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Design Process References Major Bridge Design Standard Bridge Design Current Initiatives . Functional Planning. Bridge Management. Bridge Inspection & Maintenance. New Bridge or Existing?. New. Existing. Bridge Assessment. Repair or Replace?. Replace. Repair. New Design.
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Design Process • References • Major Bridge Design • Standard Bridge Design • Current Initiatives
Functional Planning Bridge Management Bridge Inspection & Maintenance New Bridge or Existing? New Existing Bridge Assessment Repair orReplace? Replace Repair New Design Rehabilitation Design Conceptual Design Detailed Design Tender Preparation and Advertisement Construction
Design Process - Reference Section 10 and Appendix J1
AT Bridge Terminology • StandardBridges • Bridge structures built using standard bridge design drawings. • BridgeSized Culverts • Standard culverts: Diameter greater than or equal to 1500 mm and less than 4500 mm. • Major culverts: Diameter greater of 4500 mm or structures of lesser diameter having complex site constraints or specialized engineering requirements. • Major Bridges • All other bridge structures and typically built from site-specific drawings, but can also be built using standard girder drawings.
Design – Reference Documentation • Structure Alternatives Report Guidelines • Bridge Structures Design Criteria • Bridge Aesthetics Study • Engineering Drafting Guidelines for Highway and Bridge Projects • Standard Drawings and Typical Detail Drawings
Design – Reference Documentation • Best Practice Guidelines (BPG) • BPG 2 – Alternate Design • BPG 3 – Protection Systems for New Concrete Bridge Decks • BPG 7 – Spread Footings • BPG 10 – Minimum Bridge Width for SLC Girder Structures • BPG 11 – Stormwater Management at Rural Bridges • BPG 12 – Bridge Deck Drainage • Standard Bridge Guidelines • Design Guidelines for Bridge Sized Culverts
Bridge Structures Design Criteria • General Design Issues • CAN/CSA-S6 Exceptions • CL-800 Design Vehicle • Minimum deck thickness of 225 mm (vs. 175 mm) • Imperial deck limited to S/15 (vs. S/18) • Minimum clear cover requirements • Bridge Geometric Design • Together with Bridge Conceptual Design Guidelines • Materials • Substructure & Foundation Design
Bridge Structures Design Criteria • Retaining Wall Design • MSE Walls • Superstructure Design • Barrier Design • Accommodation of Utilities • Overhead Sign Structures
Design – Overhead Sign Structures • AASHTO Standard Specification for Structural Supports for Highway Signs, Luminaires and Traffic Signals • Design/build process (Section 24 – SSBC) • BSDC outlines consultant responsibilities
Structural Alternatives Report • Design Project Brief Major Bridge Design Process • 95% Design Drawings and Special Provisions for Department Review • 100% Design Drawings and Tender Document
Structural Alternatives Report Purpose: • Assemble all relevant design information (roadway standards, high ice, etc.) • Propose various bridge structure alternatives • Document decision of structure alternatives • Propose and document design exceptions Components: • Background Design Information • Geometry and Span Configurations • Structure Component Alternatives • Construction and Tendering Issues • Cost Estimates • Design Decisions and Recommendations
Structural Alternatives Report • Guidelines available on the Alberta Transportation Bridges and Structures website
Design Project Brief Key Document: More detail in the Design Project Brief Reduce the last minute design and drawing changes • Last formal opportunity for department review and acceptance until 95% drawings are submitted • Must be able to clearly communicate full understanding of all bridge components • May include sketches if required to clarify issues
Preparing Detailed Design and Drawings • Bridge Structures Design Criteria • Engineering Drafting Guidelines for Highway and Bridge Projects • Standard Drawings and Typical Detail Drawings
Preparing Detailed Design and Drawings • Engineering Drafting Guidelines for Highway and Bridge Projects • Existing version from 2005 • Major overhaul to be published fall of 2014 • Updated layering system • Sample layout sketches for each drawing • Detailed checklists for each drawing • Standard drawing notes • ‘Good’ examples of complete drawing sets
