Technical guide / Revision H
ECO-MSE®
System & design guide
From the first course to the complete wall. Explore product data, typical arrangements and documented design calculations for ECO-MSE® retaining systems.
Designed as a complete retaining system.
01 / Product information
Know what goes into your wall.
Black non-woven polypropylene bags, with a nominal geotextile mass of 140 g/m². Delivered sizes and compacted course heights serve different purposes.
| Component | Nominal dimensions | Approx. filled mass |
|---|---|---|
| Empty bag | 390 × 880 mm | — |
| Granular-filled bag | 340 × 780 × 120 mm | 35 kg |
| Compost-blend-filled bag | 340 × 780 × 150 mm | 35 kg |
| Retaining plate | 95 × 275 × 40 mm | — |
Dimensions are width × length × height, where applicable.
Delivered at 150 mm.
Installed at 140 mm.
Soil-filled bags
The mix is broadly 70–80% PAS100 peat-free compost, with added nutrients to help accelerate vegetation establishment, and a 20–30% sand blend to improve drainage and reduce water retention within the bags.
Granular-filled bags
Filled with clean, free-draining 20 mm quartz gravel for locations requiring improved drainage or submerged lower courses. At watercourses, use granular-filled bags for courses up to the confirmed high water level.
02 / Build arrangements
One system. Different site conditions.
Explore four typical arrangements. Each section is a concept: wall geometry, surcharge, foundations, drainage and reinforcement are determined by the design.
Stacked-bag wall
Connected soil-filled bags form a stepped face. The retained material, wall geometry and foundation conditions determine the design.
- Connected coursesCompact 150 mm supplied bags to 140 mm courses; follow the specified orientation, bond, setback and connections.
- Retained fillSoil strength, unit weight, surface slope and imposed loads determine the pressure behind the wall.
- A suitable foundationSelect base width, preparation and embedment for the ground conditions and tolerable movement.
- Controlled drainageAssess filter compatibility and provide the designed drainage zone and outlet. Read fabric permeability with its test conditions.
The base and every course interface need stability checks. A low visible height alone does not establish that a gravity arrangement is suitable.
Geogrid-reinforced wall
Geogrid connects the facing to a designed mass of compacted fill. The facing, reinforcement and ground work as one system.
- Reinforcement layoutGrid grade, length, vertical spacing and orientation depend on the design actions.
- Specified granular fillFill quality and compaction affect the reinforced mass and its interaction with the grid.
- Facing connectionThe connection must transfer the calculated load; grid tensile strength alone does not verify it.
- Space behind the faceAllow room for reinforcement, construction access, drainage, boundaries and services.
10 kPa documented design example: the recorded design applies 10 kPa beyond the first 1.0 m behind the wall and 5 kPa within that metre. See the complete loading example below. Each new design needs checks for reinforcement rupture, pullout, connections, external stability, bearing, settlement and overall slope stability.
Supporting a footway edge
A footway beside a ditch introduces loading, movement limits and water conditions that must be considered together.
- Define the full heightSurvey the crest, face, toe and ditch invert, including foundation depth and embedment.
- Identify the actual loadsConfirm pedestrian use, nearby vehicles, maintenance plant, barriers, signs and pavement construction.
- Protect the footway edgeAssess settlement, bag deformation and relative movement between the support and pavement.
- Design for the ditchReview water levels, scour, flood flow and outlets. Fabric permeability does not establish filled-wall drainage capacity.
A notional 45° load-influence line can flag a load-transfer concern. It is not a wall-face angle or a substitute for calculating the loads and stability of the proposed section.
Watercourse retaining wall
Use granular-filled ECO-MSE® bags for courses up to high water level, with soil-filled bags for vegetation above.
- Up to high water levelClean, free-draining 20 mm quartz gravel fills the granular bags from the base through the lower courses.
- Above high water levelThe compost and sand blend supports vegetation establishment in the soil-filled bags.
- Confirm the transitionEstablish the high water level and the course containing it before installation.
