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From page 216... ... 5- 1 CHAPTER 5 EXTERNAL (GLOBAL) STABILITY EVALUATION OF GEOFOAM EMBANKMENTS Contents Introduction...................................................................................................................................5-4 Embankment Geometry ................................................................................................................5-5 Cross-Sectional Geometry........................................................................................................5-5 Longitudinal Geometry.............................................................................................................5-7 Embankment Cover ......................................................................................................................5-7 Trapezoidal Embankments .......................................................................................................5-8 Vertical Embankments .............................................................................................................5-9 Settlement of Embankment.........................................................................................................5-10 Introduction ............................................................................................................................5-10 Settlement Due to End-Of-Primary (EOP) Read the entire page →
From page 217... ... 5- 2 Interpretation of External Bearing Capacity Design Chart.....................................................5-32 Remedial Procedures ..............................................................................................................5-32 External Slope Stability of Trapezoidal Embankments ..............................................................5-33 Introduction ............................................................................................................................5-33 Typical Cross-Section.............................................................................................................5-33 Static Stability Analysis Procedure ........................................................................................5-34 Material Properties .................................................................................................................5-35 Location of Critical Static Failure Surface .............................................................................5-40 Design Charts .........................................................................................................................5-42 Interpretation of External Slope Stability Design Chart.........................................................5-44 Remedial Procedures ..............................................................................................................5-44 External Seismic Stability of Trapezoidal Embankments...........................................................5-45 Introduction ............................................................................................................................5-45 Seismic Shear Strength Parameters ........................................................................................5-47 Horizontal Seismic Coefficient ..............................................................................................5-48 Seismic Stability Analysis Procedure.....................................................................................5-53 Design Charts .........................................................................................................................5-54 Interpretation of Seismic Slope Stability Design Chart..........................................................5-57 Remedial Procedures ..............................................................................................................5-58 External Slope Stability of Vertical Embankments ....................................................................5-59 Introduction ............................................................................................................................5-59 Typical Cross-Section.............................................................................................................5-59 Static Stability Analysis Procedure ........................................................................................5-60 Material Properties .................................................................................................................5-61 Location of Critical Static Failure Surface .............................................................................5-62 Design Charts .........................................................................................................................5-65 Read the entire page →
