Excavation shoring and earth retention field guide

What excavation shoring is

Excavation shoring, also called earth retention or support of excavation, is an engineered structure that holds back the soil so you can cut a deep, near-vertical face without the ground sliding into the hole or the neighbor's footing dropping into it. It is not a trench box and it is not a slope. It is a designed wall, with the soil and water loads behind it worked out by an engineer, an embedment depth or a row of anchors to resist those loads, and a movement budget the wall is supposed to stay inside.

The reason it exists is that on a tight site you cannot lay the walls back. A property line, a sidewalk, a live street, or an adjacent building sits a few feet off the edge of your dig, so the only way down is straight down with something holding the dirt. The system you pick, soldier pile and lagging, sheet piling, a secant or tangent pile wall, a slurry wall, or soil nailing, gets chosen by the soil, the groundwater, the depth, and what sits behind the wall. Then it is braced with tiebacks or internal struts and watched for movement as you dig.

This guide covers the engineered side. Two companion guides cover the rest. The trench and excavation safety guide handles the OSHA protective systems that keep a worker safe in a trench, and the construction dewatering and groundwater control guide handles getting the water out of the hole.

Shoring vs a trench box, and why the difference matters

The difference between earth retention and a trench protective system is the difference between holding the ground and protecting a worker, and confusing the two is how people get hurt and how property gets damaged. OSHA's protective systems under 29 CFR 1926 Subpart P, sloping, shoring, and shielding, exist to keep the person in the trench from being buried if the wall lets go. A trench box does not hold the soil back. It is a shield that takes the load of a collapse so the crew inside survives it, and the ground around it is allowed to move.

Engineered earth retention does the opposite. It is designed to hold the ground in place, limit how far it moves, and protect what sits behind the wall, the building, the street, the utility, not just the worker in front of it. A trench box would let the adjacent footing settle. A retention wall is supposed to stop it.

So the test is simple. If the only thing you need is to keep your own crew safe in a trench you can lay back or box, that is Subpart P, and the trench safety guide covers it. If there is a deep cut, a property line, a structure, or water that has to be held, that is an engineered system an engineer designs. Using a trench box for a job that needed a designed wall is the first item on the failure list, and it is a common one.

When a cut needs an engineered wall

A deep cut needs an engineered retention wall in four situations, and most real jobs hit more than one at once. The dig is deep enough that the face will not stand on its own. There is a building, a street, a sidewalk, or a utility close to the edge that cannot be allowed to move. The excavation goes below the groundwater table, so water pressure pushes on the wall and seepage tries to come in at the bottom. Or the ground movement behind the wall has to be held to a small budget to protect what is back there.

Depth alone is not the whole trigger. A 12 ft cut in the open with nothing around it might get sloped or boxed. The same 12 ft cut three feet off a hundred-year-old masonry building with a shallow footing is an engineered retention job with a preconstruction survey and monitoring, because that footing will not tolerate the movement a slope or a box allows.

The case that catches crews is the one where it looks shallow enough to box but the neighbor's structure makes it a retention job anyway. The depth says trench box. The adjacent footing and the property line say engineered wall. The adjacent footing wins.

What is soldier pile and lagging?

Soldier pile and lagging is the most common temporary earth-retention system, and it is the one most crews picture when they hear shoring. Vertical steel members, usually H-piles, are driven or set in drilled holes at a regular spacing, commonly on the order of 6 to 10 ft on center. As you excavate down in lifts, you place lagging, timber boards or other panels, horizontally between the pile flanges to hold the soil face. The piles take the load and span between supports, and the lagging spans the short distance between piles.

It is fast, it is the cheapest of the systems, and it goes in with ordinary equipment. The catch is what it cannot do. Soldier pile and lagging is a discrete wall with gaps filled by the lagging, so it does not hold water and it does not work in soft, flowing, or saturated soils that will run out between the boards before you can lag them. It wants ground that will stand for the short time it takes to expose a lift and lag it, and it wants the water table below the cut or dewatered out of the way.

Use it for temporary support in firm soils above the water table. The pile size, the spacing, the embedment, and the lagging design come from the engineer, not from a rule of thumb, because they depend on the soil, the depth, and the loads behind the wall.

