Culvert Soil Stabilization

Culvert Soil Stabilization Repair at Vandenberg AFB

EagleLIFT Completes Culvert Soil Stabilization Repair at Vandenberg AFB, Saving $1.5B Mission

Culvert Soil StabilizationIn the construction industry, deadlines are a way of life. Whether you are meeting proposal deadlines, managing costs, minimizing weather delays, meeting contract requirements, etc., the clock seems to always be ticking and pressure is continually mounting. However, recently EagleLIFT performed a culvert soil stabilization and slope repair project at Vandenberg AFB that, if not met, the deadlines would be a costly scenario.

Vandenberg AFB is a Department of Defense space and missile testing base located near Lompoc, California. Vandenberg launches a variety of critical rocket missions for military purposes and also leases launchpad facilities to SpaceX. As you can imagine, its activities are high-profile, high-budget, and highly sensitive to delays.

During the 2016-2017 rainy season, Vandenberg experienced extensive storm runoff that damaged an 84 inch, 200ft long corrugated metal drainage culvert, causing collapse at three separate locations and further degraded the culvert’s corroded bottom. The damage to the culvert caused severe inflow and infiltration (I/I) which destabilized an adjacent slope along the main supply road leading to Space Launch Complex 6 (SLC-6).

When an approximate 30ft deep sinkhole opened up by the supply road, a bypass road had to be installed in order to continue launch operations until a permanent fix was designed for the culvert. When concern began to grow that a 20ft high section of the adjacent slope would slip and the sinkhole wound endanger the new bypass road and delay an upcoming $1.5 billion mission, Vandenberg sought for a temporary fix to strengthen the culvert, slope and avert disastrous and costly delays.

When Vandenberg began designing a repair, the solution was to address 1.) culvert soil stabilization and restoring usable capacity, 2.) ensuring the slope would not slip, and 3.) not impact the environmentally sensitive habitat on the slope.

For the culvert soil stabilization, the AFB determined that chemical grout would be used to stabilize collapsed sections from degrading further into the culvert. The entire culvert was to be stabilized to prevent further soil migration and seal it against further I/I, and the corroded bottom of the CMP would be restored using a flowable fill.

For the slope, a “wedge” injection pattern was designed to provide structural stability at the bottom of the slope and lateral stability to prevent slippage that would cause structural damage to the culvert and irreparable damage to the sensitive environment the slope supports.

“Initially, Vandenberg’s solution for the slope repair consisted of using a compaction grout to provide a dense material for slope stability,” stated Cliff Frazao, Chief Operations Officer of EagleLIFT. “When we were approached for the project we had concern that the compaction grouting footprint could be detrimental to the environmental mission of the project and add too much weight to the area and cause further issues with the culvert.”

Based on these concerns, the slope “wedge” injections were rescoped to utilize a specialized formula of chemical grout that was hydroinsensitive, light-weight and highly expansive. The material’s initial permeation and structural capacity gave Vandenberg confidence in this alternative.

To meet the environmental compliance needs of the project, extensive preparations were necessary to minimize potential delays and protect endangered species that called this site their home. Some of the species included California Buckwheat, El Segundo Blue Butterflies, Tar Plants and the Red-Legged Frogs. To ensure the endangered plant/wild life habitat wasn’t inadvertently violated, environmentalists were onsite to pre-mark the plant life and be on the lookout for wildlife. If any of these species were disturbed or damaged, the project could have seen an immediate shutdown.

In regards to the culvert, EagleLIFT stabilized its entire 200 ft length. At the crushed joints, a 2ft injection of chemical grout created a thick arch of material and densified aggregate. The arch was designed to provide a convex, dense structural layer that would help provide structural stability and reinforcement to the crushed CMP. This would help mitigate further damage from occurring and re-establish limited drainage capacity.

The remaining portions of the culvert were stabilized using a consistent gridded injection pattern. The goal here was to fill any annular voids and restore the bearing capacity of the adjacent support soils.

