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Construction and testing of deep foundations
Published in An-Bin Huang, Hai-Sui Yu, Foundation Engineering Analysis and Design, 2017
Depending on the capacity of the pile, the load test can involve imposing tens to thousands of metric tons of force at the pile head and measuring the related movements. Figure 8.34 shows a schematic view of a typical pile load test setup. In this case, a stiffened steel beam is used as a reaction frame. The reaction frame is anchored by a group of tension piles or ground anchors. The axial load is applied by a hydraulic jack against the reaction frame. The spherical bearing minimizes potential bending movement created by the axial force due to eccentricity. It is often required that the axial force be measured independently with a load cell.
Investigation and treatment of bearing diseases for typical expressway and high-speed railway bridges in Eastern China: a field practice campaign
Published in Structure and Infrastructure Engineering, 2022
Fengbo Ma, Lu Zhang, Mida Cui, Xiaoxiang Cheng, Youquan Zou, Yi Cui, Gang Wu
Bearings can usually be classified into elastomeric bearings, pot bearings, spherical bearings, rocker bearings and roller bearings, according to their structural types (CEN, 2000). Elastomeric bearings, inlaid, bonded, and vulcanised by multilayer rubber and thin steel plates, are widely used in medium- and small-span highway bridges because of their advantages, such as simple structure, low cost, and easy installation and replacement (Heymsfield, Mcdonald, & Avent, 2001; Zheng et al., 2014). However, elastomeric bearings might easily be corroded due to their exposure to air, so their durability is often questionable (Heymsfield et al., 2001), and their design service life is usually 15 years at least (SAC, 2015). Pot bearings are composed of steel members and rubber, and they have the advantages of a large bearing capacity and flexible translational deformation. Therefore, they are ideal bearing types for long-span concrete bridges of HSRs before 2010 (Zhuang, 2015). Spherical bearings, due to their flexible rotating ability and the absence of low-temperature brittleness and degradation of rubber, are especially suitable for wide bridges, curved bridges and bridges in low-temperature areas (Kang, 2018; Zhuang, 2015). The design service life of pot/spherical bearing is usually more than 50 years (SAC, 2015).
An integrated design methodology for components produced by laser powder bed fusion (L-PBF) process
Published in Virtual and Physical Prototyping, 2018
Alessandro Salmi, Flaviana Calignano, Manuela Galati, Eleonora Atzeni
A bearing bracket has been re-designed for the L-PBF process according to the previously described design methodology. The bracket geometry has been taken from the GrabCAD Airplane Bearing Bracket Challenge (GrabCAD 2016). The design material is an AlSi10Mg alloy. The constraints are four high strength bolts (#10-32) that link the bracket to a plate and the bolts apply a vertical force as a consequence of the tightening torque. The bracket is subjected to three load-cases as illustrated in Table 1. The loads are applied to the centre of the spherical bearing case.