Sheet piling

Sheet piling is a continuous wall of interlocking steel sheets driven into the ground before you excavate, and its strength is the interlock. Each sheet locks into the next along its full length, so the wall is continuous and, when the interlocks are clean, close to watertight. That makes sheet piling the system to reach for when the soil is soft and when water is part of the problem, because it holds the ground and resists seepage where soldier pile and lagging would let both come through.

Sheets get driven, vibrated, or pressed in, and in soft to medium soils they go fast. They can run as a cantilever for a shallow cut, where the embedment below the dig holds the wall, or be braced with tiebacks or internal struts for a deeper one. Steel sheets are also recoverable. On a temporary job you pull them and reuse them, which offsets the cost.

Where sheet piling struggles is hard ground and obstructions. Cobbles, boulders, old foundations, or rock will stop a sheet or tear an interlock, and a torn interlock leaks. Driving also makes noise and vibration that a tight urban site or a sensitive neighbor may not tolerate. The section, the embedment, the bracing, and whether the wall works as a cantilever or needs support are the engineer's call based on the soil and the loads.

Secant and tangent pile walls

Secant and tangent pile walls are continuous walls built from overlapping or touching drilled concrete piles, and they are the stiff, quiet, watertight option for deep urban cuts. You drill and cast a line of piles. In a secant wall the reinforced piles are cut into soft, unreinforced piles between them so the wall overlaps and seals, while a tangent wall has the piles just touching without overlap, which is stiffer than discrete piles but not fully watertight.

The reasons to spend the money on a pile wall are stiffness, low vibration, and the ability to handle ground that stops a sheet. A pile wall is much stiffer than sheet piling, so the ground behind it moves less, which is what you want next to a settlement-sensitive building. It installs by drilling, so it makes far less noise and vibration than driven sheets, and it can drill through obstructions that would stop a sheet. On an integrated below-grade structure, a secant wall can become the permanent basement wall instead of a throwaway temporary system.

The trade is cost and verticality. A secant wall commonly runs on the order of 1.5 to 3 times the cost per square foot of a discrete-pile system, and the piles have to be drilled plumb or the overlap is lost at depth. Whether a secant or tangent wall is the right call, and how it is reinforced and embedded, is an engineering decision.

Slurry and diaphragm walls

Slurry walls, also called diaphragm walls, are the deepest and most watertight earth-retention system, and they are how the biggest, deepest urban excavations get built. The wall is reinforced concrete cast in a trench that is kept open by a bentonite or polymer slurry while it is dug. The slurry holds the trench walls until the rebar cage goes in and concrete is tremied from the bottom, displacing the slurry. The finished wall is a continuous, stiff, low-permeability concrete barrier that can serve as both the temporary support and the permanent structural wall.

Diaphragm walls reach depths well beyond what sheets or pile walls do, into the range of 100 m on large equipment, and their stiffness and water tightness are why they show up next to subways, deep basements, and structures that cannot move. They keep deformation low and they cut off groundwater, which protects the neighbors on a crowded site.

This is a specialty system with specialty equipment, slurry plants, and a cost to match, so it is reserved for the deep, the wet, and the permanent. The panel layout, the joints, the reinforcement, the embedment, and whether the wall is temporary or permanent all come from the geotechnical and structural engineers and the specialty contractor's design submittal.

Soil nailing and shotcrete

Soil nailing builds the wall from the top down by reinforcing the soil itself rather than installing a wall before you dig. You excavate a lift, drill into the exposed face, install and grout steel bars, the nails, on a grid, and cover the face with shotcrete to tie the nails together and protect the soil. You repeat that lift by lift down the cut. The reinforced soil mass acts as a gravity wall, and the nails carry the tension that holds it together.

Nailing is fast and economical for the right ground, and it does not need a wall driven or drilled before excavation. The ground is the constraint. Soil nailing wants soil that will stand on a near-vertical cut for the time it takes to expose a lift and shoot it, which means cohesive soils, weathered rock, or cemented sands. It does not work in clean, loose, water-bearing sands or soft clays that will not hold a face, and it is not a below-the-water-table system without separate water control.

Because nailing is built into the face as you go, it is hard to make a nail wall fully watertight, and the nails extend back into the soil behind the cut, which raises the same easement question tiebacks do. Whether nailing suits the soil, and the nail length, spacing, and face design, is the engineer's determination.

Which shoring system fits the conditions?

