MULTIPLE CRITERIA DECISION MAKING ANALYSIS OF THE PORT OF ŠVENTOJI DEVELOPMENT

Port of Šventoji is a maritime facility in the settlement of Šventoji, located within the country Lithuania, near the seaside resort town of Palanga. In this paper five Port of Šventoji development alternatives are overviewed using a multi-criteria decisionmaking (MCDM) method. The results will be compared with the ones found in “Port of Šventoji reconstruction feasibility study” (liet. Šventosios jūrų uosto atstatymo galimybių studija). Criteria weights of the analysed alternatives are determined using the entropy method. Alternative analysis is carried out using the TOPSIS multicriteria method.

ANALYSIS OF BIM AND MCDM INTEGRATION IN DESIGN, MANUFACTURING AND CONSTRUCTION STAGES

The article analyses the possibilities of synergy between MCDM (Multi Criteria Decision Making) methods and BIM (Building Information Modeling) technologies in order to identify a better integration way and propose a strategy for integrating MCDM and BIM. The two ways of integration were identified after performing literature analysis – the linear one and integrated one. The stages of the integration strategy were discussed and a key strategy for improving the synergy between MCDM and BIM was found. The key strategy intended for masonry veneer and masonry structures in design, manufacture and construction stages to make a decision.

FEM ANALYSIS OF ENERGY LOSS DUE TO WAVE PROPAGATION FOR MICRO-PARTICLE IMPACTING SUBSTRATE WITH HIGH VELOCITIES

The impact between particles and material surface is a micro-scaled physical phenomenon found in various technological processes and in the study of the mechanical properties of materials. Design of materials with desired properties is a challenging issue for most industries. And especially in aviation one of the most important factors is mass. Recently with the innovations in 3D printing technologies, the importance of this phenomenon has increased. Numerical simulation of multi-particle systems is based on considering binary interactions; therefore, a simplified but as much accurate as possible particle interaction model is required for simulations. Particular cases of axisymmetric particle to substrate contact is modelled at select impact velocities and using different layer thicknesses. When modelling the particle impact at high contact velocity, a substrate thickness dependent change in the restitution coefficient was observed. This change happens is due to elastic waves and is important both to coating and 3D printing technologies when building layers of different properties materials.

CRACKING ANALYSIS OF PRECAST – IN SITU REINFORCED CONCRETE SLAB WITH PLASTIC VOID FORMERS

In this article results of experimental and numerical analysis of precast – in situ reinforced concrete slab with plastic void formers are discussed. Slab is composed of precast and in situ concrete layers. Voids are formed inside the slab using spherical plastic void formers. Slab cracking pattern is determined by numerical analysis. Cracking pattern acquired by numerical analysis is compared to cracking pattern determined by experimental study. Shear stiffness in the bond between precast and in situ concrete layers was specified when numerical model was built.

DEVELOPING OF SUSTAINABLE SUPPLY CHAIN MANAGEMENT INDICATORS IN CONSTRUCTION

Most of the existing supply chain management methods and systems are being transferred to construction sphere regardless of the specifics of companies in the construction sector. Numerous complex factors such as ecological, social and economic are required for the continuous evaluation in the modern management of construction sector. The provided studies and the research to examine sustainable supply chain management in construction sector from a holistic perspective, concentrating on mostly longterm sustainable decision­making by the construction company rather than being centered only on the supply chain management for construction projects. This paper identifies a list of sustainability indicators for examining the supply chains of construction companies. Those indicators were categorized and assigned to one or a couple groups by reviewing their use in the previous literature agreeing to the reasoning to way better reflect the SSCM principle of their use in construction companies. The use of indicators can help develop strategies for the construction sector for sustainable policy makers and construction company managers.