- Design the toe and bankAssess founding depth, scour protection, filters, flow conditions, water-level changes and bank stability.
The watercourse arrangement requires site-specific hydraulic and stability assessment. Free-draining fill and fabric test results do not establish a whole-wall flow rating.
03 / Documented design examples
What does a kPa value tell you?
These examples come from previous design calculations. They explain the loads and checks for specific arrangements, rather than assigning a maximum capacity to every ECO-MSE® wall.
Applied surcharge
The surface load an engineer allows for behind the wall. The 5 kPa and 10 kPa values below are design inputs.
Calculated ground pressure
The pressure transferred to the foundation ground by the wall and its loading. It is an output of the calculation.
Ground bearing capacity
The ground resistance adopted for a check, which needs appropriate site verification. It is not a bag strength.
Design record A / Applied loads
A reinforced-wall example using 10 kPa.
The recorded design uses a pedestrian surcharge close to the crest and a vehicle surcharge further behind. These are the loads allowed for in that design, not a tested maximum capacity.
Load-placement schematic, not to scale. The 10 kPa zone extends 10 m in the recorded model.
Geometry in the record
Retained height 1.15 m; face at 70° from horizontal (20° from vertical); three geogrid layers, each 1.25 m long.
Fill and water
Class 6I fill with unit weight 19 kN/m³ and friction angle 35°. Groundwater assumed 2.0 m below ground; drainage required.
Additional horizontal action
A horizontal parapet load of 1.1 kN/m is included. Vehicle impact is excluded from the example.
Reading the result
A previous arrangement was designed using a 10 kPa surcharge in this zone. The documents do not establish how much higher its loading could be.
Design record B / Ground contact pressure
Pressure beneath the wall base.
This extracted component check relates to eight compacted 140 mm courses, totalling 1.12 m, with an 18° retained slope. It is not a transferable complete design.
Recorded inputs
Vertical force N = 13.2 kN/m of wall.
Base width B = 0.760 m.
Resultant eccentricity e = 0.048 m.
Full contact check
e = 0.048 m < B/6 = 0.127 m.
The resultant lies within the middle third of the base.
These values describe ground contact pressure. The adopted 50 kPa ground bearing capacity requires site verification.
Design record A / Geogrid calculation
Reinforcement strength has its own units.
Geogrid tensile resistance is measured in kN/m of grid width, rather than kPa. This example relates to the Secugrid 30/30 Q6 specified in the recorded design.
| Creep | Durability | Installation damage | Model uncertainty |
|---|---|---|---|
| 1.34 | 1.00 | 1.09 | 1.50 |
Utilisation = (3.00 / 13.69) × 100 ≈ 21.9%. The software records 3.00 kN/m maximum tensile force and 21.92% utilisation; small differences arise from rounded displayed values.
04 / Laboratory evidence
Measured material properties.
BTTG tests describe the submitted bag material under stated conditions. Read each result with its units, sample information and limitations.
Mechanical properties
Sample means and standard deviations (SD). Ten specimens were tested for each property, or in each direction for grab and tear.
| Property | Test method | Mean | SD |
|---|---|---|---|
| Mass per unit area (g/m²) | ASTM D5261 | 137.2 | 14.62 |
| Static puncture force (N) | ASTM D6241 | 1,330 | 182 |
| Grab strength, M-way (N) | ASTM D4632 | 499.90 | 69.32 |
| Grab strength, X-way (N) | ASTM D4632 | 468.50 | 35.36 |
| Grab elongation, M-way (%) | ASTM D4632 | 51.8 | 8.06 |
| Grab elongation, X-way (%) | ASTM D4632 | 70.7 | 14.58 |
| Trapezoid tear, M-way (N) | ASTM D4533 | 161.85 | 27.48 |
| Trapezoid tear, X-way (N) | ASTM D4533 | 150.17 | 16.48 |
M-way = machine direction; X-way = cross direction. Grab elongation is apparent elongation at maximum load. SD describes specimen variability.