From page 218... ... 5- 3 Interpretation of External Slope Stability Design Charts .......................................................5-67 Remedial Procedures ..............................................................................................................5-68 External Seismic Stability of Vertical Embankments.................................................................5-68 Introduction ............................................................................................................................5-68 Seismic Stability Analysis Procedure.....................................................................................5-69 Design Charts .........................................................................................................................5-70 Remedial Procedures ..............................................................................................................5-73 Overturning.............................................................................................................................5-73 Hydrostatic Uplift (Flotation) .....................................................................................................5-75 Introduction ............................................................................................................................5-75 Remedial Procedures ..............................................................................................................5-83 Translation and Overturning Due to Water (Hydrostatic Sliding and Overturning) Read the entire page →
From page 219... ... 5- 4 INTRODUCTION Design for external (global) stability of the overall EPS-block geofoam embankment involves consideration of how the combined fill mass and overlying pavement system interact with the foundation soil. Read the entire page →
From page 220... ... 5- 5 EPS-block geofoam, and the use of an EPS block with the lowest possible density. Therefore, the design procedure starts with the least expensive pavement/embankment system in the anticipation that a cost efficient design will be produced. Read the entire page →
From page 221... ... 5- 6 are shown in Figure 3.4. Unlike other types of lightweight and soil fills, EPS is actually a solid material with internal strength. Read the entire page →
From page 222... ... 5- 7 Longitudinal Geometry Two aspects of the geometry of the embankment in the longitudinal direction (parallel to the roadway) that need to be considered during design include orientation of the EPS blocks and the transition zone between the geofoam and non-geofoam sections of the roadway. Read the entire page →
From page 223... ... 5- 8 Trapezoidal Embankments For a trapezoidal fill embankment, the covering system typically consists of a thin layer of soil placed directly over the stepped edges of the EPS blocks. Vegetation is incorporated on the surface of the soil layer for erosion control. Read the entire page →
From page 224... ... 5- 9 in.) thick with a total (moist) Read the entire page →
From page 225... ... 5- 10 SETTLEMENT OF EMBANKMENT Introduction Settlement is the amount of vertical deformation that occurs from immediate or elastic settlement of the fill mass or foundation soil, consolidation and secondary compression of the foundation soil, and long-term creep of the fill mass at the top of a highway embankment. Settlement caused by lateral deformation of the foundation soil at the edges of an embankment is not considered because (7) Read the entire page →
From page 226... ... 5- 11 immediate settlements are not typically included in the total settlement estimate and the settlement analysis presented herein focuses on primary and secondary consolidation of the foundation soil and creep of the fill mass. However, immediate settlement of the foundation soil should be considered if the embankment will be placed over existing utilities. Read the entire page →
From page 227... ... 5- 12 Soils that have not been subjected to effective vertical stresses higher than the present effective overburden pressure are considered normally consolidated and have a value of σ'p/σ'vo of unity. For normally consolidated foundation soil, Equation (5.2) Read the entire page →
From page 228... ... 5- 13 Equation (5.5) Read the entire page →
From page 229... ... 5- 14 Field values of tp for layers of soil that do not contain permeable layers and peats can range from several months to many years. However, for the typical useful life of a structure, the value of the t/ tp rarely exceeds 100 and is often less than 10 (7) Read the entire page →
From page 230... ... 5- 15 lightweight fill applications even when projected for 50 years or more. The stress level at 1 percent strain corresponds to approximately 50 percent of the compressive strength or 67 percent of the yield stress. Read the entire page →
From page 231... ... 5- 16 Eti = initial tangent Young's modulus of the EPS. Values of Eti can be estimated from Table 4.1 that presents values of Eti for different geofoam densities. Read the entire page →
From page 232... ... 5- 17 only exception to this is the final step of the geofoam embankment, which can consist of one block as shown in Figure 5.1. The specific layout of the EPS blocks should be determined on a project-specific basis based on calculated differential settlements such as the criteria given in (3) Read the entire page →
From page 233... ... 5- 18 side embankment (geofoam wall) is provided because of the various types of facing systems so this weight must be estimated or provided by the supplier. Read the entire page →
From page 234... ... 5- 19 ( ) I I Z qσ sin where is in radians, α α απ∆ = + (5.10) Read the entire page →
From page 235... ... 5- 20 and the other variables are defined in Figure 5.4. The surcharge induced at the center of the embankment from the triangular loaded areas, i.e., zones II and III, is estimated below for zone II because the law of superposition and the symmetry of the embankment allows consideration of only one side of the embankment: qII = qfill + qcover (5.18) Read the entire page →