The system gets matched to the soil, the water, the depth, what sits behind the wall, and whether it is temporary or permanent, and no single system wins everywhere. Soldier pile and lagging is the cheap temporary choice in firm soil above the water table. Sheet piling is the move when the soil is soft or wet because the interlock holds water. Secant, tangent, and slurry walls are the stiff, watertight, often permanent answer for deep cuts next to structures and below the water table. Soil nailing fits cohesive ground that will stand on a cut.

The table below is the way to start the conversation, not the design. The real selection weighs cost, schedule, vibration and noise limits, obstructions, access for drilling rigs, and how much the ground behind the wall is allowed to move. That last factor, the movement budget set by the adjacent structures, often drives the choice toward a stiffer, more expensive wall than the soil alone would require.

Picking the wrong system for the soil and water is one of the classic failures. A soldier-pile wall in saturated sand below the water table holds neither the ground nor the water, and you find that out when the face runs out between the lagging and the neighbor's slab starts to drop.

Cantilever vs braced: the depth question

A retention wall is either a cantilever, where the wall's embedment below the excavation does all the work of holding it, or a braced wall, where tiebacks or internal struts add support because the embedment alone cannot. The deciding factor is depth, specifically the height of exposed face.

A cantilever wall works like a fence post in the ground. The soil below the dig resists the load above it, and the wall stands by its own embedment and stiffness. That works up to a point. As a rough industry figure, the cantilever limit for many soldier-pile and sheet-pile walls sits around 15 to 20 ft of exposed face, beyond which the deflection at the top and the bending in the wall grow faster than embedment can hold. Push a cantilever past its limit and the top of the wall leans into the excavation, the ground behind it settles, and you see it in the monitoring before you see it on the ground, if you are watching.

Past the cantilever limit, you add support. One row of tiebacks or struts handles a moderate cut, several rows stacked down the wall handle a deep one. The actual limit depends on the wall stiffness, the soil, and the loads, so the 15 to 20 ft figure is where to start asking, not a number to design to. The engineer sets the support levels and the embedment.

What is a tieback?

A tieback, or ground anchor, is a drilled-and-grouted tendon that reaches back through the wall into stable soil or rock behind the excavation and is then tensioned to hold the wall in place. You drill an angled hole through the wall face, install a steel bar or strand, grout a bond length at the far end, let it cure, then stress the anchor against the wall and lock in a holding load, commonly anywhere from tens to several hundred kips per anchor depending on the design. The anchor pulls the wall back against the soil load pushing in.

The reason tiebacks are popular is that they hold the wall without putting anything inside the hole. The excavation stays open and clear, so the digging, forming, and structure go in without struts in the way, which is faster and cheaper on a wide cut. For deep or wide excavations, anchoring is usually cheaper and quicker than internal bracing for exactly that reason.

The catch is where the anchors go. The bond length sits in the soil behind your wall, which means under the neighbor's property or under the street, so you need an easement or a permit to put it there. On a permanent job the anchors may have to be destressed or left in place rather than removed. The anchor capacity, the bond length, the angle, the spacing, and the proof-test loads are engineered and verified, not estimated in the field.

Internal bracing: struts, walers, and rakers

Internal bracing holds the wall from inside the excavation when tiebacks are not feasible. A horizontal beam called a waler runs along the wall to spread the load, and then struts brace across the hole, corner braces cut across the corners, or rakers run down at an angle to a foundation or a heel block at the base. The bracing pushes back against the wall from within the cut.

You go to internal bracing when you cannot get an easement to drill anchors under the neighbor, when the soil behind the wall will not hold an anchor, or when the cut is narrow enough that struts across it are practical. On a narrow excavation, cross-lot struts from one wall to the other are efficient. On a wide one, they get long, heavy, and expensive, which is the point where tiebacks usually win.

The downside is obvious the first time you try to dig around it. Bracing fills the excavation with steel that the equipment and the structure crew have to work around, and it has to be installed and later removed in a planned sequence as the permanent structure goes up to replace it. The strut sizes, the levels, the preload, and the removal sequence are part of the engineer's design, because pulling a brace before the permanent structure can take the load is how a braced wall fails.

Groundwater: hold it or pump it

Groundwater is the factor that most often decides the system, because below the water table you either hold the water out with the wall or you pump it down, and the two approaches lead to different walls. A watertight wall, sheet piling with clean interlocks, a secant wall, or a slurry wall, holds the soil and the water together and lets you work in the dry behind it. A discrete wall like soldier pile and lagging does not hold water, so if the cut goes below the table you have to dewater the ground first, which is its own engineered system.

