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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 [...] a reinforced slope, several factors are considered: Geologic and topographic conditions. Environmental conditions. Size and nature of the structure. Aesthetics. Durability considerations. Performance criteria. Availability of materials. Experience with a particular system or application. Cost. 50 There are several different systems that can be put in place. A decision must be made on what kind of structure to build based on the needs and expected performance of the owner. For [...] must also be considered. Then, factors of safety establish the performance requirements of the slope. These considerations include sliding, overall stability, lateral squeeze, dynamic loading, compound failure, internal slope stability, and time rate based on project requirements as per Table 3. Table 3. Factors of Safety for Stability Analysis (Berg et al., 2009). FSsliding ≥ 1.3 FSoverall stability ≥ 1.3 FSlateral squeeze ≥ 1.3 FSdynamic loading ≥ 1.1 FScompound failure ≥ 1.3 FSinternal
L
library.geosyntheticssociety.org
article
https://library.geosyntheticssociety.org/wp-content/uploads/resources/proceed…
to provide adequate slope stability. Michalowski (1997) analyzed the stability of slopes with geosynthetic layers installed at equal vertical spacing throught the slope height. The investigation produced design charts that can determine the required reinforcement strength and length to prevent slope failure. Zhu et al. (2014) prepared charts for quick assessment of the stability of stacked geotextile tubes. The charts allowed the factor of safety to be evaluated base on the slope geometry and [...] locations, if a steep slope is required, it becomes essential to reinforce the slope with one or more geotextile layers at some specific spacing to prevent slope failure and enhance slope stability. In this paper, an attempt is made to analyze the effect of shear strength parameters on the factor of safety of low-height unreinforced and geotextile-reinforced sandy slopes, using the limit equilibrium analysis based on Slope/W software. The slope height has been considered 3 m, with angles [...] may involve a low-height steep slope that may not need a stone wall support as shown in Figure 1. In such cases, the slopes can be reinforced with geosynthetic layers (geotextile or geogrid), to improve the stability, defined in terms of factor of safety F to an acceptable value. Geosynthetic layers have proven to be effective and economical in improving the mechanical properties of soils, and moreover, they allow to construct environmentally friendly and sustainable structures (Shukla et al.
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scdot.org
article
https://www.scdot.org/content/dam/scdot-legacy/business/pdf/geotech/2022-by-c…
test. Slope stability analyses should account for interface shear strength along a geocomposite drain. The geocomposite/soil interface will most likely have a friction value that is lower than that of the soil. Thus, a potential failure surface may be induced along the interface. Geotextile reinforcements (primary and intermediate layers) must be more permeable than the reinforced fill material to prevent a hydraulic build up above the geotextile layers during precipitation. Special emphasis on [...] core • Long-term inflow/outflow capacity Procedures for checking geotextile permeability and filtration/clogging criteria are presented in Geosynthetic Design and Construction Guidelines, Holtz, Christopher and Berg (2008), FHWA NHI-07-092. Long-term compressive stress and eccentric loadings on the core of a geocomposite should be considered during design and selection. Though not yet addressed in standardized test methods or standards of practice, the following criteria are suggested for [...] et al. – Vol. II (2009)) Lateral spacing of outlets is dictated by site geometry and estimated flow. Outlet design should address long-term performance and maintenance requirements. Geosynthetic drainage composites can be used in subsurface water drainage design. Drainage composites should be designed with consideration for: • Geotextile filtration/clogging • Long-term compressive strength of polymeric core • Reduction of flow capacity due to intrusion of geotextile into the core • Long-term
K
kutcresources.ku.edu
research
https://kutcresources.ku.edu/storage/1621615382_GeoProperties-Han5-9-12-2.pdf
Geopipe Reinforced fill Block Gabion Design Considerations Channel Design Criteria • Based on peak flow capacity • Consider site conditions • Design channel lining to ensure the stability Vegetation Riprap Geosynthetic liner Design Methods • Maximum permissible velocity method Predicted mean velocity < maximum permissible velocity • Tractive force (shear stress) method Predicted shear stress < maximum allowable shear stress Maximum Permissible Mean Channel Velocity USACE (1991) Max. [...] Overview of Geosynthetic Materials, Their Characteristics, Applications, and Design Considerations Jie Han, Professor, Ph.D., PE The University of Kansas Outline of Presentation Introduction Geosynthetic Products Primary Functions Material Characteristics Applications Design Considerations Geosynthetics Geo: Earth - soil or rock Synthetics: Man-made products, mainly polymers Textural Soil Classification Soil Name Particle Size (in.) U.S. Sieve No. Boulders > 12 Cobbles 12 - 3 [...] 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
