Reliability Quantification of Railway Electrification Mast Structure Considering Buckling

This paper aims to quantify and assess the reliability of mast structures as a part of ensuring structure safety. The mast structure is a basic aspect of the overhead line electrification equipment (OHLE) used in railway systems. This structure is very important as the failure of structure leads to the failure of an electric system that supplies the power to the train. To ensure structural safety and reliability, this paper thus analyses the reliability index of the mast, stay tube, and bracket tube structures. According to Eurocode, buckling resistance under compression of these parts were calculated based on specific material properties, and the load condition of these structures is based on Australian Railcorp document TMC331. In this paper, the strength load combination with the wind loading on the wire at 45° on the track is considered in particular as being the worst load combination for structures to bear, and the random variables used to affect reliability probabilistic analysis. Various parameters including self-weight, wind load, dimension parameters, materials, geometrical properties are taken into consideration. Statistical models of these parameters are taken from previous studies. The reliability index value was calculated via quantification of structure reliability using the first-order reliability method (FORM). Finally, a sensitivity analysis is used to evaluate the impacts of yield strength, length, cross-section, density, and load combination on reliability. The obtained results show that increasing length of structure can potentially reduce the reliability of mast structure to buckling resistance while the density of material also plays a major role in the reliability index. The findings will provide the structural safety criteria of the railway mast structure and improve the standard design to mitigate the risks and unplanned maintenance due to the uncertainties.

Comparative Analysis of Structure with and without Seismic Load

Engineers are mostly adopting complex non-linear methods to research multi-storey residential apartment structure to withstand earthquake forces. This paper uses much simpler Equivalent Static method to analyse G+5 storey structure to repel earthquake forces using Staad pro software. The seismic analysis is further compared with non-seismic analysis of an equivalent structure using dead load + super load combination. it had been observed that the seismic results obtained consisted of significantly increased maximum moments and shear forces than the non-seismic analysis From past earthquakes it is proved that many of structure ar completely or partly broken because of earthquake. So, it’s a necessity to figure out unstable responses of such structures. The main aim of the present work is to make a comparative study of seismic and non-Seismic structure. The analysis was performed as per the specification of IS codes IS 1893, IS 875, IS 456:2000.

Verifying the Shear Load Capacity of Masonry Walls by the V Rd–N Ed Interaction Diagram

Verification of shear load capacity is required for all shear walls that take horizontal wind loads, loads imposed by ground action or other non-mechanical (rheological or thermal) loads. Shear walls are exposed not only to shear forces, but also vertical actions caused by dead load or imposed loads as shear walls also usually function as bearing walls. This load combination is quite important as shear load capacity V Rd depends on mean design stresses σd which, in turn, depend on design forces N Ed. Interactions between shear V Rd and vertical load N Ed in shear walls are the consequence of observed combinations of actions in these types of walls. Additionally, the vertical load N Ed acts on the wall at certain eccentricity eEd, which can result in a change in the length of the compressed part of the cross-section l c. This paper describes the procedure for verifying shear load capacity by means of the interaction diagram drawn as specified in Eurocode 6 (prEN 1996-1-1:2017). Necessary equations for determining load-carrying capacity of cross-section against vertical load N Ed were worked out. The effect of wall shape and eccentricity of vertical load on the shape of the interaction diagram was analysed.

Perbaikan dan Perkuatan Fondasi Tiang Bor pada Bangunan Gedung Perkuliahan dengan Penambahan Tiang Pancang Bulat

Fondasi harus dibangun di atas tanah keras agar bangunan tetap stabil dan kokoh. Memastikan kekuatan fondasi adalah upaya dini untuk mencegah sudden collapse pada bangunan di kemudian hari. Penelitian ini dilakukan untuk mengetahui kuat dukung tanah pada ujung tiang fondasi dan mengamati sejauh apa kerusakan beton tiang bor pada bangunan yang baru masih dalam tahap pembangunan fondasi. Data penelitian diperoleh dari hasil pengujian PDA (Pile Driving Analyzer) dan PIT (Pile Integrity Test) pada fondasi bangunan jenis bored pile D80. Pada gedung yang berdekatan, yang dikerjakan dengan sistem yang sama dan menggunakan spun pile D50. Data kuat dukung ultimate hasil manometer alat uji hidraulik 175 ton untuk pile D50. Dari analisis uji PDA, diperoleh nilai kuat dukung ijin rata-rata tiang bor adalah 70,25 ton (51%). Analisis ulang terhadap kombinasi beban menghasilkan tambahan spun pile di 44 titik. Pada beton bored pile yang mengalami kerusakan, dilakukan perbaikan seperti penambahan cor pada lapisan luar (concrete-jacketing) untuk menutupi lapisan tulangan yang terekspos, dan penambahan tulangan terpisah di sisi dalam beton untuk antisipasi bila tulangan luar rusak akibat korosi.The foundation must be placed on hard rock so that the building remains stable and solid. Thus, ensuring the strength of the foundation is an early effort to prevent sudden collapse of the building in the future. This research was conducted to determine the bearing strength of the soil at the ends of the foundation piles and to observe the extent of the damage to the drill pile concrete in the new building which is still in the foundation construction stage. The research data were obtained from the results of PDA (Pile Driving Analyzer) and PIT (Pile Integrity Test) testing on the foundation of the bored pile type D80 building. The adjacent building is being worked on with the same system and using a D50 spun pile. With the ultimate bearing strength data, the results of the hydraulic tool manometer = 175 tons for D50 piles. PDA test analysis obtained the average allowable bearing strength of the drill pile is 70.25 tons (51%). The re-analysis of the load combination resulted in additional spun piles at 44 points. In the damaged bored pile concrete, namely by adding cast to the outer layer (concrete-jacketing) to cover the exposed reinforcement layer, and adding separate reinforcement on the inside of the concrete to anticipate if the outer reinforcement is damaged due to corrosion.Fondasi harus dibangun di atas tanah keras agar bangunan tetap stabil dan kokoh. Memastikan kekuatan fondasi adalah upaya dini untuk mencegah sudden collapse pada bangunan di kemudian hari. Penelitian ini dilakukan untuk mengetahui kuat dukung tanah pada ujung tiang fondasi dan mengamati sejauh apa kerusakan beton tiang bor pada bangunan yang baru masih dalam tahap pembangunan fondasi. Data penelitian diperoleh dari hasil pengujian PDA (Pile Driving Analyzer) dan PIT (Pile Integrity Test) pada fondasi bangunan jenis bored pile D80. Pada gedung yang berdekatan, yang dikerjakan dengan sistem yang sama dan menggunakan spun pile D50. Data kuat dukung ultimate hasil manometer alat uji hidraulik 175 ton untuk pile D50. Dari analisis uji PDA, diperoleh nilai kuat dukung ijin rata-rata tiang bor adalah 70,25 ton (51%). Analisis ulang terhadap kombinasi beban menghasilkan tambahan spun pile di 44 titik. Pada beton bored pile yang mengalami kerusakan, dilakukan perbaikan seperti penambahan cor pada lapisan luar (concrete-jacketing) untuk menutupi lapisan tulangan yang terekspos, dan penambahan tulangan terpisah di sisi dalam beton untuk antisipasi bila tulangan luar rusak akibat korosi.

