Experimental Study on the Behavior of Steel–Concrete Composite Decks with Different Shear Span-to-Depth Ratios

This paper presents the results of an experimental study on the mechanical behaviors of steel‒concrete composite decks with different shear span-to-depth ratios. Herein, four composite decks categorized into two types with shear span-to-depth ratios of 2.5 and 4.6 are designed for an experimental program. The decks then undergo the four-point bending tests until failure to investigate the structural responses, such as the load, displacement, crack mechanism, and failure mode. Conventional section analysis is used to derive the flexural strength of composite decks in comparison with the test results. Additionally, the ductility of the composite decks is assessed based on the displacement indices. The analysis results demonstrate that the stiffness and capacity of the composite deck increase with the decrease in the shear span length. However, the ductility of the composite slabs increases with the shear span length. The flexural strengths predicted by section analysis overestimate the actual test results. The shear span-to-depth ratio affects the crack mechanism of the composite decks.

The effect of decarburization on the fatigue life of overhead line hardware

Altering the microstructure in order to improve the tensile properties of bow shackles resulted in inconsistency in the fatigue performance. This raises the question whether the inconsistency in fatigue life can be attributed to microstructural changes along the profile of the shackle or to decarburization at the surface. Bow shackles forged from 080M40 (EN8) material were subjected to different heat treatments in order to alter the microstructure. The shackles were subjected to five different fatigue load cases, which represented typical loads experienced at termination points for an overhead power line with a span length of 400 m, with changes in conductor type, configuration, wind, and ice loading. Although the change in microstructure does improve both the tensile and fatigue performance, we found that the depth of the decarburization layer has a greater effect on the high cycle fatigue life of bow shackles than the non-homogeneous microstructure.

Break even analysis & response of longer span frames with or without post-tensioned beams in multipurpose hall

In this paper analyzed the RC a nd PT Beam against variation in the clear span length of the beam. This work includes the design and estimate of Cost/Beam from 5m span up to 15m span length of the beam. Also, The response of the frame following two variation in its modelling. Initially, The primary model consists of a conventional RCC frame with all beams and columns as RCC. The secondarily model considers peripheral beams as RCC and interior beams with PT. Such as ETABS software used to designed RC beam element and ADAPT-PTRC used to designed PT beam element. However it has been note that variation of cost with respect to the span of beam where the break-even point between RCC and PT technique is approx 7m Span. Also the control on deflection of beam by restrict the depth of beam by using unbonded Post-tensioned prestress concrete beam method. There is very good understand all aspects PT beam better than as compared with to RC beam in deflection against longer span length of beams. This paper gives suggestion about to reach a decidedly conclusion regarding which technique is superior over one another.

Enhancements for Rapidly Deployable Suspended Footbridges

<p>Walking networks can be damaged during disasters such as floods and leave people stranded. By utilizing a rapidly deployable bridge, a walking network can be quickly restored. The objective of this paper is to describe ways to improve upon an established method for rapidly deploying suspended footbridges when only one side of a crossing is initially accessible. The established method consists of using a drone to fly a pilot line around a far side anchor. The bridge structure is then pulled over the crossing using the pilot line. This established method requires that the drone operator have a clear view of the far side anchor.</p><p>Additionally, the established bridge design provides little adjustability in terms of span length and utilizes a flexible net as a deck.</p><p>The deployment method improvements described in this paper include augmenting the drone visuals during the flight, designing the bridge’s components to accommodate various spans, and increasing the deck’s stiffness. These improvements have the potential to enhance the versatility of rapidly deploying suspended footbridges in a range of environments.</p>

The design parameters improvement of wide-grip sprinkler machines of circular action

During the process of irrigation of wide-coverage sprinklers (WS) by the interaction of the wheels with the soil, the soil is pressed. In this case, the WS wheels impact the soil with a certain specific pressure. Specific pressure depends on a number of factors such as the length of vehicle, span length, vehicle weight, the diameter of water line, wheel contact area, determined by wheel geometry, pressure and tire type. The article carries out theoretical investigations determining the specific pressure of the wheel on the soil. It also given some recommendations connected with a number of wheels to be installed on the WS body compared with the calculated specific pressure of the designed vehicle with the standard specific pressure.

Effect of Shape Modification on I Girder and Box Girder Prestressed Concrete to Stiffness and Displacement

Prestressed concrete has been widely used in structural buildings, especially for big span length purposes. The prestressed concrete dimension cross sections normally are fixed, provided by the factory based on their experience for every span length. However, this size aspect can be developed to make better improvement. In this study, I and box girder shapes were modified with the same total cross-sectional area. Three types of modification have been made for each girder shape by giving the space on the middle for I girder and changing form from trapezoidal to rectangular section for box girder. The number of steel tendons for this research was made typically and same so that the stress and displacement can be compared fairly. Manual calculation was performed for all samples and was completed under three circumstances namely initial condition, loading condition, and final condition. Also, the manual calculation is according to Indonesian provisions, which are SNI 2833-2016 for the earthquake load and SNI 1725-2016 for normal loading on bridges. From the result, it is known that one shape for each girder shape has met the criteria for the smallest stress and displacement.