The decision goes past keeping your feet dry. Water pressure pushes on the wall and adds to the load the system has to carry, and seepage trying to come up at the bottom of the cut can boil or heave the base if the gradient is high enough. A watertight wall that cuts off the water also changes the groundwater behind it, which can draw the water table down off-site and settle a neighbor, the same risk dewatering carries.

Match the water strategy to the wall and the soil, and treat the discharge and the drawdown as their own job. The construction dewatering and groundwater control guide covers the pumping side, the boils and heave, and the discharge permit. The choice between a watertight wall and dewatering is one to settle with the geotechnical engineer early, because it drives the wall.

Ground movement: the wall limits it, it does not stop it

Every earth-retention wall moves, and the soil behind it settles, no matter how stiff the wall is. This is the fact that surprises owners and gets contractors into disputes. When you cut the ground in front of a wall, the soil load shifts onto the wall, the wall deflects toward the hole, and the ground behind it drops in a settlement trough that reaches back from the wall a distance related to the depth of the cut. A stiffer wall and tighter bracing limit how much, but nothing makes it zero.

What that means for the neighbor is real. The settlement behind the wall can crack a slab, rack a door frame, or distress a shallow footing if it goes past what that structure tolerates, and old, brittle, or poorly founded buildings tolerate very little. The job of the design is to keep the predicted movement inside a budget the adjacent structures can take, which is why a settlement-sensitive neighbor pushes you toward a stiffer, more expensive wall.

You cannot manage what you do not measure. The wall has a predicted movement, the structures behind it have a tolerance, and the gap between those two is the margin you are working in. Set the thresholds, monitor against them, and have an action plan before the wall reaches the action level, not after. The movement limits and the tolerances are the engineer's to set.

Monitoring the wall and the neighbors

Monitoring is how you know the wall is behaving the way the design said it would, and on any retention job next to a structure it is not optional. You set a baseline before excavation starts and then track movement as the cut goes down, because the only way to catch a problem while you can still act on it is to measure the wall and the ground around it on a schedule.

The common instruments each watch a different thing. Inclinometers, casings installed in or behind the wall, read the lateral movement of the wall and the soil at every depth, so you see where and how much the wall is deflecting. Optical survey and settlement points on the wall, on the ground behind it, and on the adjacent buildings track vertical settlement and horizontal movement. Crack gauges, tiltmeters, and on water jobs piezometers fill in the rest. Install the inclinometers and set the survey baseline before you dig, or the readings have nothing to compare against.

The numbers only matter if they are tied to thresholds and an action. A common approach sets tiered levels, an alert level where you watch more closely and an action level where work stops and the engineer is called. Decide those levels and who gets the call before the first reading, and keep the data where the engineer, the inspector, and the owner can see the trend, not just the day's number.

The engineer designs the system

The geotechnical and structural engineers design the earth-retention system, and this is not a field call or a vendor pick. Someone has to take the soil report, the groundwater, the depth, the surcharges from adjacent buildings and traffic, and the movement tolerances, and from those work out the wall type, the section, the embedment below the cut, the number and capacity of the anchors or struts, and the predicted movement. That is engineering, and it ends in a stamped design and a submittal, not a sketch on the back of a daily report.

OSHA reinforces this on the worker-safety side. For excavations deeper than 20 ft, the protective system has to be designed by a registered professional engineer, and underpinning of an adjacent structure has to be done under the direction of an engineer. The structural design of the retention wall sits on top of that, governed by the adopted building code, the geotechnical report, and the engineer of record.

The field's job is to build what the design says and to feed the design back when the ground does not match the boring logs. If you open the cut and the soil or the water is not what the report showed, that goes to the engineer, because the design assumptions just changed. The systems, the embedment, the anchor loads, and the movement limits are the engineer's, the depth triggers are OSHA's, and the permit and inspection requirements are the AHJ's. Verify all of them against the current rules rather than memory.

Excavate in lifts and install support as you go

The cardinal rule of building a braced or anchored wall is that you excavate in lifts and install each level of support before you dig below it. You take the cut down to just below the first anchor or strut level, install and stress that support, then dig to the next level, install that support, and continue down. The wall is only ever holding the load it was designed to hold at that stage, because the support is in before the load that needs it is exposed.

