Tower Shoring AHA (Activity Hazard Analysis / Job Hazard Analysis)

Updated 2026-06-23

A Tower Shoring AHA (Activity Hazard Analysis / Job Hazard Analysis) is the plan that keeps the crew erecting and using tower shoring safe from shoring collapse, from the at-height erection and plumb/bracing, and from the load transfer and removal. Tower shoring erects the vertical shoring towers that support elevated formwork and loads — combining the shoring-capacity and collapse hazard, the erection-at-height and plumb/bracing hazard, and the load-transfer and removal hazard. This guide walks through building a Tower Shoring AHA that names the shoring-capacity/collapse, erection-at-height/plumb-and-bracing, and load-transfer/removal hazards and assigns the shoring, erection, and load-transfer controls that hold up in the field.

Why tower shoring needs its own AHA

Tower shoring erects, uses, and removes the vertical shoring towers (frame shoring, shore towers) that support elevated formwork, slabs, beams, and loads during construction — the shoring that carries the weight of wet concrete and formwork until the concrete cures and can support itself. The defining feature is that shoring towers carry major structural loads (the weight of the concrete and formwork), so their capacity, erection, and load transfer are critical — a shoring collapse is one of the most catastrophic construction failures. The hazards combine the shoring-capacity and collapse (shoring towers carry the full load of the elevated formwork and wet concrete — the capacity, stability, and integrity of the shoring are a critical safety function (an under-capacity, improperly erected, or inadequately braced shoring tower can collapse, dropping the formwork, concrete, and workers, a catastrophic failure)), the erection-at-height and plumb/bracing (erecting the shoring towers to height — the at-height erection, and the plumb, level, and bracing of the towers (out-of-plumb or unbraced shoring is unstable)), the load-transfer and removal (the loading of the shoring (concrete placement) and the removal/stripping (shoring must not be removed until the concrete can support itself)), and the foundation/base. The shoring-capacity/collapse and the erection-at-height/plumb-and-bracing justify a dedicated AHA.

Breaking tower shoring into steps

The steps for a Tower Shoring AHA follow the shoring:

• Plan the shoring per the engineered design
• Prepare the foundation/base (adequate bearing)
• Erect the shoring towers (plumb, level, braced)
• Verify the shoring erection against the design
• Load the shoring (concrete placement)
• Cure before removal (concrete self-supporting)
• Remove/strip the shoring in the correct sequence
• Manage the capacity, erection, and load-transfer hazards

Each step carries a hazard, and the shoring-capacity/collapse, the erection-at-height/plumb-and-bracing, and the load-transfer/removal are where the most significant risks concentrate.

The hazards step by step

Shoring-capacity and collapse

Shoring towers carry the full load of the elevated formwork and wet concrete — the capacity, stability, and integrity of the shoring are a critical safety function (an under-capacity, improperly erected, or inadequately braced shoring tower can collapse, dropping the formwork, concrete, and workers, a catastrophic failure). The controls are an engineered shoring design (by a qualified engineer, for the actual loads), erecting per the design (correct components, spacing, capacity), adequate bracing and stability, not exceeding the shoring capacity, inspection by a competent/qualified person, and the shoring-capacity controls. The shoring-capacity/ collapse is the primary defining hazard — a shoring collapse is catastrophic. (These follow the shoring-design fundamentals.)

Erection-at-height and plumb/bracing

Erecting the shoring towers to height — the at-height erection, and the plumb, level, and bracing of the towers (out-of-plumb or unbraced shoring is unstable). The controls are fall protection for the at-height erection, erecting the towers plumb and level (within tolerance — out-of-plumb shoring loses capacity), proper bracing (as the towers rise, per the design), safe access, and the erection/bracing controls. The erection-at-height/plumb- and-bracing is a defining hazard — out-of-plumb or unbraced shoring is unstable. (These follow the shoring-erection fundamentals.)

Load-transfer and removal

The loading of the shoring (concrete placement) and the removal/stripping (shoring must not be removed until the concrete can support itself). The controls are controlled loading (concrete placement per the design/sequence), not removing shoring until the concrete has reached adequate strength (verified, per the reshoring/stripping plan), correct removal sequence, reshoring where required, and the load-transfer/removal controls. The load-transfer/removal is a defining hazard — premature shoring removal collapses the structure. (These follow the formwork-stripping fundamentals.)

Foundation/base

The foundation and base (the shoring bears on) carries the foundation hazard. The controls are adequate bearing/ foundation for the shoring (mudsills, adequate bearing capacity — shoring that sinks or settles fails), and the foundation controls. (These follow the foundation fundamentals.)

A simple Tower Shoring AHA structure

Shoring-capacity/collapse prevention and load-transfer control

A Tower Shoring AHA centers on shoring-capacity/collapse prevention and load-transfer control. The shoring-capacity/collapse prevention addresses the critical load-bearing function — controlled by an engineered shoring design for the actual loads, erecting per the design (plumb, level, braced, correct capacity), adequate bearing/foundation, not exceeding capacity, and competent/qualified inspection, since a shoring collapse is catastrophic. The load-transfer control addresses the loading and removal — controlled by controlled loading per the design, not removing shoring until the concrete has reached adequate strength (per the stripping/reshoring plan), and the correct removal sequence. And the erection gets at-height fall protection. An AHA built on shoring-capacity/collapse prevention and load-transfer control, with foundation controls, addresses the hazards that define tower shoring.

