S30114 Review of Structural Assessment Load Models in DMRB

Review of Structural assessment load models in

DMRB. There is a need for resources to support National Highways Structures Group to review of structural assessment load models in DMRB and support implementing the changes that may be required In the DMRB including liaising with NH document owners.

The contract will require the following deliverables: Phase 1

• Review the NH internal paper proposing revisions to partial factors based on a

lower target reliability level and make recommendations for amendments to

CS454 to incorporate the proposed approach.

• Review CS454 to identify areas where current design requirements are less

onerous than those in CS454. This may include, but is not limited to, the treatment

of Accidental Wheel Loading (AWL); and transverse deck stiffness for CS454 LM2

loading.

• Identify the further work required in Phase 2 to support proposed amendments to

CS454.

• Desk top review of background documents used for calibration of design

Eurocodes.

Phase 2

• Undertake the analyses identified in Phase 1 to support proposed changes to

CS454.

• Advise on the feasibility of replacing non-traffic CS454 load models (e.g. wind,

thermal actions, etc.) with equivalent Eurocode load models.

• Advise on the feasibility of adopting Eurocode traffic loading with reduced partial

factors for assessment as an alternative to CS454

• Advise on wider changes that could be implemented to CS 454 related to different

levels of traffic loading.

• Assess impact on wider DMRB documents related to structural assessment.

Phase 3

• Support changes required to CS454, and if applicable to wider DMRB documents,

within CARS to implement the recommendations arising from Phases 1 and 2,

together with any additional changes proposed by NH through prior feedback.

• Support through the various stages associated with NH's standards development

governance as defined in the Manual for Development of Documents (MDD)

• Provide editable electronic versions of all amended documents e.g. flowcharts,

drawings, etc. to NH.