ADVANCEMENT IN RETAINING WALLRetaining means to

hold back the masses

of earth or loose soil

where conditions

make it impossible to

let those masses

assume their natural

slopes.

BY,MOHD.RIZWAN

RETAINING WALL

A retaining wall is a structure designed and constructed to resist the lateral pressure of soil when there is a desired change in ground elevation that exceeds the angle of repose of the soil.

Retaining walls are structure used to retain soil, rock or other materials in a vertical condition Their purpose is to stabilize slopes and provide useful areas at different elevations, e.g. terraces for

agriculture, buildings, roads and railways.

TYPES OF RETAINING WALLS

- Gravity walls - Pre-cast crib walls - Gabion walls - Reinforced concrete walls - Sheet pile walls - MS walls (mechanically stabilized) - Slurry and Secant Walls - Soil nailing

MASSIVE GRAVITY WALLS.

Gravity walls are the earliest known retaining structures. They are built from solid concrete or rock rubble mortared together. The lateral forces from backfill is resisted by the weight of wall itself, and due to their massive nature, they develop little or no tension. Therefore, they are usually not reinforced with steel. Gravity walls are economical for heights up to 3 m (10 feet).

CRIB WALLS.

Crib walls are made up of interlocking individual boxes made from timber or pre-cast concrete. The boxes are then filled with crushed stone or other coarse granular materials to create a

freedraining structure. There are two basic types of crib wall: - Timber, and - Reinforced pre-cast concrete.

GABBION WALLS.

Gabbions are multi-celled, welded wire or rectangular wire mesh boxes, which are then rockfilled, and used for construction of erosion control structures and to stabilize steep slopes. Their applications include, - Retaining walls, - Bridge abutments, -Wing walls, - Culvert headwalls, - Outlet aprons, - Shore and beach protection walls, and - Temporary check dams.

CANTILEVER WALLS.

Cantilever walls are built of reinforced concrete and are typically composed of a horizontal

footing and a vertical stem wall. The weight of the soil mass above the heel helps keep wall

stable. Cantilever walls are economical for heights up to 10 m (32 feet).

SHEET PILE WALLS.

Used to build continuous walls for waterfront structures and for temporary construction wall

heights > 6 m if used with anchors.

Can be made of steel, plastics, wood, pre-cast concrete.

The advantages of using steel sheet-piling:1. Provides higher resistance to driving stresses;2. Is of an overall lighter weight;3. Can be reused on several projects;4. Provides a long service life above or below the water table;5. Easy to adapt the pile length by either welding or bolting; and6. Their joints are less apt to deform during driving.

Retaining Walls Materials

Retaining walls can be made out of many building materials; it really does depend on the individual •Wood sheets;- Steel and plastic interlocking sheets;- Reinforced concrete sheets;- Precast concrete elements (crib walls and block walls);- Closely spaced in-situ soil-cement piles;-Wire-mesh boxes (gabbions);- Anchors into the soil or rock mass (soil nailing).

Considerations

Some points to consider when planning your retaining wall installation:•Walls over 4 foot, should use geo-grid fabric•Use filter fabric over wet or dry soil, then cover with gravel•Ensure good drainage with the use of backfill, drain piping, filter fabric or weep holes.•Always compact between each layer of installation•For stability, slant wall a little towards backfill

Installing Retaining Walls

The following 8-steps will be outlined:1.Tools and Equipment2.Retaining Wall Plan and Layout3.Excavation4.Base Material5.Compact6.Lay the First Row7.Backfill8.Retaing Wall Capping

Retaining Wall Use

•Retaining walls are used for both commercial and •residential purposes.

•They have gained popularity in a short period of time, becoming commonly used for landscaping projects around the home and for commercial landscapes also.

•Retaining walls are found around the home garden, to highlight flower beds. Not only do they add aesthetic appeal to your landscaping. They can also have a functional application.

•Retaining walls can make use of sloping or steep land and help with storm water management and drainage

•This rise in popularity is mainly due to the advances in available designs, colors, shapes and sizes. Also, retaining walls can be self-installed, making them very cost efficient. Installation can be as simple as stacking blocks together!

