In this study, a series of laboratory tests on 100‐mm‐diameter high‐density polyethylene (HDPE) 100 PE flexible pipe buried in poorly graded Sile quartz sand with different relative densities are described. The laboratory tests were performed in a 40‐mm‐thick plexiglass fronted test tank that replicated a classical trench section in field conditions. The HDPE flexible pipe was positioned against the glass with its longitudinal axis perpendicular to the glass. This allowed direct observation of the backfill–pipe interactions. Three high‐definition photogrammetric cameras were used to capture the photogrammetric images through the glass allowing the discrete measurement and image processing of the deformation patterns of the pipe conduit during the pipe installation and incremental surcharge loading. Vertical loads were applied in increments of 10–150 kPa using air pressure membranes. Electric resistant strain gauges measured the bending moments of the pipe walls under vertical surcharge loadings. For each loading step, the vertical deformation of the pipe crown was also measured using linear position transducers. According to the test results, it is understood that the installation technique and backfill relative density have an important effect on circumferential strains, performance, and deformation characteristics of HDPE pipes. It was also observed that close‐range image processing is a very simple and appropriate method for measuring three‐dimensional pipe deformations under various conditions.

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The common technique used for the construction and maintenance of infrastructure facilities until recently involved traditional open excavation methods. Technological advancements and developments in gathering geotechnical information on our working environment have given birth to the development of new methods which will prevent problems that may have emerged due to the use of traditional methods during the construction of infrastructure facilities. One of these new methods is trenchless technology which is becoming increasingly popular in the infrastructure construction industry. One of its processes, the pipejaking process, is of special importance in busy urban centres and densely populated living quarters as it has proved to be the most sustainable method for working in such environments and for global use. The name of this process is trenchless technology. There is an increasing demand for infrastructure systems, especially in cities, because of increasing populations and varying lifestyles, and in the areas around cities which are environmentally sensitive. Routes of infrastructure (pipelines) to be constructed have many obstructions such as motorways, buildings, railways, rivers, creeks, and canals. The pipejacking process, a trenchless technology to overcome these problems and obstructions, has been achieving an important scope of application in Turkey and the rest of the world. Infrastructure facilities planned to be constructed by the application of this system can be built under every kind of ground condition in a correct, swift, and economic manner, without needing an open excavation and its associated traffic problems and conditions that may cause danger to human life and property. Within the context of this study, the collector line, constructed in Şile district by the pipejacking process (which is 1535 m in length and 800 mm in diameter), was examined, and jacking force length graphics were prepared with the use of jacking force records obtained from the machine. After analysing these graphics, change of coefficients of α adhesion was researched and, for use at cohesioned grounds, an α value was suggested in order to predict friction resistance and accordingly possible jacking force values that may be faced. First, with the assistance of the Plaxis 3D Tunnel Program, considering land conditions, the examined line was modelled. Then, stress values resulting from this modelling and graphic analyses were compared, and observed harmonies or inharmonies were discussed. Lastly, parameters that are effective on these harmonies or inharmonies were defined. In addition, considering jacking forces and stress values observed where bentonite is whether used or not, the lubricant's effect on the jacking action was examined. Within the context of this study, stoppages, lubrication during jacking process, and their effects on the jacking force and stresses were analysed. Thus, a versatile study regarding the pipejacking process has been put forward for consideration.

Aim: In this study, it is aimed to determine the success of glass fiber reinforced concrete (GFRC) in realizing the plastic effect on the works of various architects and the advantages it provides in terms of aesthetics, according to the principles determined through the works of Zaha Hadid with the success of benefiting from the aesthetic properties of concrete and emphasizing the plastic effect. By giving information on the technical features of GFRC based on the literature, attention has been drawn to the effect of technical features (lightness, strength, etc.) on realizing the plastic effect. In addition, the places where different architects preferred GFRC in their designs were analyzed and the importance of the material design relationship was tried to be emphasized in this respect. Method: In the study, data collection and comparative analysis methods from qualitative methods were used. Findings: In the buildings examined, it was observed that GFRC was used only in the landscape of Haydar Aliyev Cultural Center, but frequently on the facade and interior. It has been observed that 60% of the GFRC used in the sample buildings has a 3D texture. It has been understood that the principles that create a plastic effect are largely provided by the GFRC. Results: GFRC is a very successful material due to its technical features in terms of providing the plastic effect, and that it can be molded according to the desired form and surface properties in architecture. However, in the light of the information obtained from the literature, it has been understood that the use of GFRC in the built environment is limited, so it has been concluded that the advantages of the aesthetic and technical characteristics of the material should be introduced to the architects.