The failure is over-excavation: digging below the lowest installed anchor or strut before the next one is in. The moment you do that, the wall is cantilevering off its last support over a longer unsupported height than it was designed for, and it deflects, the ground behind it moves, and in the bad case the wall fails. This is one of the most common and most preventable ways a retention job goes wrong, and it usually happens because the excavator got ahead of the shoring crew to keep the dig moving.

Hold the sequence even when the schedule is pushing. The dig does not get ahead of the support, the support gets stressed and verified before the next lift, and the monitoring confirms the wall is behaving at each stage before you go deeper. The sequence is part of the engineered design, and the depth-of-dig limits at each stage are not suggestions.

Protecting the adjacent structure

The building next door is the reason most of this exists, and protecting it starts before any dirt moves with a preconstruction survey. You document the existing condition of the adjacent structures, the cracks, the slab elevations, the door and window racking, with photos and measurements, so that if a dispute comes later you can show what was there before you started and what, if anything, changed. Skip the survey and every preexisting crack becomes your crack in the owner's eyes.

If the adjacent foundation sits within the influence of your cut, or below the level of your excavation, it may need underpinning, extending its foundation down so your excavation does not undermine it. Underpinning is its own engineered operation and, like the retention design, has to be done under the direction of a registered engineer. OSHA also requires that sidewalks, pavement, and adjacent structures not be undermined unless a support system protects against their collapse.

There is a legal layer here too. Drilling tiebacks under the neighbor's lot, underpinning their foundation, or affecting a party wall involves easements, agreements, and sometimes local adjacent-construction rules. Settle the access and the agreements before the work, monitor the neighbor's structure throughout, and keep the engineer in the loop on anything the survey or the monitoring flags.

Permits, the engineer of record, and special inspection

Earth-retention work is permitted, inspected, and tied to an engineer of record, and the specifics are the AHJ's. Most jurisdictions require a permit for shoring or excavation support, a design stamped by a licensed engineer, and special inspection of the work as it goes in, because the wall is a structure that can hurt people and property if it fails.

Special inspection is where the field meets the design. An independent inspector verifies that the piles, sheets, anchors, or nails went in where and how the design said, and for tiebacks and soil nails that usually includes proof testing or performance testing of anchors to a multiple of their design load before they are accepted. Those test results are records the engineer and the AHJ will want to see.

What exactly is required, the permit, the submittal, the inspection scope, and the testing, varies by jurisdiction and by the size and depth of the job. Confirm it with the building department and the engineer of record early, because finding out at the wall that an anchor program needed pre-approved proof tests is an expensive way to learn the local rule.

Temporary vs permanent, and what happens to the wall

Earth-retention systems are either temporary, meant to come out or be abandoned once the permanent structure can hold the ground, or permanent, where the wall stays as part of the finished building. Knowing which one you are building changes how it gets designed, installed, and dispositioned.

Temporary systems are sized to last the construction period and then give up their job to the permanent structure. Sheet piles get pulled and reused where the ground lets them come out. Internal struts and walers get removed in sequence as the permanent floors go in to brace the wall in their place. Tiebacks get destressed, the grouted bond length usually stays, and anchors under a neighbor are often left in place because retrieving them is not practical. The disposition has to be planned, not improvised, because removing support before the permanent structure can carry the load is a collapse waiting to happen.

Permanent systems change the economics. A secant or slurry wall that becomes the basement wall does double duty, which is part of why the higher cost can pencil out on a deep building. When the wall is permanent, its design, its waterproofing, and its connection to the structure are part of the building, and it gets inspected and documented as the structure it will remain.

Worker safety in the deep cut still applies

Designing an engineered wall does not retire the worker-safety rules. It sits on top of them. People still work at the bottom of a deep cut and on the wall as it goes in, so the OSHA excavation requirements for access and egress, for keeping loads and spoil back from the edge, and for protecting against the wall or material falling on a worker all still apply. A retention wall holds the ground. It does not by itself make the hole a safe place to stand.

The hazards stack up in a deep cut. There is the fall from the edge or from the wall, the struck-by from loads swinging over the hole or from a strut or anchor component, and the same cave-in exposure during the staged excavation before the support is in. Crews working below grade also face confined-space and atmosphere risks the deeper and tighter the cut gets.

Run the worker-safety program alongside the retention design, not as an afterthought. The competent-person inspections, the ladders and ramps, the spoil setback, and the overhead protection are governed by OSHA Subpart P, and the trench and excavation safety guide covers that side in full. The engineered wall and the worker protections are two separate requirements that both have to be satisfied.

