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vulcanhammer.net
article
https://vulcanhammer.net/wp-content/uploads/2017/01/fhwa-nhi-00-043.pdf
of modifying the seepage regime in the slope. The geotextile-reinforced slope was designed in accordance with the guidelines presented in chapters 6 and 7 of this manual. The final design consisted of two reinforced zones with a constant reinforcing spacing of 0.3 m (1 ft). The reinforcement in the lower zone had an ultimate tensile strength of 100 kN/m (6,850 plf), and the reinforcement in the upper zone had a reinforcement strength of 20 kN/m (1,370 plf). The reinforcement strength was [...] Evaluate requirements for subsurface and surface water runoff control. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . -243-7.3 COMPUTER ASSISTED DESIGN . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . -245-7.4 DESIGN EXAMPLES . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . -246-a.
Example 1. Reinforced Slope Design -Road Widening . . . . . . . . . . . . . -246-b. [...] b. Design of Reinforcement for Compaction Aid For the use of geosynthetics as compaction aids, the design is relatively simple. Assuming the slope is safe without reinforcement, no reinforcement design is required. Place any geotextile or geogrid that will survive construction at every lift or every other lift in a continuous plane along the edge of the slope (see figure 4b). Only narrow strips, about 1.2 to 2 m (4 to 6 ft) in width, at 0.3 to 0.5 m (1 to 1.5 ft) vertical spacing are required.
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scdot.org
article
https://www.scdot.org/content/dam/scdot-legacy/business/pdf/geotech/2022-by-c…
Pullout Resistance (Berg, et al. – Vol. I (2009)) Friction develops at locations where there is a relative shear displacement and corresponding shear stress between soil and reinforcement surface. Reinforcing elements dependent on friction should be aligned with the direction of soil reinforcement relative movement. Examples of such reinforcing elements are steel strips, longitudinal bars in grids, geotextile, and some geogrid layers. Passive Resistance occurs through the development of bearing [...] or uniaxial) and geotextiles. These reinforcements are a wrapped face consisting of a layer of geogrid that wraps around the face and a layer of geotextile to prevent erosion of the reinforced soil materials. Inextensible reinforcements consist of bars or bar mats (metallic grids) and shall meet the requirements in STS SC-M-713 (latest version) for Geotechnical Design Manual APPENDIX D January 2022 D-25 Mechanically Stabilized Earth (MSE) Walls for the inextensible material properties. These [...] reinforced slope with a computer program. Layout includes number, length, design strength, and vertical distribution of the geosynthetic reinforcement. The charts presented in Figure D-8 provide a method for generating a preliminary layout. Note that these charts were developed with the specific assumptions noted in this figure. Analyze the reinforced soil slope with the trial geosynthetic reinforcement layouts. The most economical reinforcement layout must provide the maximum stability
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library.geosyntheticssociety.org
article
https://library.geosyntheticssociety.org/wp-content/uploads/resources/proceed…
3 m, with angles ranging from 40º to 60º. The study has shown that increasing the cohesion and friction angle of the sandy soil improves the factor of safety of both unreinforced and reinforced slopes. The best improvement in factor of safety is observed in all the soils analyzed for cohesion of 1 kPa. Design charts, for estimation of the factor of safety, have been developed for all the slope angles and various soils considered. An illustrative example has been included so that the [...] by Zonberg et al. (1998) and Tiwari and Samadhiya (2016) for reinforced slopes, a parametric study was carried out on the 40°, 50°, and 60° slopes (unreinforced and reinforced) as presented in Figure 2 (a-d) by varying the slope soil strength parameters (c’ from 0 to 5 kPa and ϕ’ from 30° to 50°), while keeping the slope height, geosynthetic layout and soil unit weight constant, to determine their effect on the factor of safety, F. The range of c’ and ϕ’ adopted in the study are typical of [...] strength parameters of the slope soil, and γ and H are unit weight of soil and slope height, respectively. (a) (b) Figure 3. Typical design chart: (a) 50° unreinforced slope; (b) 50° reinforced slope. It is observed that F improves with an increase in N and ϕ’ values in both unreinforced and reinforced slope irrespective of the slope angle. It is further noticed that for a constant value of ϕ’, N increases with increasing c’ and for a fixed value of c’, N decreases with an increase in ϕ’. The
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kutcresources.ku.edu
research
https://kutcresources.ku.edu/storage/1621615382_GeoProperties-Han5-9-12-2.pdf
AASHTO (2006) Grab strength lb 315 200 250 157 Sewn seam strength lb 280 180 220 140 Tear strength lb 110 80 90 56 Puncture strength lb 620 433 495 309 Ultraviolet stability 50% retained strength after 500 hours of exposure Geotextile Class Class 1 Class 2 Units Elongation (%) < 50 > 50 <50 >50 Design of Geotube Input: Pressure head, b1 Circumference, S Output: Tube heights, H, H’ Tube width, B, B’ Geotextile strength, T Next Presentation: Case Studies • Simple Slope with Temporary Toe [...] sin H c FS 5 0 2 2 Example: ca = 50 psf, H = 2 ft, = 120 pcf, = 30o FS = 1.0 = 40o (1:1 slope, no-seepage condition) = 27o (2:1 slope, seepage condition) Toe Protection or Support WA Active wedge Passive wedge WP R Anchorage Requirements in Erosion Control Applications ARMY TM 5-818-8 (1995) Pin Spacing Requirements in Erosion Control Applications ARMY TM 5-818-8 (1995) Steel securing pins: 8/16 in. (diameter), 18 in. (long), fitted with a 1.5-inch metal washer Longer pins are [...] Longer pins are advisable for use in loose soils Slope Pin Spacing (ft) Steeper than 3(H) : 1(V) 2 3(H) : 1(V) to 4(H) : 1(V) 3 Flatter than 4(H) : 1(V) 5 Why is Anchorage Needed Sometimes ? tan tan C tan tan FoS i Typical Ci = 0.6 to 0.8 Typical Geosynthetic Layout for Reinforced Slope FHWA NHI-07-092 Face Options for Reinforced Slopes Collin (1996) Slope Stability Analysis Courtesy of Leshchinsky From ReSSA Software MSE Wall vs. Reinforced Slope Increase Space • Slope: Face inclination <