Sustainable Repairing and Improvement of Concrete Properties Using Bacterial Consortium Isolated From Egypt

The small cracks in concrete constructions are inevitable due to deterioration during their service life throughout different load combination factors. In this study, we aimed to isolate, identify, and construct a bacterial consortium able to heal small cracks of concrete and enhance the different properties of concrete. Six isolates of bacillus, endospore-forming bacteria were isolated. There are only three isolates out of the six coded as NW-1, MK and NW-9 were showed the ability to produce urease enzyme and able to grow at 60°C with optimum growth at a temperature of 40°C. These isolates were survived in high pH, where isolate NW-1 was tolerated pH up to 11 with optimum growth at 10 while the isolates NW-9 and MK showed growth at pH 12 with an ideal growth at 10. CaCO3 production was observed by the three bacterial isolates whether in pure or mixed cultures (bacterial consortium) but the consortium consisting of MK and NW-9 was significantly the highest in productivity among them. Therefore, these two isolates were identified using 16s as Bacillus flexus MK-FYT-3 and Bacillus haynesii MK-NW-9 and deposited to GenBank under accession numbers MN965692 and MN965693 respectively. The effect of bacteria on some properties of concrete was studied, and the results showed that the compressive and tensile strengths of bio-concrete specimens were significantly increased by 31.29, 29 % after 7 days and 36.3, 39 % after 28 days of curing compared to control specimens. The results of permeability indicated that the bio-concrete specimens significantly showed less permeability than the control specimens by 21.1, 23.1% after 7 and 28 of curing, respectively. To determine the concrete density, Ultrasonic Pulse Velocity (UPV) test was performed, and the bio-concrete specimens gave higher values ​​than control specimens by 26 and 20% after curing for 7 and 28 days, respectively. Also, surface healing of concrete was observed visually, the bio-concrete showed white precipitates around and inside the cracks after 7 days, which led to almost complete sealing of concrete after 28 days of curing, while the control samples were showed only very slight deposits on the surface and away from the cracks. The micro-analysis of concrete samples using SEM and XRD were done. It was found that the bio-concrete specimens showed crystalline precipitate with different shapes under SEM, while no such deposits appeared in the control specimens. On the other hand, the XRD profile was explained the characteristic peaks of calcium carbonate in both the bio-concrete and the control specimens, but the peak intensity was higher in the bio-concrete than the control specimens. This reflects the effectiveness of bacterial consortium in repairing and preventing the concrete cracks from spreading in addition to improving the various properties of concrete leading to increasing its life and sustainability.

A review on stability of polyhouse structures

Naturally ventilated polyhouse is popular all over the world for growing high value cropssuch as capsicum, tomato, lettuce, herbs etc. and these polyhouses are available in different designs as per different climatic conditions. Structure failure is the major problem faced by farmers throughout the world. The several studies carried out throughout the world shows that the single design of polyhouse cannot be adopted throughout the country due to different agro-climatic conditions.As per differentstudies, polyhousestability designs are analyzed for dead load, live load, snow load, wind load and load combination and Loads were calculated by adoptingdifferent National Standards. Moreover, Truss members, columns and foundation stability analysis is carried out by considering dead loads, live loads and wind loads in most of the studies. Support reactions arealso calculated on truss joints and column joints. The optimum design of any polyhouse generally depends on its structural design, specific mechanical and physical properties of the individual structural components i.e., foundation, hoops, lateral support, polygrip, assembly and end frame. From all the studies it is reported that in most parts of the world, wind is the major force responsible for the failure of any polyhouse structure.

Environmental Load Evaluation of Nipigon River Bridge

If current climate trends continue, climate change will be inevitable and designing infrastructure which can withstand changing environmental loads will be a concern. Furthermore, current infrastructure will be affected and may require retrofitting or rehabilitation in order to meet safety and code requirements. The scope of this report is to determine the effect of increased environmental load factor coefficients on Nipigon River Bridge. An FEA model was created and the results from the model show that the bridge is sensitive to changes in environmental loads, particularly those of wind and temperature. An increase of 10% in wind and temperature load coefficients was enough to change the governing load combination and surpass the estimated moment capacities.