Different Technologies

Retained Earth MSE Precast Panel Retaining WallMSE retaining walls are coherent gravity structures engineered to resist specific loading requirements.The primary components of a Reinforced Earth wall consist of alternating layers of granular backfill, and linear metallic, high-adherence soil reinforcing strips or ladders to which a modular precast concrete facing is attached.  Its strength and stability are derived from the frictional interaction between the granular backfill and the reinforcements, resulting in a permanent and predictable bond that creates a unique composite construction material.   

Advantages Considerable advantages over cast-in-place, both in construction time and quantity of

materials

Flexibility, making it possible to build directly upon compressible soils

High load-carrying capabilities, both to static and dynamic loads Ease of installation since construction using prefabricated components is rapid and

predictable

The Mesa Systems were chosen because of their dependable connection strength to withstand extremely difficult site conditions

Terratrel MSE Wire Faced Retaining Wall

Terratrel's wire facing and soil reinforcing elements are lightweight and easily transported to remote sites where they can be rapidly installed.

The system can be designed to utilize discrete steel strip, welded wire bar mat or high-tenacity polyester based geostrap soil reinforcements, depending on the site specific requirements of the project

Terratrel may be used for permanent and temporary applications, such as federal lands service roads, low volume state and county roads, fire and logging roads, industrial sites

Flexibility to accommodate significant post-construction settlement

Standardized wire-facing units are easily adjusted for unexpected field conditions

Lightweight components are rapidly erected without the need for heavy equipment

Advantages

Piano Wall – MSE Precast Retaining Wall with Traffic Barrier

Piano Wall is a combination precast traffic barrier and MSE retaining wall which is a coherent gravity structure engineered to resist specific loading requirements

The primary components of a Piano Wall consist of alternating layers of granular backfill, and linear metallic, high-adherence soil reinforcing strips to which a full height 10-foot-long precast composite MSE wall/traffic barrier unit is attached. The lower portion of each Piano Wall unit serves as the precast concrete facing for the MSE wall and ranges in height from 5- to 10-feet.

Durable precast concrete offers a long service life with minimal maintenance

Considerable cost advantages over cast-in-place, by eliminating

the need of forming, curing and anchoring mechanisms

Rapid and predictable construction with the simultaneous

installation of both traffic barrier and retaining wall segments

Advantages

TechSpan Precast Arch

TechSpan is a state-of-the-art, three-hinged precast concrete arch system that consists of half arch units that meet at the crown and are supported by a footing that is sized for site specific conditions.

The innovation of this technology is to customize and optimize the system to each specific project’s special loading requirements.

Design methods using Finite Element Method (FEM) accurately defines the optimal radius of curvature of the arch to minimize tensile stresses

TechSpan generates a very competitive alternative system for the construction of bridges, culverts, rail/roadway tunnels, mining/industrial tunnels and pedestrian/animal crossings

Advantages

Durable precast concrete offers a long service life with minimal maintenance

Erection is simple, rapid and predictable without disruption to flow of traffic

Advanced design procedures and unique fabrication capabilities provide the most efficient use of concrete and steel

Customize and optimize design for project specific loading conditions and geometry

TechWall Precast Counterfort Retaining Wall

TechWall is a precast retaining wall system which combines a full height facing panel and counterfort into one unit.

The system is designed and detailed to meet project-specific requirements.

TechWall precast retaining walls are an effective solution when site conditions preclude the use of linear soil reinforcing strips, such as severe right-of-way restriction, large utility conflict, construction in cut conditions, and roadway widening.

TechWall precast retaining walls are an effective solution when site conditions preclude the use of linear soil reinforcing strips, such as severe right-of-way restriction, large utility conflict, construction in cut conditions, and roadway widening.

Advantages

Durable precast concrete offers a long service life with minimal maintenance 

Considerable advantages over cast-in-place, both in construction time and quantity of materials

Simple, rapid, and predictable construction

Fan wall Noisewall/Security Barrier

Fan wall is a precast permanent or temporary barrier system which consists of precast modular panels and stainless steel connector cables that can be used for nearly every noise or security problem.