From page 236... ... 5- 21 where IIZ σ∆ is multiplied by 2 to account for the vertical stress increase caused by zone III. The total increase in vertical stress at the center of a vertical embankment is only due to the vertical stress increase applied by zone I, i.e., no contributions from zones II and III because of the vertical sides of the embankment, and is estimated as follows: @center IZ Z σ σ∆ = ∆ (5.21) Read the entire page →
From page 237... ... 5- 22 ( ) II II Z q∆σ sin 2 2π δ= where δ is in radians, (5.22) Read the entire page →
From page 238... ... 5- 23 a 2barctan Z α δ+ = −   where δ and α is calculated in radians, (5.29) and the variables are defined in Figure 5.8. Read the entire page →
From page 239... ... 5- 24 3. Determine the final effective vertical stress, σ′vf , at the mid-height of each sublayer, which includes the change in effective vertical stress, ∆ σ′Z. Read the entire page →
From page 240... ... 5- 25 two categories of soft ground treatment methods indicated in Table 1.1: reducing the load by using EPS-block geofoam and replacing the problem materials by more competent materials. If the foundation soil is partially excavated, the excavation will typically need to be widened from the toe of the embankment so that the excavation side slopes remain stable during construction. Read the entire page →
From page 241... ... 5- 26 where: c = Mohr-Coulomb shear strength parameter termed cohesion, kN/m2, Nc, Nγ, Nq = Terzaghi shearing resistance bearing capacity factors, γ = unit weight of soil, kN/m3, BW = bottom width of embankment, m, and Df = depth of embedment, m. It is anticipated that most, if not all, EPS-block geofoam embankments will be founded on soft, saturated cohesive soils, because traditional fill material cannot be used in this situation without pre-treatment. Read the entire page →
From page 242... ... 5- 27 because Df equals zero, Equation (5.37) simplifies to: W c BN =5 (1+0.2 ) Read the entire page →
From page 244... ... 5- 29 σn, pavement = normal stress applied by pavement at top of embankment, kPa, σn, traffic = normal stress applied by traffic surcharge at top of embankment, kPa, and TW = top width of embankment, m. The 2V:1H stress distribution method was used because full-scale instrumented geofoam embankments in Norway (27,28) Read the entire page →
From page 245... ... 5- 30 was used in the development of the external bearing capacity design chart presented subsequently. In accordance with (30) Read the entire page →
From page 246... ... 5- 31 shoulders that are 1.2 m (4 ft) wide, and a 6-lane roadway (34 m or 112 ft) Read the entire page →
From page 247... ... 5- 32 materials that have higher unit weights because the reduction of stress-distribution effects with increasing road width will also occur in these materials. Figure 5.10 Design chart for obtaining the minimum thickness or height of geofoam, TEPS, for a factor of safety of 3 against external bearing capacity failure of a geofoam embankment. Read the entire page →
From page 248... ... 5- 33 height of the embankment will also increase the external bearing capacity because the pavement and traffic stresses are distributed over a larger height which reduces the increase in vertical stress at the top of the foundation soil resulting in an increase in bearing capacity resistance. EXTERNAL SLOPE STABILITY OF TRAPEZOIDAL EMBANKMENTS Introduction This section presents an evaluation of external slope stability as a potential failure mode of EPS-block geofoam trapezoidal embankments or embankments with sloped sides. Read the entire page →
From page 249... ... 5- 34 is placed on top of the embankment. The soil cover is 0.46 m (1.5 ft) Read the entire page →
From page 250... ... 5- 35 critical static failure surface. The Simplified Janbu stability method (31) Read the entire page →
From page 251... ... 5- 36 Selection of the shear strength parameters for the EPS-block geofoam within the embankment revealed some uncertainties in the modeling of geofoam in slope stability analyses. The lack of field case histories that illustrate the actual failure mode of the geofoam during an external slope stability failure resulted in uncertainty in whether during such a failure sliding occurs between the EPS blocks or through the EPS blocks. Read the entire page →
From page 252... ... 5- 37 surcharges so the strength of the geofoam did not have to be considered. This approach was not selected because it could not be used for seismic stability analyses because the seismic force is applied at the center of gravity of the slide mass (see following section of this chapter) Read the entire page →
From page 253... ... 5- 38 be used to model the geofoam in the internal stability analyses in Chapter 6 because failure is assumed to occur between the EPS blocks and thus the EPS/EPS interface strength is applicable. The scenario used to model the geofoam strength for external slope stability analyses assumes that failure occurs through the EPS blocks and thus a cohesion value that adequately represents the shear strength of a geofoam block was sought. Read the entire page →
From page 254... ... 5- 39 used in conjunction with the peak strength of the foundation soil in order to prevent progressive failure of the embankment. Progressive failure can occur when one material fails, e.g., the geofoam, and the stresses that were being resisted by that material are transferred to the another material, e.g., the foundation soil, which can result in overstressing of this material especially if it does not mobilize its peak strength at the same strain as the failed material. Read the entire page →