Water permeability & opening size
| Property | Method | Result | Specimens |
|---|---|---|---|
| Opening size O90 | EN ISO 12956 | 60 µm | 3 |
| Velocity index VH50 | EN ISO 11058 | 0.106 m/s | 5 |
| Mean flow rate | EN ISO 11058 | 106.40 L/m²/s | 5 |
Permeability was tested normal to the fabric plane, without load, at 50 mm head loss. VH50 range: 0.079–0.130 m/s. Flow-rate SD: 20.91 L/m²/s.
Accelerated weathering
EN 12224:2000: UVA-340 exposure for 370 hours, totalling 50 MJ/m². Tensile specimens were prepared and tested to EN 12226:2012. The specimen count is not stated.
| Direction | Control mean (SD), N/50 mm | Exposed mean (SD), N/50 mm | Retained mean strength |
|---|---|---|---|
| M-way | 323.76 (18.85) | 359.22 (40.79) | 110.95% |
| X-way | 289.56 (11.82) | 310.89 (35.51) | 107.37% |
Material traceability: the reports identify “140g Black Polypropylene Bag 40 × 88 cm”; the product datasheet specifies an empty bag of 390 × 880 mm. Confirm the supplied material and relevant test evidence for each new design.
05 / Design & installation
Check the complete system.
Build to the issued design.
A complete design considers the facing, reinforced or retained soil, foundation and surrounding ground, including water and construction stages.
External stability
Sliding, overturning, bearing and the location of the ground reaction for the relevant load combinations.
Local & internal stability
Course interfaces, connections and, where present, reinforcement rupture and pullout.
Overall stability
Slip surfaces passing through or behind the structure and the surrounding slope.
Movement & water
Settlement and deformation, groundwater, blocked drains, uplift, erosion and scour where relevant.
Construction stages
Excavation, temporary support, incomplete wall stages and construction plant.
Design evidence
Appropriate ground data, verified component properties, load cases and agreed approval requirements.
Set out and prepare
Confirm levels, boundaries, services, access and temporary excavation requirements. Establish restrictions for plant and stockpiles.
Inspect the formation
Confirm the founding ground and complete the specified inspections or tests before the base is covered.
Form the base and drainage
Install the designed foundation, embedment, filters, drainage material and outlet. Protect the toe where required.
Place the connected facing
Use granular-filled courses up to high water at watercourses. Compact the 150 mm soil-filled bags to 140 mm courses where specified; check bond, setbacks, levels and connections.
Build the fill and reinforcement
Place and compact fill in controlled lifts. Install grid, where required, at the designed level, length and orientation.
Complete and record
Check levels and outlets, record concealed work and finish the specified planting. Provide as-built and maintenance information.
Agree the inspection points: record formation acceptance, material and batch identity, connections, grid installation, compaction and drainage. Refer changed conditions to the designer before continuing affected work. Dimensions, materials and acceptance criteria come from the site-specific documents.
Technical information adapted from the ECO-MSE® System & Design Guide, Revision H. Information only; not for construction. This resource is not a construction design, product certificate or universal ECO-MSE® load rating.
06 / Start an enquiry
Let’s understand your site.
A clear brief allows the arrangement, quantities and design services to be priced on agreed assumptions. Share the information below with the Green Gravity Walls team.
Geometry & drawings
Site plan, wall length, survey levels and critical sections, including crest, toe, retained height and available construction space.
Ground & water
Ground investigation, relevant logs and tests, groundwater levels, drainage arrangements and ditch or watercourse details.
Loads & use
Pedestrians, vehicles, adjacent structures, barriers, signs, pavement build-up, maintenance plant and temporary loads.
Performance & approval
Required design life, movement limits, authority comments, checking requirements and submission dates.
Scope of supply
Design, supply and installation responsibilities, including excavation, base, fill, grid, drainage, planting and maintenance.
Site logistics
Access restrictions, delivery area, lifting and handling, programme and working constraints.
The agreed design package may include calculations, coordinated sections and plans, material specifications, connection details, drainage requirements and inspection criteria.