“This was a high-profile project with an approximate $1.5B mission and national security at stake,” stated Carlos Castillejo, Project Manager for EXBON, the General Contractor for the project. “All eyes were on the EXBON-EagleLIFT Team to complete the project successfully and without delay, something we did with absolute success!”

The terms of the project were to complete the project in a 30-day window, spanning from September 14 – October 14, 2017. The project was completed in 8 days with no delays or adverse environmental impacts.

“We would like to thank both Vandenberg and EXBON for their confidence in EagleLIFT, and we were glad to be a small part of ensuring the missions of our military are executed with the utmost quality and efficiency,” says Donald J. Moody, President and Owner of EagleLIFT. “As a retired USAF Colonel, I take great pride to ensure that EagleLIFT’s operations are top notch especially for our military clients.”

About EagleLIFT
EagleLIFT has offices in Ontario, CA, Concord, CA, Las Vegas, NV and Rialto, CA. EagleLIFT is a Class “A” General Engineering Contractor and holds SB, SBE and DVBE certifications and services Arizona, California and Nevada.

Gila County Courthouse Soil Densification 2

Gila County Courthouse Soil Densification

Utilize Chemical Grout Shallow Surface Injection for soil densification and to lift and level the southwest corner of the building.

Gila County Courthouse Soil Densification 2

Project Challenges

Client:   Gila County Courthouse
Location:   Globe, AZ
Project Summary: Utilize chemical grout for soil densification and to lift and level the southwest corner of the building as much as is practicable.

An area of soil at the southwest corner of the building subsided after a recent rain storm. The subsided area measured approximately 30 feet in diameter and had a depression roughly 6 to 8 inches lower relative to surrounding areas

Solutions and Results

Utilize chemical grout to lift and level the southwest corner of the building as much as is practicable. This scope of work included underpinning approximately 40 linear feet of the building extending east and north from the southwest corner of the building.

Since there were no foundation or pavement to provide confinement, trench plates were used to resist the expanding material for the greatest densification of subgrade possible. Weak soils were successfully densified.

Our Projects

CMP Trenchless Sewer Repair

Sewer Repair Glendale California

Sewer Repair Glendale California

CMP Trenchless Sewer Repair

Project Challenges

Client:   City of Glendale, CA
Location:   City of Glendale, CA
Surface Area: 450,000 m2
Year Completed:   2014

The 130 foot long culvert ran on an angle, approximately 30’ below grade in a north south direction. Over time, the stream had begun to erode the base soils beneath the culvert creating a void along the base and sides. The concern was that the weakening and erosion of these base soils would eventually lead to subsidence and/or shifting of the culvert and deflection at the surface where there were future plans for construction.

EagleLIFT was chosen for the following reasons. First, all work could be completed with zero excavation and no disruption to the surroundings on the surface. Secondly, laboratory testing of the material used proved that it maintains its integrity for more than 10 years with no shrinkage or degradation. Recent studies of other one-part grouts found that conventional grouts are significantly impacted by the factor of time and “wet/dry” cycles.

Solutions and Results

Chemical Grout Deep Injection was used by the City of Glendale to void fill and stabilize a local culvert. This unique process relies on the expansive properties of a two-part expanding resin system (an expansion co-efficient of twenty to one) and a quick cure (25 second cure time), to seal and void fill while stabilizing weak soils around the structure.


The two-part polymer material is injected from within the culvert through five-eighths inch diameter holes drilled through the sidewalls of the culvert. The hydro-insensitive material then expanded and travelled the path of least resistance filling any voids and essentially encapsulating the bottom half of the culvert.


The injection process took three days to complete with all voids filled and soils stabilized. The process was quick, clean extremely cost effective, and will certainly maintain and prolong the lifespan of the two culverts.

All parties were very pleased with the work done, the short length of time it took to successfully complete the project and the cost savings that resulted from hiring EagleLIFT.

Our Projects