From page 255... ... 5- 40 Therefore, consideration of strain incompatibility results in a reduction of the cohesion value used to represent the shear strength of the geofoam of approximately 20 to 40 percent. The value of cohesion shown in Table 5.2 was reduced by the appropriate reduction factor and the resulting value was used in the external slope stability analyses to model the geofoam. Read the entire page →
From page 256... ... 5- 41 The transition from the critical failure surface remaining in the foundation soil versus remaining in the embankment can be used to identify the value of su for the foundation soil that corresponds to internal stability being more critical than external stability. For example, if the su value for the foundation soil at a particular site is equal to or greater than 36 kPa (752 lbs/ft2) Read the entire page →
From page 257... ... 5- 42 Design Charts The results of the stability analyses were used to develop the static external slope stability design charts in Figures 5.14 through 5.16 for a 2-lane (road width of 11 m (36 ft) Read the entire page →
From page 258... ... 5- 43 of the foundation soil exceeds the value that corresponds to the maximum value of the appropriate relationship in Figures 5.14 through 5.16, internal stability is more critical than external stability. In summary, external slope stability does not appear to be the controlling external failure mechanism, instead it appears that settlement will be the controlling external failure mechanism. Read the entire page →
From page 259... ... 5- 44 Interpretation of External Slope Stability Design Chart Comparison of the factors of safety in Figures 5.14 through 5.16 also reveals that the critical case for external slope stability is a 6-lane embankment (34.1 m or 112 ft) with a 2H:1V slope and a height of EPS block equal to 12.2 m (40 ft) Read the entire page →
From page 260... ... 5- 45 EXTERNAL SEISMIC STABILITY OF TRAPEZOIDAL EMBANKMENTS Introduction Seismic loading is a short-term event that must be considered in geotechnical problems including road embankments. Seismic loading can affect both external and internal stability of an embankment containing EPS-block geofoam. Read the entire page →
From page 261... ... 5- 46 force is applied to the center of gravity of each vertical slice that simulates the inertial forces generated by horizontal shaking. This horizontal force (F) Read the entire page →
From page 262... ... 5- 47 4. Calculate the pseudo-static factor of safety, FS', for the critical static failure surface and ensure it meets the required value. Read the entire page →
From page 263... ... 5- 48 interface strength. However, this value of shear strength should be reduced for strain incompatibility with the foundation soil as was described for the external slope stability analyses. Read the entire page →
From page 264... ... 5- 49 relationships that relate the bedrock acceleration to the ground surface acceleration for different soil types. If a one-dimensional site response analysis is conducted using a program such as SHAKE (46) Read the entire page →
From page 265... ... 5- 50 Additional discussion of one-dimensional site response analyses for geofoam embankments is beyond the scope of this project. Thus, the use of existing empirical relationships for estimating the base acceleration from the bedrock acceleration is discussed in detail. Read the entire page →
From page 266... ... 5- 51 characterized as a soft clay or peat, the site response relationship in Figure 5.18 should be used to estimate the ground surface acceleration from the bedrock acceleration. It can be seen that the median relationship at bedrock accelerations less than 0.4g predicts ground surface accelerations that are greater than the bedrock accelerations with a maximum amplification factor of approximately two. Read the entire page →
From page 267... ... 5- 52 vertically through the embankment. Amplification has been observed in soil embankments (37) Read the entire page →
From page 268... ... 5- 53 was disregarded because of the potential for slippage between the blocks and the deep cohesionless soil relationship provides a more conservative design. In summary, Figure 5.17 can be used with the base acceleration to estimate the acceleration at the top of the embankment and linear interpolation can be used to estimate the acceleration, and thus horizontal seismic coefficient, at the center of gravity of the critical static slide mass. Read the entire page →
From page 269... ... 5- 54 embankment a unit weight of 71.8 kN/m3 (460 lbf/ft³) Read the entire page →
From page 270... ... 5- 55 seismic coefficient greater 0.20 indicate a severe seismic environment and a site-specific seismic analysis, including a site response analysis, should be conducted instead of using simplified design charts. The pseudo-static factor of safety for the critical static failure surfaces previously identified using the Simplified Janbu stability method was calculated for each geometry considered for the development of the design charts. Read the entire page →
From page 271... ... 5- 56 (3) A horizontal seismic coefficient of 0.20 results in values of FS' that do not satisfy the required value of 1.2 for all embankment inclinations (see Figure 5.23) Read the entire page →
From page 272... ... 5- 57 factor of safety of 1.2. It can been seen in Figure 5.26 that an su of at least 36 kPa (750 lbs/ft²) Read the entire page →
From page 273... ... 5- 58 slope inclination, using a value of su that reflects seismic loading and the thickness or height of EPS used in the embankment to obtain the pseudo-static factor of safety. For example, a 6-lane geofoam roadway embankment is proposed for a soft foundation soil that exhibits an undrained shear strength of 20 kPa (418 lbs/ft²) Read the entire page →