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solmax.com
article
https://www.solmax.com/ca/en/blog/what-are-the-key-considerations-in-designin…
### Design principles of reinforced soil slopes
The design of reinforced soil slopes hinges on two critical components: the facing system and the reinforcement strategy. The facing system is integral to erosion protection and structural support, enabling the formation of slopes that surpass natural stable inclinations without compromising stability. Secondary reinforcement, typically comprising geosynthetic materials, aids in compaction and mitigates surficial sloughing at the slope face. [...] Erosion poses a significant threat to slope stability, driven by factors such as rainwater impact and surface runoff. The risks escalate under conditions of water currents and wave attack. Slope face erosion can create rills and gullies, leading to surface sloughing and deep-seated failure surfaces. To address these challenges, reinforced slope designs should incorporate comprehensive erosion control measures and re-vegetation strategies, underscoring the necessity of integrating environmental [...] In situations where reinforced slopes are subjected to severe erosive forces associated with water currents and wave attack, the erosion protection system must be specifically designed to resist these forces. Typically, such severe cases will require a ‘hard’ armor erosion protection system such as riprap, gabions, articulating concrete blocks, or fabric-formed concrete. While these systems do not incorporate a geosynthetic face wrap, a geotextile filter is typically installed beneath the
C
cherokeemfg.com
article
https://cherokeemfg.com/reinforced-soil-slope-walls-rss-walls-installation
There are two primary considerations when designing a reinforced slope: [...] When building a reinforced slope, we will primarily depend on a secondary reinforcement with a light to moderate geosynthetic fabric or grid in tight vertical spacing with relatively short embedment lengths (how far horizontally into the slope these extend). These layers will provide superficial stability to protect the embankment from shallow plane failure at the surface, while also giving compaction equipment a good platform in which to compact soil lifts all the way to the face of the slope. [...] ### Step 2 – Reinforcement Placement
Place reinforcement as determined by construction drawings to match embedment, elevation, and orientation as determined by the design engineer. Ensure geosynthetic reinforcement is free of wrinkles and folds and is pulled taught by using soil staples or pins. Splicing in the direction parallel to the face of the slope is prohibited.
### Step 3 – Fill Placement
G
geosyntheticsmagazine.com
article
https://geosyntheticsmagazine.com/2010/08/01/green-geosynthetic-reinforced-so…
It was also important to construct a drainage system at the base and the rear of the slope. For this component of the project, a geocomposite drain was built, as later described in 3.5. A superficial drainage system over the retaining slope and the terrain beside the slope was necessary to control and avoid infiltration of water in the slope.
### 3.2 Design considerations
Geometry dimensions: [...] ## 3. Design for a ‘green’ reinforced soil wall or slope
A case history to describe the process of design for a geosynthetic-reinforced soil retaining wall or slope was designed and constructed in Costa Rica in January 2008. This slope was designed to have an erosion resistant facade of vegetation and for this it is referred to as a “green” reinforced soil slope.
### 3.1 Initial conditions [...] The maximum height recommended for the green reinforced wall or slope is 12m (40ft) in one block. If the height is greater than 12m, the recommendation is to design a wall or slope with terraces and a berm of 1m (3.3ft) minimum between terraces. (For an 18m wall, the recommendation is to design three terraces, each 6m high with a 1m berm between each terrace.)
## 2. Design methodology
### 2.1 Overview
D
dot.ca.gov
official
https://dot.ca.gov/-/media/dot-media/programs/engineering/documents/geotechni…
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 [...] capacity evaluation as needed. Refer to the Embankment module. 4.7 Design for Slope Restoration GRE may be an effective option for restoring failed slopes. For this application, remove landslide debris by excavating below and beyond the failure surface. The excavation may be constrained at the landslide scarp due to the need to keep the highway open. Establish sufficient space, at least 10 feet horizontally near the top of the slope for the installation of geosynthetic reinforcements. If [...] System Water that infiltrates through deteriorated pavement or the retained slope may compromise the stability of the GRE. To drain water in the soils, provide a drainage system between the reinforced soil and the retained soil (Figure 1) especially when design for highway widening or slope restoration. A typical drainage system for GRE includes: • • • Subdrain placed behind and near the bottom of the reinforced soil and along the alignment of the GRE. The subdrain includes 4-inch diameter