From the field: what actually goes wrong

In fourteen years across federal, heavy civil, and industrial projects, tower shoring carries one of the most catastrophic hazards in construction — shoring collapse — because the shoring holds up the weight of elevated formwork and wet concrete until it cures. The shoring-capacity and collapse hazard is the defining concern: shoring towers carry the full load of the elevated formwork and the wet concrete above them (which is enormously heavy), so the capacity, stability, and integrity of the shoring are a critical safety function. An under-capacity, improperly erected, or inadequately braced shoring tower can collapse, dropping the formwork, the wet concrete, and the workers on and below it — one of the most catastrophic failures in construction, because it happens suddenly and drops massive weight. So an engineered shoring design (by a qualified engineer, for the actual loads — shoring must be engineered, never improvised), erecting exactly per the design (correct components, spacing, and capacity), adequate bracing and stability, not exceeding the shoring capacity, and inspection by a competent or qualified person are the controls. Shoring is one of the areas where the engineering and the field erection must match precisely.

The erection-at-height/plumb-and-bracing and the load-transfer/removal are the other defining hazards. On the projects I have run, erecting the shoring towers to height brings the at-height erection hazard (fall protection) and — critically — the requirement that the towers be plumb, level, and properly braced, because out-of-plumb or unbraced shoring loses capacity and becomes unstable (a shoring tower even slightly out of plumb can buckle under load). So fall protection for the erection, erecting the towers plumb and level within tolerance, proper bracing as the towers rise, and safe access are the controls. The load-transfer and removal hazard is about timing: the shoring is loaded when the concrete is placed, and — the critical rule — the shoring must not be removed until the concrete has cured enough to support itself, because premature shoring removal collapses the structure. So controlled loading, not removing shoring until the concrete has reached adequate verified strength, the correct removal sequence, and reshoring where required are the controls. The foundation and base (adequate bearing so the shoring does not sink or settle) rounds it out. The AHA built on shoring-capacity/ collapse prevention and load-transfer control is the one that protects the shoring crew and everyone near the elevated work.

The bottom line

A Tower Shoring AHA names the shoring-capacity/collapse, the erection-at-height/plumb-and-bracing, and the load-transfer/removal hazards with specific controls — an engineered design erected precisely per the design with adequate bracing and competent inspection (a shoring collapse is catastrophic), fall protection with plumb/ level erection, and controlled loading with no premature removal before the concrete can support itself. The shoring capacity/collapse and the load transfer are the defining concerns. The AHA that manages both is the one that protects the crew and everyone near the work.

Frequently asked questions

Why is shoring collapse one of the most catastrophic construction failures?

Shoring towers carry the full load of the elevated formwork and the enormously heavy wet concrete above them, so an under-capacity, improperly erected, or inadequately braced shoring tower can collapse suddenly — dropping the formwork, wet concrete, and workers on and below it. Controls are an engineered shoring design (by a qualified engineer, for the actual loads — never improvised), erecting per the design (correct components, spacing, capacity), adequate bracing and stability, not exceeding the shoring capacity, competent/qualified inspection, and the shoring-capacity controls.

Why must shoring be plumb, level, and braced?

Out-of-plumb or unbraced shoring loses capacity and becomes unstable — a shoring tower even slightly out of plumb can buckle under load. Controls are erecting the towers plumb and level (within tolerance), proper bracing as the towers rise (per the design), fall protection for the at-height erection, safe access, and the erection/bracing controls.

Why is premature shoring removal dangerous?

The shoring holds up the wet concrete until it cures, so removing the shoring before the concrete has cured enough to support itself collapses the structure — the shoring must not be removed until the concrete has reached adequate strength. Controls are not removing shoring until the concrete has reached adequate verified strength (per the stripping/reshoring plan), the correct removal sequence, reshoring where required, controlled loading during placement, and the load-transfer/removal controls.

What is tower shoring?

Tower shoring erects, uses, and removes the vertical shoring towers (frame shoring, shore towers) that support elevated formwork, slabs, beams, and loads during construction — carrying the weight of wet concrete and formwork until the concrete cures and can support itself. Because the shoring carries major structural loads (collapse hazard) erected at height and requires careful load transfer/removal, the shoring-capacity, erection, and load-transfer hazards apply.

Related AHAs and JHAs

• Swing-Stage Scaffolding AHA — related suspended-access equipment
• Pump Jack Scaffolding AHA — related scaffolding
• Scaffold Erection and Dismantling JHA — the scaffold-erection fundamentals
• Precast Concrete Installation JHA — related concrete-structure work

Written by Mustafa Tok, CSP, ASP, CHST — OSHA Authorized Outreach Trainer with 14+ years of international construction safety experience across federal, heavy civil, and industrial projects.