From page 274... ... 5- 59 using a ground improvement method. A discussion on ground improvement is provided in Chapter 1. Read the entire page →
From page 275... ... 5- 60 (21.5 kPa (450 lbs/ft²) Read the entire page →
From page 276... ... 5- 61 involved calculating the factor of safety for the critical static failure surface. The Simplified Janbu stability method (31) Read the entire page →
From page 277... ... 5- 62 incompatibility as discussed previously in the sub-section entitled "Material Properties" and in the section entitled "External Slope Stability of Trapezoidal Embankments." The phreatic surface was located at or near the ground surface and the foundation soil was assumed to be saturated as is typically the case at most EPS-block geofoam sites. Location of Critical Static Failure Surface The first step in the external slope stability analyses was to locate the critical static failure surface in the foundation soil. Read the entire page →
From page 278... ... 5- 63 search for the critical failure surface was limited to critical failure surfaces that extend into the foundation soil. Figure 5.31(a) Read the entire page →
From page 279... ... 5- 64 similar and the failure surface originates near the toe of the embankment and terminates near the center of the embankment. At the smaller embankment width of 11 m (36 ft) Read the entire page →
From page 280... ... 5- 65 of 6.1 m (20 ft) than 3.1 m (10 ft) Read the entire page →
From page 281... ... 5- 66 roadway embankment, respectively, and the three graphs correspond to the three embankment heights considered, i.e., 3.1 m (10 ft) Read the entire page →
From page 282... ... 5- 67 heavier foundation soil below the toe of the embankment provides more of the resisting load to the failure surface. Figure 5.35. Read the entire page →
From page 283... ... 5- 68 lbs/ft²) because this case may yield factors of safety of less than 1.5. Read the entire page →
From page 284... ... 5- 69 The same steps outlined in this chapter in the sub-sections entitled "Introduction," "Seismic Shear Strength," and "Horizontal Seismic Coefficient" of the section entitled "External Seismic Stability of Trapezoidal Embankments" are used in an external pseudo-static stability analysis of EPS-block geofoam vertical embankments. In seismic design of vertical embankments the following two analyses should be performed: 1) Read the entire page →
From page 285... ... 5- 70 horizontal seismic coefficient. It can be seen that the pavement and traffic surcharges yield the largest horizontal force because the weight of the soil layer used to model the surcharge results in the largest weight. Read the entire page →
From page 286... ... 5- 71 converge for the vertical wall embankment geometries investigated and Bishop's simplified method was also used for these cases. The seismic analyses were conducted without reducing the shear strength of the foundation soil to account for strain incompatibility or seismic loading as discussed in this chapter in the sub-section entitled "Material Properties" of the section entitled "External Slope Stability of Trapezoidal Embankments" because the design charts present the pseudo-static factor of safety for the critical versus undrained shear strength (see Figure 5.37) Read the entire page →
From page 287... ... 5- 72 required to satisfy a factor of safety of 1.2 especially for the 4H:1V embankment. Read the entire page →
From page 288... ... 5- 73 embankment and a total width of 23 m (76 ft) Read the entire page →
From page 289... ... 5- 74 The soil pressure under a vertical embankment is a function of the location of the vertical and horizontal forces. It is generally desirable that the resultant of the vertical and horizontal forces be located within the middle third of the base of the embankment, i.e., eccentricity, e ≤ (TW/6) Read the entire page →
From page 290... ... 5- 75 The soil pressures should not exceed the allowable soil pressure, qa, which is given by Equation (5.39) Read the entire page →
From page 291... ... 5- 76 the tailwater side. With postconstruction settlements of 0.3 to 0.6 m (1 to 2 ft) Read the entire page →
From page 292... ... 5- 77 Figure 5.41. Variables for determining hydrostatic uplift for the case of water equal on both sides of the embankment. Read the entire page →
From page 293... ... 5- 78 covercover TH . Read the entire page →
From page 294... ... 5- 79 Equation (5.59) also can be rearranged and used to obtain the value of OREQ required to obtain the desired factor of safety of 1.2. Read the entire page →
From page 295... ... 5- 80 Wpavement = 21.5 kN/m2 * 23.2 m = 498.8 kN/m of roadway (5.70) Read the entire page →
From page 296... ... 5- 81 dam structure that may require unreasonable overburden forces on top of the EPS blocks to obtain the desired factor of safety. The design charts were only created for EPS40 and not EPS50, 70, or 100 because the results of a sensitivity analysis revealed that the value of OREQ required on top of an EPS-block geofoam embankment for a factor of safety of 1.2 is not sensitive to the density of the EPS geofoam. Read the entire page →
From page 297... ... 5- 82 For the case of the total vertical height of tailwater, h'+Stotal, equals zero (see Figure 5.47) , Equation (5.59) Read the entire page →
From page 298... ... 5- 83 Figure 5.51. Hydrostatic uplift (flotation) Read the entire page →
