ir viens no jautājumiem, kas jārisina Igaunijas satiksmes drošības stratēģisko mērķu sasniegšanas kontekstā.

Atslēgvārdi: satiksmes dalībnieku uzvedība, satiksmes dalībnieku uzvedības monitorings, Igaunija, satiksmes

drošības indikatori, satiksmes drošība, satiksmes izpēte.

Valentinas Šaulys, Oksana Survilė, Mindaugas Klimašauskas, Lina Bagdžiūnaitė-Litvinaitienė, Andrius Litvinaitis, Rasa Stankevičienė, Aja Tumavičė. 2017. Vaļējo drenāžas sistēmu caurlaides spējas novērtējums autoceļu drošības zonās, The Baltic Journal of Road and Bridge Engineering 12(3): 174–180.

Kopsavilkums. Palielinoties ūdensnovades sistēmu skaitam, pētījumu nozīmīgums par virszemes ūdens

novadīšanu no nosusināmām teritorijām ir strauji palielinājies. Daudz virszemes ūdens savācējgūliju ir izvietots sa-tiksmes drošības zonu grāvjos vai pazeminājumos, kur akumulējas tekošais virszemes ūdens. Lietuvas ceļu būvniecības un pārbūves prakse rāda, ka katrs jauns ceļa posms bieži vien šķērso meliorētu teritoriju un izmaina šī sektora ūdens noteces raksturlielumus. Ikviena ceļa zemes klātne, kas šķērso virszemes ūdens plūsmu ir lokāls dambis. Ūdens, kas akumulējas ceļa drošības zonās ir jānovada, lai izvairītos no ceļa konstrukciju bojājumiem un plūdiem meliorētās ceļam piegulošajās teritorijās. Rakstā apskatīta tādu hidrotehnisko pasākumu kā virszemes ūdens gūliju efektivitāte ierakumos un izcelta hidrulisko aprēķinu specifika gadījumā, ja visu Inlet–Water Drainage Line drenāžas sistēmu izvērtē integrāli. Rakstā arī sniegta a Inlet–Water Drainage Line drenāžas sistēmas hidraulisko aprēķinu metodika. Rakstā sniegti rezultāti par gūliju F – 5 un PN – 42 stāvokli. 2017.gadā veikto pētījumu rezultāti rāda, ka tikai 15.3% gūliju bij a pilnīgi tīras, 45.2% bija pilnībā piesārņotas un 39.5% bija daļēji piesārņotas. Līdz ar to skaidri iezīmējas pieaugoša gūliju piesārņošanas tendence ar grunti un zāļaugu saknēm un tīru gūliju samazināšanās tendence. 22.6% gūliju bija bojātas ar lauksaimniecībā izmantojamo augsnes apstrādes tehniku.

Atslēgvārdi: drenāža, Inlet–Water Drainage Line, ceļa drošības zonas, virszemes ūdens.

Adam Zofka, Maciej Maliszewski, Ewa Zofka, Miglė Paliukaitė, Laura Žalimienė. 2017. Asfalta segu ģeorežģu stiegrojums, The Baltic Journal of Road and Bridge Engineering 12(3): 181–186.

Kopsavilkums. Ģeorežģus izmanto asfalta segās lai aizkavētu vai novērstu caurejošu plaisu veidošanos. Tie būtiski

palielina segas kalpošanas laiku un uzlabo ieguvumu/izmaksu analīzi. Kopš 1970 gadiem daudzi pētījumi demonstrējuši ģeorežģu izmantošanas priekšrocības asfalta segās, bet šīs zināšanas nav guvušas plašu lietojumu aktuālajā būvniecības praksē. Potenciālie šīs situācijas iemesli ir augstākas izmaksas, padziļinātu zināšanu trūkums par darbības mehānismu starp blakus esošajiem asfalta slāņiem un kopēju projektēšanas standartu trūkums. Dotajā rakstā atainots pētījums, kurā izanalizēta ģeorežģa ietekme uz asfalta maisījumu paraugiem. Tika veikti divu tipu laboratorijas eksperimenti, proti, monotoniskie (stiprība un sabrukums) un cikliskie (nogurums un modulis). Rezultāti parādīja, ka ģeorežģis būtiski palielina stiprību, ko varēja novērot kā palielinātu sabrukuma slodzi un noguruma testā. Rakstā dots īss piemērs, kurā apskatīta segas ielieču un pieļaujamo ass slodžu saistība, kas demonstrē ģeorežģa stiegrojuma praktisko efektu. Analīze parādīja, ka, lietojot ģeorežģus, samazinās segas ielieces un tas būtiski pagarina segas kalpošanas laiku. Raksta nobeigumā dotas vairākas rekomendācijas turpmākai izpētei ģeorežģu stiegrojuma jomā.