Slopes and Retaining Structures
Southern California is hills. Almost every project of any size involves either building a slope that has to stand up for fifty years or building a wall so it does not have to.
Both are geotechnical work as much as construction work, and both fail in ways that are expensive and public.
Slopes are geotechnical work that happens to involve equipment
A fill slope is a structure. Its stability depends on the keyway it sits on, the benching that ties it into the native ground, the drainage behind it, the material it is built from, and the compaction achieved at the face. Every one of those is specified by the geotechnical engineer and every one of them is invisible once the slope is finished.
That is why slope work rewards a contractor who reads the geotechnical report as a construction document rather than a formality, and who understands that the inspector signing the keyway is the last person who will ever see it.
What we build
Retaining wall alternatives are a cost decision
Wall type is frequently treated as a design choice when it is largely an economic one. Cost per square foot of exposed face varies by a factor of three or more across wall systems, and the cheapest system at one height is rarely the cheapest at another. Where the design is still open, we will price the alternatives so the decision is made on numbers.
Drainage is what fails
Retaining structures and slopes very rarely fail because the wall was too weak. They fail because water got behind them and nobody gave it a way out. Subdrains, backdrains, filter fabric, gravel section, and outlet locations are the part of the detail most likely to be built casually and most likely to cause the callback.
Working with the geotechnical engineer
On slope work the geotechnical engineer of record inspects and certifies critical elements as they are built. We schedule around those observations rather than around them, and we do not cover a keyway that has not been signed.
Slope and wall capabilities
- Keyway construction and certification
- Benching and slope tie-in
- Fill slope construction and face compaction
- Cut slope excavation and shaping
- Subdrain and backdrain installation
- Buttress and stabilization fills
- CMU and masonry walls
- Cast in place concrete walls
- Segmental block wall systems
- Gravity and crib walls
- Wall drainage and waterproofing
- Slope erosion control
How we run this work
Every scope is bid against real quantities and built to the governing agency's standard.
Priced wall alternatives
Where the design is still open, a comparison of wall systems by cost per square foot of exposed face at your actual heights.
Geotechnical coordination plan
Which elements require observation and certification, and how the schedule accommodates them.
Keyway and benching record
Documented and signed before cover, because nobody can inspect it afterward.
Subdrain as-built
Actual subdrain locations, inverts, and outlets recorded, which matters enormously if water shows up later.
Face compaction record
Compaction achieved at the slope face, which is where fill slopes are most commonly deficient.
Wall submittal package
Materials, shop drawings where applicable, and the testing required for acceptance.
Questions we get on this scope
Can you build to a geotechnical report that seems conservative?
We build what the report requires. If we think a recommendation is materially more conservative than the condition warrants, we will say so and suggest you ask the geotechnical engineer whether additional investigation could support a lighter section. That conversation belongs with them, not with us.
Do you design the retaining walls?
No. Wall design comes from your structural or geotechnical engineer. We build it, and where the system is a proprietary one we coordinate the supplier's engineering under our contract.
What is the most common slope defect you see?
Inadequate face compaction and missing or misplaced subdrain. Both are invisible at completion and both surface in the first wet winter. We have evaluated plenty of them from the forensic side. See construction defect analysis.
Can you repair a failing slope or wall?
Yes. Remedial slope and wall work is a regular scope for us, usually starting with an assessment of why it moved before anything gets rebuilt. See remedial and corrective work.
Get a bid on slopes and retaining structures
Send us the plans, the specification, and the schedule you are working to. We will tell you whether we are the right contractor for it and what it will cost.
Send us the project
Tell us the site, the scope, and the deadline. Initial consultations carry no fee and no obligation.