Structural Engineering & Statics
where the load goes
Concept

Lateral pressure — where it appears

Horizontal pressure from soil, water or stored material on a surface retaining it. Its magnitude depends on what is retaining it as well as on what is retained, which is why the same soil pushes differently on a wall that can move and one that cannot.

Named by 2 essays across 2 fields — each of them below, with the objects they name alongside it.

the whole profile185.7 kN/mat 1.90 m0246surcharge20.0 kN/mat 3.00 msoil above water12.0 kN/mat 4.67 msoil at the water table48.0 kN/mat 2.00 m0246submerged soil27.2 kN/mat 1.33 mwater78.5 kN/mat 1.33 mresultant at 1.90 m, which is 0.317 of the height — one third only for a pure trianglethe water term is the largest single one, at 78.5 kN/m of 185.7 kN/m

The load that depends on what carries it

Every other load in this collection is a number the structure is given. Retained soil is not — it pushes with a fraction of its own weight, and the fraction is decided by how far the wall moves. Six millimetres of retreat on a six-metre wall takes a third off the load, and being held still puts it back.

equilibrium · lateral pressure 0.0000.0050.0100.0150.0200.0250.030010203040compressive strainstress (N/mm²)44.4 N/mm² at 0.0068unconfined: 30 at 0.002still carryingstrength × 1.48 · ultimate strain × 8.0 · toughness × 11

Squeezed sideways into a different material

Concrete in a cylinder test fails by splitting apart sideways under a load pushing it down. Put a hoop round it and the splitting has to stretch steel — and a lateral pressure of a twelfth of the strength raises the strength by half and the ultimate strain by eight.

materials · confinement

Named alongside it

The objects these essays reach for when they reach for this one.

ArchingBearing pressureConfinementDuctilityEnergy dissipationFrictionHoopLever armMiddle thirdMoment curvatureOverturningPlastic hinge

All concepts