These engineered wall systems include both freestanding concrete barriers and post-and-panel structures.

Fan wall provides a low cost, effective and aesthetically pleasing permanent or temporary barrier solution for transportation, utility, industrial and commercial applications.

The barrier system can incorporate either a full height precast panel or a stacked panel configuration.

The most efficient and economical design is of a repeating trapezoidal layout where panels are connected at engineered angles in a wind-stable pattern and can be completely dismantled, relocated and reassembled if necessary; where sufficient right-of-way is not available the post-and-panel Fan wall system can be utilized.

Advantages

Superior appearance since the facing is highly suited for architectural finishes 

Minimal site preparation

Simple, rapid, and predictable construction

Maintenance-free and reusable

Highly resistant to wind loads and overturning

RE/Tension Precast Counterfort Retaining Wall

RE/Tension is a precast counterfort retaining wall system consisting of integral hollow box attached to the backside of standard MSE concrete facing panels stacked on a continuous, cast-in-place, reinforced concrete footing.

The attached box serves as a form for a cast-in-place concrete column of which flexural rebar is carried and connected to the cast-in-place footing.

The counterfort acts as an equivalent cantilever beam, which transfers horizontal earth pressures from the precast facing system to the concrete foundation.

RE/Tension is a unique retaining wall solution that can be used for areas where constraints prohibit installation of linear soil reinforcements such as severe right-of-way restriction, large utility conflict, construction in rock cut conditions, and roadway widening.

The system is easily constructed by pouring a continuous strip footing with protruding dowels and stacking the prefabricated precast concrete panels consisting of two elements, a U-shaped concrete counterfort box and standard MSE facing over the dowels in the footing and then onto one another in lifts.

At periodic intervals, the counterfort blockouts are filled with concrete and reinforcing steel extended vertically as needed.

This procedure continues with each successive row until the desired wall height is reached. RE/Tension can be easily combined with other Reinforced Earth Company wall systems using the same fascia panels and giving a uniform appearance to the entire

Superior appearance since the facing is highly suited for architectural finishes

Considerable advantages over CIP, both in construction time and quantity of materials

Simple, rapid, and predictable construction

Durable precast concrete offers a long service life with minimal maintenance

Advantages

MODULAR BLOCK

Modular block, or segmental, retaining walls employ interlocking concrete units that tie-back into the earth to efficiently resist loads.

The inherent design flexibility can accommodate a wide variety of site constraints, project sizes, and aesthetic preferences

These pre-engineered modular systems are an attractive, economical, and durable alternative to stone or poured concrete retaining walls.

These systems have been installed all over the U.S

ARES(Advanced Reinforced Soil)

The ARES Retaining Wall Systems offer a variety of options depending on your particular site needs and applications.Available with Modular or Full-Height Facing Panels (FHP),the ARES Systems offer non-metallic earth reinforcement and are especially suited in areas where salt, chemically active soils or stray currents are a concern.

StoneTerraA retaining wall block that takes advantage of the positive attributes that specifiers and customers are trying to find. The patented StoneTerra System offers an attractive architectural face and simple installation all at a sensible per square foot cost. StoneTerra offers more possibilities with less effort.

Retaining Wall Block System offers an attractive architectural face and simple installation all at a sensible per square metre/foot cost.

Advantages:•Interlocking•Fast and simple installation•Can easily be set with small equipment•Curved or straight walls•Ability to build in limited space•Cost effective

SierraScapeSierraScape is the only wire-formed retaining wall system with a positive connection between the wire form and geogrid reinforcement. Finished facing options can include stone, and vegetation.

Anchor Reinforced Vegetation (ARV)

It system is a durable, flexible armouring system for severe erosion and surficial slope stability challenges. Constructed of a woven three-dimensional High Performance Turf Reinforcement Mat

Sierra slope retention system

The Sierra Slope Retention System is a premier reinforced soil slope retention system designed to blend naturally with the surrounding environment.

THANKYOU