Mechanics of Solids

A: Getting this wrong risks uplift during hydrotest, cracking the pedestal and stopping the turnaround cold. Older GA triangle symbols often flagged "by civil" with no grade intent, and assuming high-strength steel pushes you into unconservative uplift checks. Treating them as low-strength A307 keeps allowable tension low, forcing conservative load limits and temporary hold-downs if needed, which avoids overstressing unknown steel and aged concrete.

A: A bad call here can dump load abruptly into unknown anchors, spalling grout or snapping rods. Verifying that nuts are engaged and grout is intact before pressure comes off avoids transferring load through loose anchors, and controlled depressurisation prevents sudden uplift or settlement when the temporary steel is removed.

A: If you miss this, you crack the lug at first pick and the crane sits idle. Bearing stress at the pin-hole interface usually governs for eccentric lifts, and increasing pin diameter drops that stress directly, while plate thickness alone doesn't address it and higher yield steel leaves stress concentration unchanged.

A: Picking the wrong mode leads to pointless replacements across the plant. A quick check shows the slenderness is low for Euler buckling, and bending stress from 1 kN over 1.1 m is far below yield for a 48 mm tube, so yielding governs with margin; shell and shear effects are secondary at this scale.