MSE Wall Design by LRFD

This example is from AASHTO LRFD Bridge Design Specifications:

Project Information:

User Name: Anna Date: 8/23/2009 Seismic Analysis OFF A= 0 g

Wall Unit Data Wall DataHu=SRW unit height 0.5 m H=Wall height 7 mWu=SRW unit width 1 m Hemb=Embedded depth 0.35 mγu=Unit Weight of SRW unit 120 kn/m^3 β=Angle of back slope 0 degω=Wall batter 0 deg ql=Live Surcharge 12.283 KN/Mαsu=Shear Capacity between segmental unit 400 KN/M qd=Dead Surcharge 0 KN/Mλu=apparent angle of friction between segmental unit 30 deg ψ=Front slope 0.00 deg

Reinforced Soil Data Retained Soil Dataφi=Angle of friction of reinforced soil 38 deg φe=Angle of friction of retained soil 38 degγi=Unit Weight of reinforced soil 17.3 kn/m^3 γe=Unit Weight of retained soil 17.3 kn/m^3

Foundation Soil Data Groundwaterφf=Angle of friction of foundation soil 28 deg Hwd -1.9 mCf=cohesion of foundation soil 0 kn/m^2 Hwi 0 mγf=Unit Weight of foundation soil 20.5 kn/m^3 Hwe 0 m

Reinforcement Data

mMetal Strip Width Horizontal Spacing Metal Strip Load Capacity

Metal Strip-PanelConnection Capacity

Geogrid1.0m KN KN

LRFD-2 32.100 0.80

REPORT OF SEGMENTAL RETAINING WALL ANALYSIS

LRFD-Example 2

INPUT DATA

WITH AASHTO METHOD (LRFD)

Name

8/23/2009 1 Visual Slope

0.1656 m

0.24Kae=Dynamic Coefficient of Lateral Earth Pressure from Retained Soil 0.24Δkdyn=Kae-Ka 0.00e 0.378 e/L 0.076 Nc 25.80 Nγ 16.72Direct Sliding Fsl 1.72 Overturning Fot 3.17 Bearing Capacity Fbr 12.06

Layer # Elevation Length AllowableStrength

AnchorageLength Eccentricity CDR

overstress CDR pullout CDR sliding CDR overturning

CDR connection

1 11.7 5.0 32.1 1.8 0.00 6.25 9.18 45.10 1157.36 4.612 11.0 5.0 32.1 2.1 0.02 4.02 10.71 17.09 156.36 5.963 10.3 5.0 32.1 2.4 0.04 2.97 12.33 11.03 63.43 6.624 9.7 5.0 32.1 2.7 0.07 2.34 13.78 8.27 35.28 6.935 9.0 5.0 32.1 3.0 0.11 1.89 15.02 6.64 22.53 7.026 8.3 5.0 32.1 3.4 0.16 1.60 16.36 5.55 15.71 7.117 7.7 5.0 32.1 3.7 0.21 1.36 17.46 4.79 11.66 7.078 7.0 5.0 32.1 4.0 0.28 1.16 18.27 4.21 8.98 6.919 6.3 5.0 32.1 4.3 0.35 1.02 19.18 3.75 7.13 6.8210 5.7 5.0 32.1 4.8 0.43 0.59 13.39 3.39 5.82 4.41

LRFD-2LRFD-2LRFD-2LRFD-2LRFD-2LRFD-2LRFD-2

Settlement

RESULT OF ANALYSIS

External Stability

Ka=Coefficient of Lateral Earth Pressure from Retained Soil

Internal Stability

Name

LRFD-2LRFD-2LRFD-2

8/23/2009 2 Visual Slope

Dead Load Surcharge, ES - γp-ES 1.5 1.5 Geosynthetic Tensile Strength & Connection, φ 0.9 1.2Metal Strip Tensile Strength & Connection, φ 0.75 1

Live Load Surcharge, LS - γp-LS 1.75 1.75 Metal Grid Tensile Strength & Connection, φ 0.65 0.85

Seismic Load, EQ - γp-EQ 0 1 Pullout Resistance, φ 0.9 1.2

Vertical Earth Pressure, EV - γp-EV 1.35 1.35 Bearing Capacity, φ 0.5 0.5

1 1 1 1

Active Horizontal Earth Pressure, EH - γp-EH 1.5 1.5 1 1

AASHTO LRFD FACTORS

Vertical Earth Pressure, EV - γp-EV

(Sliding & Eccentricity)

Load Factors

Static Static-Seismic

Sear Resistance, φτ(reinforced soil and foundation soil)

Sear Resistance, φτ(reinforced soil and foundation soil)

Resistance Factor

Static Static-Seismic

8/23/2009 3 Visual Slope