Superstructure Loads What Precast Pipe and Box Designers

Superstructure Loads What Precast Pipe and Box Designers Need to Know About Mechanically Stabilized Earth (MSE) Walls American Concrete Pipe Association Short Course Orlando Florida Tuesday March 3 rd, 2015 WAYNE HODGE, PE

INTRODUCTION www. concrete-pipe. org (Ohio Department of Transportation, 2013)

3 Presentation Topics: • Overview of MSE Walls • Culvert / MSE Interaction • Understanding and Addressing the Complexities of Designing Each Structure • Open Discussion www. concrete-pipe. org

4 OVERVIEW OF MSE WALLS www. concrete-pipe. org

What Are MSE Walls? • MSE walls are earth retaining structures that are constructed by placing alternating layers of reinforcement and compacted soil behind a facing element to form a composite material which acts integrally to restrain lateral forces. www. concrete-pipe. org

MSE Wall Usage • MSE walls have been constructed in every state in the United States. • Major users include transportation agencies in Georgia, Florida, Texas, Pennsylvania, New York, and California, which rank among the largest road building states. • It is estimated that more than 9, 000 ft 2 of MSE retaining walls with precast facing are constructed on average every year in the United States, which may represent more than half of all retaining wall usage for transportation applications. www. concrete-pipe. org (Berg, Christopher, & Samtani, 2009)

Common MSE Wall Applications • • Retaining Walls Access Ramps Waterfront Structures Bridge Abutments www. concrete-pipe. org

Retaining Walls (Earth. Tec, n. d. ) www. concrete-pipe. org

Access Ramps (NTE Mobility Partners, 2015) www. concrete-pipe. org

Waterfront Structures (Earth. Tec, n. d. ) www. concrete-pipe. org

Bridge Abutments (Passe, 2000) www. concrete-pipe. org

Types of MSE Bridge Abutments • MSE True Abutment • MSE Mixed Abutment www. concrete-pipe. org

MSE True Abutments (Anderson, Gladstone, & Sankey, 2012) www. concrete-pipe. org

MSE Mixed Abutments (Anderson, Gladstone, & Sankey, 2012) www. concrete-pipe. org

Usage of MSE Bridge Abutments (Anderson & Brabant, 2005) www. concrete-pipe. org

Advantages of Using MSE Walls • Low Cost • Ease of Construction • Structural Tolerance to Foundation Settlement • Performance under seismic loading events • Wide range of possible facing types, colors, and textures.

Cost Advantages In general, the use of MSE walls results in savings on the order of 25 to 50 percent and possibly more with a conventional reinforced concrete retaining structure, especially when the latter is supported on a deep foundation system (poor foundation condition). (Berg, Christopher, & Samtani, 2009)

Tolerance to Settlement The ability of MSE walls and abutments to withstand extreme settlements is a wellrecognized benefit of this construction technology. MSE structures have accommodated total settlements of nearly 3 feet, as well as differential settlements greater than 1 foot in 100 feet (1%), without loss of structural function and without showing facing panel distress. Thus, at sites where down-drag forces could overload piles beneath a traditional abutment or require heavier pile sections to carry the added load, MSE abutments will be virtually unaffected by the settlement, built at lower cost, and will require less maintenance during the bridge's service life. (Anderson & Brabant, 2005)

Ability to Withstand Seismic Loading The seismic performance capabilities of MSE abutments make them an ideal choice for bridges in earthquakeprone regions. • Twenty-one Reinforced Earth walls and two Reinforced Earth abutments experienced the 6. 7 Richter magnitude Northridge earthquake in 1994, in the densely populated San Fernando Valley 20 miles northwest of Los Angeles. Buildings, bridges and freeways all suffered severe damage, yet all Reinforced Earth structures performed extremely well, with only superficial damage to a few facing panels of one wall. 14 • Three abutments and several high retaining walls, within 2 miles of the epicenter of the 1983 5. 0 Richter magnitude earthquake in Liege, Belgium, suffered no damage or deformation. (Anderson & Brabant, 2005)

Wide Selection of Available Facing (Passe, 2000)

Wide Selection of Available Facing

Systems / Manufacturers • Key. System I by Keystone Retaining Wall Systems, Inc. • Mesa HP System by Tensar Earth Technologies, Inc. • Reinforced Earth Classic Panel by The Reinforced Earth Company • Earth. Trac HA by Earth Tec International, LLC • Sanders MSE Wall by Sanders Pre-Cast Concrete Systems Company • Strengthened Soil by Shaw Technologies • Sine Wall by Sine Wall, LLC • MSE Plus by SSL Construction Products • Vist-A-Wall by Vist-A-Wall Systems, LLC • Tricon Retained Soil by Tricon Precast

Historical Background / Timeline What year was the modern method of MSE walls developed? • 1895 • 1921 • 1957 • 1982

Historical Overview of MSE Walls 1957 (The Reinforced Earth Company, 2011) • Henri Vidal develops reinforced earth concept.