What to document

The record of an earth-retention job is what proves the wall was built to the design and behaved the way it was supposed to, and it is what you reach for when a neighbor claims your dig cracked their wall. Keep the stamped design and submittal, the as-built location and embedment of the piles or sheets, the anchor or nail installation and proof-test results, the excavation-sequence sign-offs at each lift, and the monitoring data with its baseline and thresholds.

The monitoring trend is the record that matters most in a dispute, because it shows the wall and the neighbor's structure over time against the action levels, not just a single reading. Capture it as you go, with dates, locations, and the person who read it, in a field system like FieldOS where the photos, the readings, and the sign-offs live together and can be pulled up by the engineer, the inspector, or the owner instead of living on a clipboard that disappears when the job closes.

Common mistakes

• Treating an engineered earth-retention job like a trench box, when the depth, the water, or the neighbor called for a designed wall.
• Building the wall with no engineer designing the system, the embedment, and the anchor or strut loads.
• Over-excavating below the lowest installed anchor or strut before the next level of support is in.
• Ignoring the ground movement and the settlement behind the wall, and skipping the monitoring that would catch it.
• Not controlling groundwater, using a wall that does not hold water below the table without dewatering.
• Picking the wrong system for the soil and water, such as soldier pile and lagging in saturated sand.
• Removing struts or destressing tiebacks before the permanent structure can carry the load.
• Skipping the preconstruction survey, so every preexisting crack on the neighbor becomes your liability.

Field checklist

Standards and references

Earth-retention work answers to several authorities at once, and they cover different parts of the job. The structural design of the wall is governed by the building code the jurisdiction has adopted and by the geotechnical report and the engineer of record, who set the loads, the wall type, the embedment, and the anchor or strut design. Earth-retention and anchored-wall practice is documented in federal and industry references, including FHWA guidance on ground anchors, soldier-pile, and soil-nail walls, and AASHTO provisions where the work touches transportation structures, but the controlling design is the project's stamped engineering, not a generic standard.

On the worker-safety side, OSHA 29 CFR 1926 Subpart P governs the excavation: protective systems, access and egress, spoil setback, the requirement that excavations deeper than 20 ft have a protective system designed by a registered professional engineer, and the rule that adjacent structures not be undermined without engineered support or underpinning. The trench and excavation safety guide covers that standard in depth.

The AHJ ties it together through the permit, the engineer of record, and special inspection, including proof testing of anchors and nails. The systems, the embedment, the anchor loads, and the movement limits are the engineer's to set, the protective-system and depth triggers are OSHA's, and the permit, inspection, and testing requirements are the AHJ's. Edition and local amendments change these, so verify the current rules with the engineer and the building department rather than relying on memory.

Earth-retention terms

Earth retention carries a vocabulary that shows up across the geotechnical report, the shoring drawings, and the specialty contractor's submittal, and the same idea can read differently between them.

The terms below are the ones a foreman needs to read a shoring plan and follow the design intent, defined the way the trade uses them rather than the way a textbook states them.

Earth retention / shoring

An engineered structure that holds back soil for a deep excavation and limits ground movement, distinct from an OSHA trench protective system that protects the worker.

Soldier pile and lagging

Vertical H-piles at intervals with lagging spanning between them, a discrete, non-watertight wall for firm soil above the water table.

Sheet piling

Interlocking steel sheets driven to form a continuous, near-watertight wall for soft or wet soil.

Secant / tangent pile wall

A wall of overlapping (secant) or touching (tangent) drilled concrete piles, stiff and low-vibration, and watertight when secant.

Slurry / diaphragm wall

A reinforced concrete wall cast in a slurry-supported trench, the deepest and most watertight system, often permanent.

Soil nailing

Grouted steel bars drilled into the cut face with a shotcrete facing, built top-down in cohesive soil that stands on a cut.

Tieback / ground anchor

A drilled, grouted, post-tensioned tendon anchored in soil or rock behind the wall to hold it without bracing inside the hole.

Cantilever vs braced

A cantilever wall is held by its embedment alone, while a braced wall adds tiebacks or struts when the cut is too deep for embedment to hold it.

Related tools

Calculators and readiness checks for this work

Compare your options

FAQ

People also ask

• When does a trench need protection?
• What is construction dewatering?
• What is concrete formwork?
• What is retainage in construction?
• What are snow guards?