From page 299... ... 5- 84 pavement system materials on top of the EPS thereby increasing the overburden over the EPS blocks. • A drainage system can be incorporated to minimize the potential for water to accumulate along the embankment. Read the entire page →
From page 300... ... 5- 85 foundation soil) , the resisting force (which equals the dead weight times the tangent of δ) Read the entire page →
From page 301... ... 5- 86 Stotal=total settlement as defined by Equation (5.1) BW = bottom of embankment width As described for the analysis of hydrostatic uplift, OREQ is the additional overburden force required above the EPS blocks to obtain the desired factor of safety. Read the entire page →
From page 302... ... 5- 87 safety of 1.2 against hydrostatic sliding at the EPS block/foundation soil interface as was demonstrated for the hydrostatic uplift design charts. Embankment top widths of 11m (36 ft) Read the entire page →
From page 303... ... 5- 88 start of construction and the estimated total settlement, i.e., h+Stotal. The design charts only extend to a maximum ratio of accumulated water level to embankment height of 0.5, which means the total water depth plus the estimated total settlement is limited to 50 percent of the embankment height. Read the entire page →
From page 304... ... 5- 89 Overturning For vertical embankments, the tendency of the entire embankment to overturn at the interface between the bottom of the assemblage of EPS blocks and the underlying foundation soil is a result of an unbalanced water pressure acting on the embankment. Overturning may be critical for tall and narrow vertical embankments. Read the entire page →
From page 305... ... 5- 90 Equation (5.79) can be used to obtain the required value of OREQ for a factor of safety of 1.2 to resist hydrostatic overturning. Read the entire page →
From page 306... ... 5- 91 Figure 5.53. Hydrostatic sliding (translation due to water) Read the entire page →
From page 307... ... 5- 92 with the variable definitions re-defined for calculating wind forces instead of hydrostatic forces. Figure 5.57 defines the forces and pressures acting on a generic trapezoidal embankment with a side-slope inclination of θ, height of H, and top-width of TW. Read the entire page →
From page 308... ... 5- 93 2D Dp 0.75V sin= θ (3.5) with V = the wind speed in meters per second, pU and pD have units of kilopascals and the other variables are defined in Figure 5.57. Read the entire page →
From page 309... ... 5- 94 The components usually contributing to OREQ are the weight of the pavement system and the cover soil on the embankment side slopes. Therefore, to ensure the desired factor of safety, the calculated value of OREQ should be less than the sum of the pavement and cover soil weights as shown in Equation (5.65) Read the entire page →
From page 310... ... 5- 95 safety of 1.2 against translation to wind is not sensitive to other values of EPS density as noted previously in the hydrostatic uplift and hydrostatic sliding sections of this chapter. Figure 5.58. Read the entire page →
From page 311... ... 5- 96 to provide sufficient stability against a 40 m/s (90 mph) wind speed. Read the entire page →
From page 312... ... 5- 97 assumed to be horizontal instead of perpendicular to the side-sloped surface, which would yield both a horizontal and a vertical component to the wind pressure. • No guidance is provided in (60) Read the entire page →
From page 313... ... 5- 98 Overturning For vertical embankments, the entire embankment can overturn at the interface between the bottom of the assemblage of EPS blocks and the underlying foundation soil due to horizontal wind forces acting on the embankment. These wind forces can create an overturning moment about the toe at point O as shown in Figure 5.59. Read the entire page →
From page 314... ... 5- 99 the potential for the wall to overturn. Equations (5.55) Read the entire page →
From page 315... ... 5- 100 12. Nishida, Y., "A brief note on compression index of soil." Journal of the Soil Mechanics and Foundations Division, ASCE, Vol. Read the entire page →
From page 316... ... 5- 101 29. Boussinesq, J., Application des Potentiels à l' Étude de l' Équilibre et du Mouvement des Solides Élastiques, Gauthier-Villard, Paris (1885) Read the entire page →
From page 317... ... 5- 102 45. Yegian, M Read the entire page →
From page 318... ... 5- 103 60. Magnan, J.-P., "Recommandations pour L'Utilisation de Polystyrene Expanse en Remblai Routier." Laboratoire Central Ponts et Chaussées, France (1989) Read the entire page →
From page 319... ... FIGURE 5.1 PROJ 24-11.doc 5-104 Read the entire page →
From page 320... ... FIGURE 5.2 PROJ 24-11.doc 5-105 Read the entire page →
From page 321... ... FIGURE 5.3 PROJ 24-11.doc α Ι 5-106 Read the entire page →
From page 322... ... FIGURE 5.4 PROJ 24-11.doc α δ ΙΙ 5-107 Read the entire page →
From page 323... ... FIGURE 5.5 PROJ 24-11.doc Pavement System So il c ov er coverT EPST EPS Soil coverEPST ba ab Centeredge θ θ (a) EPS Inner Edge of Outer edge of Soil Cover T T Block Thickness Step Length EPS Blocks EPS Blocks block edges cover (b) Read the entire page →
From page 324... ... FIGURE 5.6 PROJ 24-11.doc δ ΙΙ 5-109 Read the entire page →
From page 325... ... FIGURE 5.7 PROJ 24-11.doc δ α ΙΙΙ 5-110 Read the entire page →
From page 326... ... FIGURE 5.8 PROJ 24-11.doc αδ Ι 5-111 Read the entire page →
From page 327... ... FIGURE 5.9 PROJ 24-11.doc α Ι 5-112 Read the entire page →
From page 328... ... FIGURE 5.10 PROJ 24-11.doc M in im u m th ic kn es s o f E PS -b lo ck g eo fo am , T E PS (m ) 10 11 12 13 14 15 16 17 18 19 20 Undrained Shear Strength, s u (kPa) Read the entire page →