ANALYSIS OF THE TRAFFIC LOAD–INDUCED STRESSES OF EMBANKMENT

This article represents traffic loads on the road structure distribution and evaluation of the vertical and horizontal stresses formation in the soil embankment. This evaluation allows to predict the depth and intensity of the propagation of additional stresses resulting from traffic loads. The calculations were performed in accordance with four normative documents applied in Lithuania, which define the loads on the road structure. The obtained results showed that the area to which the load is distributed has the greatest influence on the intensity of stresses and the distance of propagation. The maximum horizontal stress in the embankment was found to be no more than 70 kPa and the maximum stress propagation depth did not exceed 0.9 m. The results can be applied to a triaxial test apparatus to restore horizontal stresses in the embankment. It is recommended to select a lateral pressure from 20 kPa to 70 kPa for tests provided with triaxial test device. The mechanical properties of the soil determined with triaxial test device and recommended lateral pressure would be representative of the test results obtained in the field of embankment.

ANALYSIS OF EMBANKMENT SLOPE STEEPNESS AND STABILITY

This paper describes the stability calculations of the most common road embankments slopes and their results using the modified Bishop method. By searching for the smallest possible effective angle of internal friction of the different slope steepness embankments, the possible different bases of the embankment, the weight of the embankment soil, the load caused by transport and the location of load application (shoulder) were evaluated. Analyzing the obtained calculation results, it was determined that at a slope of 1:2 (26.57°) steepness, to ensure slope stability, the calculated effective internal friction angle of the embankment soil should be φʹd ≥ 28.5°, and at a slope of 1:1.75 (29.74°) steepness – φʹd ≥ 29.8°. When the slope is 2:3 (33.69°) steepness, the stability of the slope cannot be guaranteed.

INFLUENCE OF APARTMENTS’ MODERNIZATION ON THE TEMPERATURES OF HEATING SYSTEM IN THE BUILDING

When modernizing apartment buildings, heating appliances are replaced or old ones are left, high thermal temperatures are usually maintained, thus limiting the increase in the DH system’s efficiency. In the article, in order to evaluate the impact of the reduced thermal temperature of the building on space heating when the radiator area remains constant, 3 alternatives have been analyzed. They include cases when after the building modernization old heating appliances are left, but the temperature of the heat carrier is reduced up to 60/40/20 °C in one case or even up to 45/25/20 in another alternative. There has also been examined the possibility of reducing the heat carrier temperature of the heating system without modernization of the building. An hourly data analysis of the heating system model for two typical months of the heating season has been performed. The analysis shows that after the modernization of the building, when heating device areas are left the same, the existing heating temperature can be reduced to 60/40/2020 °C.

EFFECT OF REJUVENATORS ON PENETRATION AND SOFTENING POIND OF AGED POLYMER-MODIFIED ROAD BITUMEN

The article describes the effiency of polymer-modified road bitumen regeneration with two types of rejuvenators. Two alternative rejuvenators have been selected aromatic oil Nygen 910 and soft road bitumen V12000. PMB 45/80-55 bitumen, which is used in the upper and lower layers of asphalt pavement, was investigated. During the life time of the asphalt pvement, due to the effects of solar UV radiation, temperature and oxygen, of all the layers of the structure asphalt top layer reaches the highest degree of aging. Short-term and long-term aging were performed to simulate the aging of the bitmen under laboratory conditions. To determine the optimal amount of rejuvenator experiments were performed with 8%, 10% ir 14% rejuvenator by bitumen mass. The effect of rejuvenators were evaluated by studying the main physical properties of bitumen: penetration and softening temperature. Ina n experimental study, aromatic oil was found to be more than 2.5 times more effective than soft bitumen.

ASSESSMENT OF ENERGY PERFORMANCE GAP OF AN OFFICE BUILDING

The high share of global energy costs to create an indoor climate has been of increasing interest to the global community for several decades and is increasingly the focus of policy. This paper analyses the energy performance gap between actual energy consumption and energy demand obtained during the dynamic energy simulation and building certification. To identify the energy performance gap, an existing office of energy efficiency class B was selected as a case study. The simulation program IDA Indoor Climate and Energy was used to create a dynamic energy model, based on the designed documentation and the actual indoor climate parameters recorded by the building management system. The results of the case study showed that the accuracy and reliability of the results presented by the dynamic energy model of the building directly depend on the assumptions. The correct values of the internal heat gains, indoor climate parameters, human behavior, air quality levels at different times of the day and season, HVAC system operation parameters and operation modes, specific fan powers of ventilation systems, the seasonal energy efficiency of cooling equipment and characteristics of sun protection measures have to be selected.