Historical Overview of MSE Walls 1963 (The Reinforced Earth Company, 2011) • Vidal first publishes his research and files the patent for Reinforced Earth®

Historical Overview of MSE Walls 1971 - 1972 (The Reinforced Earth Company, 2011) • 1971 - At the invitation of FHWA, Vidal brought his technology to the US to address a major landslide repair on Highway 39 in the Angeles National Forest. • 1972 - First Reinforced Earth structure constructed in the United States, as part of Federal Highway Administration Demonstration Project 15

Historical Overview of MSE Walls 1974 • The first MSE abutments in the United States were constructed on I-80 near Lovelock, Nevada. These true abutments carry four lanes of traffic on a 70 -foot span crossing Big Meadow Ranch Road northeast of Reno. (Anderson & Brabant, 2005)

Historical Overview of MSE Walls • 1970’s – Introduction of competitive wall systems using welded wire grids. • 1980’s – Introduction of geosynthetic reinforced walls. • 1990’s – dramatic increase in the use of geosynthetic reinforced walls with the introduction of segmental retaining walls.

30 Notable MSE Wall Projects www. concrete-pipe. org

Sea-Tac Third Runway Project (Stuedlein, Bailey, Lindquist, Sankey, & Neely, 2010) www. concrete-pipe. org

Sea-Tac Third Runway Project West MSE Wall www. concrete-pipe. org (Hart Crowser, 2015)

Muscat Expressway (Parsons Corportation, 2015) www. concrete-pipe. org

MSE Wall Components • Facing Panels • Backfill • Soil Reinforcement www. concrete-pipe. org (Passe, 2000)

Facing Systems • Segmental Precast Concrete Panels • Dry Cast Modular Block Wall (MBW) Units • Welded Wire Mesh (WWM) • Gabion Facing • Geosynthetic Facing • Post-Construction Facing

Segmental Precast Concrete Panels (Ohio Department of Transportation, 2013)

Dry Cast Modular Block Wall (MBW) Units (Passe, 2000)

Welded Wire Mesh (WWM) Facing (Site Supply, Inc. , 2015)

Facing Systems - Gabion (Hilfiker Retaining Walls, 2014)

Soil Reinforcement • Types § Inextensible (Metallic) § Extensible (Geosynthetics) • Configurations § § Strips Straps Grids Mesh

Metallic Ribbed Strips (Passe, 2000)

Metallic Grid (Passe, 2000)

Geogrid (Xiao, Tehrani, & Zoghi, 2013) (Passe, 2000)

Failure Modes of MSE Walls • External Stability • Internal Stability • Compound Stability

External Stability • Sliding • Bearing Capacity • Eccentricity (Overturning) • Settlement • Overall/Global Stability

Internal Stability • Reinforcement Rupture • Reinforcement Interaction with Reinforced Fill (Pullout Strength) • Connection Strength

Compound Stability • Modes initiated outside the reinforced zone and exit through the reinforcement and facing.

Construction Sequence of MSE Walls with Precast Panel Facings • Preparation of subgrade. • Placement of a leveling pad for the erection of the facing elements. • Erection of the first row of facing panels on the prepared leveling pad. • Placement and compaction of reinforced wall fill on the subgrade to the level of the first layer of reinforcement and its compaction. • Placement of the first layer of reinforcing elements on the wall fill. • Placement of the wall fill over the reinforcing elements to the level of the next reinforcement layer and compaction of the wall fill. • Construction of traffic barriers and copings.

Placement of Leveling Pad (Ohio Department of Transportation, 2013)

Placement of First Row of Panels on Leveling Pad (Ohio Department of Transportation, 2013)

54 CULVERT / MSE WALL INTERACTION www. concrete-pipe. org

Common Questions • Loads – Factored or Unfactored • Load Type – Dead Load or Live Load (Traffic Surcharge) • Influence Zone of Load • Load Distribution Through Soil • Back-to-Back Walls • Culvert Placement and Orientation • Effect of Copings and Safety Barriers • Effects of Settlement

Comparison of MSE Wall Project Data

59 UNDERSTANDING AND ADDRESSING THE COMPLEXITIES WHEN DESIGNING EACH SYSTEM www. concrete-pipe. org

Involvement of Multiple Entities • • • Owner / Agency Project Civil / Structural Design Engineer Geotechnical Engineer MSE Wall Design Engineer MSE Wall Supplier MSE Wall Installer QA Testing Firm Precast Pipe/Box Supplier Precast Pipe/Box Designer