Preparing Detailed Design and Drawings • Standard Drawings and Typical Detail Drawings • Available on Alberta Transportation Bridges and Structures website
Preparing Detailed Design and Drawings • Standard Drawings and Typical Detail Drawings • Barriers • Precast Girders • Steel Girders • Deck and Deck Joints • Bearings • Culverts • Bridge Construction Specification Drawings • Miscellaneous
Preparing Detailed Design and Drawings • Standard Drawings are engineered documents • Consultant refers directly to these on the project detailed drawings and includes a copy of the standard drawings in the tender set • Site specific information is often required to supplement the Standard Drawings (dimensions, reinforcement, etc.) • Consultant needs to ensure latest version is included in tender set as these are occasionally updated
Preparing Detailed Design and Drawings • Typical Detail Drawings are not engineered documents • Show Department’s preferred details • Consultant to use these preferred details unless otherwise permitted by the Department • Consultant designs and takes full responsibility • Typical Detail drawings are not included or referred to in Consultant’s drawing set
Preparing Detailed Design and Drawings • 95% Drawing Submission • Expect 95% complete • QC completed by Consultant prior to submission to Department
Preparing Special Provisions • Standard Specifications for Bridge Construction • Tender Templates, Special Provisions and Specification Amendments • Submit 95% Special Provisions at the same time as the 95% Drawings
Standard Bridges • Department has Standard Bridge Design packages • Intended for smaller stream crossings • Virtually stand-alone design packages including abutments, piers, girders, decks and barriers • Consultant required to complete a few drawings to reflect site specific information (general layout drawing, skews, widths, barlist, etc) • Standard SL and SLW Bridges • Intended for use on low volume and low speed local roads • Precast girders with steel or concrete substructures • Standard SL Bridges where de-icing salts are not expected • Standard SLW Bridges with membrane and ACP where de-icing salts are expected
Standard Bridges • Standard SLC Bridges • Intended for use on higher volume and higher speed highways with ACP wearing surface • Precast girders with steel or concrete substructures • Concrete deck with membrane and ACP
Standard Bridges • Important to understand the limitations of each of these standard designs when determining which is appropriate for a given site. • Guidelines available on Alberta Transportation Bridges and Structures website. Standard Bridge Selected Does Site Meet Standard SL/SLW Requirements? Yes No Does Site MeetStandard SLCRequirement? Yes No Review Bridge PlanningMay NeedMajor Bridge Follow Guidelines forStandard SL / SLWBridge Design Follow Guidelines forStandard SLCBridge Design
Standard Bridge Girders • Standard SL/SLW and SLC girders exist • These standard girder drawings may be used outside of a Standard Bridge Design package • In this case, Consultant must follow the process for Major Bridge design
Current Initiatives • Orthotropic Decks for bridge deck replacements • Lightweight deck option • Allow wide deck • Address load carrying capacity • Accelerated construction schedule • Tailored to any configuration • Can be staged Conducting Trial Project at the RedwillowRiver Bridge
Current Initiatives • Accelerated Bridge Construction • Considering various possibilities • Revised Engineering Drafting Guidelines for Highway and Bridge Projects • Fall 2014 • Revised Bridge Structures Design Criteria • 2015
Current Initiatives • Bridge Load Evaluation Manual • Bridge assessments • Bridge strengthening and rehabilitations • Overload vehicle moves (ie. to Fort McMurray) • Evaluating our bridge inventory capacity to accommodate requests by industry to increase allowable vehicle loads • Logging industry requesting up to 88t log haul vehicles • Oilsands industry requesting up to 450t gross vehicle loads for divisible modules
Current Initiatives • Bridge Load Evaluation Manual • Consultants now complete 99% of the load evaluations in Alberta • Manual to improve consistency: • Approach to load evaluations and inspections • Knowledge of historical AT bridges • Interpretation of Clause 14 in CHBDC • Load evaluation report submission • Release in spring 2014