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library.ctr.utexas.edu
research
https://library.ctr.utexas.edu/hostedpdfs/tsusm/0-6792-1.pdf
design guidelines for GRSS. The existing topography, subsurface conditions, and soil properties must be considered when evaluating the site for construction. The investigation should include determining the availability of the required type of reinforced fill and backfill materials. 3. Geogrid or geotextile constructed of polyester, polypropylene, or polyethylene are recommended for soil slope reinforcement. The material should be resistant to heat, ultraviolet light, attack by bacteria and [...] Polypropylene Geotextile Embankment Soil: Sandy Soil Slope Height: 79 ft Slope Angle: 1H:1.2V Construction Sequence: The landslide debris was removed from the site to clear the road and provide an adequate zone for the new reinforced slope. At the rear of the excavated zone, a subsurface drainage layer was provided behind the reinforced soil zone to intercept ground water seepage from the natural strata. At the toe of the slope, a low gabion structure is incorporated to enhance toe [...] at Castleberry Engineer: Soil Reinforcement Design Contractor: ECM Purpose: Maximize Available Land Geosynthetic Material: Reinforcement: Geocomposite Facing: Polypropylene Mesh Slope Height: 30 ft Slope Face: 71,000 ft2 Construction Sequence: The base was a well compacted subgrade and geosynthetics were installed as primary reinforcement. Geotextile was placed inside the 3 ft welded wire baskets to provide a stable platform for hydroseeding. The embedment lengths varied, but were
C
cdn.glenraven.net
article
https://cdn.glenraven.net/geogrid/pdf/en_us/StrataSlope_Reinforced-soil-slope…
EXAMPLE CALCULATION 26-33 EXAMPLE NO.1 – REINFORCED STEEP SLOPE 27-32 COMMENTS 33 STANDARD GEOGRID SPECIFICATION 34-41 SLOPE REINFORCEMENT – PRELIMINARY DESIGN & COST ESTIMATE SHEET 42-44 The information contained in this document has been carefully compiled by Strata Systems, Inc., and to the best of our knowledge is accurate. Final determination of the suitability of any information or material is the sole responsibility of the user. Structural design shall be performed by a licensed design [...] a licensed design professional. ________________________________________________________________________ © Copyright 2010 by Strata Systems, Inc. Page 3 Version 100119 REINFORCED SOIL SLOPES AND EMBANKMENTS For the purposes of this document, a reinforced slope is defined as a compacted fill embankment that incorporates the use of horizontally placed geosynthetic reinforcement to enhance the stability of the soil structure. This broad definition encompasses many and varied applications. In this [...] STEEP SLOPES 3-10 DESCRIPTION 3-4 ANALYSIS 4 Detailed Analysis Methods 5-7 Simple Wedge Methods 7-10 SURFICIAL STABILITY 11-14 DESCRIPTION 11 Slope Angles < 45 degrees 11-12 Slope Angles ≈ 45 degrees 12 Slope Angles > 45 degrees 13-14 SURFICIAL STABILITY DESIGN 15-16 DESCRIPTION 15 ANALYSIS 15-16 EMBANKMENTS OVER SOFT SOILS 17-21 DESCRIPTION 17 ANALYSIS 18-21 TEMPORARY WALLS 22 DESCRIPTION 22 ANALYSIS 22 PRESSURE RELIEF WALLS 23-24 DESCRIPTION 23 ANALYSIS 23-24 SUMMARY 25 EXAMPLE CALCULATION
D
dot.ca.gov
official
https://dot.ca.gov/-/media/dot-media/programs/engineering/documents/geotechni…
on slope facing selection and design. 11) Provide District Design: • • • • • Elevation view plans produced in step 5. Plan sheets produced in step 7. A typical cross section of the GRE produced in step 8 Subdrain produced in step 9. Slope facing details produced in step 10. The templates for the plans described in the above list are presented in Appendix 1 and the corresponding MicroStation (.dgn) files can be download from the Geotechnical Design Aids webpage. The MicroStation (.dgn) template [...] needs for slope surface treatments. • • • • The embedment length of secondary reinforcements should be at least 4 feet. For slopes steeper than 1.5H:1V, use wrap-around or welded-wire mesh faced slope to prevent erosion. For wrap-around slope face, the embedment lengths of the wrapped-back must be at least 3 feet. The wrapped-back secondary reinforcement layer may be placed on top of the previously placed layer without separation by a soil layer. In the design detail, provide at least 3-inch [...] Geosynthetic Reinforced Embankments September 2023 Page 1 of 17 1 Reinforced Embankments Geosynthetic Reinforced Embankment (GRE) is a system that incorporates planar geosynthetic reinforcement within a slope (Figure 1) for slope inclinations less than 70 degrees from horizontal. A GRE is also referred to as a Reinforced Soil Slope. Situations where GRE may be used include: • • • • Limited right of way Shortage of fill quantity for slope construction Excess of excavated materials Distressed or
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sciencedirect.com
article
https://www.sciencedirect.com/science/article/pii/S0266114417301024
by AH Abd · 2017 · Cited by 130 — This paper is to provide a method for the design of slope reinforcements where the effect of cohesion is accounted for that may feed into future new guidelines.