Division of Responsibility • External Stability – Owner / Geotech Consultant § Global stability of structure § Bearing capacity analysis § Settlement analysis • Internal Stability – MSE Wall System Supplier / Designer § § Pullout and rupture of reinforcements Design of all wall system components Check sliding and overturning Determine eccentricity of structure and applied bearing pressure at base of structure

Design Methods • • • Coherent Gravity Method Tieback Wedge Design Method AASHTO Simplified Method FHWA Structure Stiffness Method K-Stiffness Method Ehrlich and Mitchell Method

MSE Wall Specifications • ASD / LRFD • US / Metric Units • FHWA Standard Specifications for Reinforced Earth (MSE Walls) • AASHTO Standard Specification for Highway Bridge • AASHTO LRFD Bridge Design Specification • State DOT Specifications

Recommendations • Review project plans closely. • Get as much information upfront as possible. • Communicate with all involved parties. • Clearly indicate any assumptions that were used, and who should verify them.

65 QUESTIONS AND COMMENTS www. concrete-pipe. org

REFERENCES • • Anderson, P. L. , & Brabant, K. (2005, June). Increased use of MSE Abutments. In International Bridge Conference. Anderson, P. L. , Gladstone, R. A. , & Sankey, J. E. (2012). State of the practice of MSE wall design for highway structures. Proceedings of the Geocongress 2012, state of the art and practice in geotechnical engineering, Oakland, March 25, 29. Berg, R. R. , Christopher, B. R. , & Samtani, N. C. (2009). Design of Mechanically Stabilized Earth Walls and Reinforced Soil Slopes–Volume I (No. FHWA-NHI-10 -024). Bourdeau, P. L. , Fox, P. J. , Runser, D. J. , & Lee, J. P. (2001). Development of Low Cost Retaining Walls for Indiana Highways (No. FHWA/IN/JTRP-2001/3, ). Earth. Tec (n. d. ) Retrieved from http: //www. earthteccorp. com/applications Freyssinet. (2005, First Half). The Saga of a Very Constructive Idea. Soils & Structures. Retrieved from http: //www. freyssinet. com/freyssinet/wfreyssinet_en. nsf/0/89 B 671553128 F 0 BCC 1257 C 6 A 00337305/$file/221 GB. PDF Hart Crowser. (2015). Sea-Tac Third Runway. Retrieved from http: //www. hartcrowser. com/roads-bridges-highways---shoring-projects. html Hilfiker Retaining Walls. (2014). Artweld Gabions. Retrieved from http: //www. hilfiker. com/awg. html www. concrete-pipe. org

REFERENCES • • • NTE Mobility Partners. (2015). March 2013: Retaining walls on eastbound IH 820 frontage road near Holiday Lane. Retrieved from http: //www. northtarrantexpress. com/Photos/MSE%20 walls%20 on%20 the%20 eastbound %20 IH%20820%20 frontage%20 road%20 just%20 before%20 Holiday%20 Lane. JPG Ohio Department of Transportation (2013). 2013 Construction Administration Manual of Procedures. Columbus, OH: Author. Retrieved from http: //www. dot. state. oh. us/Divisions/Construction. Mgt/Online. Docs/2013 MOP/Supplemen ts/SS_840. htm Parsons Corporation. (2015). New Expressway Alleviates Congestion and Accommodates Future Growth. Retrieved from http: //www. parsons. com/projects/Pages/muscat-expressway. aspx Passe, P. D. (2000). Mechanically Stabilized Earth Wall Inspector's Handbook. State of Florida, Department of Transportation. Stuedlein, A. W. , Bailey, M. , Lindquist, D. , Sankey, J. , & Neely, W. J. (2010). Design and performance of a 46 -m-high MSE wall. Journal of Geotechnical and Geoenvironmental Engineering, 136(6), 786 -796. Stuedlein, A. W. , Allen, T. M. , Holtz, R. D. , & Christopher, B. R. (2011). Assessment of reinforcement strains in very tall mechanically stabilized earth walls. Journal of Geotechnical and Geoenvironmental Engineering, 138(3), 345 -356. www. concrete-pipe. org

REFERENCES • • The Reinforced Earth Company. (2011). Forty Years of Innovation. Retrieved from http: //www. reinforcedearth. com/sites/default/files/40 th_anniversary_brochure_0. pdf Xiao, M. , Tehrani, F. , & Zoghi, M. (2013). Seismic Responses of MSE Walls Using Accelerated Alternative Backfill Materials with Recycled Tires Shreds and Lightweight Expanded Aggregates (No. CA 13 -2416). www. concrete-pipe. org