From page 329... ... FIGURE 5.11 PROJ 24-11.doc 0.46 m 0.46 m Soil Cover EPS T EPS Traffic and Pavement Surcharge 2 1 2 1 Not to Scale (soil cover thickness exaggerated) Read the entire page →
From page 330... ... FIGURE 5.12 PROJ 24-11.doc 5-115 Read the entire page →
From page 331... ... FIGURE 5.13 PROJ 24-11.doc 5-116 Read the entire page →
From page 332... ... FIGURE 5.14 PROJ 24-11.doc Undrained Shear Strength, su (kPa) 10 15 20 25 30 35 40 45 50 Fa ct or o f S af et y, FS 1.0 2.0 3.0 4.0 5.0 6.0 7.0 8.0 Undrained Shear Strength, su (kPa) Read the entire page →
From page 333... ... FIGURE 5.15 PROJ 24-11.doc Undrained Shear Strength, su (kPa) 10 15 20 25 30 35 40 45 50 Fa ct o r o f S af et y, F S 1.0 2.0 3.0 4.0 5.0 6.0 7.0 8.0 Undrained Shear Strength, su (kPa) Read the entire page →
From page 334... ... FIGURE 5.16 PROJ 24-11.doc Undrained Shear Strength, su (kPa) 10 15 20 25 30 35 40 45 50 Fa ct o r o f S af et y, FS 1.0 2.0 3.0 4.0 5.0 6.0 7.0 8.0 Undrained Shear Strength, su (kPa) Read the entire page →
From page 335... ... FIGURE 5.17 PROJ 24-11.doc Maximum Acceleration on Rock, g 0.0 0.1 0.2 0.3 0.4 0.5 0.6 0.7 M ax im u m A cc el er at io n , g 0.0 0.1 0.2 0.3 0.4 0.5 0.6 Rock Stiff Soils Deep Cohesionless Soils Medium Stiff Clay and Sand 5-120 Read the entire page →
From page 336... ... FIGURE 5.18 PROJ 24-11.doc 5-121 Read the entire page →
From page 337... ... FIGURE 5.19 PROJ 24-11.doc γ 5-122 Read the entire page →
From page 338... ... FIGURE 5.20 PROJ 24-11.doc 5-123 Read the entire page →
From page 339... ... FIGURE 5.21 PROJ 24-11.doc 11 m pavement, kh=0.05 Undrained Shear Strength, su (kPa) 10 20 30 40 50 Se ism ic Fa ct o r o f S af et y, F S' 0.0 1.0 2.0 3.0 4.0 Undrained Shear Strength, su (kPa) Read the entire page →
From page 340... ... FIGURE 5.22 PROJ 24-11.doc 11 m pavement, kh=0.10 Undrained Shear Strength, su (kPa) 10 20 30 40 50 Se ism ic Fa ct or o f S af et y, FS ' 0.0 1.0 2.0 3.0 4.0 Undrained Shear Strength, su (kPa) Read the entire page →
From page 341... ... FIGURE 5.23 PROJ 24-11.doc 11 m pavement, kh=0.20 Undrained Shear Strength, su (kPa) 10 20 30 40 50 Se ism ic Fa ct or o f S af et y, FS ' 0.0 1.0 2.0 3.0 4.0 Undrained Shear Strength, su (kPa) Read the entire page →
From page 342... ... FIGURE 5.24 PROJ 24-11.doc 23 m pavement, kh=0.05 Undrained Shear Strength, su (kPa) 10 20 30 40 50 Se ism ic F ac to r o f S af et y, FS ' 0.0 1.0 2.0 3.0 4.0 5.0 Undrained Shear Strength, su (kPa) Read the entire page →
From page 343... ... FIGURE 5.25 PROJ 24-11.doc 23 m pavement, kh=0.10 Undrained Shear Strength, su (kPa) 10 20 30 40 50 Se ism ic F ac to r o f S af et y, FS ' 0.0 1.0 2.0 3.0 4.0 5.0 Undrained Shear Strength, su (kPa) Read the entire page →
From page 344... ... FIGURE 5.26 PROJ 24-11.doc 23 m pavement, kh=0.20 Undrained Shear Strength, su (kPa) 10 20 30 40 50 Se ism ic Fa ct o r o f S af et y, FS ' 0.0 1.0 2.0 3.0 4.0 5.0 Undrained Shear Strength, su (kPa) Read the entire page →
From page 345... ... FIGURE 5.27 PROJ 24-11.doc 34 m pavement, kh=0.05 Undrained Shear Strength, su (kPa) 10 20 30 40 50 Se ism ic F ac to r o f S af et y, FS ' 0.0 1.0 2.0 3.0 4.0 5.0 Undrained Shear Strength, su (kPa) Read the entire page →
From page 346... ... FIGURE 5.28 PROJ 24-11.doc 34 m pavement, kh=0.10 Undrained Shear Strength, su (kPa) 10 20 30 40 50 Se is m ic F ac to r o f S af et y, FS ' 0.0 1.0 2.0 3.0 4.0 5.0 Undrained Shear Strength, su (kPa) Read the entire page →
From page 347... ... FIGURE 5.29 PROJ 24-11.doc 34 m pavement, kh=0.20 Undrained Shear Strength, su (kPa) 10 20 30 40 50 Se ism ic F ac to r o f S af et y, FS ' 0.0 1.0 2.0 3.0 4.0 5.0 Undrained Shear Strength, su (kPa) Read the entire page →
From page 348... ... FIGURE 5.30 PROJ 24-11.doc γ 5-133 Read the entire page →
From page 349... ... FIGURE 5.31A PROJ 24-11.doc 5-134 Read the entire page →
From page 350... ... FIGURE 5.31B PROJ 24-11.doc 5-135 Read the entire page →
From page 351... ... FIGURE 5.32 PROJ 24-11.doc 5-136 Read the entire page →
From page 352... ... FIGURE 5.33 PROJ 24-11.doc 5-137 Read the entire page →
From page 353... ... FIGURE 5.34 PROJ 24-11.doc Undrained Shear Strength, su (kPa) 10 15 20 25 30 35 40 45 50 Fa ct o r o f S af et y, FS 1.0 2.0 3.0 4.0 5.0 6.0 7.0 Undrained Shear Strength, su (kPa) Read the entire page →
From page 354... ... FIGURE 5.35 PROJ 24-11.doc Undrained Shear Strength, su (kPa) 10 15 20 25 30 35 40 45 50 Fa ct o r o f S af et y, FS 1.0 2.0 3.0 4.0 5.0 Undrained Shear Strength, su (kPa) Read the entire page →
From page 355... ... FIGURE 5.36 PROJ 24-11.doc 5-140 Read the entire page →
From page 356... ... FIGURE 5.37 PROJ 24-11.doc Undrained Shear Strength, su (kPa) 10 20 30 40 50 Se ism ic Fa ct o r o f S af et y, FS ' 0.0 1.0 2.0 3.0 4.0 5.0 Undrained Shear Strength, su (kPa) Read the entire page →
From page 357... ... FIGURE 5.38 PROJ 24-11.doc Undrained Shear Strength, su (kPa) 10 20 30 40 50 Se ism ic Fa ct o r o f S af et y, FS ' 0.0 1.0 2.0 3.0 4.0 5.0 Undrained Shear Strength, su (kPa) Read the entire page →
From page 358... ... FIGURE 5.39 PROJ 24-11.doc Undrained Shear Strength, su (kPa) 10 20 30 40 50 Se ism ic Fa ct o r o f S af et y, FS ' 0.0 1.0 2.0 3.0 4.0 5.0 Undrained Shear Strength, su (kPa) Read the entire page →
From page 359... ... FIGURE 5.40 PROJ 24-11.doc 5-144 Read the entire page →
From page 360... ... FIGURE 5.41 PROJ 24-11.doc θ θ 5-145 Read the entire page →
From page 361... ... FIGURE 5.42 PROJ 24-11.doc θ 5-146 Read the entire page →
