In a facility near the Santa Ana River channel, the team prepares remolded or undisturbed specimens for the laboratory CBR test in Anaheim. A 50-lb surcharge weight is placed on the sample before the penetration piston advances at 0.05 in/min. The load-dial readings produce the force-penetration curve used to calculate the California Bearing Ratio at 0.1 in and 0.2 in penetration. For projects on the alluvial soils of Orange County, this value becomes the primary input for flexible pavement thickness design per AASHTO Guide. The soaked CBR condition — four days of submersion — replicates the worst-case moisture scenario that occurs after winter rains in the region.
A soaked CBR below 5 in Anaheim's alluvial clays signals the need for subgrade improvement before placing pavement sections.
Methodology and scope
Anaheim's subsurface consists of sandy to silty alluvium with intermittent clay lenses deposited by ancient river channels. The laboratory CBR test in Anaheim captures exactly how these layers behave when compacted at optimum moisture content determined through the ensayo Proctor. Because the local groundwater fluctuates seasonally, the soaked CBR simulation becomes critical: the four-day submersion period followed by penetration testing reveals the strength loss that saturated subgrades experience. The team also correlates CBR values with soil classification using ASTM D2487, linking results to the clasificación de suelos for unified reports. When the design requires a CBR of 15 or higher for base course approval, the lab verifies compaction energy and moisture control. For projects in the Platinum Triangle, where heavy truck traffic is expected, the test is run on samples compacted at modified Proctor energy to match higher stress levels.
Technical reference image — Anaheim
Local considerations
IBC 2018 and ASCE 7-22 require that pavement subgrades in Seismic Site Class D be evaluated for strength loss under saturated conditions. The laboratory CBR test in Anaheim addresses this directly: the soaked test replicates post-seismic saturation where alluvial sands can lose up to 40% of their dry bearing capacity. Without this data, a pavement designed for dry California summer conditions could fail within two wet seasons. Caltrans Standard Plans reference soaked CBR as the basis for aggregate base thickness in urban arterials. The test also detects expansive clays — those with swell over 2% during soaking — which require lime treatment or removal before paving.
Standard (12,400 ft-lbf/ft³) or Modified (56,000 ft-lbf/ft³)
Penetration rate
0.05 in/min ± 0.002 in/min
Surcharge weight
10 lb (4.54 kg) standard
Soaking period
96 hours (four days) with swell measurement
Reported values
CBR at 0.1 in and 0.2 in penetration; swell percentage; moisture content
Sample type
Remolded at OMC or undisturbed ring samples
Associated technical services
01
Modified Proctor Compaction
Determines the maximum dry density and optimum moisture content at modified energy levels (56,000 ft-lbf/ft³) for base and subbase materials that will support heavy traffic loads on arterial roads.
02
Resistance Value (R-Value) Test
Performed per ASTM D2844 to measure the lateral support capacity of subgrade soils; used by Caltrans as an alternative or complement to CBR for flexible pavement design in Orange County projects.
03
Swell-Consolidation Testing
Evaluates the volume change potential of expansive clays in Anaheim's river-adjacent zones; provides the swell pressure data needed to design moisture barriers or lime-treated subgrades.
04
Hydraulic Conductivity of Compacted Soils
Measures the permeability of compacted subgrade at field density using falling-head or constant-head methods per ASTM D5084, critical for drainage layer verification under pavement sections.
Applicable standards
ASTM D1883-21 Standard Test Method for California Bearing Ratio of Laboratory-Compacted Soils, AASHTO T 193 Standard Method of Test for the California Bearing Ratio, Caltrans Standard Specifications Section 26 (Subgrade Preparation), IBC 2018 Chapter 18 (Soils and Foundations)
Frequently asked questions
What is the difference between soaked and unsoaked CBR, and which one does Caltrans require?
The soaked CBR simulates the worst-case moisture condition by submerging the compacted specimen for four days before penetration. Caltrans typically requires soaked CBR values for pavement design in urban areas like Anaheim because seasonal rainfall and irrigation can saturate the subgrade. Unsoaked CBR is rarely used for final design and is only acceptable for temporary access roads or when the pavement is protected by a waterproof membrane.
How much does a laboratory CBR test cost in Anaheim?
The cost for a standard laboratory CBR test with one moisture condition (soaked or unsoaked) ranges between US$130 and US$220 per sample. This includes compaction at optimum moisture content, four-day soaking with swell measurement, and penetration testing at two depths. Additional surcharges apply for modified Proctor energy, multiple moisture conditions, or swell pressure determination.
What CBR value is considered acceptable for pavement subgrade in Anaheim?
For residential streets and light-traffic roads, a minimum soaked CBR of 5 is generally acceptable for the subgrade. For arterial roads in the Anaheim Resort district or industrial zones, engineers typically require a CBR of 10 or higher. When the laboratory CBR falls below 3, the subgrade must be stabilized with lime, cement, or a geotextile separation layer before placing aggregate base.
Can the CBR test be performed on undisturbed samples from the field?
Yes. While most CBR tests use remolded specimens compacted at Proctor optimum moisture, undisturbed ring samples taken from test pits or thin-walled Shelby tubes can also be tested. This approach is recommended for existing pavement evaluation or when the natural soil fabric and structure significantly influence bearing capacity. The laboratory trims the sample to the required dimensions and performs the penetration test without recompaction.
Location and service area
We serve projects across Anaheim and its metropolitan area.
