Micropiles & Anchored Geostructural Foundations
GRW delivers micropile and anchored foundation systems for structures, towers, retaining works where conventional foundations wont hold up.
We create reliable load paths into competent ground so new builds, retrofits, and underpinning can be supported in challenging subsurface and access conditions
Understanding Micropile Foundations
What are micropile's?
Micropiles are small-diameter drilled and grouted piles that transfer load to stronger ground or rock. Anchors (tiebacks) are drilled, grouted, and tensioned elements that hold structures back or down when lateral or uplift forces are high
What it solves
Solves problems when soils are weak, groundwater is an issue, excavation is constrained, vibrations must be limited, or you need high capacity in a small footprint
Where it applies
Used for bridge abutments, towers and poles foundations, retaining works and retrofits and underpinnings
Micropile Foundations Techniques
What Micropiles Are: Small-diameter, high-capacity drilled and grouted piles (often steel-cased and/or bar-reinforced) designed to carry compression, tension, and lateral demands
Why We Do It: Provides deep load transfer where shallow foundations are not feasible due to weak soils, scour, fill, liquefiable zones, or access constraints
How We Do It: GRW executes drilling, casing advancement as required, reinforcement placement, and pressure grouting. We sequence work to control spoil, groundwater, and vibrations, with installation records and QA/QC tied to the design assumptions
What Anchor/ Tiebacks Are: Anchors with defined bond lengths and free lengths; tensioned and locked off to meet design loads
Why We Do It: Controls lateral deformation and uplift where wall or foundation stability is governed by sliding/overturning or buoyancy
How We Do It: GRW installs, tests, locks off, and records the full anchor history (drilling conditions, grout take, tendon details, test curves, and final lock-off)
What Are Access & Constructibility: We excel in tight sites: low headroom, steep slopes, remote mobilization, limited crane time, traffic control, and constrained laydown
Why We Do It: Foundation work requires deailed planning and tight execution, considering access, sequencing, and safety controls willl determine whether production is on target
How We Do It: GRW plans and self-performs with purpose-built equipment, disciplined teams, and attentive supervision
Why work with us
Experience: GRW is a construction contractor at heart—our crews scale slopes, drill holes, hang mesh, stand posts, and build barriers every season GRW has been operating for 20 years on projects ranging from $10,000 to $20,000,000 across diverse industries, geographies and climates.
Rope Access: We are North America’s first SPRAT certified geohazard contractor, with 100% of field technicians certified to work on steep slopes, cliffs, and canyons.
Safety: Our extensive safety program is 3rd party audited and recognized as best in class. Safety is in our DNA and extends throughout the organization as our leading priority.
Equipment: GRW utilizes track-mounted drills, spider excavators, telehandlers, heli-portable and custom equipment so we can reach and stabilize slopes that conventional equipment cannot.
Project Management: Our teams include PMP-certified project managers, engineers, and geologists who use structured planning, risk registers, and an internal ERP, supported by tools like MS Project and Safety Evolution, to ensure we stay on top of our projects.
Collaboration: We build relationships and communicate early with our clients, subcontractors and vendors to ensure joint succes. We are prequalifed and preferred with many agencies, utilities and GC’s.
Emergency Response: GRW can respond immediately for emergency landslides and rockfall often caused from storms, floods, earthquakes or gravity
Frequently Asked Questions
What are micropiles
When should I choose micropiles over traditional foundations?
What projects are best suited for micropile foundations?
A near miss with rockfall just occurred, what do I do?
First secure the area and keep people and traffic from the impact zone. Assess if additional debris can come down and notify your geotechnical enginee.
Contact a rockfall contractor to complete a rapid site assessment and temporary risk control measures as a permanent mitigation plan is put into place..
How early should we involve GRW in project planning
As early as possible once rockfall hazards are identified or new cuts are being considered.
We add the most value when we can advise on access, staging, and practical mitigation options before designs are finalized and traffic or outage plans are locked in
How does GRW handle differing ground conditions
We expect ground conditions to vary on steep slopes and rock faces, and understand subsurface samples may not always be economical to provide.
When we encounter conditions that differ from assumptions, we document them, raise them quickly through RFIs or change notices, recommend means and methods modifications, and work with the owner and engineer to agree on scope and pricing adjustments
Can GRW respond to emergencies
Yes, we can!
We frequently mobilize quickly after rockfall or slope failures to secure the area, remove immediate hazards, and reopen access, then work with owners and engineers to transition into permanent engineered rockfall mitigation systems.
How does GRW work with our internal or contracted engineer of record
We typically build to the engineer of record’s design, asking questions early about access, staging, and constructibility.
On many projects we also support design-assist, providing field feedback and options so the final design can be built safely and efficiently in the terrain you actually have.
Does GRW offer design-build solutions?
Yes. When fitting we deliver design-build in partnership with trusted geotechnical engineers so owners get a single, coordinated team for investigation, design, and construction This approach works well on time-sensitive or complex projects where access, staging, and differing ground conditions need to be resolved quickly and turned into constructible, defensible engineered solutions.