From page 362... ... FIGURE 5.43 PROJ 24-11.doc 2-Lane Road Width = 11 m Accumulated Water Level Embankment Height 0.0 0.1 0.2 0.3 0.4 0.5 0.6 0.7 R e q u i r e d O v e r b u r d e n F o r F a c t o r o f S a f e t y o f 1 . Read the entire page →
From page 363... ... FIGURE 5.44 PROJ 24-11.doc 2-Lane Road Width = 11 m Accumulated Water Level Embankment Height 0.0 0.1 0.2 0.3 0.4 0.5 0.6 0.7 R e q u i r e d O v e r b u r d e n F o r F a c t o r o f S a f e t y o f 1 . Read the entire page →
From page 364... ... FIGURE 5.45 PROJ 24-11.doc 2 Lane Road Width = 11 m Accumulated Water Level Embankment Height 0.0 0.1 0.2 0.3 0.4 0.5 0.6 0.7 R e q u i r e d O v e r b u r d e n F o r F a c t o r o f S a f e t y o f 1 . Read the entire page →
From page 365... ... FIGURE 5.46 PROJ 24-11.doc 2-Lane Road Width = 11 m Accumulated Water Level Embankment Height 0.0 0.1 0.2 0.3 0.4 0.5 0.6 0.7 R e q u i r e d O v e r b u r d e n F o r F a c t o r o f S a f e t y o f 1 . Read the entire page →
From page 366... ... FIGURE 5.47 PROJ 24-11.doc θ θ 5-151 Read the entire page →
From page 367... ... FIGURE 5.48 PROJ 24-11.doc 2-Lane Road Width = 11 m Accumulated Water Level Embankment Height 0.0 0.1 0.2 0.3 0.4 0.5 0.6 0.7 R e q u i r e d O v e r b u r d e n F o r F a c t o r o f S a f e t y o f 1 . Read the entire page →
From page 368... ... FIGURE 5.49 PROJ 24-11.doc 2-Lane Road Width = 11 m Accumulated Water Level Embankment Height 0.0 0.1 0.2 0.3 0.4 0.5 0.6 0.7 R e q u i r e d O v e r b u r d e n F o r F a c t o r o f S a f e t y o f 1 . Read the entire page →
From page 369... ... FIGURE 5.50 PROJ 24-11.doc H=16 m H=12 m H=8 m H=1.5 m, H=2 m H=4 m 2-Lane Road Width = 11 m Accumulated Water Level Embankment Height 0.0 0.1 0.2 0.3 0.4 0.5 0.6 0.7 R e q u i r e d O v e r b u r d e n F o r F a c t o r o f S a f e t y o f 1 . Read the entire page →
From page 370... ... FIGURE 5.51 PROJ 24-11.doc 2-Lane Road Width = 11 m Accumulated Water Level Embankment Height 0.0 0.1 0.2 0.3 0.4 0.5 0.6 0.7 R e q u i r e d O v e r b u r d e n F o r F a c t o r o f S a f e t y o f 1 . Read the entire page →
From page 371... ... FIGURE 5.52 PROJ 24-11.doc 5-156 Read the entire page →
From page 372... ... FIGURE 5.53 PROJ 24-11.doc 2-Lane Road Width = 11 m δ = 40o Accumulated Water Level Embankment Height 0.0 0.1 0.2 0.3 0.4 0.5 0.6 0.7 R e q u i r e d O v e r b u r d e n F o r F a c t o r o f S a f e t y o f 1 . Read the entire page →
From page 373... ... FIGURE 5.54 PROJ 24-11.doc 2-Lane Road Width = 11 m δ = 40o Accumulated Water Level Embankment Height 0.0 0.1 0.2 0.3 0.4 0.5 0.6 0.7 R e q u i r e d O v e r b u r d e n F o r F a c t o r o f S a f e t y o f 1 . Read the entire page →
From page 374... ... FIGURE 5.55 PROJ 24-11.doc Accumulated Water Level Embankment Height 0.0 0.1 0.2 0.3 0.4 0.5 0.6 0.7 R e q u i r e d O v e r b u r d e n F o r F a c t o r o f S a f e t y o f 1 . Read the entire page →
From page 375... ... FIGURE 5.56 PROJ 24-11.doc 2-Lane Road Width = 11 m δ = 40o Accumulated Water Level Embankment Height 0.0 0.1 0.2 0.3 0.4 0.5 0.6 0.7 R e q u i r e d O v e r b u r d e n F o r F a c t o r o f S a f e t y o f 1 . Read the entire page →
From page 376... ... FIGURE 5.57 PROJ 24-11.doc θ θ 5-161 Read the entire page →
From page 377... ... FIGURE 5.58 PROJ 24-11.doc 0(H) Read the entire page →
From page 378... ... FIGURE 5.59 PROJ 24-11.doc 5-163 Read the entire page →
From page 379... ... TABLE 5.1 PROJ 24-11.doc Material Cα/Cc Inorganic clays and silts 0.04 ± 0.01 Organic clays and silts 0.05 ± 0.01 Peat and Muskeg 0.06 ± 0.01 5-164 Read the entire page →
From page 380... ... TABLE 5.2 PROJ 24-11.doc Total Stress Shear Strength Parameters Effective Stress Shear Strength Parameters Material Moist Unit Weight, γmoist kN/m3 (lbf/ft3) Saturated Unit Weight, γsat kN/m3 (lbf/ft3) Read the entire page →
From page 381... ... TABLE 5.3 PROJ 24-11.doc Undrained Shear Strength, su kPa (lbs/ft2) Read the entire page →
From page 382... ... TABLE 5.4 PROJ 24-11.doc Material Designation Dry Density/Unit Weight for Block as a Whole, kg/m3 (lbf/ft3) Initial Tangent Young's Modulus, MPa (lbs/in2) Read the entire page →
From page 383... ... TABLE 5.5 PROJ 24-11.doc δ Slope (H:V) Read the entire page →

From page 216...

... 5- 1 CHAPTER 5 EXTERNAL (GLOBAL) STABILITY EVALUATION OF GEOFOAM EMBANKMENTS Contents Introduction...................................................................................................................................5-4 Embankment Geometry ................................................................................................................5-5 Cross-Sectional Geometry........................................................................................................5-5 Longitudinal Geometry.............................................................................................................5-7 Embankment Cover ......................................................................................................................5-7 Trapezoidal Embankments .......................................................................................................5-8 Vertical Embankments .............................................................................................................5-9 Settlement of Embankment.........................................................................................................5-10 Introduction ............................................................................................................................5-10 Settlement Due to End-Of-Primary (EOP)